"Ask Andy": the first six monthsAbout ten years ago I hosted a freewheeling question and answer folder in my friend Gen's "Kids Only On Line" area on America Online. Here's a transcript of the first six months' worth of questions and answers. As you can see, we had a lot of fun! Return to previous page.
Subj: Asking Andy - 93-09-30 18:54:47 EST
From: GenK
Posted on: America Online
Many of you know AFC Andy from Mac Graphics — but most of you do not know that he knows a lot about
lots of other things. So bring your science and nature questions here...ask Andy.
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Subj: OK, let's have 'em! 93-10-01 08:05:42 EST
From: AFC Andy
Posted on: America Online
When I was a kid (before I got tall enough to fool people into thinking I was an adult ;-) the
Pittsburgh Post-Gazette used to run a weekly column called "Ask Andy," where you could get an
answer to any kind of question about science, nature or the universe.
Well, I love questions, and I know a lot of answers...and even more important, I know where to look
to find out the answers I don't know. So here I am making the same offer—bring on your questions
and see if you can "stump the professor"! This'll be fun! :-)
Andy :-)
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Subj: Call out the Natural Guard! 93-10-01 08:16:56 EST
From: AFC Andy
Posted on: America Online
Let's start with a question that came up awhile ago:
"Why does your white blood cell count go up when you're sick?"
For the same reason that after a hurricane passes through, you see a lot of police and National
Guard people swarming around, helping to protect your neighborhood against looters and other
criminals. White blood cells (lymphocytes) are like your body's National Guard—you could call them
the Natural Guard. Their job is to fight off invaders like disease bacteria...so when you have an
infection, your body sends in the troops!
That's why if your doctor takes a blood sample when you're sick, there will probably be more white
blood cells than usual—in fact, you can often guess how bad the infection is by how many extra
white blood cells there are. Those extra WBCs mean that your body is defending itself against the
disease.
Next question?
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Well... 93-10-01 14:05:49 EST
From: WalterGL
Posted on: America Online
This is a GRAPHICS question, but I guess it could go in here. Actually, it goes under the catagory
of "Stump the Professor." :-)
Okay, there's this color painting program I'm thinking of. It runs on a major platform (millions of
users), and the number of users of this program would probably run in the ten thousands. That's
clue #1.
Clue #2: It requires a mouse, and comes with one.
Clue #3: The only way to save files is onto a VCR (there's an adapter for that too).
That should be enough clues for now...
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Subj: Ya got me, Walter! ;-) 93-10-01 17:05:05 EST
From: AFC Andy
Posted on: America Online
If it comes with a mouse, it must be a DOS or Windows program—all Macs, Amigas and Ataris already
*have* mice!
But what kind of painting program would *only* be able to save files to a VCR? Hey, what if you
create something and want to save your work and come back to it later? Are you gonna read it back
in from videotape? Not likely. Sounds pretty impractical to me. OK, I give up. What is it?
Hey, let's have some science questions here...like "Why is the sky green?" (Oops—forgot to take
off my sunglasses! ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Actually, 93-10-01 17:32:11 EST
From: WalterGL
Posted on: America Online
Clue #4: Users DO read their files back from the VCR.
Clue #5: It operates on none of the platforms you have thus mentioned, but Clue #1 still holds
true. (that is, it's a major platform).
Starting to get interesting, eh?
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Subj: Oh, forgot... 93-10-01 17:34:11 EST
From: WalterGL
Posted on: America Online
The sky is blue because Mother Earth's GIF viewer messes up the system color palette quite often,
although it also can be black, gray, or magenta (rarely magenta).
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Subj: A major platform without a mouse 93-10-02 09:48:52 EST
From: AFC Andy
Posted on: America Online
IBM System/360? Univac? ENIAC? ;-)
The only major platform not mentioned so far is the Unix workstation market. I don't know what's
available in the way of painting programs there, so you'll just have to tell us, Walter!
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Okay... 93-10-02 10:48:17 EST
From: WalterGL
Posted on: America Online
Clue #5: It is designed for kids. (kinda like Kid Pix).
Clue #6: It is the ONLY graphics applications available for its platform.
Clue #7: Did I also mention it can do music and animation too?
After this round of clues, I'll give it to you (and anyone else who is reading in). :-)
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Subj: Another question... 93-10-02 17:11:08 EST
From: Dave911
Posted on: America Online
Can any dogs see color? :-)
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Subj: NintendoPaint? 93-10-02 18:01:58 EST
From: AFC Andy
Posted on: America Online
Photoshop For Gameboy? All right, I give up!
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Can dogs see color? 93-10-02 18:13:27 EST
From: AFC Andy
Posted on: America Online
As far as I can determine, no dogs can see color. They just see grays, like an old movie or a black
and white TV. However, dogs don't rely on sight the way we do, so they probably don't miss being
able to see in color. Most humans rely on sight for much of their impression of the world around
them. But a dog lives in a rich world of smells that we can hardly begin to understand. An average
dog's nose has more than *ten times* as many smell receptors as a human has! You can imagine how
many things that dog is smelling that we are not aware of.
So somewhere in some canine universe right now, a dog is probably asking "Can humans really smell
anything?"—and the answer coming back is "Hardly anything at all, but they rely heavily on sight,
so they probably don't realize what they are missing!" ;-)
By the way, cats *can* see colors—but they don't pay much attention to them unless they're very
bright and large (or close, which makes them look large). Cats have better smell than humans but
not as good as dogs; better sight than dogs but not as good as humans—so you could say they're
somewhere in between when it comes to the senses of sight and smell.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Oh, Andy! 93-10-03 00:22:43 EST
From: WalterGL
Posted on: America Online
Photoshop for Game Boy! LOL! Nope, I don't think the 2-bit graphics would suffice...
Seriously, you were VERY close. The answer?
Mario Paint!
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Subj: A question and an answer 93-10-03 10:16:24 EST
From: ACT CLEAN
Posted on: America Online
Why do hurricanes always turn clockwise?
As far as dogs go ?? Most everyone here knows of my years on the police department and that I
worked with dogs during that time. Dogs do not see color. Just as Andy said, they see what we
would see if we were watching a black and white television.
What makes dogs such good animals to sniff out drugs and people is that their noses are up to ONE
BILLION times stronger than ours, depending on the breed. The best dogs to use as "drug dogs" are
poodles, they have the best noses but are not used that much because they are not really the type
of dogs a police officer would feel proud of searching someones house with. A police officer would
feel better telling a German Sheherd named BUTCH to search than a Poodle named PIERE.
By the way, Pigs have better noses than dogs and some police departments are experimenting with the
use of pigs to find drugs.
BUT what I want to know is why hurricanes turn clockwise ?
Scott
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Subj: Round and round it goes... 93-10-03 12:46:27 EST
From: AFC Andy
Posted on: America Online
...but which *way* it goes around depends on where you are. North of the equator, hurricanes do
indeed turn clockwise. (I'll get to the "why" in a minute.) But south of the equator, the storms
spin the other way—counterclockwise!
If that sounds as if a storm that just happens to cross the equator has to reverse its spin
direction—well, no. That would be a pretty tall order! ;-) What really happens is that storms that
are *born* north of the equator spin clockwise, and storms that are born south of the equator spin
counterclockwise—and they stay that way throughout their lives, no matter where their travels take
them. (What happens if a hurricane is born exactly *on* the equator? It has a fifty-fifty chance of
spinning one way or the other.)
OK, the real question is *why*? Well, it has to do with the fact that all this is taking place on
the surface of a spinning earth. This will take a bit of explaining, so stick with me! You'll learn
some weird facts along the way.
OK, imagine that you're standing on a tall mountain at the equator. You don't realize it, but
you're traveling east at a thousand miles an hour! That's because the earth is always spinning,
turning toward the east, and you're standing on it. (Luckily, the atmosphere is traveling at the
same speed, so you don't get blown off the mountain by a 1,000 mph wind! ;-)
How fast you're traveling eastward depends on where you're standing on the earth's surface. At the
equator, your speed is greatest, because you're farthest from the earth's axis there. On the other
hand, if you were at the north or south pole, you wouldn't be moving east at all...just spinning
around in place. You'd be standing on the axle as the wheel turned, so to speak. And in
between—well, at the latitude of New York you'd be going about 750 mph, because New York is closer
to the earth's axis than the equator is.
To see how this applies to hurricanes, go on to the next message...
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Straight line or curve? 93-10-03 12:59:48 EST
From: AFC Andy
Posted on: America Online
Got all that? OK. Now, let's go back to that equatorial mountain. You pick up your super-powered
ultra-long-range rocket launcher. You carefully aim straight north, and fire a shot at New York.
(Don't worry, there's no warhead!) The rocket flies north—but it also is traveling 1,000 mph east,
just as you are. To somebody on the ground, tracking it by radar, the rocket's eastward movement
won't be noticed at first, because the radar station is also moving east at the same 1,000 mph
speed. 1,000 - 1,000 = 0. So the rocket will just seem to be flying straight north.
*But* when the rocket has gone a few thousand miles north, things start to look different. The
radar station at New York, for example, is also traveling east with the earth—but at only 750 mph,
not 1,000 mph. So it sees the rocket as moving to the east at 250 mph! (1,000 - 750 = 250.) In
fact, the further north the rocket goes, the further its course *seems* to curve to the east (as
seen by ground observers).
Confusing? You bet! Think of it this way: if you were hovering up in space, you could see that the
rocket was really travelling in a straight line...but the earth is rotating under it, and that
makes things look quite different to somebody on the ground.
So when do we get to hurricanes? Right about now! Imagine that instead of a rocket, you send a big
*wind* northward. (You gotta be a real blowhard for this experiment! ;-) Picture it as it heads
north...the radar stations on the ground are tracking it...hey! it's curving to the east, just like
the rocket did!...it's curving CLOCKWISE! :-)
Needless to say, if you stand on that same equatorial mountain and face south, your rocket or your
wind will appear to curve to the west—counterclockwise. In general, any object in the northern
hemisphere will seem to be deflected clockwise, and any object in the southern hemisphere will seem
to head counterclockwise.
For the thrilling conclusion of our story, see the next message...
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Wrapping it up 93-10-03 13:24:26 EST
From: AFC Andy
Posted on: America Online
So if you're north of the equator, things that are heading north seem to curve to the east. Well,
then how come when I ride my bike on a road that goes north, I don't end up curving to the right
and going into the ditch? Because the effect I just described is only really noticeable when you're
dealing with things that are moving hundreds or thousands of miles.
Think about it—standing here in my driveway in NJ I'm traveling maybe 760 mph eastward. So I ride
my bike a mile north...now maybe I'm traveling 759.9999 mph. Not much of a difference! So the
effect isn't noticeable.
That's why if anybody tries to tell you that the water always swirls down the drain clockwise, but
if you cross the equator it will go counterclockwise...you can just smile and wink. You're talking
about a distance of a few inches, and this effect isn't visible until you get into the hundreds of
miles. In a kitchen sink? No way! ;-)
By the way, this effect has a name. It's called the "Coriolis effect," named after the Frenchman G.
G. Coriolis who discovered it 150 years ago. If you want, you could always look up his paper
"Traite de la Mecanique de Corps Solide," ("Mechanical Characteristics of Solid Bodies"), published
in Paris in 1844. ;-)
There is an easy way to demonstrate the Coriolis effect on a small scale. Get on a merry-go-round
with a friend, each of you on opposite sides. Now try to throw a rubber ball to your friend. You
throw straight toward her, and you *know* the ball is traveling in a straight line...but it CURVES
VISIBLY TO ONE SIDE! It's the weirdest thing you ever saw—you gotta try it to believe it. Really
spooky.
Whew! That's it! Hope you were able to follow this longwinded explanation. Coriolis effect is one
of the trickier concepts to explain...if you're still not sure about all this, try the
merry-go-round experiment.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Next question: 93-10-03 14:05:37 EST
From: GenK
Posted on: America Online
Where's the closest merry-go-round?
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Subj: Why... 93-10-03 18:15:27 EST
From: AFC Andy
Posted on: America Online
...about a mile west of you, in that little amusement park on Rt. 28! ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Oh yeah... 93-10-03 18:20:40 EST
From: WalterGL
Posted on: America Online
I remember learning about that concept with a bathtub. Like as in why does the water always swirl
clockwise when you pull the plug. Of course, if you're in Argentina...
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Subj: Above/below... 93-10-03 18:56:54 EST
From: Dave911
Posted on: America Online
Your paper towels spool differently above and below the equator, too! :-) Wanna know why THAT
happens? :-)
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Subj: Paper towels 93-10-03 21:00:32 EST
From: AFC Andy
Posted on: America Online
I should imagine that's more cultural than geographical... ;-) But go ahead—what's your
explanation?
And Walter—whoever told you that bathtub fairytale had obviously never tried it, because if you
actually do it ten times, the odds are you'll get five clockwise and five counter, no matter which
hemisphere you're in. Dimwitted science teachers have been laying this myth on generations of kids
for probably the past hundred years, when just a little experimentation would show that at this
small scale, the global Coriolis effect can have *no* measurable effect—-as I pointed out in my
explanation.
Technically, the probability of water swirling clockwise in the northern hemisphere due to Coriolis
effect (as opposed to being due to the way you pulled the plug, or the currents in the water at the
instant you pulled it) is something on the order of 50.0000001%—so close to even that you'll never
see the effect.
Next question? Anybody wanna talk about about dinosaurs? ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Here's a stumper.... 93-10-03 22:36:45 EST
From: Beckles
Posted on: America Online
Here are some REAL good ones. 1.) what does abcedarian mean ? 2.) What's the name of Monet's
second wife? 3.) Who wrote the book "Main Street" ?
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Subj: One More 93-10-03 22:38:48 EST
From: Beckles
Posted on: America Online
What was Agatha Christie's second husband's profession? Here's a hint: Dinosaurs, sort of.
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Subj: Walter in the bathtub (haha) 93-10-04 01:32:53 EST
From: ACT CLEAN
Posted on: America Online
Andy, the explaination of the direction hurricanes travel was most excellent.
I bet Gen got you to argue the point about the bathtub water just so Walter would take a bath
(hahaha)
WALTER, *before* you take aim and let me have it: JUST KIDDING !!!!!
Scott
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Subj: Well... 93-10-04 05:40:57 EST
From: AFC Andy
Posted on: America Online
....those questions are not exactly in the science and the universe category, but what the heck.
1) "Abecedarian" (note spelling) means a person learning or teaching the alphabet. It can also mean
something really elementary ("Your abecedarian theories are merely laughable, Dr. Crenshaw!") You
can tell it has to do with alphabets because it starts with the ABCs...ABeCeDarian!
2) Monet's second wife was Mrs. Monet. Shucks, anybody knows that! :-)
3) I haven't read "Main Street." But I know somebody in this area who works in a bookstore and
might be able to tell us who wrote it...
4) "What was Agatha Christie's second husband's profession?" Paleontologist, maybe? Of course, if
it had to do with dinosaurs...he might have been an Edsel repairman. ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Main Street - 93-10-04 07:49:01 EST
From: GenK
Posted on: America Online
I read this when I was younger than Walter — (and no, it was NOT still in manuscript!)
Sinclair Lewis
One of the things Andy will do in this folder is help you figure out where to go for answers to
questions — but I didn't think one source would be ME!!
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Subj: OK, let's head back... 93-10-04 11:33:54 EST
From: AFC Andy
Posted on: America Online
...toward what the folder description says: questions about science and nature. And know what?
Let's leave out computers, because there's already ten thousand other places on AOL to ask computer
questions.
So...what's your science teacher throwing at you these days? What kinda questions do you get in
your homework? Bring 'em here...no question too easy, no question too hard.
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
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Subj: Gen... 93-10-04 15:41:32 EST
From: WalterGL
Posted on: America Online
Wow! You read it when you were younger than I was? Let's see, had the printing press come out yet
or was it one of those handwritten novels? :-)
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Subj: ACT... 93-10-04 17:18:41 EST
From: Dave911
Posted on: America Online
Walter couldn't "let you have it"... See, he lives on the equator on a high high mountain, so if he
shot a rocket at you it would miss you by about 250 miles. :D
Gen, of course, CAN let Walter have it. ;-)
Well, actually... (Andy, hope you're still reading) What would happen to that rocket on its way
from Cape Cod to the high high mountain on the Equator? :/
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Subj: Let me take this one Andy :-))) 93-10-04 17:23:58 EST
From: GenK
Posted on: America Online
Why it would be a virtual direct hit, of course!
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Subj: And even - 93-10-04 17:24:51 EST
From: GenK
Posted on: America Online
illuminated, Walter.
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Subj: Infinity to the 5th power 93-10-04 18:40:14 EST
From: Leto III
Posted on: America Online
The universe has lasted about 10 to the 10th years since the Big Bang. There are about 3*10 to the
7th seconds in a year. According to quantum machanics, the usual conception of continuus time does
not extend to intervals shorter than 5*10 to the -44th seconds, so we might think of this unit as
an 'instant', faster than which nothing can happen. How many instants does that come to so far?
Is it reasonable to argue that larger numbers such as 10 to the 1000th do not yet exist?
Postscript: The abovementioned interval of time is sometimes called a "jiffy". This "jiffy" is
about 10 to the -44th seconds. As in "I'll be back in a Jiffy".
I'm sorry. I'll go away now.
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Subj: Leto... 93-10-04 19:13:10 EST
From: WalterGL
Posted on: America Online
That's an interesting thought. But just a question here— how can someone prove that nothing can be
done in 10^-44 seconds?
Besides, I doubt if NOTHING can be accomplished in 10^-44 seconds. Given the number of jiffies in a
second is x, and that there is no movement in a jiffy, then the movement in jiffy*x (one second)
would be nothing*x (nothing). Well, that seems to be the LOGICAL approach, anyway....
Hey- the perfect excuse for not doing homework! "There were only ___ jiffies last night, and
because nothing can be done in 1 jiffy, I could therefore accomplish nothing * ___, which is
nothing!"
(And there is no such thing as infinity^5, since infinity does not represent a real [or imaginary]
number).
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Subj: Shucks, I can do that one... 93-10-04 19:30:12 EST
From: AFC Andy
Posted on: America Online
... in my head! It's 6 x 10^62 jiffies so far, give or take a few. Not even a googol yet—the
universe is still young! ;-)
For the record, the answer is found by simple multiplication, which is why I really *could* do it
in my head (and so could you):
(1 x 10^11) x (3 x 10^7) x (2 x 10^44) = 6 x 10^62
In other words, following the rules for multiplying scientific notation, you multiply 1 x 3 x 2
(easy!) to get 6 and then add 11 + 7 + 44 (not too tough) to get 10^62.
If you're wondering why I started with 1 x 10^11, when you said "10 to the 10th years"—it's
because 10 to the 10th is improperly stated. In scientific notation the first number is always less
than ten, so 10^10 is properly written 1 x 10^11.
As for your second question, "Is it reasonable to argue that larger numbers such as 10 to the
1000th do not yet exist?", the answer is no. Since numbers are purely mental constructs and have no
real existence, they can go as high as we can imagine them to. Indeed, we already have the googol
(1 x 10^100) and googolplex (1 x 10^100^100, if I remember correctly) to prove that!
That was a good one! Thanks, Leto. Next question, anybody? How about something biological?
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Gen's rocket from Cape Cod... 93-10-04 19:50:26 EST
From: AFC Andy
Posted on: America Online
...would seem (and I emphasize *seem*) to curve to the west. Think about the example I gave before:
if it curves east when traveling north, stands to reason it will curve west when traveling south.
(Of course, south of the equator the opposite holds true.)
So by the time Gen's rocket got to the equator, it would seem to be traveling 250 mph westward, in
addition to its southward speed. Result: a miss. Bet Walter is relieved! ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: and do you actually think 93-10-04 20:34:36 EST
From: GenK
Posted on: America Online
I would not have compensated for that? Silly people———
::::::KABLOOOOOOOOOIE::::::
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Subj: a biological question: 93-10-05 11:51:57 EST
From: JackP
Posted on: America Online
(but first, I apologize for the frivolous behavior of my cohosts)
Andy, are there any animal species who have a "language" based on sounds, that they use to
communicate with each other?
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Subj: Jack... 93-10-05 15:11:52 EST
From: WalterGL
Posted on: America Online
Frivolous? Frivolous??? FIRVOLOUS??!!
Anyway, I can't type for long- it's long distance from down here on the equator! :-)
As for biological questions, I don't have any at the moment. I am taking molecular biology this
year, but there's nothing too difficult..... (yet)
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Subj: Oh! Oh! Language... 93-10-05 18:32:45 EST
From: Dave911
Posted on: America Online
Jack, read "Congo" by Michael Crichton. Besides being a great book, the second chapter has lot of
fact-based stuff on animal language research. Aural languages, though, I'm not so sure about...
Andy, we still need you! :-)
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Subj: Animal vocal languages 93-10-05 20:04:59 EST
From: AFC Andy
Posted on: America Online
Oh, my goodness, yes! In fact, it's more the rule than the exception. You gave a pretty good
working definition of a language—"they use [it] to communicate with each other." Let's see what
kinds of animal vocalizations fit that definition.
OK, first example: distress calls. Birds have 'em, so do squirrels, monkeys... Hmmm...notice
anything those three have in common? Yup, they're all tree dwellers. Arboreal animals seem to be
especially big on distress calls.
And some of them are fairly sophisticated. You might think when I say 'distress call,' I just mean
some kind of squawk that means "Look out!" But it gets much more interesting than that. Some
species have *different* distress calls for things like "Look out! Snake crawling up the tree!" as
opposed to "Take cover! Hawk swooping down!"
Next: Mating calls. Many, many species have these, including humans. ("Hey, baby!" ;-) They're used
not only to send the message "I'm looking for some company," but to identify species—"I'm looking
for another red-breasted warbler."
And then there are the territorial calls—"Get off my turf, buddy!" 99% of all dog barking falls
into this category. A lot of birdsong does too. ("This is *my* tree, turkeys, so buzz off!")
Any advanced mammal—monkeys, apes, humans or whales—has a pretty wide vocabulary of sounds to
express the things I just mentioned, plus anger, sorrow, delight, fear and so forth. Even cats and
dogs use at least a dozen calls or sounds among themselves, and of course dogs can recognize many
more than that when spoken by humans. (Cats may recognize them too, but they pretend not to notice.
;-)
Of course, the *non*vocal animal languages are in many ways even more interesting...
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Ah, yes... 93-10-05 20:27:44 EST
From: WalterGL
Posted on: America Online
...Congo, interesting novel. Unfortunately, my brother borrowed (read: abducted) my copy so I don't
have it with me at the moment, but I distinctly remembered Amy's sign of hitting her fist under her
chin. Of course, I can't explain what it means in public... :-)
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Subj: Congo... 93-10-05 20:32:10 EST
From: JTatum
Posted on: America Online
I read congo, but I must say I didn't like it as much as Crichton's other books... I'd have to say
my favorite crichton was sphere, andromeda strain was good, terminal man was good, congo was OK,
what else...
Jamie
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Subj: Walter, "jiffies", infinity 93-10-06 02:00:46 EST
From: Cherubim
Posted on: America Online
Walter writes:
"Besides, I doubt if NOTHING can be accomplished in 10^-44 seconds. Given the number of jiffies in
a second is x, and that there is no movement in a jiffy, then the movement in jiffy*x (one second)
would be nothing*x (nothing). Well, that seems to be the LOGICAL approach, anyway...."
I believe that the idea behind quantum theories of time is not that "nothing happens" in a jiffy,
hence as you say above, "there is no movement in a jiffy," but that it does not make sense to speak
of units of time smaller than that. That is, that time (and space, these being part of the same
thing) are discrete, not continuous, phenomena.
"(And there is no such thing as infinity^5, since infinity does not represent a real [or imaginary]
number)."
This is wrong and misleading. Infinite numbers are a very basic part of modern mathematics, ever
since Georg Cantor gave the first coherent account of them at the end of the nineteenth century.
[See Kaplansky's "Set Theory and Metric Spaces" for a nice introduction to transfinite arithmetic.]
The need for "infinite" numbers is clear: we use numbers to denote the size of sets. What number,
then, corresponds to the size of the set of natural numbers, {0,1,2,3,...}? No one of the these
numbers, obviously. The usual symbol used today for this number is the one coined by Cantor
himself: the Hebrew letter "aleph" with a 0 subscript, usually pronounced "aleph-zero." And not
all infinite sets are of the same size: although the sets of natural numbers, integers, and
rational numbers are all of size aleph-0, the set of real numbers (i.e. the set of points on a line
segment) is bigger; its size is usually denoted by "c," the cardinality of the continuum.
One can add and multiply infinite numbers (or "cardinals," as they are called) using definitions
which extend those covering the finite cardinals, and in this setting "infinity^5" makes perfectly
good sense. If by "infinity" he means the size of the set of natural numbers, then it is a theorem
that infinity^5 = infinity.
In fact, aleph_0^n = aleph_0 for any finite cardinal n (i.e. ordinary natural number)... but
aleph_0^aleph_0 = aleph_1 (which in fact = n^aleph_0 for any finite n), and aleph_1 is bigger than
aleph_0.
- Richard
————————————————————-
Subj: Two questions... 93-10-06 14:39:34 EST
From: WalterGL
Posted on: America Online
If the size of the set of real numbers is larger than the set of rational numbers, why isn't the
set or rational numbers larger than the set of natural numbers?
Also, if aleph_0^aleph_0 = aleph_1, then what would aleph_1^aleph_0 be? Aleph_1^aleph_1?
————————————————————-
Subj: Anybody ever read... 93-10-06 19:24:30 EST
From: AFC Andy
Posted on: America Online
..."The World of Aleph Null" by A.E. Van Vogt? I warn you, it isn't quantum mechanics or
transfinite mathematics...more like "general semantics." It's a science fiction novel, anyway.
Interesting...but confusing.
Never mind. Maybe we should set up a folder for math questions. Me, I flunked freshman algebra in
high school, so there are definite limits on what I can tell ya here! ;-) Hey, some minds work with
numbers, some work with words, some work with pictures. I'm pretty good with words and
pictures—two outta three ain't bad!
Well, onward to...
————————————————————-
Subj: ...animal languages (non-vocal) 93-10-06 19:56:19 EST
From: AFC Andy
Posted on: America Online
Here we get to some of the more interesting ways of communicating! Anybody can squawk or squeek or
honk, but communicating without sound takes some cleverness. Basically you can do it by sight,
scent or touch.
Let's start with the language of dance. When a honeybee happens on a really lush flowerbed, she
flies back to the hive and tells her fellows where to find the goodies...by dancing out a story! By
her movements, she conveys the direction and the distance to the treasure. (She also lets them
smell the samples she's brought back, to whet their appetites.)
Another visual language is one we use every day: facial expressions. Many animals use them
too—baring their teeth, pulling their ears back, raising eyebrows (used as a threat display by
baboons) Every time I see a picture of a chimpanzee in a magazine or a movie, dressed up in kids'
clothes and "grinning" widely with those big teeth, I have to cringe. That "grin" is chimp-ese for
"I'M ANGRY! GET AWAY!" But Hollywood insists on it, because in human eyes it's supposed to look
"cute." Ugh. I call it animal abuse.
Here's another visual language you've seen many times: fireflies. Their flashes advertise that
they're looking for a mate, and the distinctive flashing patterns (dot-dot-dot, dash-dash, or even
a "J" pattern) tell other fireflies what species is out there in the dark.
What about smell? There are lots of ways animals communicate with smells, but the range of ideas is
not usually very large. I don't think anybody ever told a bedtime story with smells! Most often
smell is used either as a warning or as a sexual come-on (chemicals called "pheromones" are the
ones used for this). In fact, tests have shown that a male emperor moth can smell a single female
moth from seven miles away! Obviously this guy has no trouble finding a girlfriend. ;-)
And then of course there's the skunk. Actually, it uses both visual *and* smell languages: first it
turns around, raises its tail and stamps its hind feet to say "Better get away fast!" If you don't
heed this warning—then comes the smell part! Phew! (The chemical, by the way, is ethyl mercaptan,
one of the most potent-smelling substances in the world.)
Stay tuned for our next installment...
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Head bobbing and signing 93-10-06 20:35:53 EST
From: AFC Andy
Posted on: America Online
Visual languages (the most common non-vocal kind) can be as simple as a white-tailed deer flashing
her tail to signal "Danger!", or as complex as a peacock's mating dance. One example I ran across a
few years back was head bobbing. No kidding! Not a very subtle language, but it gets the message
across.
Many years ago I had an old cyclura—that's a reptile related to the iguanas, but roughly the size
of a cocker spaniel. Maybe five feet long, including tail. Big, muscular jaws that could bite
through broomsticks. And he was a *small* cyclura!
Anyway, I found out that almost all the iguana-like reptiles use head bobbing as a way of
challenging invaders on their turf. And sure enough, when I walked up to this old fellow and bobbed
my head up and down, he bobbed right back! We used to have head-bobbing contests to see who'd get
tired first. He usually won. ;-)
One visual language I'm sure you've seen is sign language. Anybody who's seen Linda Bove on "Sesame
Street," or Marlee Matlin on "Reasonable Doubts," knows that American Sign Language is a
sophisticated, expressive language. And you may have heard that experimenters claim to have taught
chimpanzees like Nim Chimpsky and and gorillas like Koko to use sign language to communicate.
Well, actually there's a lot of controversy about those claims. It turns out that all of the
researchers were hearing people who were, by all accounts, lousy signers. (It wasn't exactly their
native language, after all.) I've talked with deaf people who were allowed to watch this research,
and gotten a *very* different story. One deaf woman, a fluent ASL signer who worked with Koko for
some time, signed this to me when I asked about the research:
"No, Koko couldn't use ASL! Are you kidding? She'd sign 'BANANA' real crudely and make a grab for
it—and those hearing researchers would go "Look, look, she's signing 'I want a banana!' Anything
Koko did—scratching, waving her arms around, anything at all—those hearing people would say she
was signing something, when she wasn't. And when occasionally she did manage to produce a simple
sign that they had spent months teaching her, she did it so badly that a signing person would
probably not even recognize it—but the researchers said she was 'being creative' with the sign."
Written accounts by native deaf signers (as opposed to hearing researchers) reveal similar stories
about the chimpanzee experiments. Every random move was hailed as a sign by hearing researchers
whose grasp of ASL was feeble at best. To the deaf people watching these experiments, it was
obvious that these animals could not really communicate in sign language. But it was the hearing
researchers who wrote the scientific papers claiming success!
So next time somebody tells you gorillas can use ASL, take it with a big grain of salt—unless that
person happens to be a native ASL signer! Until proven otherwise, I rate this research as bogus
with a big "B."
By the way, some books I used to get info for this piece: "Peterson's First Guide to Insects," the
old faithful "Guinness Book of Records" and "Koko's Kitten."
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Question? 93-10-07 07:54:01 EST
From: GenK
Posted on: America Online
Andy, has anyone ever said WHY native ASL signers were not used to teach in these experiments?
————————————————————-
Subj: Another question. 93-10-07 08:58:32 EST
From: GenK
Posted on: America Online
Andy - Got a question for you.
You know Sprite. Sort of an independent cuss most of the time. When I am sick, sad, or really upset
about something, he seems very concerned. He stays very close to me, generally touching me with a
paw. How does he KNOW when I need comfort or attention? Once I had a cat like that — paid no
attention to me at all unless I had a problem or he was hungry. Then that animal was in my lap or
under my feet all the time. What is it I am communicating and why do pets respond to the needs of
their humans?
————————————————————-
Subj: Why no deaf people? 93-10-07 18:10:58 EST
From: AFC Andy
Posted on: America Online
"has anyone ever said WHY native ASL signers were not used to teach in these experiments?" Because
there were and are relatively few deaf scientists, and because the hearing scientists fooled
themselves into thinking their own signing skills were just fine. (They weren't.)
How come so few deaf scientists? Same old story. It goes like this:
Born deaf? Then by definition, English is not your native language. (If you're lucky, ASL is.)
So...not fluent with English? Then you can't pass standard tests like the SAT—after all, you can't
answer the questions if you can't understand them!
Can't pass the SAT? Can't get into college.
Can't get into college? Can't get a degree.
No degree? Can't become a scientist...and so forth.
So even the most brilliant deaf people have usually been stuck in low-level jobs. The few deaf
folks on the chimp experiments were mostly animal caretakers—they cleaned the cages and so on. A
couple were brought in as sign language consultants, but the hearing scientists didn't like it when
they were told the chimps weren't really signing...so the deaf consultants were basically ignored.
Read Arden Neisser's fascinating book, "The Other Side of Silence," for a full account.
As to the problem I mentioned above—well, that's why I'm working to get more hearing people to
learn ASL, and at the same time building computer systems to help deaf kids polish up their English
skills so they can pass those tests! If we all learn to communicate better with each other, we'll
all be better off. (Besides, ASL is really cool! :-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: How do pets know? 93-10-07 18:18:44 EST
From: AFC Andy
Posted on: America Online
That's a really tough one, Gen! Without getting inside a dog's head, how can you tell what he or
she is sensing about your moods? You can't. Who knows? Maybe it's your tone of voice, as many
people believe. Maybe you *smell* different when you're upset or depressed or sick. Most likely
it's a combination of things.
One thing I can suggest if you want to learn more about this: read the book "Dog Watching" by
Desmond Morris. It's a really fascinating explanation of dog behavior. Morris has been watching
animals a long time, both in homes and streets and in the wild, and he can certainly tell you more
than I just did about how dogs sense our moods.
And cat lovers—read "Cat Watching" (same author). Great book! You'll learn a lot, I promise. Also,
another wonderful cat book with a similar title: "A Cat is Watching" (I forget the author, but your
bookstore can look it up in their files). Also a "must-read." Put both books on your list!
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Is This True? 93-10-07 20:06:22 EST
From: Leto III
Posted on: America Online
This Sentence is not true.
or
'This Sentence is not true' is not true.
or
''This Sentence is not true' is not true' is not true.
or
'...'This Sentence is not true'...' is not true.
or maybe 'Appended to its own quotation is not true' appended to its own quotation is
not true.
-Leto III
Postscript:
"Pilate said to him, 'So you are a king?' Jesus answered, 'You say that I am a king. For this I
was born, and for this I have come into the world, to bear witness to the truth. Everyone who is of
truth hears my voice.' Pilate said to him, 'What is truth?'"
————————————————————-
Subj: OK, a question for *you* 93-10-08 05:34:29 EST
From: AFC Andy
Posted on: America Online
How are Chee-tos (and similar puffed snacks and cereals) made?
The answer is rather interesting! I was able to find it in less than half an hour of browsing in my
local public library. So let's see who can come up with the explanation. Hint: try looking up "Food
processing" and "Food technology" in the card catalog.
No prizes—this is just for fun! :-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Was Dad pulling my leg ???? 93-10-08 22:52:10 EST
From: ACT CLEAN
Posted on: America Online
When I was growing up, (I was around 8 years old) I remember my family was having a Big out door
party with lots of guests.
As with any party with lots of guests, you need lots of ice. I was emptying the ice trays and
filling them back up with water when my dad walked through and said, "fill them up with hot water,
they will freeze faster". Being only a young lass I did not question my father's infinate wisdom
and did as he said from that day on thinking he knew some magic trick.
I have since asked my dad about this and he now swears that is the most ridiculous thing he has
ever heard of and denies he would ever say such a thing. I have heard this somewhere else, but I
can't remember where, but there was a molecular explination for the hot water freezing faster.
Andy, was dad pulling my leg when I was younger or did he know what he was talking about?
If I took two freezers both set at the same temp and put an ice trey in both, one with hot water
and one with cold, which would freeze faster?
Scott
————————————————————-
Subj: Cool question/hot question 93-10-09 20:51:39 EST
From: AFC Andy
Posted on: America Online
Does hot water freeze faster than cold? Common sense says no, but I remember reading about this
years ago in Jearl Walker's "Amateur Scientist" column of the "Scientific American" magazine. As I
recall (fuzzily! ;-) there *was* some truth to this, but I can't remember the explanation. (If I
had any idea what issue it was, I'd look it up—but I couldn't tell you to within +/- 15 years! ;-)
I'm gonna hazard a wild guess: hot water has a lot more dissolved gases in it, and as the water
cools in the freezer, these gases may come out of solution and form bubbles that provide "seeds"
(nucleation sites) for ice crystals, thus hastening the start of the freezing process. But that is
only a guess, and may be entirely wrong!
One thing I can do, even if I can't provide a certain explanation: make the experiment. Why don't
you do it too, folks, and let's all report on what we find! Take two ice cube trays, fill one with
cold water and one with hot water and put them both in the freezer. Check every half hour to see
which one freezes first.
I'll try this out tomorrow—then let's compare results. Remember, scientific results are worthless
if they can't be duplicated by anyone following the same procedure!
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Leto III, it was simpler... 93-10-09 22:56:27 EST
From: JackP
Posted on: America Online
than it appears. My impression was that Jesus's reply to Pilate was an elaborate way of saying,
"You said it." Pilate's answer was incredibly cynical, but I find myself wondering the same thing
sometimes when I see how facts are distorted in the media.
————————————————————-
Subj: Hmm... 93-10-09 23:13:54 EST
From: WalterGL
Posted on: America Online
That's an interesting concept. If you wanted to test if hot water would freeze faster than the cold
water, I recommend that you check more frequently than half-an-hour or use a large cup or bowl
rather than just small ice cubes, so the difference would be greater. Besides, I have an automatic
ice maker anyway... :-)
————————————————————-
Subj: soccer 93-10-10 10:39:24 EST
From: JoeCloo
Posted on: America Online
yesterday I played a soccer game. I feel that I need tips on playing goalie. HELP?!
————————————————————-
Subj: Joe, try reposting in Sports 93-10-10 10:49:44 EST
From: Host JackP
Posted on: America Online
Joe, you're more likely to find other soccer players in the Sports folder. AshleyNo1, for instance,
is a deadly goalie. She can give you some advice.
————————————————————-
Subj: Sorry, folks! 93-10-11 07:42:53 EST
From: AFC Andy
Posted on: America Online
I was tied up yesterday and didn't have a chance to do the ice cube experiment. I'll tackle it
tonight. Did anybody else give it a try? One tray of cold water, one tray of warm or hot—see which
one freezes first. I'll keep you posted!
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
————————————————————-
Subj: It's a draw! 93-10-11 19:57:18 EST
From: AFC Andy
Posted on: America Online
Well, I did the experiment tonight. Following Walter's suggestion, I filled two glass cups with
water (250 ml each). One had cold tap water at 19 degrees Celsius (65 Fahrenheit), the other had
hot tap water at 32 degrees Celsius (90 Fahrenheit). I put them in the freezer 25 cm apart so they
wouldn't influence each other too much, and checked them every half hour. (The freezer was at -18
degrees Celsius, zero Fahrenheit.) Results:
After 30 minutes—both were still liquid.
After 1 hour—both had a thin (about 3mm) layer of ice on top. Both layers were the same thickness.
Conclusion: at the temperatures I tried, it makes no difference whether the water is hot or cold.
When you think about it, that's pretty strange! The cold water really should freeze first. So
there's something funny going on that I can't explain, but in my experiment, at least, the hot
water did *not* freeze first. Anybody else try this? What did you come up with?
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: *I* have a question 93-10-14 07:23:52 EST
From: AFC Andy
Posted on: America Online
What is scar tissue?
When I was ten, I burned my foot while playing with a highway flare. (Ouch! It hurt so bad, I
couldn't sleep for a week.) Many years later, I still have a scar there: a small area of skin that
feels smooth, looks kinda shiny and doesn't seem to have the same "stretchiness" as normal skin.
Now, we all learned in school that your skin replaces itself constantly—I think the figure I heard
was that every seven years it will have been completely replaced. So why is it that this burned
skin didn't get replaced by normal skin? Why does it keep growing back as scar tissue? (Or does it
grow at all? This *can't* be the same skin I had when I was ten, can it??)
So what *is* scar tissue? How does it differ from normal tissue, and why does it stay the way it is
instead of being repaired by the normal body processes?
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
————————————————————-
Subj: Hmm... 93-10-14 14:41:28 EST
From: WalterGL
Posted on: America Online
Yes, your body does continously shed and replace your skin cells. (What do you think DUST is?) I
don't know about scarred tissue though....
————————————————————-
Subj: More on water... 93-10-14 16:52:27 EST
From: Dave911
Posted on: America Online
Andy, I have another question—will hot water BOIL faster than cold? :-)
————————————————————-
Subj: Yes... 93-10-14 17:50:45 EST
From: WalterGL
Posted on: America Online
It would at least seem logical that warm water would boil faster... but I'll assume that question
was a sarcastic one. :-)
But seriously, it doesn't seem very logical that warm water would freeze faster than cold water.
Warm water is warm because it's molecules are moving faster, and when placed in cold air, it will
slow until it becomes a solid. Cold water molecules aren't as fast as warm water molecules to begin
with, so it should slow down to the point of freezing faster than warm water. That is, assuming
that the rate of this "slowing down" is the same.... :/
————————————————————-
Subj: Well reasoned, Walter! 93-10-14 19:17:33 EST
From: AFC Andy
Posted on: America Online
It makes sense that warm water would take longer to freeze, since its molecules will require more
time to slow down to the sluggish speed at which they start to form ice crystals.
But following that seemingly sensible reasoning, the cold water I put into my freezer should
definitely have frozen before the hot water, and it didn't—they both froze at the same time,
despite an initial temperature difference of 13 degrees C. I'm still wondering why.
This result is as surprising and counterintuitive as if I had dropped a brick from a high tower,
then dropped another one 13 seconds later—and they both landed at the same time! What gives?
Considering the peculiar results of my freezing experiment, I think we had better take Dave's
question seriously. *Does* hot water boil faster? Common sense says "yes," but...I think I'd better
try it and see. I'll get back to you tomorrow with results....
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Actually, Walter... 93-10-14 20:19:24 EST
From: Dave911
Posted on: America Online
Yes, I would think hot water _would_ boil faster. But most of us here (I think) also thought that
cold water would freeze faster! The question was serious. :-)
————————————————————-
Subj: Boiling... 93-10-16 10:34:07 EST
From: JTatum
Posted on: America Online
Boiling is a cooling process, a process which occours when the substance is between two states of
matter (liquid and gas). In the case of water, it will attain the temperature needed to begin
transformation to a gas faster when it is already started at a relatively high temprature, as
opposed to a colder one...
Jamie
————————————————————-
Subj: How long does it take... 93-10-18 21:21:55 EST
From: AFC Andy
Posted on: America Online
...for water to boil? Well so far it's been five days and I haven't done that experiment I promised
you I'd do. I never thought it would take *that* long to boil! LOL!
My apologies, folks. I'm up to my neck in shooting sign language video and I've just been putting
off the experimental stuff...but I promise I will get back to it in the next day or so!
Meanwhile, I'm still waiting for an answer on the question of scar tissue. Walter? Anybody?
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Th' Speed o' Light? 93-10-28 18:53:11 EST
From: Alia A
Posted on: America Online
Why is it that many scientists insist that nothing can travel faster than light? Were they just
really bored that day?
It would seem to me that since velocity is relative and ( do not forget that the universe is
created by the participation of its parcipitants) there is an infinite number of observers (most
people do not realize that pencils, trees, and anti-lepton particles are observers also, it is just
another example of human arrogance :-) ), then there would be an infinite number of people all
observing you from different points of view which would mean that you would be traveling at all
speeds simultaneously (bad news for Olympic runners!) even (GASP!) at the 'speed of light' and
beyond ( velocity is 'space' divided by 'time', but there is no longer an absolute space or
absolute time (again, it is just relative)).
Whew!
That didn't make a lot of sense, did it?
————————————————————-
Subj: Yes... 93-10-28 19:12:00 EST
From: WalterGL
Posted on: America Online
Speed is always releative. A car might be going 55 miles per hour, but is it REALLY going 55 miles
per hour? Since the entire planet is revolving and rotating, when compared to the sun, that car is
going MUCH faster. Then, the sun is also hurtling through space, so compared to some other star,
the car might be going a different speed. Velocity is always a comparison.
Now, what if you were flying faster than the speed of light, what would happen when you turned on
your headlights? :-)))
————————————————————-
Subj: I'm ashamed to ask this... 93-10-29 12:01:48 EST
From: JackP
Posted on: America Online
considering the previous posts, but I was wondering why cats "knead" pillows and people before they
curl up and go to sleep on them.
————————————————————-
Subj: Cats... 93-10-29 12:45:15 EST
From: WalterGL
Posted on: America Online
They do? Really? Never heard of that (then again, I don't own a cat....)
————————————————————-
Subj: ANDY......... 93-10-29 18:55:03 EST
From: JULIEZZZZZ
Posted on: America Online
I HAVE A QUESTION. WHAT'S THE MEANING OF LIFE///
————————————————————-
Subj: recycling 93-10-30 18:24:14 EST
From: DarrylL983
Posted on: America Online
CAN YOU TELL ME WHAT THE NUMBERS ON PLASTIC
ITEMS REPRESENT IN REFERENCE TO RECYCLING
————————————————————-
Subj: Kneading 93-10-31 07:01:06 EST
From: AFC Andy
Posted on: America Online
Cats knead mostly because they did it when they were kittens. That gentle alternating paw pressure
stimulates milk to flow from mama cat's nipples. It's a motion that cats never forget, even when
grown up—it reminds them of a time when they were tiny and mama took care of everything.
Adult cats really have two personalities. When they are alone or with other cats, they are
*cats*—grown-up hunters with errands of their own. A cat watching a bird out the window is living
in this cat world, and is pretty surely not thinking about us humans.
But when cats are with us, they slip into another role: big kittens. A lot of the affectionate cat
behaviors we enjoy—purring, ankle rubbing and so on—come from a cat who is basically reliving its
kittenhood, with humans in the role of substitute mothers. So when cats are really relaxed, they
knead—going back to the time when they were still tiny fluff-balls who were completely dependent
on mama.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: JULIEZZZZZ... 93-10-31 07:04:50 EST
From: AFC Andy
Posted on: America Online
This isn't science, but I'll tackle it anyway. The meaning of life is different for each person.
Some folks even say there isn't any...and maybe for them , there isn't. You have to try to figure
it out as you go along, but you never *completely* understand it. (If you think you understand life
completely, you are kidding yourself!)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: The speed of light 93-10-31 08:28:30 EST
From: AFC Andy
Posted on: America Online
Alia, this speed of light stuff is tough! I'm still trying to figure out some of it myself. But
let's start with an experiment. As you and Walter pointed out, the earth is traveling pretty fast.
You'd expect that if you measured the speed of a beam of light moving in the same direction as the
earth and compared it against the speed of a beam of light moving at right angles to the earth,
you'd see some difference, right? The beam moving in the same direction as the earth ought to be
moving faster, getting a boost from the earth's own speed.
Well, back in the 1880s, a fellow named Albert Michelson wondered about this. So he built an
extremely sensitive gadget called an interferometer, that could compare the speed of two beams of
light with incredible precision. He tried it with two light beams, one of which was moving in the
same direction as the earth and the other at right angles.
Well, surprise! The speeds of the two beams were exactly the same! At first nobody could believe
it, but Michelson's equipment was reliable and others were able to duplicate his results. There was
no doubt about it. The speed of light was constant, no matter which way it was traveling.
(continued in next post)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Lightspeed squash-o-rama 93-10-31 08:44:23 EST
From: AFC Andy
Posted on: America Online
(continued from previous post)
When Michelson published his results—that the speed of light was the same no matter what—the
other physicists freaked out. This result made no sense! Some people just wouldn't believe it. Then
two guys named Fitzgerald and Lorentz suggested an explanation: maybe when an object (like the
earth, carrying Michelson's measuring equipment) was moving, it *shrank* on the axis it was moving
along. For example, if a 12 x 12" square was moving due east, maybe it was really only 11 3/4" on
one side...that is, if it was moving very fast. If that were true, it could explain Michelson's
measurements: the speeds of the two right-angled beams of light might be different, but the fact
that the measuring equipment was squashed along one axis compensated for that, so the speeds would
*seem* to be the same. (I know, this is confusing. Think about it for awhile. It does make sense.
;-)
When they heard this crazy idea—the faster you move, the more you get squashed front-to-back—most
scientists really went bananas. "No way!" they insisted. (You can't really blame them.) But fifteen
years later, Albert Einstein (an obscure clerk in the Swiss patent office) came up with an
explanation: his 1905 theory of Special Relativity said that the contraction really *was*
happening, but only at speeds very close to the speed of light. Not only that, but astronomical
observations confirmed that Einstein was right. It was hard to swallow at first, but eventually all
scientists agreed that Einstein was right.
(continued in next post)
————————————————————-
Subj: It's all relative 93-10-31 09:14:31 EST
From: AFC Andy
Posted on: America Online
(continued from previous post)
So what exactly did Einstein figure out? Well, here it is in basic terms. Einstein's explanation of
the puzzling results from the Michelson experiment was to start with these three rules:
1) All the laws of physics are the same in all systems that have the same motion with respect to
each other. Therefore, an observer in one system has *no way* to detect the motion of that system
by using measurements that are confined to that system—and all his possible meaurements *are*
necessarily confined to that system.
2) The velocity of light in any system is independent of the veocity of the source of light. So if
light travels 186,000 miles per second and your spaceship is flying 1,000 miles per second, the
light from its headlights is still traveling 186,000 mps—not 187,000!
3) This means that the velocity of light of light is independent of the relative velocity of its
source and the observer. In other words, if you measure light from headlights coming toward you or
from taillights going away, it will have the same speed.
All of this is not exactly common-sense stuff! A lot of people were very skeptical at first. In the
75 years since Einstein thought of this explanation, lots of experiments have been done to try to
test, and if possible disprove his theory. But all measurements so far have backed up the theory of
relativity to the zillionth decimal place. So until somebody comes up with something better, it's
the best explanation we have. :-)
I had to look up some of this stuff to be sure I remembered it right. The books I used: Mitchell
Wilson's facinating "American Science and Invention," a book I got when I was in 8th grade and
still refer to all the time, and the massive Van Nostrand Scientific Encyclopedia, fifth edition.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Faster-than-light light? 93-10-31 09:19:20 EST
From: AFC Andy
Posted on: America Online
Walter raises an intriguing question: "if you were flying faster than the speed of light, what
would happen when you turned on your headlights?"
Well, the theory as I understand it (which is to say, incompletely ;-) says that you can't fly
faster than light. But let's set that aside for a minute and ask a more reasonable question: if you
were flying at, say, 90% of the speed of light and you turned on your headlights, how fast would
the light from your headlights be traveling?
Common sense says that it would be travelling at the speed of light, plus your own speed—for a
total of 190% of the speed of light. Light traveling faster than light? Sounds weird, to say the
least!
In fact, the light from your headlights would be traveling at exactly the speed of light *if you
measured it*. Einstein's theory of special relativity says (among other things) that "the speed of
light is the same, as measured by any of a set of observers moving at *constant relative
velocity*." In other words, if you're all on the same spaceship and all moving at the same speed,
you'll all come up with the same speed-of-light measurement.
Now, suppose you're flying along at 90% of the speed of light, and you whiz past an observer who is
standing still. What would she measure as the speed of the light from your headlights? Well,
according to Einstein (and the experiments that back him up), the *speed* of light would still be
the same. However, the *wavelength* (color) would be greatly shortened. This is why light from
stars moving toward us is shifted toward blue (higher frequencies), while light from stars moving
away shifted toward red (lower frequencies).
The same thing happens on a smaller scale when an ambulance or cop car is coming toward you: its
siren sounds higher-pitched (shorter wavelength) as it comes toward you, then as it passes and
heads away from you, the sound drops in pitch (lower frequency). It's called "Doppler effect,"
after the guy who discovered it.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Invasion!!! 93-10-31 09:35:29 EST
From: GenK
Posted on: America Online
I woke up this morning to find DOZENS of flies in my office. They weren't here last night. No
windows were open. We are talking DOZENS. (Like walking through a buzzing black snowstorm - really
yukky) There aren't any in any other room.
NOW — does this mean these things all hatched at once in here? How does such a concentration of
insects happen? How can it be prevented? (I zapped them and now I have to vacuum up the dead ones.)
————————————————————-
Subj: Okay... 93-10-31 12:55:31 EST
From: WalterGL
Posted on: America Online
If a ship was flying faster than the speed of light, and it turned on headlights, would it
experience some major turbulence from crashing into its own light? Kind of like when an airplane
breaks the sound barrier? An airplane generates sound in all directions, so it will end up crashing
into its own sound waves, so supersonic jets are specially designed to withstand it.
————————————————————-
Subj: Walter... 93-10-31 14:59:17 EST
From: AFC Andy
Posted on: America Online
...I can't answer that, because current theory says a material object *cannot* travel faster than
light—so the question, although it sounds reasonable, is meaningless. It's like those "If I could
go back in time and kill my great-great grandfather, would I still be born?" type questions. You
*can't* go back in time, so the question is unanswerable.
Come to think of it, that raises a semi-interesting point: one of the curious things about language
is that there are many questions that are askable but not answerable. A simple question like "How
high is up?" can be thought up by a toddler, yet can never be answered, even by the smartest person
in the world.
Hmmm. Wonder whether there are any questions that are answerable but not askable? ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Plague of flies 93-10-31 15:10:05 EST
From: AFC Andy
Posted on: America Online
I can think of a couple possible explanations for Gen's invasion.
First, if you're talking about flying ants—well, they do tend to all hatch at once (in mating
season—that's their function) and swarm for a day or two. And they can get into houses in ways
that are sometimes surprising. It's happened in my basement several times in years gone by.
But I assume you probably meant true houseflies. Well, something like this happened to me only
once. I was 12 and was supposed to take care of my cat, including cleaning her litter pan. The pan
was in the basement and so it was easy to ignore—which I did, for at least a week or maybe two.
Then one day there was a plague of flies, and I couldn't figure out where they had all come from
all of a sudden.
I found out when I went down to the basement. I could actually see them hatching! It seems I had
left the litter pan for so long that it was piled up with...uh...cat poops, and some fly had come
along and laid a zillion fly eggs in them. Naturally, they all hatched more or less at once. Bingo!
Plague of flies.
I know you don't have a cat, of course, but...well, is it possible that Sprite had an accident
somewhere in a forgotten corner a week or two ago?
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: DON'T READ THIS AFTER EATING! 93-10-31 15:45:13 EST
From: AFC Andy
Posted on: America Online
Or before eating. In fact, if you're squeamish, you shouldn't read it at all.;-) This is a really,
really gross story. But since the subject of flies came up...for those of you who *enjoy* gross
stories...
Way, way back, I used to work for a scientific lab at Princeton University. They did research on
the hearing of all kinds of animals, which basically meant testing their hearing (under anesthesia)
and then killing them and dissecting their ears to see what different kinds of animal ear insides
looked like and how they worked. I took care of the animals. At one time or another they had just
about everything you could imagine—birds, snakes, toads, insects, bats, dolphins, lizards,
penguins, sea turtles, chinchillas, rats, mice, fish, you name it.
The hearing experiments went faster than the dissections, so there was always a big backlog of
specimens waiting to be dissected. We kept them in a huge chest freezer in one of the buildings. I
have to explain that the lab was built as six small buildings surrounding a larger one. That was so
that each building could be isolated from the others. The measurements were very sensitive!
So all the dead animals were frozen solid in that big chest freezer in building "E," and it was
packed to the gills. Now as it happened, nobody was working in building "E" the summer I'm talking
about, so nobody went in there for weeks at a time. It was just shut up tight...and it was a hot
summer, so of course it was broiling in there.
Well, on the hottest day of August, I was walking past building "E" on my way to somewhere else
when I thought I heard something. It was a buzz or hum, like an electrical transformer. I thought
maybe some equipment was acting up, so I walked over and looked in the window. Weird—at first I
thought there was a cloud of smoke in there, and I was about ready to call the fire department, but
the "smoke" was writhing and twisting and...swarming...in a peculiar way. I looked closer...it was
a cloud of flies!
There must've been thousands of them, maybe tens of thousands. You literally could not see the
other side of the room—the air was *black* with flies. "Where did they all come from?" I wondered.
I called my assistants and we unlocked the door of the building and opened it—very carefully!
First the flies swarmed out, like smoke pouring out of a burning building, but with a noise like a
giant beehive. They just kept coming and coming...it was unbelievable. Then the *smell* hit me like
a baseball bat across the bridge of my nose. I staggered back and almost fell down. You guessed it:
that old freezer had given up the ghost, probably a week or two previously, and the contents had
sat there in the baking August heat until they rotted so badly that the gases of decomposition blew
the lid off. Then the flies came...and bred and bred and bred on all that rotten meat: dead fish
and dolphin heads and dead lizards and dead rats and hundreds of dead cicadas from the last 17-year
locust cycle...
I had to help clean it out. I wore a gas mask and rubber gloves, but that wasn't enough—I had to
take a deep breath, run in, load a bunch of rotted corpses into a plastic garbage bag while holding
my breath, then run out and gasp in some fresh air....while thousands of flies buzzed around my
head. We had to keep doing that over and over until we'd emptied the whole freezer. It took all
afternoon. I went home and took a shower and scrubbed for half an hour, but I still didn't feel
clean. I didn't eat supper that night. You can guess why.
And that is about the grossest story I know. ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Wow... 93-10-31 17:15:55 EST
From: WalterGL
Posted on: America Online
From then on, I'm sure you checked the freezer on a regular basis!
————————————————————-
Subj: Vampire bats invade New Jersey! 93-10-31 18:21:57 EST
From: AFC Andy
Posted on: America Online
OK, put away your pitchforks and your torches—I was just kidding! Everybody knows (at least I hope
so!) that there are no vampire bats living within two thousand miles of New Jersey. All the bats
around here are *good* bats that kill flying insects faster than any spray can you ever saw—the
little brown bat Myotis lucifugus, the "big" brown bat Eptesicus fuscus (actually, she's about the
size of an underfed mouse) and the occasional red bat Lasiurus cinereus. Vampire bats live in
central and south America and practically never get as far north as Mexico, let alone the US.
But there actually *were* vampire bats in New Jersey a few years ago—living in a cage in the same
lab I worked in that had the ill-fated freezer. ;-) We had lots of different kinds of bats, from
teeny little ones the size of a baby's thumb...to nectar bats that hovered like hummingbirds and
sipped nectar with tongues longer than their bodies...to flying foxes with big soulful brown eyes
and a two-foot wingspan...to vampires. And since it's Halloween, I thought maybe you'd like to hear
a bit about my pals the vamps.
Vampire bats come in a few species, and there are some bats with names like Vampyrum spectrum that
aren't blood-eating vamps at all—instead, they eat small animals like mice and other bats. True
vampires—Desmodeus rotundus—are lively little fellows who hop around on their elbows. Most bats
don't move too well on the ground—their home is in the air, where they can fly rings around any
bird—but vamps are the acrobats of the bats ;-) and are very agile. They're actually quite cute!
(You'll have to take my word for this ;-) By the way, a vamp is about the size of a large mouse,
with maybe a six-inch wingspread. Not exactly the picture of a killer bat! But then, they aren't
killer bats.
(continued in next message)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: The bloody truth about vampires 93-10-31 18:40:30 EST
From: AFC Andy
Posted on: America Online
OK, so when do we get to the gory part? Right now. ;-) Vamps drink blood. Well, shucks, you all
knew that! Many people think they *suck* blood, but that's not true. Vampires have two razor-sharp
incisor teeth. (Think of a rabbit's two front teeth....but super sharp, like two tiny daggers.)
With these teeth, the bat makes a pair of slitlike wounds, and then it laps up the blood that oozes
out, just like a cat lapping milk from a saucer. The vamp's teeth are so sharp that you may not
even feel the bite—it's like cutting yourself with a fresh razor blade.
Do they really bite you in the neck? Rarely! They're much too shy for that. More likely in the
toe...if you're camping in central America, especially in cattle country, and you leave a bare toe
hanging out of your sleeping bag. Mostly vamps bite cattle, though...they flutter down and land,
then very cautiously hop and skip their way to the nearest cow and climb up just like a big
deerfly. Often the cow is unaware that it has been bitten. A vamp takes very little blood—it's a
small bat—so the cow probably doesn't even feel bad the next day. It wouldn't be a problem for the
cattle ranchers...except that vamps can spread rabies.
Now you're probably wondering how we fed those caged vamps at the lab. Did I stick my arm in every
morning so they could have brunch? No way! ;-) I got human blood from the hospital to feed them.
You see, blood doesn't last forever, even refrigerated, so hospitals often end up with outdated
blood that they can't use any more. Maybe it's a rare type that there isn't much call for, but they
keep it around, just in case a patient came in with that type...until it gets too old to use on
humans. (By the way, this does *not* mean that hospitals have too many blood donors—they *never*
have enough! So if you're thinking of giving blood, by all means do so.)
The outdated blood is in plastic pouches with little tubes attached. I used to go to Princeton
Hospital every two weeks and ask for blood for my pet vampires. I got some really weird looks, as
you can imagine—that was the fun part! ;-) —but they always gave it to me. Then I'd bring it back
and keep it in the fridge, and twice a day I'd pour out a little bit into a wide, flat Petri dish
and give it to the vamps. (I always wore leather gloves when I opened their cage, and of course I
had had my rabies shots before I started this job—not that these shy little bats were likely to
attack my hand, but just in case.) And the vamps would hop, skip and jump over to the dish and go
slurp-slurp-slurp with their tiny tongues. Cute. ;-)
Well, I left that job fifteen years ago, and the vamps moved to Florida with a friend of mine, so I
haven't seen them since. But I always kinda liked them.
Happy Halloween! :-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: OK... 93-11-07 21:25:26 EST
From: Dave911
Posted on: America Online
I have two questions, which someone sparked my interest about...
1. What was the name of Shakespeare's dog? :-)
2. How does one feed a praying mantis? :-)
Thanks! :-)
————————————————————-
Subj: Parents 93-11-08 21:19:02 EST
From: Court4
Posted on: America Online
My parents fight often. They're divorced and are going through custody battles, and I'm caught in
the middle. Besides having problems at school, I feel like choking them sometimes, what should I
do?
————————————————————-
Subj: Caught in the middle 93-11-10 15:07:31 EST
From: AFC Andy
Posted on: America Online
I went through that, Courtney, and it was awful! I tried to make peace between my parents but it
didn't help at all. Sometimes it even seemed to make things worse. :( I felt helpless and terrible.
I don't have any easy answers for you. But then this is a "science, nature and the universe"
questions folder, so parent disputes are a bit out of our territory. But don't worry! Gen and Jack
will be here in a jiffy with pointers to other places in KOOL where you can talk about this and
even get some advice, maybe. Good luck! And remember, they may be fighting with each other, but
they still love *you*. A cliche, but true.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Sex and violence ;-) 93-11-10 15:22:03 EST
From: AFC Andy
Posted on: America Online
"How does one feed a praying mantis?" Well, the old story was that the female ate the male after
they mated. but recent research says that isn't true. Mantids eat spiders and all kinds of other
insects. They're generally regarded as good pest-killers, like ladybugs. In fact, in some states
it's illegal to kill a mantis! For example, New Jersey, where I live, has a law against harming a
praying mantis.
So I'd say to feed a mantis, just put a smaller insect in front of it. If it's hungry, the mantis
will do the rest!
By the way, I got the info about mantids from my copy of the Peterson's First Guide to Insects, a
neat little pocket-sized reference book on common North American insects. It has pictures and
descriptions of everything you're likely to run into. And the pictures have little arrows pointing
to the key features to look for, so you can easily tell one bug from another. They have these books
for fishes, birds, widflowers, mammals and reptiles too. Good books to have around.
Shakespeare's dog's name? Hmmm...not exactly in the science and nature category, Dave! Sounds
suspiciously like a trick question to me. OK, I give up. What was its name?
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Praying mantis... 93-11-10 17:50:45 EST
From: WalterGL
Posted on: America Online
Yes, I believe it's a $300 fine for killing a praying mantis in New Jersey. Sounds really stupid, I
know....
————————————————————-
Subj: Andy... 93-11-10 18:11:20 EST
From: Dave911
Posted on: America Online
If I knew the name of Shakespeare's dog, I wouldn't be ASKing ANDY, would I? :-)
But, moving right along... about what percentage of kids have had chicken pox by age 14-15? :-)
I wonder if these weren't quite the questions you were expecting... ;-)
————————————————————-
Subj: Chickenpox 93-11-13 10:03:42 EST
From: AFC Andy
Posted on: America Online
My guess would be that most kids have already had chickenpox by age 14-15. My Merck Manual (a good
all-around reference for medical stuff) says that it's caused by Varicella zoster, a virus closely
related to the herpes family that causes "cold sores," "shingles" and other, nastier problems.
The book says about chickenpox "Almost universal (children); occasionally in adults." But it
doesn't answer your specific question, Dave. I bet ol' doc JackP could tell us the answer right off
the top of his head, though! :-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: :-) 93-11-13 19:22:14 EST
From: Alia A
Posted on: America Online
How much wood would Leto III chuck if Leto III could chuck wood?
————————————————————-
Subj: Regarding :-) 93-11-13 19:25:53 EST
From: Leto III
Posted on: America Online
I would chuck as much wood as I could chuck, if I could chuck wood!
:-)
————————————————————-
Subj: Silly question, Alia! 93-11-14 15:18:16 EST
From: AFC Andy
Posted on: America Online
They don't have wood on Arrakis! (Except what's imported, of course—and that's far too valuable to
go chucking around.)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: I think that Leto III was... 93-11-14 21:35:11 EST
From: JackP
Posted on: America Online
chucking wood all the way to Arrakis. That's how the wood gets there.
————————————————————-
Subj: Chickenpox? How many? 93-11-14 21:40:58 EST
From: JackP
Posted on: America Online
Probably over 95% of 15-year-olds have had chickenpox, as Andy says. This number is an estimate
because many folks who think they've had chickenpox, have not had them but something that looks
like them. Others can have a very mild case, and it's missed. Chickenpox can recur to a limited
extent (in a sense). A chickenpox rash over one area of the body is called "shingles" or "Herpes
Zoster"; people might just call it chickenpox. Zoster can last for weeks, though, and happens in
folks who've had chickenpox already. Zoster in someone who's NOT had chickenpox is rare (but my
lovely wife had it). There's more to say, but I'll stop.
————————————————————-
Subj: ARE YOU CUTE ANDY 93-11-14 22:46:55 EST
From: Katsmantom
Posted on: America Online
I WANT TO KNOW IF YOUR CUTE AND IF YOUR AGES 11-13 WRITE BACK TO KATSAMANTOM!!!!!!
PS SOOOOOOOOON
————————————————————-
Subj: Katsmantom... 93-11-15 16:14:14 EST
From: WalterGL
Posted on: America Online
<< I WANT TO KNOW IF YOUR CUTE AND IF YOUR AGES 11-13 >>
I don't think so. (the answer to the *second* question, that is).
————————————————————-
Subj: Computers 93-11-15 16:15:28 EST
From: Aquamarine
Posted on: America Online
I know this is not exactly about science but It is computer science dealing with AOL. My question
is.....
Do you know what cyber space is?
————————————————————-
Subj: Cyberspace... 93-11-15 22:24:47 EST
From: WalterGL
Posted on: America Online
Cyberspace as many meanings. Sometimes, it's just another name for the Internet, which connects
hundreds of networks across the world (including AOL). See the "Telecommunications" folder for more
info.
But, cyberspace usually referrs to where people meet during telecommunications. For example, if I
were talking to a friend over the phone, where would we be meeting? We can't be meeting at my
house, since only I'm at my house. We can't be meeting at his house either. We are meeting in
CYBERSPACE.
Same thing for chatting and sending e-mail with modems.
————————————————————-
Subj: Thanks, Walter! 93-11-20 11:58:13 EST
From: AFC Andy
Posted on: America Online
I couldn't have said it better myself!
Katsmantom, I hate to disappoint you, but I'm 43 (going on 44), short, bald and bearded. If you
thought Rumpelstiltskin was cute, you might think I am. ;-) But most folks would probably say no.
Dave911 has actually met me, and I doubt he would call me "cute." LOL! Weird-looking or comical,
maybe...or just plain silly! ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: trees 93-11-23 23:42:05 EST
From: Luv 2 Jump
Posted on: America Online
Andy,
How do the nutrients and water get from the roots to the leaves on a tree?
————————————————————-
Subj: ANDY FROM KATSAMANTOM 93-11-24 23:41:58 EST
From: Katsmantom
Posted on: America Online
WHAT ARE YOU DOING IN A KIDS PROGRAM ?????????????????????????????????????
THATS NOT FAIR !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
————————————————————-
Subj: WALTER FROM KATSAMANTOM 93-11-24 23:44:59 EST
From: Katsmantom
Posted on: America Online
i'M 12 AND I LIVE IN DENVER COLORADO AND I'M VERRY CUT IF I DO SAY SO
MYSELF!!!!!!!!!!!!!!!!!!!!!!!!
————————————————————-
Subj: Hey Sam - 93-11-24 23:47:19 EST
From: GenK
Posted on: America Online
Andy is a good friend of mine and of KOOL's — he was here a year ago when we started :-)
He also knows more STUFF than anyone else I know. I am really glad he is here.
————————————————————-
Subj: Trees 93-11-25 09:35:30 EST
From: AFC Andy
Posted on: America Online
"How do the nutrients and water get from the roots to the leaves on a tree?"
Good question. Seems as if it would take big pumps to get the stuff up there—and we all know trees
don't have pumps! ;-) The answer is something called capillary action. It means that if you take a
really skinny tube (say, as thick as a hair) and dip one end in liquid, the liquid will be pulled
into the tube and will fill it up. Trees and most plants have lots of tiny tubes called
"capillaries" that carry nutrients around—even going straight up, against the force of gravity!
Here's an experiment you can do to show how capillary action works. Take a glass and put a quarter
cup of water in it. Put a few drops of red food coloring in the water so it's really, really red.
(Be careful not to get any on your clothes or the tablecloth! ;-) Now take a stalk of celery and
cut off the ends so they are clean and fresh. Dip one end of the celery in the red water and leave
it there, propped upright. In an hour or so, you'll find that the red has been pulled right up to
the top!
But how does capillary action work? How can it pull liquids uphill, working against gravity? Here's
why it happens.
Most atoms and molecules attract each other, sort of like tiny magnets (although it's not magnetism
at work here). They want to stick together. Water molecules attract each other, so they tend to
clump together. (That's what causes "surface tension"—but we'll talk about that another time.)
But some molecules are *especially* attracted to certain other molecules. And that's the key: water
molecules are even *more* strongly attracted to solids like glass or cellulose (the stuff plants
are made of) than they are to each other! So when you have a hollow tube of cellulose—a capillary
in a tree trunk or in a piece of celery—and one end touches a source of water, the water molecules
pull themselves up against the walls and keep pulling. More and more water molecules want to touch
the walls of the tube, so it fills up with water.
This molecular attraction is even stronger than gravity—strong enough to pull water all the way up
to the top of a tall tree. It only works in very skinny tubes, though. You won't see capillary
action in your garden hose, or even in a drinking straw! Why? Because in a very thin tube, most of
the molecules are pretty close to the walls and they can feel that attraction. But in a wider tube,
like a straw or a garden hose, most of the molecules are so far away from the walls that they don't
feel the pull—so they sit right where they are.
There's one last question: if capillary action is always pulling water (with nutrients dissolved in
it) to the top of the tree, how come treetops aren't all soggy and wet? Because the water
constantly evaporates from the leaves of the tree. That helps cool the tree in hot weather, just as
sweating cools you. And it makes room for more nutrient-laden water to be pulled up from the roots.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: C 93-11-25 18:57:04 EST
From: Alia A
Posted on: America Online
Another message on the ever-popular speed o' light...
Would traveling faster (relatively) than light produce a visual equivelant to the sonic boom
produced by traveling faster than sound?
————————————————————-
Subj: Capillary action... 93-11-26 01:06:04 EST
From: WalterGL
Posted on: America Online
Yes, water tends to attract to certain surfaces. Water molecules use polar covalent bonds between
the hydrogen and oxygen atoms. Water sticks to certain materials, like glass (hydrophilic), while
it separates from other things, like oil (hydrophobic).
—Walter Lee, the esteemed, award-winning, Nobel prize biochemist :D
————————————————————-
Subj: 0:001 93-11-27 18:25:54 EST
From: Leto III
Posted on: America Online
Let a be some real number between -1 and 1. Consider the some S of the geometric series given by
the equation S=1 +a +a^2 +a^3 +... Prove that S is 1/(1-a) by multiplying both sides of the definig
equation by a, and by then subtracting the new equation from the old. Test the formula out on a=
1/2, -1/2, 1/3, 2/3, and .1. What happens for a= 1, -1, or 2?
————————————————————-
Subj: About C 93-12-01 14:54:03 EST
From: AFC Andy
Posted on: America Online
Hate to give a pat answer, Alia...but since we can't travel faster than light, the question is not
meaningful.
A hypothetical answer, however, would have to be "no." A sonic boom is caused when air (the medium
through which sound is transmitted) is highly compressed. Since there is no medium that transmits
light, no such compression could occur.
Folks used to believe that light was a compression wave in something called "aether" (not the
chemical kind)—but the existence of aether was conclusively disproved by the famous
Michelson-Morley experiment. (See my previous messages "The speed of light" and "Lightspeed
squash-o-rama".)
So the answer is no—not in theory, and certainly not in practice! ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Why did......... 93-12-02 20:33:29 EST
From: LesleyAS
Posted on: America Online
Why did people start taking slaves in the first place, couldn't they do the work themselves?
————————————————————-
Subj: Oh Yeah? 93-12-02 21:30:30 EST
From: Alia A
Posted on: America Online
The medium through which light travels is the local gravitational field.
————————————————————-
Subj: M-M 93-12-02 21:37:38 EST
From: Alia A
Posted on: America Online
The (in-)famous M-M experiment doesn't mean much because there actually was an 'ethereal drift',
only it was 1/1000th (or some such fraction) of what they expected. Even if they had suspected
this, the measuring instruments of that time were not sensitive enough to detect it. It can be
easily measured today by the astronauts riding around orbiting the earth.
————————————————————-
Subj: Science is Cool - reposted 93-12-04 08:01:34 EST
From: GenK
Posted on: America Online
————————————————————-
Subj: SCIENCE 1 FOR THE SCI 93-12-03 20:13:56 EST
From: Elwjr1
Posted on: America Online
SCIENCE IS COOL. I ESPECIALLY LIKE INVESTIGATING MATTER. A CHAPTER IN MY SCIENCE BOOK.
LESLIE
————————————————————-
Subj: Andy... 93-12-04 09:17:29 EST
From: JTatum
Posted on: America Online
could you give me the scoop on plasmas???
Jamie
————————————————————-
Subj: A gravitational field... 93-12-04 10:44:35 EST
From: AFC Andy
Posted on: America Online
...is not a "medium," Alia, any more than a magnetic field is. A medium in physics is a fluid or
fluid-like substance—a dispersion of particles of matter, in other words. A gravitational field
doesn't meet this definition.
Yes, light *passes through* the local gravitational field, and can even be affected if the field is
strong enough—but that's not the same thing as saying that the gravitational field is the medium
in which light is propagated. It isn't. To draw an analogy: a magnetic field can pass through a
glass of water and attract a piece of iron on the other side, but water is not the medium through
which magnetism is propagated. In fact, there is no such medium.
On the question of ether, I have to disagree with you. No reputable scientist has argued for the
existence of aether (or ether) in this century, because the evidence just plain isn't there. Your
astronauts in orbit may be indeed measuring something, but it isn't ether drift, that's for
certain. It's a thoroughly disproved hypothesis.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Fun with plasma 93-12-04 11:20:00 EST
From: AFC Andy
Posted on: America Online
Jamie, glad you asked. Did I ever mention that I worked for ten years at the Princeton Plasma
Physics Lab? ;-) 'S true!
Let's start by defining what kind of plasma we're *not* talking about here: blood plasma. Jack can
tell you all about that kind. What we mean here is the kind of plasma physicists deal with: a kind
of superhot gas found in stars, neon lights...and tokamaks. (I'll explain the tokamak part later.)
You know the definition of a gas: it's a fluid with no fixed volume. Its molecules or atoms are
flying around, not bound to each other but just bouncing off the walls of whatever container you
put it in. Gas expands to fill whatever space you give it.
OK, now take a gas and heat it really hot. Make it hot enough, he atoms fly around so fast that
they start to lose the electrons that normally circle their nuclei! It's kind of like when you ride
a roller coaster and lose your glasses. ;-)
So now you have this hot gas-like stuff consisting of a bunch of unattached electrons (negatively
charged, of course) and a bunch of nuclei (positively charged), all bouncing around together.
That's a plasma.
So what is it good for? Well, an atom (or molecule) of an ordinary gas has no electrical
charge—the negative electrons balance out the positive nucleus. But in a plasma, every particle
has some kind of cherge, and that means you can push it around with external electrical or magnetic
fields.
Take a fluorescent lamp. It's filled with a gas (mercury vapor or something similar) that can be
heated to a plasma. When in that state, we apply an electric field across the ends of the tube—and
presto! the plasma's electrons get so energetic that they start giving off ultraviolet light.
If that was all, the lamp would only be good for getting a sunburn. ;-) But the walls of the tube
just happen to be coated with a special paint that gives off visible light when it's struck by UV
light. That's how you get light from a plasma.
(continued in next message)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Hot stuff! 93-12-04 11:57:36 EST
From: AFC Andy
Posted on: America Online
(continued from previous message)
Now we get to the really hot stuff: stars and tokamaks. You know stars are pretty hot: our sun has
temperatures of about 15 million degrees C. inside. You'd better believe that at those
temperatures, the electrons have all been flung off the nuclei, so we're talking plasma here. In
fact, although we normally say that the sun is made up mostly of hydrogen, the truth is that it's a
plasma of nuclei and electrons that *used* to be hydrogen atoms before things got a too hot for
comfort! ;-)
The hot hydrogen nuclei in the sun collide with enough force that they often fuse together—like
throwing two blobs of jelly at each other, and having them stick together to form a bigger blob.
;-) In the sun's case, the "bigger blob" is a helium nucleus.
But there's a side effect: the fusion process also spits out a fast-moving neutron. It bumps into
other particles in the plasma and heats them up, keeping the whole mess nice and toasty. That's
what makes the sun so hot.
Now, if we could duplicate this process here on earth, we'd have a good inexpensive energy source.
(After all, the fuel is hydrogen—and guess what makes up two-thirds of every drop of water?) The
problem is this: the plasma has to be *extremely* hot, so how do you hold it all together? No
container would hold a 15-million-degree plasma!
But remember what I said before: "in a plasma, every particle has some kind of charge, and that
means you can push it around with external electrical or magnetic fields." You can't hold a plasma
in a physical bottle...but a *magnetic* "bottle" just might do the trick.
Great idea! In theory, that is. In practice, it turns out that trying to hold plasma with a magnet
field is like trying to hold Jell-O with rubber bands. ;-) The slippery stuff tends to squirt out
between the lines of magnetic force.
(continued in next message)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Toka-what? (and a contest) 93-12-04 12:38:34 EST
From: AFC Andy
Posted on: America Online
(continued from previous message)
So for the past fifty years, scientists and engineers have been working on ways to make better
magnetic bottles. It's a very difficult task—some say the most difficult thing humans have ever
tried to do—but they've been making progress. The world's leading fusion lab is the one I used to
work for: the Princeton Plasma Physics Lab (PPPL).
There are several different ways to try to use magnetic fields to hold in a plasma. Here are a
few...
1) Put the plasma in a sphere and use wraparound electromagnets to try to hold it in. Result: too
hard to get perfectly even magnetic fields. (All those magnets interfere with each other!) Plasma
squirts out.
2) Put it in a tube and use powerful circular magnetic fields to "pinch" off the ends. Result:
better, but the plasma still leaks out the ends.
3) Use a shorter tube, and construct "magnetic mirrors" at the ends to reflect the plasma back.
Result: even better, but there's still some leakage through the mirror fields at the ends.
4) If the problem is with the ends, why not build a tube with *no* ends? Wrap it around and make it
into a donut shape—what mathematicians call a "torus." Result: best approach so far, but still
very tricky to get even magnetic fields over the whole thing.
The fourth kind of fusion device is called a "tokamak," which comes from a Russian phrase meaning
roughly "toroidal confinement chamber." Yes, the tokamak was invented in Russia....but they didn't
have the money to build a big one! So we did. Fusion research is really an international effort.
:-)
I used to work on PPPL's biggest machine: the Tokamak Fusion Test Reactor, or TFTR. Just to give
you an idea of how big it is, TFTR's power supply can put out 950 million watts during an
experimental "pulse" (which lasts for a few seconds). That's enough to run the entire city of
Newark, NJ! And just to make things hotter, TFTR has a giant microwave heating system—like your
microwave oven, only instead of a few hundred watts, this one puts out 12 million watts!
Even with all this going for it, TFTR is still many years away from being an operating power
generator. (If the government keeps cutting the funds, it may never happen!) But it's still the
most advanced fusion reactor in the world.
OK, now for the contest: I have two 8 x 10 color glossies of TFTR ( a *most* impressive piece of
hardware, I can tell you!) and a packet of official info about plasma physics, straight from PPPL.
The person who comes closest to guessing the maximum temperature achieved by TFTR wins them!
Deadline is December 15th, 1993, and each KOOL kid gets only one guess. DO NOT post your address
here! The winner will be notified, and Gen will see to it that you get your prize.
Oh, a hint—the max temperature is somewhere between a 100 million and 1,000 million degrees C.
Good luck!
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Slavery 93-12-04 12:49:33 EST
From: AFC Andy
Posted on: America Online
Leslie asks "Why did people start taking slaves in the first place, couldn't they do the work them
selves?"
They could, Leslie, but they were too lazy. It was easier to enslave a person and order him or her
around. A shameful business, but lots of people did it for many years.
Why did slaves let other people boss them around? Several reasons. First, they were threatened with
whipping or even shooting if they ran away. Many of them figured it was better to be alive in
slavery than dead.
Second, many slaves had only very basic skills, so they couldn't easily have gotten a job or earned
a living even if they were freed. Slaves were mostly used for the hardest kind of physical
labor—like sawing wood and picking cotton—jobs that took more muscle than thinking skills. Most
slaves could not even read or write, because theoir owners never bothered to send them to school.
And third, in this country all slaves were black and all blacks were slaves—so if you ran away,
the color of your skin would give you away as a slave! Anybody who saw you would probably call the
police, and you'd be shot, lynched (hanged) or re-enslaved. :(
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Only two more days! 93-12-13 09:36:19 EST
From: AFC Andy
Posted on: America Online
Shucks, folks, I'm surprised nobody has taken a guess yet in the big Fusion Temperature Contest!
;-) Just to remind you, you have until midnight on Wednesday, Dec. 15 to make your best guess of
the highest operating temperature ever reached by the Tokamac Fusion Test Reactor at Princeton. To
help you get closer, I'll tell you that it's somewhere between 100 million and 800 million degrees
C.
The person who gets closest gets two color photos of the TFTR reactor (which is a truly *awesome*
machine!) and some other info about plasmas and fusion, straight from my friends at the Plasma
Physics Lab. So go ahead and take a guess! Right now I have zero entries, which means your chences
of winning are excellent! ;-)
By the way, you may have heard on the news that TFTR reached a new breakthrough last week: *** 5
million watts *** of output power! Hot stuff indeed!
So come on, take a guess—what's to lose? Whoever comes closest will win!
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Hmm... 93-12-13 16:43:12 EST
From: WalterGL
Posted on: America Online
Although the range you gave us seems a little illogical, I think it was somewhere around 150
million.
————————————————————-
Subj: Illogical? 93-12-13 19:43:04 EST
From: AFC Andy
Posted on: America Online
How so, Walter?
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Well... 93-12-13 21:33:36 EST
From: WalterGL
Posted on: America Online
It would seem logical that if the answer was 150 million, then you would say that the number was
from 50 to 200 or so. Giving a range usually implies that the number is somewhere in the middle.
But, with reverse psychology.... :-)
————————————————————-
Subj: Plasmas 93-12-14 21:02:22 EST
From: JTatum
Posted on: America Online
Well, since most plasmas start at around 100 000 000 C, I'd guess 500 000 000 C... :-)
Jamie
————————————————————-
Subj: Anybody else? 93-12-15 15:09:13 EST
From: AFC Andy
Posted on: America Online
You've got till midnight tonight (EST) to post your guesses here. The big winner will be announced
tomorrow evening...and anybody who didn't bother to enter will just have to live with that sorry
fact for the rest of their lives! LOL! ;-)
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
————————————————————-
Subj: I want to answer... 93-12-15 19:01:23 EST
From: Dave911
Posted on: America Online
I wish I could answer... but I saw the answer somewhere already. :( (no I won't tell where... till
tomorrow!) :-)
————————————————————-
Subj: The winner is... 93-12-16 10:42:46 EST
From: AFC Andy
Posted on: America Online
...Jamie Tatum! :-)
The highest plasma temperature ever reached by the Tokamak Fusion Test Reactor was 400,000,000
degrees C., so Jamie's guess of 500 million was the closest. Of course, with the new series of
high-energy experiments that started last week on TFTR, that record is likely to be broken—but as
of now, 400 million is the number and Jamie is the winner! :-)
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
————————————————————-
Subj: Strategy... 93-12-16 15:52:14 EST
From: WalterGL
Posted on: America Online
I should have waited until 11:55 PM ET, and looked at all the guesses. After seeing Jamie's guess
of 500,000,000, I'd just guess 499,999,999. That's the usual strategy with "closest guess wins"
contests. Although if I got kicked off AOL at 11:58... :D
————————————————————-
Subj: Really? :/ 93-12-16 18:15:35 EST
From: Dave911
Posted on: America Online
I thought Time said that the hottest it had gotten was 100,000,000. :/ Oh well—maybe that was just
the latest test or something. :-)
————————————————————-
Subj: Hey, who ya gonna listen to... 93-12-17 13:52:23 EST
From: AFC Andy
Posted on: America Online
...me or some science reporter? ;-) I helped build TFTR and I know the guys who are running it now.
Trust me, it was 400,000,000 degrees! :-)
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
————————————————————-
Subj: How was that temperature... 93-12-19 12:25:36 EST
From: JackP
Posted on: America Online
measured? The thermometers in our house only go up to 108 degrees.
————————————————————-
Subj: Thermometers... 93-12-19 14:03:34 EST
From: WalterGL
Posted on: America Online
Jack, I'm sure they used something other than puny mercury or alcohol termometers. :D
————————————————————-
Subj: Oops... 93-12-19 14:04:11 EST
From: WalterGL
Posted on: America Online
I meant "thermometers." Difficult word to type at 65 wpm. :-)))
————————————————————-
Subj: Excellent question! 93-12-19 17:43:33 EST
From: AFC Andy
Posted on: America Online
How was the temperature measured? Well, obviously nothing solid can exist at 400,000,000
degrees—so they couldn't do it with liquid (alcohol or mercury) thermometers, or even with
electronic thermocouples or diode sensors. So...how can you tell how hot something is, without
touching a thermometer to it?
Suppose you hold a piece of metal in a flame. How can you tell when it's really, really hot? It
glows, of course. The hotter it is, the brighter it glows—and the color changes too, from dull
red, through orange and yellow, to bright white. In fact, a metallurgist (a person who studies
metals) could tell you exactly what the temperature is for each color, as long as she knew what
kind of metal you were heating.
The TFTR crew did the same thing. They had sensors of various kinds that looked at the glowing
plasma, and analyzed the radiation (light and X-rays) coming from it. That's how they were able to
measure the temperature without anything physically touching the plasma—just by looking! :-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Measuring plasma... 93-12-20 16:29:37 EST
From: WalterGL
Posted on: America Online
Physically touching the plasma would sort of hurt. :D
And besides, if they touched ANY instrument to the plasma, one of two things would happen (correct
me if I am wrong):
1) the instrument would get fried, or
2) the plasma would cool down, and would no longer be plasma. :-)
————————————————————-
Subj: Yup! 93-12-22 10:04:19 EST
From: AFC Andy
Posted on: America Online
Number 2 ("the plasma would cool down") is the more likely case. One of the important reasons we
need the magnetic confinement is that if the plasma touches anything material, it cools
instantly—so we have to keep it away from the container walls. It's actually a pretty thin soup in
there—most people would say it's a near-vacuum—so it doesn't take much to cool off the plasma.
Maybe that sounds a bit odd—I mean, a 400-million-degree plasma is HOT! So how come it's so easy
to cool off? The answer lies in the difference between temperature and heat. A lot of folks don't
understand this, but it's really simple—so listen up, and you can impress your friends and parents
with your knowledge. ;-)
Temperature is really just speed, in a submicroscopic sense: how fast the atoms and molecules are
moving. The faster they bounce around, the higher the temperature. But notice that this definition
doesn't say anything about how many of them there are—how much mass is involved, in other words.
That's where heat comes in.
For example, you can heat the head of a pin to a thousand degrees, which is pretty hot—but leave
it alone for five minutes, and it will be cool enough to touch. The key here is that although the
*temperature* was high, the amount of material at that temperature was tiny—just a pinhead. So the
amount of *heat* was small.
On the other hand, you can take a bathtub full of water and warm it up to a hundred degrees...and
it will stay warm for maybe an hour. That isn't a high *temperature*, but the amount of *heat* in
all that water is a lot more than in the 1,000-degree pinhead! The water has much more mass, so it
has more heat (in this case), even though its temperature is much lower than that of the pinhead.
The situation with the plasma in TFTR is like the pinhead: small mass, high temperature. In fact,
the whole huge machine—it's the size of a house—contains less than five grams (a third of an
ounce) of plasma. Those atoms are spread pretty thin in all that space—but they're moving REALLY
fast! ;-) Hence you have a 400,000,000 degree temperature, but relatively low heat.
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
————————————————————-
Subj: Too cold to snow ??? 93-12-28 13:55:04 EST
From: ACT CLEAN
Posted on: America Online
Hi Andy !
Interesting question came up in conversation today. I know it can be too warm to snow (then it is
rain) but can it get too cold to snow ??
Scott
————————————————————-
Subj: To cold? Naaah! ;-) 93-12-30 12:05:03 EST
From: AFC Andy
Posted on: America Online
It can never get too cold to snow. Take Antarctica—there are places where it gets down below -120
degrees F.—that's 150 degrees below freezing!--but you'd better believe it still snows. :-) In
fact, snow is about all you'll see in Vostok, Antarctica, where according to Guinness the
temperature dropped to -128.6 degrees F. back in July of 1983.
In July?! Yes...remember, Antarctica is in the southern hemisphere, so July is wintertime down
there. In weather terms, it's equivalent to February up here!
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Re:To cold? Naaah! ;-) 93-12-31 16:13:02 EST
From: Dave911
Posted on: America Online
Andy, why does it snow sometimes, but other times hail? And since snow is just a form of frozen
water, why doesn't water (or ice) turn to snow on the ground? It seems that snow can get pretty icy
on the ground, but not the other way around. :/
————————————————————-
Subj: Acid rain 94-01-01 21:19:32 EST
From: Karen1982
Posted on: America Online
Any info on this subject?In what cities do acid rain occur most? Or if you know anything else about
acid rain,MR.ANDY.
Thanks!
Karen1982
————————————————————-
Subj: Re:Acid rain 94-01-03 22:29:35 EST
From: JTatum
Posted on: America Online
acid rain is caused by evaporating sources of acidic water. usually where acids are used as
solvents, near labs, etc. dunno if there is one primary source of acid rain.
re: hail, they occour in thunderstorms where the clouds are below freezing temperature. I don't
know much about their formation, and my meteorology book is upstairs and the plane has tired me out
too much!!! :-)
————————————————————-
Subj: Snow and hail 94-01-12 13:02:41 EST
From: AFC Andy
Posted on: America Online
"why does it snow sometimes, but other times hail?" That depends on a number of things. The
temperature of the lower atmosphere is the biggest factor: if it's cold, you get snow, but if it's
above freezing you're more likely to get either rain, hail or both.
In the simplest terms, snow is just rain that froze. More precisely, it's tiny drops of water that
froze into snowflakes before they could clump together into raindrops, and then stayed frozen
because the air temperature at ground level was cold enough.
Hail is more of a summer phenomenon. It happens when you have a rain cloud (cumulonimbus, for all
you meteorology buffs; ) with strong updrafts. Because it's generally colder at the high altitudes
where clouds live, raindrops often start out as frozen ice drops and melt on the way down.
But if the cloud has strong updrafts, the ice droplets can be carried back up into the cloud to
accumulate another layer of ice. (In fact, if you take a hailstone and cut it in half, you can see
all the layers—just like tree rings!) This can happen over and over, with the ice fragment getting
thicker and thicker...until the resulting hailstone becomes too heavy for the upward-blowing winds
to support. At that point, it falls out of the cloud and bruises your head. ;-)
Summer rainclouds are the ones most likely to have the strong updrafts needed to produce hail, so
that's when we most often get bombarded with ice pellets. In winter, snow is the rule, because the
updrafts that build hailstones don't happen as often. (Why not? I don't know.)
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
————————————————————-
Subj: Water to snow 94-01-12 13:12:18 EST
From: AFC Andy
Posted on: America Online
"why doesn't water (or ice) turn to snow on the ground?"
Well, that's sorta like asking "Why doesn't cream (or butter) turn to whipped cream?" ;-) Snow, as
you know, has a lot of air in it—the rule of thumb is that ten inches of snow are equal to one
inch of rain. That's nine inches of air and one inch of water!
When water is lying there in a puddle and the temperature goes below 32 degrees F., it just quietly
freezes—all in a lump. But up in a cloud, you have tiny (even microscopic) water droplets floating
around. When they freeze, they turn into snow crystals—and anybody who has ever looked at a
snowflake knows that it has six arms and a lacy appearance. The result is that when snow falls to
the ground, a lot of air is trapped between the arms and "lacework" of the snow crystals, so snow
ends up being only one tenth as dense as water or ice.
If the snow melts and then refreezes, the air will bubble out and you'll end up with ice. But ice
on the ground can't magically acquire the air it needs to become light, fluffy snow, so the
transformation only works one way.
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
————————————————————-
Subj: Re:Acid rain 94-01-12 13:22:49 EST
From: AFC Andy
Posted on: America Online
Acid rain most often comes not from evaporating acid, but from from water in the atmosphere mixing
with pollutants we pump out every day.
One major cause is sulfur compounds. Our coal-fired electric generators, wood-burning stoves and
chemical plants (especially paper mills) spew *tons* of sulfur into the air every day. Once it's up
there, it combines with atmospheric moisture to create sulfuric acid. True, it's a pretty weak
solution of acid—but strong enough to do damage when it falls as rain.
The worst places for acid rain are near sources of pollution, especially sulfur pollution. That's
why it's a big issue in Canada: US power plants, paper mills (in the Pacific Northwest) and
wood-burning stoves near the US/Canada border are creating acid rain all over the northern US and
southern Canada. The Canadians don't like that, needless to say!
By the way, if you thought woodburning stoves and fireplaces were "natural" and ecologically safe,
think again! Wood smoke is a major source of pollution in many places—just ask any resident of
Denver! ;-) In fact, wood smoke is one of the dirtiest pollutants around.
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
————————————————————-
Subj: hmm 94-01-13 18:48:48 EST
From: JTatum
Posted on: America Online
I'm thirsty, where's the di-hydrogen oxide dispensary device?
————————————————————-
Subj: Re:hmm 94-01-14 14:30:15 EST
From: AFC Andy
Posted on: America Online
Down the hall in the cleansing cubicle, of course! ;
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
————————————————————-
Subj: Re: acid rain 94-01-14 15:23:12 EST
From: JackP
Posted on: America Online
I thought that volcanoes put out far more sulfur than industry does. Is that true?
————————————————————-
Subj: Differences... 94-01-14 17:59:44 EST
From: SIZZLEBUG
Posted on: America Online
I have a couple of things that are the same, yet I know that there are some differences to. Here
they are:
What is the difference between cement, concrete, and mortar?
What is the difference between rock and stone?
Finally...
What is the difference between a porch, deck, and patio?
————————————————————-
Subj: Re: acid rain and volcanoes 94-01-16 15:14:48 EST
From: AFC Andy
Posted on: America Online
Good point, Jack. I don't have the numbers in front of me, so you could be right. But industry is a
major contributor to the problem any way you slice it. After all, we don't have any active
volcanoes in the continental US (Mount St. Helens is dormant right now), yet we still have major
problems with acid rain!
Bottom line: volcanoes may contribute a lot of sulfur, but we have no control over that. We *do*
have control over man-made pollution, though—and we oughta do something about it.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Re:Differences... 94-01-16 15:40:43 EST
From: AFC Andy
Posted on: America Online
Good questions, SIZZLEBUG! I did a little research in my dictionary, and this is what I came up
with:
Cement is a mixture of powdered lime and clay with water added. When it dries, it hardens like
stone. It's used to hold building stones or bricks together.
If you add some sand to cement, you get mortar, which is also used to hold stones or bricks
together. But if you add *too much* sand—a practice used for centuries by shoddy building
contractors—you get cheap mortar that soon crumbles and falls out of the joints. You can sometimes
see this in old buildings...especially public buildings that were built by the lowest bidder! ;-)
Concrete is a mixture of cement, sand or gravel, and water. If that sounds a lot like mortar,
you're right—but concrete generally has coarser sand or gravel than mortar. And concrete is used
as a building material in its own right, whereas mortar is just used to hold other stuff together.
What's the difference between rock and stone? None, really. They're just different words for the
same thing. Rock is from old French "roche"; stone is from German "stein." Different languages, same
concept.
A deck is any platform or floor that's like a ship's deck. (Oddly, the word comes from Latin
"tectum," meaning roof!) A patio is an inner area or courtyard that's open to the sky (from Latin
"patere," to lie open). A porch, on the other hand, is a covered area (usually an entrance)
attached to a building.
I'll leave it to you to look up portico, veranda and terrace! ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
————————————————————-
Subj: Reposted from EskimoArt 94-01-18 12:09:41 EST
From: GenK
Posted on: America Online
Go for it, Andy! THIS is a good question :-))
Gen
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Subj: PONDERABLES OF THE WORLD 94-01-18 11:14:58 EST
From: ESKIMOART
Posted on: America Online
WHY DO HOT DOGS COME IN PACKS OF EIGHT AND HOT DOG BUNS COME IN PACKS OF TEN?
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Subj: Dogs and buns 94-01-20 10:35:24 EST
From: AFC Andy
Posted on: America Online
"WHY DO HOT DOGS COME IN PACKS OF EIGHT AND HOT DOG BUNS COME IN PACKS OF TEN?"
Simple. The answer is that they don't. ;-) I checked three brands of hot dog buns and eleven brands
of hot dogs at my local supermarket, and here's what I found:
BUNS
10 per pack—1 brand
8 per pack—2 brands
HOT DOGS
10 per pack—3 brands
8 per pack—5 brands
6 per pack—2 brands
In other words, there's no rule. Manufacturers do whatever they please, it seems...but the most
common package for *both* dogs and buns is the 8-pack.
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
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Subj: Dear Andy (not Abby) 94-01-22 19:50:48 EST
From: RKECPA
Posted on: America Online
Dear Andy. I have a question that has been plauging my family for a while and I was wondering if
you could answer it. We were arguing if there is anything in this world that exists in the 1st or
2nd dimension. My brother said that a straight line would but I say that that line has some height.
My logic says that anything we can see has at least three dimensions even though some of them may
be offly small as in the case of a line. Whats the answer? P.S. I meant that a line is drawn. A
line made on a peice of paper has the height of the lead away from the paper and is therefor not
perfectly flat. Thanks.
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Subj: Re:Dear Andy (not Abby) 94-01-23 13:38:16 EST
From: AFC Andy
Posted on: America Online
You're right. Anything in the real world exists in 3 dimensions (at least! ;-) even if it's really,
really thin or flat. Truly 2-dimensional or 1-dimensional objects like straight lines or planes
only "exist" in mathematics—not in real life. In other words, a true 1-dimensional line is purely
an imaginary concept.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Re:Dear Andy (not Abby) 94-01-24 21:45:35 EST
From: JTatum
Posted on: America Online
missing dimention there. time... so that's a 4 dimention minimum... :-)
now on to my question. in chemistry, we are just getting on to ions, and ionic bonding, so I know
how atoms are held together to form molecules. the question is how do molecules hold themselves
together? in other words, if I pick up a disk, why aren't all the molecules seperate?
I'm sure we will learn this later, but I just wanted to clear it up now because the question has
been killing me...
:-)
~Jamie
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Subj: Bonding 94-01-25 17:48:11 EST
From: AFC Andy
Posted on: America Online
Ah, but Jamie— I did say "3 dimensions (at least! ;-)" I was being careful to leave room for time
and whatever additional dimensions y'all might come up with. :-)
"how do molecules hold themselves together?" With Krazy Glue, of course! LOL! Seriously, I gotta
think about that. I believe it's the same forces that hold atoms together, but I'm a bit rusty on
the details...let me do some poking around and get back to you on this one. I wouldn't want to give
you a misleading answer!
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: The Dance of the little lumps... 94-01-28 15:35:40 EST
From: SIZZLEBUG
Posted on: America Online
Jamie, the reason matter doesn't fall apart is because the molecules are doing a "dance" in the
solid, being mutually attracted and repulsed by the other over and over (sound like someone you
like?). Each time they get in close, they separate until they get attacted again. This Dance of
these little lumps keep the solid intact (in fact, little in latin is cules, and lumps is Moles.
switch them around and delete some letters and you have MOLECULES!)
In a liquid, a solid is heated too much (taking in mind that the hotter the molecules are, the
faster they move). They Lumps break the "dance" and it turns into a freeforall!
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Subj: Re:The Dance of the little lumps 94-02-02 16:18:36 EST
From: JTatum
Posted on: America Online
okay, but what keeps the molecules in perpetual motion? (probably the same stuff that keeps atoms
from imploding...)
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Subj: Pollution (water) 94-02-03 17:20:22 EST
From: HarryS1058
Posted on: America Online
Where can I find more information about water pollution without going to the library. I have
already used AOL Comptons Encyclopedia.
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Subj: Re:Pollution (water) 94-02-04 10:08:22 EST
From: AFC Andy
Posted on: America Online
Shucks, Harry, libraries are great places! But if you want more info on pollution here on AOL, just
go to keyword ENVIRONMMENT. That'll take you to the E-Forum, where all kinds of environmental
issues are discussed. You're sure to find lots of info on water pollution there! :-)
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
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Subj: Re:The Dance of the little lumps 94-02-04 10:11:05 EST
From: AFC Andy
Posted on: America Online
"what keeps the molecules in perpetual motion?" Heat. Or to put it another way, the motion of the
molecules *is* heat. If you reduce the temperature to absolute zero (-273.15 degrees C.), the
motion stops.
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
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Subj: Re:The Dance of the little lumps 94-02-05 12:35:36 EST
From: JTatum
Posted on: America Online
ach, good point. okay, then, what keeps the baseline energy in atoms? certainly not heat? in
other words, why aren't the atoms just imploding. is it like the way satellites orbit the earth?
i.e. the gravitation is always constant, so they stay at the same height while orbiting? hmmmm...
~Jamie
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Subj: Re:The Dance of the little lumps 94-02-05 20:47:04 EST
From: AFC Andy
Posted on: America Online
"what keeps the baseline energy in atoms?" I guess the answer is 'conservation of energy,' or
something like that. I mean, if it weren't in the atoms, it would have to go somewhere else, right?
And since there are atoms all around, it would just end up agitating other atoms.
And in fact that's just what it does. Take a hot cup of cocoa and set it on top of a block of ice.
The atoms and molecules in the coffee are dashing around like mad. They bump into the atoms of the
mug and transfer some energy to them—just as a moving marble hitting a stationary marble makes the
second marble roll. Then the mug's atoms get going pretty fast and start bumping into the ice
atoms, making *them* move faster. And pretty soon you have lukewarm coffee in a pool of cold water.
If you let this process continue, the heat energy (or motion energy—it's the same thing on an
atomic level) will eventually spread out evenly, so that everything ends up at the same
temperature. It's kinda like water seeking its own level in a hose. Hot things lose energy, cold
things gain energy...and eventually everything ends up lukewarm.
On a large scale, this is happening to the universe all the time. It's possible that in a few
billion years, everything will be at the same temperature—a fairly cool one—and all matter will
be pretty much evenly distributed thoughout the cosmos. If you ever hear the phrase "the heat death
of the universe," this is what they're talking about. A universe full of lukewarm soup—sounds like
a pretty boring place to live, hmmm? But of course nothing would be living by then.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Re:Another question 94-02-11 00:06:03 EST
From: DanH831083
Posted on: America Online
No, they have rods, but no cones in their eyes. Cones see color.
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Subj: Re:The Dance of the little lumps 94-02-11 12:55:06 EST
From: JTatum
Posted on: America Online
okay, conservation of energy. energy is neither created nor destroyed, it just changes from form
to form. but wouldn't the motion of the atoms encounter friction, thus converting some of the
energy to heat???
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Subj: Re:The Dance of the little lumps 94-02-12 16:19:06 EST
From: AFC Andy
Posted on: America Online
"but wouldn't the motion of the atoms encounter friction, thus converting some of the energy to
heat?"
But what *is* friction? It's the collisions between the atoms on the surfaces of solids that rub
together. In short, it's collisions between atoms—just what I was talking about before. Really,
it's more accurate to say that "friction" as we normally use the word does not exist at the atomic
level. Atoms don't rub together. They either hit and bounce off, or they miss. And when they hit,
they transfer energy to each other. Occasionally when a very energetic collision happens, energy is
radiated as photons (infrared light, for example). When the photon is absorbed by another atom, the
result can be increased motion—heat again.
So no, they don't encounter friction in the common sense...but energy is being passed around as
heat, all right—heat in the form of atomic motion, as I described in the last message, or in the
form of photons of energy. Does that make things clearer?
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Re:The Dance of the little lumps 94-02-24 23:21:31 EST
From: JTatum
Posted on: America Online
all good points.... although I am still unclear about the molecules moving around to form
solids... ?
I.e., why don't all the little moving molecules seperate from their larger groups? :/
~Jamie
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Subj: Re:The Dance of the little lumps 94-02-25 13:37:01 EST
From: AFC Andy
Posted on: America Online
"why don't all the little moving molecules seperate from their larger groups?"
They do, if you get 'em moving fast enough. Let's do a thought experiment. Suppose you have a big
jar with 50 magnetic marbles (Edmund Scientific Co. stock number R37,623) in it. At rest, all the
marbles form a bunch of irregular clumps at the bottom of the jar. (This is like molecules in a
solid state.) If you shake the jar gently and do it just right, they may even fall into a regular
pattern. (This is like a crystalline solid.)
If you start to shake the jar a little harder, the marbles in the clumps start to move around a
little—but they still keep in contact with their neighbors. (This is like a *hot* solid.) The
attraction between them is enough that even if they break contact for a fraction of a second,
they're still pulled back together immediately.
Now if you shake the jar really hard, the clumps start to break apart and some of the marbles fly
around and bounce off the walls of the jar—but they still occasionally hit and cling to each
other. (This is like water that's starting to boil: the loose marbles flying around are the steam.)
And if you huff and puff and shake like crazy, you can get the marbles moving so fast and furiously
that they never cling to each other—they just hit and bounce off. (This is like a gas or plasma.)
The energy of motion—same thing as heat—is so great that it overcomes the energy of attraction.
So the atomic forces can hold the moving molecules together up to a point, but once things get hot
enough, they do indeed separate from their larger groups.
—Andy Baird, Mac Graphics, Multimedia and CAD Forum Consultant
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Subj: Figure skating jumps! 94-03-03 06:57:12 EST
From: SIZZLEBUG
Posted on: America Online
Andy, with the Olympics, Here's a good question.
What's the difference between an Axle, a Toeloop, a toe jump, a loop, a lutz, a SowCow, and a Split
jump??
(Gotcha!!))
SIZZLEBUG
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Subj: Re:Figure skating jumps! 94-03-05 08:15:20 EST
From: AFC Andy
Posted on: America Online
Sorry, SIZZLE! Questions about nature and science, yes. Skating, no. ;-) I don't have to answer
sports questions here...so I can cheerfully say "I don't know!" ;-)
Oh, by the way, it's "Axel," not "axle." It's a proper name, not part of a car. Gotcha! LOL! ;-)
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Murderers! Assassins! 94-03-10 21:57:26 EST
From: Alia A
Posted on: America Online
What is the minimum number of animals in a species that could create a stable gene pool?
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Subj: Re:Murderers! Assassins! 94-03-11 19:28:40 EST
From: AFC Andy
Posted on: America Online
One—if we are talking about a species that reproduces asexually (like an amoeba). One individual
reproducing by fission pretty much guarantees a stable gene pool, since all offspring will have
exactly the same genes as the parent. Naturally, this assumes there are no environmental mutagens
to mess things up!
Of course even in the absence of external mutagens, genes will be altered sooner or later in the
process of replication—so in the long run, no population can be perfectly stable.
—Andy Baird, Mac Graphics, Multimedia & CAD Forum Consultant
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Subj: Re:Murderers! Assassins! 94-03-11 21:15:39 EST
From: Alia A
Posted on: America Online
How about mammals?
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Subj: Re:Asking Andy -dolphins 94-03-12 00:42:08 EST
From: PWDOLPHIN
Posted on: America Online
know anything about the dolphins? Ever seen them? thanx.
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Subj: Re:Murderers! Assassins! 94-03-13 13:57:14 EST
From: WalterGL
Posted on: America Online
I would think that sexually reproducing species would require quite a few members to produce a
stable gene pool, although it probably varies according to species. Of course, two would be the
minimum, but you asked about a *stable* gene pool.
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Subj: electricity 94-03-16 20:49:30 EST
From: Meagan8yrs
Posted on: America Online
Andy how do you make electricity from magnets?
Meagan
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Subj: Re:Murderers! Assassins! 94-03-18 20:30:42 EST
From: AFC Andy
Posted on: America Online
"What is the minimum number of animals in a species that could create a stable gene pool?...How
about mammals?"
I asked the most knowledgable person I know: my friend Craig Pizzuti, a lifelong student of
biology. He said that the question as you posed it it cannot be answered—for mammals or other any
other animal or plant that reproduces sexually. Why not? Well, to begin with, because what
constitutes a "stable" gene pool is open to argument. And even if you could arrive at a hard and
fast definition of that phrase, you still could not determine what number of individuals would make
up a stable gene pool without knowing many, many factors—things like litter size, generation
length, gestation period, ecological niche, geographical range...and social structure.
For example, you'd come up with wildly different answers for mice (large litter, short gestation,
short reproductive lifespan), humans (small litter, long gestation, long reproductive lifespan),
sea tytles (large litter, short gestation, very long lifespan)...and so forth. Add in migratory
habits (swallows, whales, movie stars ;-) and social structures (solitary, like wild cats? pack
hunters, like lions or dogs? hive dwellers, like bees or some small rodents?) and you've got an
almost endless number of possibilities.
So according to Craig, this is one that you just can't answer as a general question. He said, "even
if you asked me about a particular species, I'd have trouble giving you an answer that wasn't
hedged all around with 'ifs' and 'howevers'."
—Andy Baird, Mac Graphics & CAD Forum Consultant
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Subj: P.S. for Walter 94-03-18 20:41:11 EST
From: AFC Andy
Posted on: America Online
"sexually reproducing species would require quite a few members to produce a stable gene pool...Of
course, two would be the minimum..."
I can't resist pointing out that even in a normally sexually reproducing species, a single
individual *can* produce a population with a stable gene pool. How? By reproducing
parthenogentically (what a word!), as is possible in a number of species such as frogs and toads
that normally reproduce sexually. In parthenogenesis, a female lays eggs which—without having been
fertilized!--develop into normal females. Of course, they share exactly the same genes as their
parent.
You can only get females this way, because as you know, sex is determined by chromosomes: XX gives
you a female and XY gives you a male. Since a female frog (or whatever) has no Y chromosomes to
begin with, just XX, her offpring can only be XX's—more females.
It was discovered long ago that unfertilized frogs' eggs can sometimes be stimulated to develop
this way by immersing them in salt water, poking them with a needle (!) or other kinds of physical
stimulation. It doesn't seem to work with higher animals such as mammals, however. But at any rate,
it *is* possible for a normally sexual species to reproduce asexually under certain conditions—and
in that case, one individual is all you need for a stable gene pool (stable barring mutations,
anyway).
Another bit of useless science trivia from...
—Andy Baird, Mac Graphics & CAD Forum Consultant
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Subj: Electricity from magnets 94-03-18 21:00:14 EST
From: AFC Andy
Posted on: America Online
Good question, Meagan. Electricity and magnetism are closely related—you can use one to help make
the other. Let's start with making electricity.
Suppose you have a piece of wire. You connect a voltmeter to the ends of the wire, so you'll be
able to tell when electricity is flowing in the wire.
You look at the voltmeter—it's showing zero volts, no electricity flowing. OK, now you bring over
a magnet and set it down right next to the middle of the wire. What happens? Well, the voltmeter
takes a little jump, but then it falls back to zero—even though the magnet is sitting right there
next to the wire! No electricity is flowing. How come?
You decide to take the magnet away, since nothing seems to be happening. Hey! The voltmeter jumped
again, but in the other direction—and then right away it went to zero again. What's going on here?
Well, let's write down what we've seen:
1) magnet sitting far away from wire: no electricity
2) magnet sitting next to wire: no electricity
3) magnet moving toward wire: electricity, but only while the magnet is moving
4) magnet moving away from wire: electricity, but only while the magnet is moving
Looking this over, we can see that the only time we got electricity in the wire was when the magnet
was moving. So maybe the question "how do you make electricity from magnets?" is a bit misleading,
because it looks as if what makes the electricity is not the magnet itself, but the *motion* of the
magnet. (Remember, when the magnet was just sitting there, nothing happened.)
And that's just how it works. Magnets by themselves don't make electricity (any more than a churn
by itself makes butter), but if you *move* a magnet near a wire, it converts that movement into
electricity. So it's really your moving hand that's providing the energy here, not the magnet. Just
as a churn helps you turn movement into butter, a magnet helps you turn movement into electricity.
;-)
—Andy Baird, Mac Graphics & CAD Forum Consultant
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