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Stupid Science Questions 2

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21:26 / 18.05.06

I remember reading somwhere that nothing, and I mean nothing that exists is completely massless - or energyless, for that matter - not even photons. (requires confirmation). Sooo, all bets are still off, aren't they?

20:03 / 19.05.06

Photons must be massless or else they would not travel at the speed of light. The same goes with gravitons but they are still theoretical.

Photons can still have energy though, which is a function of their frequency times the Plank constant.

I dunno about gravitons having a frequency though.

10:35 / 13.06.06

Stupid science questions asked by kids- Why is the sky blue? Why does the wind dry things? What are trees made of?
My answers are water vapour in the air, increased moisture gradient, and carbon from the air, but children never seem satisfied.
Anyone got better answers? Any other good examples of the things kids ask that stump adults?

18:42 / 14.06.06

Why is water wet?

----

I tend to think the questions are framed in such a way that slightly poetic answers are best. The sky is blue because that's the color of sunlight on water.

In a way, that's a meaningless answer -- it's blue because it's blue.

tom-karika nukes it from orbit

08:35 / 16.06.06

The sky is blue because the atmosphere acts like a big prism. The light hitting the atmosphere is bent - the blue light more so than the red light at the other end of the spectrum. So overall the red light flies out into space, and blue light is bent down to earth - so we have a net blue colouration.

If there was no refraction, the sky would be white as the light from the sun scatters in all directions from the atmosphere. The colour of sunilght on water is white - water from the tap is clear, no?

tom-karika nukes it from orbit

08:38 / 16.06.06

Oh, and it is the same effect that makes the sky red/yellow at sunset - we see light coming through the atmosphere at a different angle, so we're seeing a different part of a spectrum scattered through a prism.

http://en.wikipedia.org/wiki/Diffuse_sky_radiation

Is I think pretty good, even if not really suitable for kids

09:25 / 17.06.06

Try explaining this to a child-
This is how air molecules scatter light: the oscillating electric field of the incoming wave makes the molecules develop oscillating dipoles, which in turn give off radiation.

I think the poetic lying method is best!

23:17 / 19.06.06

Oh! Oh!

Amazingly retarded question queued up!

Hum.

Hum.

Are we particularly facially varied, as a species? And I mean compared to simians and whatnot. Is there a greater degree of variation from individual to individual in the human race than there is, say, among chimps, or is it just that we learn how to distinguish human faces much better than, errm, non-human ones?

*blush*.

Cloned Christ on a HoverDonkey

00:28 / 20.06.06

That's a good question.

From the few things I've gathered through reading various disjointed texts, I'd say that we as a species have less facial variation than many other similar species.

Our genetic variation is minimal compared to most species, probably because we started from fewer individuals than most.

I may be (and most probably am) wrong, though.

10:56 / 20.06.06

You're right as far as my limited knowledge goes. We were reduced to a very small population at one point, and that considerably limits our genetic diversity.

Apparently (though this could just be one of those oh-so-useful internet "facts") there's more genetic variation in one troup of Bonobo chimps than there is in the entire human race.

22:01 / 20.06.06

OK, I think this qualifies as a Stupid Question.

Here's the thing. I have chickens. Three of them. Chickens will eat nearly anything -- they're like little compost machines. Put in kitchen waste, get eggs out the other end. Their requirements are minimal, but one thing they do need is lots of calcium.

Eggshells are a rich source of calcium. I've read references to systems for making eggshells a decent food supplement for chickens. The main problem that occurs to me is a chicken's tendency to become an egg-eater. They'll start eating their own eggs if they're not getting enough nutrition, or sometimes just because they figure out that it tastes good. So, I did a half-assed thing. I remembered that you can make "rubber eggs" by sticking them in vinegar. The vinegar reacts with the calcium, extracts it from the shell, and the egg becomes soft and rubbery.

So, I've been sticking eggshells in a mason jar filled with vinegar. They've gotten pretty much half-dissolved. So here's the stupid question:

How do I get the calcium out of the vinegar and into the chickens?

10:54 / 21.06.06

Thank you, Cloned Christ and nameinuse. Hopefully I'll stumble upon a bit of definitive info eventually. *purely conceptual smiley face here*

14:19 / 21.06.06

Grant -
Assuming that the calcium is suspended in the vinegar as calcium acetate, you could precipitate the calcium by boiling out the water and acetic acid in the vinegar. Keep it about 120 - 130 C. DO NOT let it get above 160 C. The solution might produce acetone, which is somewhat explosive, plus it's poisonous to chickens (and people).

Calcium acetate is very hygroscopic, though, so it'll be difficult to get out all the water. I suggest soaking something else in the boiled down solution and trying to feed that to them.

But....hmm...actually, scratch all that. You may just concentrate the acectic acid in the vinegar, whcih would be dangerous.

17:34 / 21.06.06

See, I know they do something like this to extract alkaloids from plants for, uh, purposes we'll not go into here: put source in solvent, evaporate/concentrate solution, then put the solution on some kind of vehicle (like mint leaves or cigarettes or saltines or something).

"Scratch," by the way, is a kind of chicken feed made of cracked corn. So I won't be scratching that, exactly.

Stymied!

13:18 / 27.06.06

Couldn't you evaporate the vinegar without boiling by leaving it in a pan out in the sun? Plenty of surface area, vinegar's relatively volatile, hopefully the calcium won't evaporate? Just a thought.

My stupid science question- will driftwood eventually sink? How long does it take for a piece of wood to become waterlogged and lose buoyancy? I've tried googling it and wikipedia and boat design sites etc. but come up with very little. Obviously the density of the wood and how oily it is and the salinity and temperature of the water will all be factors, but to what extent? There's a bit of driftwood in a lake in Oregon IIRC that's been there for over a century, due to the cold water preserving it, but does wood in the sea just get broken down by gribbles and gradually eaten or does it actually sink? The Kontiki reconstruction attempt used fresh cut balsa, and apparently if they had used cured wood the raft would have sunk because dry balsa is so porous.
But what about oak trunks? Treated ship's masts? Could I throw a Hazel tree into the sea and find it washed up on my doorstep again a couple of centuries later having gone right round the world?

15:49 / 27.06.06

I *think* you could, yes. This suggests to me that "waterloggedness" is a result of bacterial action. The Cutty Sark is still floating off Greenwich -- have they replaced all the wood on that?

Things I've realized about my chicken/egg question: 1. eggshells are used by organic farmers to increase soil alkalinity. 2. evaporation is evaporation, it's always going to concentrate the solution, whether it's boiled or just left out to dry.

Hmmmmm.

18:57 / 27.06.06

It's one of the trickier things I've had to google which is unusual in itself. Basically my friend reckons wood will eventually sink due to waterlog (obviously) while I reckon wood floats (obviously) and just gets eaten by gribbles.
His contention is that The Cutty Sark is still floating off Greenwich because it's caulked and tarred, preventing water absorption, while I think it is to prevent rot etc.
I'd love to be able to say 'Driftwood never sinks' but I have to be able to back it up, thank you for that link grant, anybody else?

15:19 / 28.06.06

Excellent, I'd never have counted "gribble" as a real word...

About the calcium thing - the first thing to point out is that the calcium in an egg shell is in the form of calcium phospate (or similar) and that feeding pure calcium to your chickens would not go down well at all, particularly when they exploded from the hydrogen the reaction would produce. You'd be better finely grinding the eggshells and including them in whatever wet feed you give them than trying to separate out nutrients by chemical means.

The driftwood thing - it depends on conditions and the type of wood as to whether wood sinks or not. Normaly it rots then sinks, or sinks then rots, unless it's been treated (taring and caulking make a ship watertight, as even as long ago as the cutty sark ships relied on more than wood's natural boyancy - tarring preserves the wood from rotting, and also repels water - it's applied over and over to maintain the ship, though, instead of replacing the wood). Wood's more likely to float at sea than in fresh water, though, as the sea gives greater bouyancy.

20:24 / 28.06.06

You'd be better finely grinding the eggshells and including them in whatever wet feed you give them

Damn. That's just what I've been doing (and trying to weasel out of doing -- hard work!).

10:54 / 29.06.06

Normaly it rots then sinks, or sinks then rots, unless it's been treated

Wow, nameinuse, that really clears it up for me. Thanks so much.
Researching density I discovered that the specific gravity of wood is generally between 0.5 and 0.9 (water is 1 of course) except for ironwood and lignum vitae (the stuff they make bowling balls out of) which are over 1 and thus sink. In order to sink the wood has to reach the same density as the water or more, so the waterlogging has to be pretty extensive, and since it takes quite a long time for most wood to absorb water I'm thinking driftwood won't sink for ages.
For example a cedar log would have to absorb it's own weight in water again before it sank, so the porosity (?) and surface area are the crucial factors. Fresh wood or waterproofed will last for longer, big logs will last longer than sawdust or woodchips, I found this site on absorption but not much else.
Still working it out...

MattShepherd: I WEDDED KALI!

13:14 / 06.07.06

Medically (and hypothetically, obviously), if you took two people -- one diabetic, and the other hypoglycemic -- of the same blood type, and just hooked 'em up to each other with a few blood-transfer tubes, would they sort of self-regulate?

01:26 / 07.07.06

no. hypoglycemia is caused by a problem with glucagon not being released (the "opposite" of insulin) and in diabetics this can be present as well. glucagon causes glucose to be released by the breakdown of glycogen in the liver and cells of the body. If you have diabetes, this glucagon response to hypoglycemia may be impaired, making it harder for your glucose levels to return to the normal range. Also your body is much more complicated than a positive negative system like that. probably both people would experience massive fluctuations that would need to be corrected continuosly.

01:10 / 13.07.06

I have a rainbow question. Why don't the colors change continuously or gradually instead as more or less distinct bands?

11:36 / 13.07.06

"Why don't the colors change continuously?"
They do.

A rainbow is an optical and meteorological phenomenon that causes a nearly continuous spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere. It takes the form of a multicoloured arc, with red on the outside and violet on the inside. Even though a rainbow spans a continuous spectrum of colours...

Wikipedia is your friend.

11:38 / 13.07.06

The common fallacy of bands are due to Newton's mad alchemical beliefs "It is commonly thought that indigo was included due to the different religious connotations of the numbers six and seven at the time of Isaac Newton's work on light".

Henningjohnathan

15:42 / 13.07.06

A couple from another thread:

If there are only five fundamental interactions(gravitational, electrical, magnetic,strong and weak nuclear)and there is no repellant force counterpart to gravity, then what accounts for the expansion of the universe?

I prefer "quintessence, a dynamic field whose energy density can vary in time and space" to the cosmo constant personally.

But how is that much different from an anti-gravity force weaker than gravity at a local steller or planetary level but much stronger when on the scale of galaxies or when massive amounts of matter are compressed into a very small space. A galaxy sized version of the relationship between the strong and weak nuclear forces.

And if Quasars are/were super dense black holes and they existed before galaxies and stars, then where are the black holes now? If there was a repellant force that overcame gravity at a certain density then could it rip a sufficiently dense black hole apart - essentially reverse it - after a certain period of time?

17:01 / 13.07.06

Not everyone agrees that gravity is a force/interaction on the same level as electromagnetic or nuclear forces.

From the above wikipedia links:

In classical mechanics, gravitation arises out of the force of gravity (which is often used as a synonym for gravitation). In general relativity, gravitation arises out of spacetime being curved by the presence of mass, and is not a force. In quantum gravity theories, either the graviton is the postulated carrier of the gravitational force[1], or time-space itself is envisioned as discrete in nature, or both.

Henningjohnathan

17:11 / 13.07.06

That's very true and interesting. To restate the question:

In the absence of a fundamental opponent to gravity, what accounts for the expansion of the universe?

Could there be an opposing force to gravity that is imperceptible except when dealing with masses the size of galaxies and the distances between them?

Essentially, could there be an anti-gravitation inherent to all matter (in the same way that gravity is) with effects that are imperceptibly small when dealing with distances inside galaxies and solar systems but this "force" does not diminish as fast as gravity when the distances are the millions and billions of light years between galaxies and the masses are the collective size of galaxies?

Essentially, inside a galaxy (or solar system), gravity could be so strong as to make this repellant interaction imperceptible while the gravitational effect is so weak between galaxies that the otherwise imperceptible anti-gravitational force is now much stronger.

Henningjohnathan

17:40 / 13.07.06

And, sorry to keep harping on this, but if you look at the universe as an expanding multi-dimensional bubble, could gravity be described as the tendency to "fall" toward the "center" of the bubble? Could the relative "edge" versus the "center" of space-time exert different tendencies or "behavior" on material objects?

I know this is not an actual three-dimensional bubble, but in terms of what we think we know about the multi-dimensional nature of space and time.

17:42 / 13.07.06

'what accounts for the expansion of the universe?'

I think it's the momentum from the big bang. If there's enough stuff in the universe gravity will eventually suck it all back in (big crunch, heat death) if there isn't the universe will expand indefinitely and the stars will burn out (cold death).

Henningjohnathan

18:08 / 13.07.06

Yeah, the "momentum" makes sense, but it doesn't account for the perceived acceleration of the expansion that led to the idea of "dark energy."

http://en.wikipedia.org/wiki/Dark_energy
"In physical cosmology, dark energy is a hypothetical form of energy which permeates all of space and has strong negative pressure. According to the theory of relativity, the effect of such a negative pressure is qualitatively similar to a force acting in opposition to gravity at large scales. Invoking such an effect is currently the most popular method for explaining recent observations that the universe appears to be expanding at an accelerating rate, as well as accounting for a significant portion of the missing mass in the universe.
---
During the late 1990s, observations of type Ia supernovae ("one-A") by the Supernova Cosmology Project and the High-z Supernova Search Team suggested that the expansion of the universe is accelerating. These observations have been corroborated by several independent sources. Since then, measurements of the cosmic microwave background, gravitational lensing, and the large scale structure of the cosmos as well as improved measurements of supernovae have been consistent with the Lambda-CDM model."

I'm wondering why the theory about the existence of "dark energy" and "matter" that no one's ever discovered is better than the idea of a counterpart opponent to gravity that is so weak to appear imperceptibal at the "local" galactic, steller and planetary scale, but could have more of an effect at intergalactic distances because it doesn't diminish as much as gravity over that amount of space.

21:42 / 13.07.06

With gravity, some think of it in terms of a "membrane" or "brane" for short, instead of a kind of force caused by gravitons. I'm sure some of you are a little better-read on this than I, but I did have an in-depth discussion about it once upon a time in a usenet physics site in which I had begun by expressing my skepticism about the graviton idea.

10:22 / 14.07.06

Brane isn't short for membrane, it's an independant word;
"In theoretical physics, branes or p-branes are spatially extended objects that appear in string theory and its relatives (M-theory and brane cosmology). The variable p refers to the dimension of the brane. That is, a 0-brane is a zero-dimensional particle, a 1-brane is a string, a 2-brane is a "membrane", etc. Every p-brane sweeps out a (p+1)-dimensional world-volume as it propagates through spacetime."

Here's a link on Brane Cosmology. It's to do with string theory, and thus very very complicated theoretical physics.

wikipedia is still your friend.

11:54 / 14.07.06

This thread has some stuff about possible antigravity you may be interested in HenningJonathon, and I think I'm going to start a thread on dark energy to discuss the implications of accelerating expansion. Could be the universe will end in a Big Rip.

Henningjohnathan

21:02 / 14.07.06

On another topic, does the Anthropic Principle really have anything to it that makes it more reasonable than Intelligent Design?

In Tipler's PHYSICS OF IMMORTALITY, it basically sounds like he's saying that the simply evidence of intelligent life on Earth means that eventually "somewhere" and "some time" there will arise a lifeform that can manipulate all space and time (God, I suppose).

It just seems to me that there is about as much probability of that happening as of Superman breaking out of his fictional world and into our real one.

Is it reasonable to think that given an eternity in infinity EVERYTHING will happen or just that EVERYTHING THAT CAN POSSIBLY HAPPEN will happen still leaving an infinite amount of impossible things undone?

Is there anything more to it than a conceptual (and what seems in essence flawwed) argument?

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