Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: qpan on 07/12/2003 17:53:21
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As you all know, we live in a world made up of baryons (and leptons), but scientists think (speculate) that less than 10% of the universe is actually made up of baryonic matter- the rest of the universe is made up of so called "dark" matter - also known as non-baryonic matter. My question is, why is there no contamination in our solar system or even on this planet? If the universe started with the big bang, there should be a random distribution of baryonic and non-baryonic matter- and if over 90% of the universe is made up of non-baryonic matter, there is a VERY low probability that the solar system would be purely baryonic!
Are scientists wrong? Does dark matter actually not exist? (explaining why they can't seem to find any). May dark matter have strange chemical properties such as antigravity? (explaining why the universe's accleration is speeding up) Do these strange properties explain why there is no dark matter in our solar sysyem?
Just curious- maybe someone knows something about dark matter!
"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
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A related question is if the solar system started as a coalescence of hydrogen, helium, and other more complex elements (the nucleosynthetic progeny of stars long - gone see Brian Fulton's page for more information : http://www.thenakedscientists.com/astrophysics)how did all of the hydrogen and helium end up together in the sun, but not in the planets ? What produced that partition ?
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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Isn't the reason for most of the hydrogen and helium being in the Sun due to gravity? The earth's gravity is insufficient to trap hydrogen (and helium) gas for very long, so that is why there is so very little of it in the atmosphere and so much trapped as water in the sea, as it would have escaped in its gaseous form. Only larger bodies, such as the Sun, Jupiter, saturn, uranus and neptune are able to trap these gases, and that is why the concentrations are so high in them. However, there are still traces of hydrogen and helium in the atmosphere- why are there not even traces of dark matter in our vicinity of space?
"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
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Couldn't the trace amounts hydrogen and helium in our atmosphere come from chemical reactions of substances on the surface? Who says they're artifacts in the same state as a million years ago? For instance, alpha radioactive decay releases a helium nucleus...do this in an environment with free electrons and you get a helium atom. Radical reactions on water and hydrocarbons can leave hydrogen gas as a by product.
I'm not saying that's the answer, I'm just offering a possibility.
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Ok- trace amounts of hydrogen and helium may be found in the atmosphere, and yes- you do make a valid statement by saying that other processes such as nuclear fission may produce them.
But what about the vast amount of hydrogen in the sea? I do believe that it would take a lot of neutrons decaying to produce that amount of hydrogen, and i therefore believe that most of those hydrogen molecules are from the hydrogen which was about billions of years ago!
This is evidence that the earth once did have a lot of hydrogen gas in its atmosphere, and that some of it reacted with oxygen to form water, which is preserved on the surface whereas most of the hydrogen gas was lost out into space and eventually much of it probably got sucked into the Sun.
"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
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Much of the planets hydrogen is stored in our oceans as H2O. We do not lose a great deal as, although water is evaporated off from the seas to, very little of the H2O molecules make it past the cold trap. This is where the air temperature falls to around -60 degrees centigrade. Water condenses here and forms clouds (you can often see the flat layer of clouds from out of a plane window). After the cold trap the temperature actually rises again.
Any H20 that makes it past the cold trap moves into the atmosphere and is broken apart by radiation from the sun, the lighter Hydrogen molecules are then lost to space.
Resident Tour Operator - The Naked Scientists
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So is our planet slowly being dessicated then ? How much 'water' (in the form of hydrogen) do we lose to space each day ?
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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No- the amount of hydrogen we lose as water is virtually negligable, as we are also being bombarded by protons from the sun (solar winds). The amount we would lose, however, if the hydrogen was just in gaseous form would be very significant indeed! And that is my point- the reason the hydrogen and helium is concentrated in the sun is because of gravity- and the only reason we have lots of hydrogen in water is because it is locked up in a compound which is far heavier and therefore cannot even escape our mere gravitational field.
But is this also the case with Dark matter? What property of dark matter would cause it not to even be in trace form in our solar system?
"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
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I was actually referring to the point made by Exodus about the loss of 'water' in the form of hydrogen derived from water.
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx