Dark Matter?

Question

It is an interesting and speculative thing. I know plenty on the subject but I want to see what you think.

For those of you who want to know more, dark matter is about 90-99 percent of all matter in the univerese. But scientists are still undure exactly what it might be. It is the, let's say, framework of the universe, like the cytoskeleton in the cell, this dark matter holds the universe together. It does not appear in telesopes and such. But speculations have been made that it is either ultra supermassive black holes (not very likely) or smaller than electrons particles. Scientists use telescope images at different angles to locate certain galaxies that may not be present at one angle but there at another, this indicates dark matter. They also use concentrated light beams to see where the light reflects though nothing appeares to be there. (The big dark matter is called MACHOs Massive Astrophysical Compact Halo Objects, the small WIMPs Weakly Interacting Massive Particles (easy to remeber). Gravitational effect can also be used to detect dark matter. WIMPS are nearly immpossible to find

Answer 1

People are searching for the physical explanation for dark matter at quite a pace. Check or "dark matter search":

http://lpsc.in2p3.fr/mayet/dm.php

http://arxiv.org/abs/hep-ph/0404175
(click on PDF for the paper!)

Essentially dark matter can be seen in all of cosmology. Most models need it to be consistent with the currently observed universe and it is visible in practically all of the galactic rotation curves. What we don't have is the microscopic particle that is responsible for the observed excess mass.

Eventually we will find "it". And once we do, physics will open a completely new page in the book of nature. Very exciting!

Answer 2

all i know is that in spiral galaxies, the rotation of the arms is too great for the galaxy to be held togethor by a collection of stars at its center. This is where we get the evidence that there is dark matter. The only explination would be something called "dark matter" that is unimaginably dense and has a gravitational force like we've never seen. In fact, there is strongly beleived to be a black hole at the center of our galaxy that is smaller than a speck of dust and has the mass of over 300 million suns!!

Answer 3

well, we know what it isn't, and we know something is there that we don't observe because otherwise galaxies would be flying apart because they don't contain enough of the stuff (ordinary baryonic matter) that we do know about.

see:

http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970731a.html

http://www.europhysicsnews.com/full/12/article15/article15.html

personally, i'm hoping that the large hadron collider will next year be able to produce not only some answers on dark matter, but will also be able to show evidence (or not, which would be really interesting) of the so-called higgs particle.

http://www.citebase.org/abstract?id=oai%3AarXiv.org%3Ahep-ph%2F0406147

Answer 4

It is hard to talk about things that you cannot see and understand. It is also rather difficult to discuss things which
canot be examined in the laboratory. So, this question is a
bit out of my league, and I will let the proponents of theories handle this one.

Answer 5

You may well know more than I; my understanding is that it is posited to provide enough gravitational attraction to keep galaxies together, but we know nothing of its mathematical or physical properties. If you have anything beyond this, I'd like to hear about it.

Answer 6

There isn't much to talking about dark matter when no one has ever seen it. By our observations of universe cosmology, It's supposed to be there; we just don't know why it isn't.