The universe comprises mainly of dark matter. What is dark matter?

Answer 1

I think I have already answered this question for you but here it is again....

If I could answer that one I would be up for the Noble Prize!

You see the thing is that the stars in galaxies whip round far too quickly for the gravity of the galaxy to held them in - big problem. So there must be a lot of matter which we can't see - ie it doesn't interact with photons, that lies outside the visible part of a galaxy holding the stars in. We can't see it, it's dark, hence dark matter.

If this is the case there is about 10 times more dark matter than light matter.

Lots of strange things have been put forward. Neutrino's could account for about 10%, then there is black holes and strange and yet unproven particles such as aixons just to name a few.

There is also work work trying to find out if there problem is with gravity itself - which would also solve this problem without needing dark matter.

There are a number of Dark matter detectors currently being built which may solve this problem. These is also a recent paper published that suggests that dark matter has been detected by the effect it is having on colliding galaxies. Visit
http://home.slac.stanford.edu/pressrelea...

Answer 2

n astrophysics, dark matter is matter that does not emit or reflect enough electromagnetic radiation (such as light, X-rays and so on) to be detected directly, but whose presence may be inferred from its gravitational effects on visible matter. Among the observed phenomena consistent with the existence of dark matter are the rotational speeds of galaxies and orbital velocities of galaxies in clusters, gravitational lensing of background objects by galaxy clusters such as the Bullet cluster, and the temperature distribution of hot gas in galaxies and clusters of galaxies. Dark matter also plays a central role in structure formation and Big Bang nucleosynthesis, and has measurable effects on the anisotropy of the cosmic microwave background. All these lines of evidence suggest that galaxies, clusters of galaxies, and the universe as a whole contain far more matter than is directly observable, indicating that the remainder is dark.

Answer 3

In layman's words (and that i'm no longer a physicist) that is the jist of darkish count number: count number won't be able to be created or destroyed. yet, it may shift sort. the full e=mc^2 challenge describes the interchangability of count number and ability. on each and every occasion there are astronomical "explosions" that create count number from skill or vice versa, there's a byproduct of this procedure. that's darkish count number. darkish count number is nearly the meantime between count number and ability. It would not truly behave like both one, even with the indisputable fact that that's there, though. it may no longer sign in as a actual merchandise, even with the indisputable fact that it possesses the elements (i.e. neutrons, electrons, protons) of count number. And, it possesses a huge degree of gravitational rigidity, exhibiting us that that's there. Astrophysicists believe that when the "huge bang" got here about, fairly some the count number/skill that went from being particularly compressed to being the universe all of us understand now develop into transfered into this darkish count number state. This explains the "gaps" that exist after we attempt to locate issues which could be there, yet are not. case in point, if a galaxy is revolving round some thing, yet we do no longer have a actual counterpoint for this revolution. we deduce that the "some thing" is darkish count number. It balances the first component to the equasion with the right outcome, in a sense. My handle all of this: i'm no longer a huge proponent of massive Bang, even with the indisputable fact that the universe is an exceedingly huge position. darkish count number might want to exist, yet the way it were given there, who knows? that's easily one of issues we would want to imagine we understand now, yet one hundred years from now, our theories might want to look lower than-knowledgeable. earnings from the secret and the technique of discovery.

Answer 4

Many of the above give more than adequate definitions of dark matter. I would only add that the most widely held guess is that it may be composed of neutrinos.

Answer 5

undetectable so far. but they know it must be there because of the gravity in the universe.

In astrophysics, dark matter is matter that does not emit or reflect enough electromagnetic radiation (such as light, X-rays and so on) to be detected directly, but whose presence may be inferred from its gravitational effects on visible matter.

Answer 6

Its matter that does not emit or reflect radiation so it can't be visibly detected (which is why its called "dark" matter.) Its presence is detected by the gravitational effects it has on matter that we can see.

Answer 7

As Spock would say, "Unknown."
But it is the name given to that effect upon gravity that keeps each Galaxy from flying apart due to the speed of their rotation.
Dark energy, on the other hand, is that unknown special something which is causing the galaxies to spread out away from each other at ever increasing speed.

Answer 8

The story of dark matter is best divided into two parts. First we have the reasons that we know that it exists. Second is the collection of possible explanations as to what it is.
http://math.ucr.edu/home/baez/physics/Relativity/GR/dark_matter.html
http://uk.search.yahoo.com/search?p=What+is+dark+matter&prssweb=Search&ei=UTF-8&fr=FP-tab-web-t340&x=wrt&meta=vc%3D

Answer 9

Stars glow. Dark matter doesn't bother. The earth turns into dark matter at night.

Answer 10

if u watched the episode of futurama its the poo of lela's little freaky pet