What is dark matter??

[funguy]

i have searched,and come up with no results on this ''dark matter'' i keep
hearing about.

i was talking to a freind,and he said that he heard that dark matter is a substance that is a liquid but a solid at the same time.it has liquid properties as in you can put your hand into it as long as you move slowly,but solid properties as in if you throw something at it,it will repel it with great speed.

is there any truth to this dark matter??

ps why is the max allowed avatar size only 40x40?? a bit small isint it?

 

[Pangloss]

Dark matter is a term used by astronomers to refer to that matter in the universe which cannot be seen because it is not lit by a nearby star.

Over time, however, such matter has become "visible" either by radio astronomy or by other measurements and estimations. What's mainly interesting about this is that there doesn't seem to be enough of it to account for the speed of expansion in the universe (or rather lack thereof -- the universe isn't expanding fast enough; something is holding it back, but there's not enough matter to account for that hold-back by gravitational means).

So usually today you hear the problem referred to as the "missing mass problem", and the term "dark matter" has been relegated to the backwaters of old astronomy books. More or less.

I have no idea how it might be applicable to pseudoscience.