What is 'dark matter'? In laymans terms if possible?

Answer 1

Basically, "dark matter" is supposed to be a kind of matter that produces neither light nor heat. Hence the "dark" in the name. The big thing about it, whatever it is, is that it is massive and fairly heavy--meaning it produces a lot of gravity, is fairly dense.

Researchers are still looking for more than *indirect* proof that this stuff exists, however, as dark matter hasn't been detected directly as yet. Why look?

Because there's no other way, currently, to *explain things* about modern physics--like how older galaxies stick together--without assuming that there's a *LOT* more mass to the universe than what we can see in light and heat (in electro-magnetic forms of radiation). Basically things are behaving as if there are at least three or four times more mass and gravity than what we can reasonably associate with the stuff we see out there. At current estimates, "dark matter" is supposed to make up as much as 70% of the total mass of the observable universe.

But don't just take my word for it, search the site below, using the phrases "dark matter", "dark energy", and "estimates of the mass of the universe".

http://www.sciam.com/

It can be a little dry but it is as close to layman's language as it gets. Basically what it boils down to is, modern physics is looking into the *last* ten percent or so of the statistical inferences that *should* be true if modern, large-scale physics (think Einstein's theories of relativity, and Stephen Hawking's modifications thereof, among others) actually works as predicted on the very large scale. Meaning, yes, the question has to be asked: "If the universe has been expanding like it has been, and it's still doing it, *what* is holding existing galaxies together?"

I hope this helps....thanks for your time! ^_^

Answer 2

Some things (by observation) in the heavens don't look quite right based on classical physics. Galaxies spin but do not seem to obey Newtons formula for gravity. One proposal to correct this discrepancy is dark matter. It would add enough gravitational force and the seemingly galactic mis-behavior would be explained.

There are other proposals to account for this but dark matter is leading the pack right now.

If you read James Hogan's "Kicking the Sacred Cow", he explains dark matter and also a very likely alternative. Lot's of other good stuff in that book but don't get to carried away.

Answer 3

In short, dark matter absorbers all light and sound and does not emit any. Scientists do not know what it is made out of, but we know that it does exists because it has a gravitational impact of other bodies. Most of the universe is made out of dark matter.

Answer 4

You might want to try this. Its quite impossible to use layman's term to explain science without losing something in the translation

Answer 5

It is matter that does not reflect light. Scientists believe that dark matter makes up 90% of the mass of the universe but they can not find it.

Answer 6

Exotic dark matter is a mathematical fudge factor included to explain why galaxies hold together better than we can explain otherwise.

Speculation is that it's something that's invisible and interacts with "normal" matter through its gravity only. Again, it's speculation.

Answer 7

What is dark matter? It is a hoax perpetrated by scientists who have suddenly noticed that their theories aren't working. Rather than admit their theories are wrong, they introduce an impossible type of matter that is undetectable and say how it magically accounts for everything they can't explain.

Answer 8

Dark Matter is matter that only interacts gravitationaly. Its exact nature is unknown.

Answer 9

Dark matter is a mysterious matter which is detectable by it's gravity/weight, but is so far undetectable by any other means. Scientists know it's there, but they are uncertain what it is. That's the very short and oversimplified answer.

Answer 10

Here's the most recent guess as what they think dark matter is:

http://www.physorg.com/news105703818.html