What is dark matter? is it dangerous?

Answer 1

Here is a definition...

In astrophysics, dark matter is matter that does not emit or reflect enough electromagnetic radiation 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.

The composition of dark matter is unknown, but may include new elementary particles such as WIMPs and axions, ordinary and heavy neutrinos, dwarf stars and planets collectively called MACHOs, and clouds of nonluminous gas. Current evidence favors models in which the primary component of dark matter is new elementary particles, collectively called non-baryonic dark matter.

The dark matter component has vastly more mass than the "visible" component of the universe.[1] At present, the density of ordinary baryons and radiation in the universe is estimated to be equivalent to about one hydrogen atom per cubic metre of space. Only about 4% of the total energy density in the universe (as inferred from gravitational effects) can be seen directly. About 22% is thought to be composed of dark matter. The remaining 74% is thought to consist of dark energy, an even stranger component, distributed diffusely in space.[2] Some hard-to-detect baryonic matter (see baryonic dark matter) makes a contribution to dark matter, but constitutes only a small portion.[3][4] Determining the nature of this missing mass is one of the most important problems in modern cosmology and particle physics. It has been noted that the names "dark matter" and "dark energy" serve mainly as expressions of our ignorance, much as the marking of early maps with terra incognita.[2]

Answer 2

Dark matter is a very recently confirmed to exist type of matter that doesn't emit, absorb or reflect light. The only way it can be detected is by its gravitational effects on light. Dark matter is all around us. It's always been there. It is quite harmless, as it doesn't interact with normal matter, and passes through us harmlessly. It's not dangerous at all.

Answer 3

It is all the matter in the universe that we cannot see, mainly because it's not close enough to any source of light and doesn't omit any detectable radiation. It is potential dangerous if it comes into contact with our planet and is big enough.

The reason we know it exists is because scientists calculated that all the visible matter in the universe is not enough to account for the rate of universal expansion. There has to be a lot more that we cannot see for this to be occurring.

Answer 4

Yes it very dangerous, Stay light years for that matter

Answer 5

I just saw a program about it on the science channel. Simple answer: It is anything in space that they can't see with all of the different kinds of telescopes that they use. No, it isn't dangerous.

Answer 6

It depends how much Guinness I had to drink the night before.

Answer 7

all i know is dont ever be in the same dark room as me

Answer 8

check out this link

http://en.wikipedia.org/wiki/Dark_matter

Answer 9

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Check this site, it tells you all about it

http://en.wikipedia.org/wiki/Dark_matter

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