Dark Matter Found? $2 Billion Orbital Experiment Detects Hints

astroengine writes "A $2 billion particle detector attached to the International Space Station has detected the potential signature of dark matter annihilation in the Cosmos, scientists have announced today. The Alpha Magnetic Spectrometer (AMS) was attached to the space station in May 2011 by space shuttle Endeavour — the second-to last shuttle mission to the orbital outpost. Since then, the AMS has been detecting electrons and positrons (the electron's anti-particle) originating from deep space and assessing their energies. By doing a tally of electrons and positrons, physicists hope the AMS will help to answer one of the most enduring mysteries in science: Does dark matter exist? And today, it looks like the answer is a cautious, yet exciting, affirmative."

Comments

But what is it?

[Hatta]

Of course dark matter exists. There's a discrepancy in our observations, and dark matter is defined as whatever is responsible for that discrepancy. The real question is, what is dark matter? How do we explain its existence?

Re:But what is it?

[lgw]

Of course dark matter exists. There's a discrepancy in our observations, and dark matter is defined as whatever is responsible for that discrepancy

To clarify: the "dark matter" hypothesis of the discrepancy in our observations of galaxy (and cluster) rotation rates has already been confirmed by observations of the cosmic microwave background radiation. There were many hypotheses for that discrepancy, but dark matter predicted the correct ratio of baryonic/non-baryonic matter in the early universe - to multiple significant digits (rare in cosmology).

So while most properties of dark matter have yet to be understood, some are well defined. As far as "how do we explain its existence?", that same question applies equally to "normal" matter.

Re:But what is it?

[idontgno]

Like luminiferous aether existed until it didn't.

That said, these particle detections seem analogous to if Morley and Michelson had detected discrepancies in the speed of light attributable to earth's motion through the universe (and therefore relative to the aether). They didn't and the aether theory began to be disproved

In this case, the theoretical construct (dark matter) is beginning be supported by experimental observations, rather than disproved. So dark matter continues to be a useful concept, even if we're not sure what its tangible form of existence is.

Re:Dark matter

[TheRealMindChild]

You are describing Aether in which Einstein proved does not exist

Re:Dark matter

[lgw]

Morbo says "Gravity Assist does not work that way!" Gravity assist uses a planet moving in the direction you want to go - you speed up by slowing down the planet. Energy is conserved.

You still have to expend the same energy to get to the same destination, if you have to put a moving planet there in the first place! Plus a bunch of overhead.

You gain little by being able to move through the planet - gravity assist works fine with normal planets.

Dark matter doesn't clump the way normal matter does (clumping requires friction, which is a very non-dark process): there's no obvious way to grab or move a bunch of it around. Think diffuse cloud of non-interacting particles.

Re:Dark matter

[wonkey_monkey]

Could such a thing be used to make some sort of dark matter highway to provide a gravity well between stars for ships to travel down without expending much energy?

No more than it could be used to create a unicorn that poops cookie dough.

Re:Dark matter

[lgw]

Look, if you just want to ignore science, fine, believe whatever, but don't expect adult conversation. So far all you've said is "what if dark matter, instead of being what we think it is, were magic in this very convenient way?". Beyond that, did you have some coherent point to make?