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.