Thursday, December 24, 2009

Dark Matter and Us

Zyg & Mea- graphic novel pages by marguerita bornstein

,published in Poignant Frog previously

A consensus has emerged that dark matter mostly consists of massive particles coughed out of the big bang. The reason for the appellation "dark" is because, unlike atomic particles, they have no electric charge, so cannot emit or scatter light. Nor do they feel the strong nuclear force that traps protons and neutrons in atomic nuclei. As a result, the dark particles interact so feebly with ordinary matter that they mostly pass right through it.

The race to detect and identify these particles started in the 1980s. Because the solar system orbits the galaxy at more than 200km per second, it should be ploughing through an ocean of primordial dark matter. As a result, there is a small probability that a dark matter particle will bump into an atomic nucleus and send it flying.

The challenge is to detect such a collision.

One such experiment, known as the Cryogenic Dark Matter Search, in Minnesota, has been gathering data for several years. Now, following painstaking analysis, project scientists have declared that they have recorded a couple of likely looking dark matter events. Theoretical physicists long ago predicted the existence of various weakly interacting massive particles.

One of these theories, called supersymmetry, links the nature of fundamental particles to the structure of space and time, and is an essential ingredient of string theory, the scheme that seeks to unify all nature.

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