If dark matter particles exist, scientists say, they should be able to observe a small amount of light given off when they hit the nucleus of a xenon atom.

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When struck by light, the electrons in an atom of silver vibrate in a way that causes them to radiate small amounts of light themselves.

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The principle behind these experiments is that particles hitting the xenon cause the nucleus of the atom to give off a little bit of light.

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"As humans we can identify galaxies light years away, we can study particles smaller than the atom, but we still haven't unlocked the mystery of the 3lb of matter that sits between our ears, " he said.

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