(PhysOrg.com) -- Up close, they look simple as can be: a pair of metal bars, each with one side polished to a brilliant shine. One bar faces up, the other to one side.
Read More »(PhysOrg.com) -- Up close, they look simple as can be: a pair of metal bars, each with one side polished to a brilliant shine. One bar faces up, the other to one side.
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