D-shaped magnets form part of a tokamak that is being built for a nuclear-fusion pilot project. Credit: Commonwealth Fusion Systems About a dozen technicians, in hard hats and protective clothing, move around a large, double-height room. Some are checking pipes coming up through the floor into a raised, circular platform. Others work on instruments installed
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Whether a beam of light passes through an object often depends on the material of the object and the properties of the light, such as its frequency, color, and polarization. These properties can be assigned to individual photons, but some characteristics of light emerge only collectively, through quantum correlations between many photons. Developing materials that
