Physics World January 2026

Cosmic dawn: seeking the elusive signal from the earliest atoms

Astronomers around the world are hunting for an elusive 21 cm signal from hydrogen atoms in the primordial universe to gain a better understanding of our cosmic history. But despite more teams joining the search every year, no-one has yet had a confirmed detection of these photons. Sarah Wild explores who will win the race to find this signal and how the hunt is being carried out. Also this month, Tami Freeman looks at the work of UK medical start-up firm Crainio, Honor Powrie wonders when is “good enough” really “good enough”, while Iulia Georgescu examines the contributions of some of the forgotten pioneers of computational physics.

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