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A mysterious object that repeatedly bursts with ultra-powerful radio waves must live in an extreme environment — something like the one around a supermassive black hole.
For decades, physicists have struggled to create a quantum theory of gravity. Now an approach that dates to the 1970s is attracting newfound attention.
A complete classification could lead to a wealth of new materials and technologies. But some exotic phases continue to resist understanding.
The mother of all string theories passes a litmus test that, so far, no other candidate theory of quantum gravity has been able to match.
Updated results from a Japanese neutrino experiment continue to reveal an inconsistency in the way that matter and antimatter behave.
It weighs as much as 780 million suns and helped to cast off the cosmic Dark Ages. But now that astronomers have found the earliest known black hole, they wonder: How could this giant have grown so big, so fast?
Edward Witten reflects on the meaning of dualities in physics and math, emergent space-time, and the pursuit of a complete description of nature.