Nature: An Anglo-Saxon historical text may shed light on a mysterious radiation spike recorded in Japanese cedar tree rings in AD 774 or 775, writes Richard Lovett for Nature. The connection was made by a biochemistry undergraduate at the University of California, Santa Cruz. After hearing about a team of researchers in Japan who had found the odd spike, Jonathon Allen did “a quick Google search.” In the eighth-century pages of the Anglo-Saxon Chronicle, whose online version is part of Yale University’s Avalon Project, he found a reference to a “red crucifix” that appeared in the sky “after sunset.” In a Nature Correspondence, Allen proposes that the phenomenon could have been a supernova explosion that created a burst of high-energy radiation, which struck Earth’s upper atmosphere and was recorded in the Japanese tree rings.
An ultracold atomic gas can sync into a single quantum state. Researchers uncovered a speed limit for the process that has implications for quantum computing and the evolution of the early universe.
January 09, 2026 02:51 PM
Get PT in your inbox
PT The Week in Physics
A collection of PT's content from the previous week delivered every Monday.
One email per week
PT New Issue Alert
Be notified about the new issue with links to highlights and the full TOC.
One email per month
PT Webinars & White Papers
The latest webinars, white papers and other informational resources.