Jul 28, 2017

Gamma-ray bursts give explosive insight into early universe

Nathaniel Butler / ASU

When stars die and collapse to form black holes, a powerful explosion — second only to the Big Bang itself — occurs. These gamma-ray bursts take place billions of light years away. Across space and therefore time, they're a window into the early universe that opens for just a few milliseconds to a minute. By the time a telescope is turned, they're typically gone.

Last year though, researchers were able to observe an unusually bright one — GRB 160625B, pictured above— using six telescopes on the ground and in space. They caught it early to enough to measure strong changes in the polarized light of the burst for the first time. "That, in turn, tells us that the release of magnetic energy is an important ingredient in these exotic explosions," says Arizona State University's Nathaniel Butler.

A new picture: Spiraling electrons cause radiation that powers magnetic jets in the first moments of the explosion. The magnetic fields then break down and are largely replaced by matter from the dying star that falls into the black hole and is ejected again. Researchers have known about these two processes but thought only one was responsible. Now, it seems it could be both.

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Twitter came under fire on Tuesday for allowing President Trump to tweet conspiracy theories about Joe Scarborough and the 2001 death of one of his staffers, despite the objections of the staffer's family. The company came under further fire from Trump himself for fact-checking two of his tweets about mail-in voting.

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12 mins ago - Technology

Coronavirus dashboard

Illustration: Aïda Amer/Axios

  1. Global: Total confirmed cases as of 11:30 a.m. ET: 5,618,829 — Total deaths: 351,146 — Total recoveries — 2,311,404Map.
  2. U.S.: Total confirmed cases as of 11:30 a.m. ET: 1,681,793 — Total deaths: 98,933 — Total recoveries: 384,902 — Total tested: 14,907,041Map.
  3. Public health: Fauci says data is "really quite evident" against hydroxychloroquine — Nearly half of Americans say someone in their household has delayed medical care.
  4. Tech: Zipline drones deliver masks to hospitals; vaccines could be next
  5. Business: Boeing to lay off 6,770 more U.S. employees.
  6. 🏒Sports: NHL unveils 24-team playoff plan to return from hiatus.
  7. What should I do? When you can be around others after contracting the coronavirus — Traveling, asthma, dishes, disinfectants and being contagiousMasks, lending books and self-isolatingExercise, laundry, what counts as soap — Pets, moving and personal healthAnswers about the virus from Axios expertsWhat to know about social distancingHow to minimize your risk.
  8. Other resources: CDC on how to avoid the virus, what to do if you get it, the right mask to wear.

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Updated 17 mins ago - Politics & Policy

U.S. coronavirus updates

Data: The Center for Systems Science and Engineering at Johns Hopkins; Map: Andrew Witherspoon/Axios. This graphic includes "probable deaths" that New York City began reporting on April 14.

D.C. Mayor Muriel Bowser said Wednesday the city will start to lift coronavirus restrictions on May 29 after seeing a 14-day decline in community spread of the virus. The city’s current stay-at-home and business closure orders were set to run through June 8.

By the numbers: More than 98,900 people have died from the novel coronavirus and over 1.6 million have tested positive in the U.S. Over 384,900 Americans have recovered and more than 14.9 million tests have been conducted.