May 7, 2019

Gravitational waves in real time

Artist's illustration of two black holes. Photo: LIGO/Caltech/MIT/Sonoma State

Ever since scientists first detected gravitational waves — ripples in the fabric of space and time created during the cataclysmic mergers of black holes and neutron stars — in 2015, discoveries have come in a slow trickle, released every few months.

Driving the news: Now we can expect those findings to come more like a firehose, and you can follow along in real time.

The big picture: Under previous guidelines, the researchers behind the LIGO and Virgo detectors would have waited to release discoveries until after thorough vetting and even peer review. But now, Virgo and LIGO are releasing possible detections as they occur.

  • Real-time release allows scientists to quickly work to make follow-up observations of any possible gravitational wave sources.
  • Members of the public can also follow along with the gravitational wave signals through the Gravitational Wave Events app and a database.
  • The app will use a gravitational wave "chirp" — the noise a gravitational wave would make if converted into sound waves — to alert users to new detections.

Details: The LIGO and Virgo detectors are now 40% more sensitive thanks to upgrades made following the last observing run.

  • Since coming back online in April, the collaboration has discovered 5 possible detections of gravitational waves.
  • If these detections are confirmed, it would suggest these kinds of cosmic crashes are even more common than originally thought.
  • One of those 5 possible detections appears to have been made by the collision of a black hole and a neutron star, which would be the first time such an event has been recorded.
  • The signal from that merger was relatively faint, but the detection bodes well for LIGO and Virgo's future sensitivity.
  • Scientists hope that the instruments will be able to pick up the signals from exploding supernovas as well.

How it works: LIGO and Virgo are designed to pick up the most minute signals from gravitational waves that warp space-time as they pass through the universe.

  • LIGO’s two L-shaped detectors each have a laser running down the arms. Mirrors at the ends of the arms bounce the light of the laser back to the middle.
  • If both make it back at the same time, no gravitational wave has passed, but if they don’t line up, there may have been a signal.

Go deeper

Sign of the times: A pro-Warren super PAC

Democratic presidential candidate Sen. Elizabeth Warren at a rally in Nevada. Photo: Alex Wong/Getty Images

A group of women progressives who back Sen. Elizabeth Warren has formed Persist PAC, a super PAC airing pro-Warren ads starting Wednesday in an effort to boost her performance ahead of Saturday's crucial Nevada caucuses, a spokesman told Axios.

Why it matters: Warren has spoken adamantly against the influence of unlimited spending and dark money in politics. But these supporters have concluded that before Warren can reform the system, she must win under the rules that exist — and that whether she likes it or not, their uncoordinated help may be needed to keep her viable through this weekend's contest and into South Carolina and Super Tuesday.

Go deeperArrowUpdated 1 hour ago - Politics & Policy

Pentagon policy chief resigns amid reported discord with Trump

John Rood. Photo: Mark Wilson/Getty Images

John Rood, the Pentagon's top policy official, will resign from his post at the end of the month, CNN first reported and President Trump confirmed.

The state of play: CNN said Rood "was perceived as not embracing some of the changes in policy the White House and senior Pentagon officials wanted," such as peace talks in Afghanistan with the Taliban and a decision to cut back on military exercises with South Korea as the president courted North Korea's Kim Jong-un.

Coronavirus cases rise, as warnings of global pandemic grow

Data: The Center for Systems Science and Engineering at Johns Hopkins, the CDC, and China's NHC; Note: China refers to mainland China and the Diamond Princess is the cruise ship offshore Yokohama, Japan. Map: Danielle Alberti/Axios

We may be "at the brink" of a global pandemic, warns a top U.S. public health official, as cases continue to spread despite containment efforts. Meanwhile, the global economy is being affected, including the tech manufacturing industry.

The big picture: COVID-19 has now killed more than 2,000 people and infected over 75,000 others, mostly in mainland China, where the National Health Commission announced 136 new deaths since Tuesday.

Go deeperArrowUpdated 2 hours ago - Health