Nov 22, 2017

Lightning can start nuclear reactions in the sky

Lightning. Photo: 4FR / iStock

Lightning can create fusion reactions in the air around it, according to research published today in the journal Nature. Nuclear reactions were thought to occur in some thunderstorms but the study provides the first conclusive evidence they are happening.

Why it matters: It's unclear how thunderstorms and lightning work. "How lightning initiates inside thunderstorms is a complete mystery, and how lightning initially moves inside the storms is not at all clear," lightning expert Joseph Dwyer from the University of New Hampshire tells Axios in an email. He says figuring out how some thunderstorms emit huge gamma-ray flashes thought to trigger the reactions "might tell us something interesting about what's going on inside the storms."

The question: It seems theoretically impossible for lightning to produce nuclear fusion reactions because the fuel for the reactions — a form of hydrogen called deuterium — isn't available in large enough amounts in the atmosphere. The 50,000°F temperature of lightning is also a lot cooler than the 30,000,000°F near the center of the Sun where nuclear fusion occurs. Yet scientists have observed by-products of these reactions being produced from lightning.

How it works: Lightning can emit high-energy bursts known as gamma-ray flashes. (How and when they occur — they are associated with a small fraction of lightning seen around the world each day — is a mystery itself.) The flashes are energetic enough to knock neutrons out of the nuclei of nitrogen and oxygen in the air, creating radioactive versions of them for a short time.

Researchers have seen signatures of neutrons being formed just after a lightning flash before. The new paper reports a second such observation on February 6, 2017 Japan along with detection of the radioactive nitrogen and oxygen produced when neutrons are removed from their nuclei.

"It leaves no possible doubt as to what's going on, and it's a beautiful and thorough analysis," says David Smith, a physicist at the University of California Santa Cruz who studies gamma-rays produced by lightning and wasn't involved in the research.

What's next: The gamma-ray flashes themselves were too bright for the researchers' instruments to record. Dwyer says having better instrumentation in places where there are lots of thunderstorms and on aircraft flying near storms would be a very important next step to confirm the bursts start the reactions.

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Republicans sue California over mail-out ballot plan

California Gov. Gavin Newsom during a February news conference in Sacramento, California. Photo: Justin Sullivan/Getty Images

Republicans filed a lawsuit against California in an attempt to stop Gov. Gavin Newsom (D) from mailing ballots to all registered voters ahead of the November general election.

Driving the news: Newsom signed an executive order this month in response to the coronavirus pandemic ensuring that all registered voters in the state receive a mail-in ballot.

Coronavirus dashboard

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  1. Global: Total confirmed cases as of 7 p.m. ET: 5,383,582 — Total deaths: 344,077 — Total recoveries — 2,158,031Map.
  2. U.S.: Total confirmed cases as of 7 p.m. ET: 1,640,972 — Total deaths: 97,679 — Total recoveries: 366,736 — Total tested: 14,163,195Map.
  3. World: White House announces travel restrictions on Brazil, coronavirus hotspot in Southern Hemisphere Over 100 coronavirus cases in Germany tied to single day of church services — Boris Johnson backs top aide amid reports that he broke U.K. lockdown while exhibiting symptoms.
  4. Public health: Officials are urging Americans to wear masks headed into Memorial Day weekend Report finds "little evidence" coronavirus under control in most statesHurricanes, wildfires, the flu could strain COVID-19 response
  5. Economy: White House economic adviser Kevin Hassett says it's possible the unemployment rate could still be in double digits by November's election — Public employees brace for layoffs.
  6. Federal government: Trump attacks a Columbia University study that suggests earlier lockdown could have saved 36,000 American lives.
  7. What should I do? Hydroxychloroquine questions answeredTraveling, 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 1 hour ago - Politics & Policy

Federal judge strikes down Florida law requiring felons to pay fines before voting

Gov. Ron DeSantis. Photo: oe Raedle/Getty Images

A federal judge on Sunday ruled that a Florida law requiring convicted felons to pay all court fines and fees before registering to vote is unconstitutional.

Why it matters: The ruling, which will likely be appealed by state Republicans, would clear the way for hundreds of thousands of ex-felons in Florida to register to vote ahead of November's election.