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Scientists have proven what causes the northern lights : NPR



The northern lights (aurora borealis) light up the sky above the Reinfjorden in Reine on the island of Lofoten in the Arctic Circle on Sept. 8, 2017.

Jonathan Nackstrand/AFP via Getty Images


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Jonathan Nackstrand/AFP via Getty Images


The northern lights (aurora borealis) light up the sky above the Reinfjorden in Reine on the island of Lofoten in the Arctic Circle on Sept. 8, 2017.

Jonathan Nackstrand/AFP via Getty Images

Nothing can ruin our happiness in the aurora or northern lights, blue, green and purple ribbons that fall from the sky. I don’t even know what caused it.

Physicists have long guessed what causes the specific light phenomenon that occurs in Earth’s polar regions.

They are now confident.

articles published in journals nature communication This week shows that the natural light show began when interference from the sun pulled Earth’s magnetic field. That produces cosmic waves known as alfalfa waves that emit electrons at high speed into Earth’s atmosphere, where they create auroras.

Gregory Howes, an associate professor of physics and astronomy at the University of Iowa, said: “It is a theory that that is the beginning of the energy exchange. “But no one has ever thought of giving a clear demonstration that these electrons can actually accelerate these electrons under the ideal conditions you have in space above the aurora.”

How Aurora is Formed

the sun fluctuates and extreme events there, such as storms from the Earth’s magnetic field. can be reflected in the universe

In some cases, the sun’s interference is so intense that it pulls the Earth’s magnetic field like a rubber band pulls it away from our planet.

But like a rubber band, it is taut when released. The magnetic field is reversed. And that recoil creates powerful waves known as the Alvene waves about 80,000 miles from the ground. They then move faster with the magnetism of the planets.

On the same space highway, there are also electrons traveling to Earth. But not as fast as the Alfven wave.

Sometimes electrons are attached to these very fast alfalfa waves. It reaches speeds of up to 45 million miles per hour as it descends.

“Think about surfing,” says Jim Schroeder, a physics professor at Wheaton College and lead author. “In the surf You have to paddle at the right speed for the waves to pick you up and accelerate you. And we find that electrons are surfing. If they move at a reasonable speed relative to the wave, they will pick up and accelerate.”

Illustration of how electrons “surf” through Alfven waves.

Austin Montelius/College of Arts and Sciences University of Iowa University


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Austin Montelius/College of Arts and Sciences University of Iowa University


Illustration of how electrons “surf” through Alfven waves.

Austin Montelius/College of Arts and Sciences University of Iowa

When electrons reach Earth’s thin atmosphere, they collide with nitrogen and oxygen molecules. causing them to be in a state of excitement. Eventually, the excited electrons calm down and emit light. which is what we see as Aurora.

what the experiment showed

For decades, while scientists assumed that Alfvén waves were responsible for the acceleration of electrons. This laboratory experiment has produced the only clear proof.

“Nobody has ever measured this between an electron and an alfven wave,” Schroeder told NPR.

The researchers used what is known as the Large Plasma Device at UCLA’s Basic Plasma Science Facility to create interactions between Alfvén waves and electrons.

Such studies would be impossible in space. Because researchers cannot predict when the aurora will occur. and cannot explain other factors in the universe.

The researchers suggest that their discovery could help a broader understanding of how particles gain energy. It also provides a clearer picture of how events on the sun affect near-Earth space. including the technological infrastructure we have such as satellites

for Schroeder There is another much simpler benefit from this kind of research.

“This captures our sense of awe and wonder,” he said. “We have been fascinated by the aurora for millenia and look at the night sky and admire their beauty. And I’ve found a greater understanding of how certain things are made. It adds to my appreciation of beauty.”


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