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Solar Winds Hitting Earth Are Hotter Than They Should Be, And We May Finally Know Why – ScienceAlert

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Our planet is constantly bathed in the winds coming off the blistering sphere at the centre of our Solar System. But even though the Sun itself is so ridiculously hot, once the solar winds reach Earth, they are hotter than they should be – and we might finally know why.

We know that particles making up the plasma of the Sun’s heliosphere cool as they spread out. The problem is that they seem to take their sweet time doing so, dropping in temperature far slower than models predict.

“People have been studying the solar wind since its discovery in 1959, but there are many important properties of this plasma which are still not well understood,” says physicist Stas Boldyrev from the University of Wisconsin–Madison.

“Initially, researchers thought the solar wind has to cool down very rapidly as it expands from the Sun, but satellite measurements show that as it reaches the Earth, its temperature is 10 times larger than expected.”

The research team used laboratory equipment to study moving plasma, and now think the answer to the problem lies in a trapped sea of electrons that just can’t seem to escape the Sun’s grip.

The expansion process itself has long been assumed to be subject to adiabatic laws, a term that simply means heat energy isn’t added or removed from a system. This keeps the numbers nice and simple, but assumes there aren’t places where energy slips in or out of the flow of particles.

Unfortunately, an electron’s journey is anything but simple, shoved around at the mercy of vast magnetic fields like a roller coaster from Hell. This chaos leaves plenty of opportunity for heat to be passed back and forth.

Just to complicate matters further, thanks to its tiny mass, electrons get a good head start over heavier ions as they shoot forth from the Sun’s atmosphere, leaving a largely positive cloud of particles in their wake.

Eventually the growing attraction between the two opposing charges takes over the inertia of those flying electrons, pulling them back to the starting line where magnetic fields once again play havoc with their paths.

“Such returning electrons are reflected so that they stream away from the Sun, but again they cannot escape because of the attractive electric force of the Sun,” says Boldyrev.

“So, their destiny is to bounce back and forth, creating a large population of so-called trapped electrons.”

Boldyrev and his crew recognised a similar game of electron ping-pong playing out in their own laboratory, inside an apparatus commonly used to study plasma called a mirror machine.

A linear fusion reactor, or ‘mirror machine’. (Cary Forest)

Mirror machines don’t actually contain any mirrors. At least, not the familiar shiny kind. Also known as magnetic mirrors or magnetic traps, these linear fusion devices are little more than long tubes with a bottle-neck at either end.

Their reflective nature is created as streams of plasma passing through the bottle pinch in at either end, altering the surrounding magnetic fields in such a way that particles within the stream reflect back inside again.

“But some particles can escape, and when they do, they stream along expanding magnetic field lines outside the bottle,” Boldyrev says.

“Because the physicists want to keep this plasma very hot, they want to figure out how the temperature of the electrons that escape the bottle declines outside this opening.”

Or if you’re Boldyrev and his team, those leaking electrons can be studied to better understand what’s happening with our very own solar wind.

He and his colleagues suggest the population of trapped electrons that yo-yo back and forth play a major role in the way electrons distribute their heat energy, changing the typical distributions of particle velocities and temperatures in predictable ways.

“It turns out that our results agree very well with measurements of the temperature profile of the solar wind and they may explain why the electron temperature declines with the distance so slowly,” says Boldyrev.

Finding such a good match between the mirror machine’s figures and what we see in space suggests there could be other solar phenomena worth studying this way.

This research was published in PNAS.

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The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.

Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.

She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.

Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.

“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.

It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.

Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.

Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.

Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.

“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.

He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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B.C. sets up a panel on bear deaths, will review conservation officer training

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VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.

Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”

Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.

“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.

B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.

Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.

Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.

Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.

“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”

Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”

“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.

Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.

“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.

This report by The Canadian Press was first published Sept. 9, 2024.

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