The Solar Neutrino Problem

via THE UNIVERSE — The Solar Neutrino Problem As the sun converts….

As the sun converts hydrogen to helium within its core, there are always different particles released at each stage. These particles are essentially waste so they depart the sun, although at various rates.

During the first phase of fusion two Hydrogen atoms fuse together to make Deuterium, a heavier form of Hydrogen that contains a neutron. Usually Hydrogen contains only 1 proton and NO neutrons. According to our best solar models, the first neutrino produced during the fusion process comes from this step.

Neutrinos are electrically neutral particles with an extremely low mass. They interact with other particles so weakly that they travel through ordinary matter with extraordinary ease. Every second, huge numbers of neutrinos are emitted from the sun, carrying a very small fraction of the energy that is liberated from fusion reactions. They leave the sun and stream right through Earth. In fact, while you are reading this sentence, more than a billion neutrinos will pass through your head. The incredibly low interaction rate of the neutrino makes them difficult to study. I mean, how do we even know they are there??

Experiments to detect them have been running since 1970; the first was set deep in an abandoned gold mine in South Dakota. Being underground helped minimise possible false results by cutting out various other particles.

The neutrino detector consisted of a large tank containing over 600 tonnes of tetrachloroethene – a liquid used in dry cleaning that contains carbon and chlorine. As neutrinos flooded the tank, one would occasionally interact with a chlorine nucleus. Quite surprisingly, every time this interaction happened an argon nucleus was produced. At the end of an 80 day run the contents of the tank were emptied and the argon nuclei counted. What lay before them was an almighty task, as usually only 50 or so argon nuclei were found amongst the approximately 100000000000000000000000000000000 nuclei in the tank (that’s 10 with 31 zeros after it by the way).

The results of this experiment led to what is now known as the solar neutrino problem. The observed neutrinos implied a rate of production that was only one third of that expected. Since this initial experiment in the South Dakota mine, the deficit of solar neutrinos has been confirmed by other experiments that detect neutrinos in a variety of ways.

The answer turned out to be that there are actually three different types of solar neutrino: the electron neutrino, the muon neutrino and the tauon neutrino. Although only the electron neutrino is emitted by the sun, some of them can change type on their journey through space. The South Dakota mine experiment could only detect the electron neutrino type, and the experiments that followed could only detect one type of neutrino at a time. These results made sense as the experiments always detected only one third of the expected neutrinos.

In the late twentieth century solar astronomers finally cracked the issue when they set up an experiment in Canada that could detect all 3 types of neutrino. It used a spherical tank that held 1000 tonnes of “heavy” water surrounded by 9500 photosensitive cells that could detect tiny flashes of light from any particle interactions (the photo shows some technicians cleaning the cells inside such a tank). When they announced their results, it was confirmed that the theory from solar models regarding nuclear reactions, was in fact correct.


Further reading
Image credit: Michael Richmond, licensed under a Creative Commons license




via Republican Idiots – ‘A substantial screw up’: Maine Gov. Paul LePage….

9TH JULY 2015


Oponents of Maine Gov. Paul LePage ® said that they were delighted this week after the governor and his staff misunderstood the veto process for nearly 20 bills, destining them to become law.

The Bangor Daily News reported on Wednesday that LePage had attempted to use a “pocket veto” maneuver to kill at least 19 bills. Under “Maine’s Path of Legislation” rules, a governor may effectively veto a bill by declining to sign it in a 10-day time frame after the bill has passed.

The catch is that the “pocket veto” only works if the Legislature has adjourned. Otherwise, the bill becomes law, according to the rules. And in this case, Maine’s Legislature is still in session.

“I can’t even process this right now, that this is his latest move,” House Majority Leader Jeff McCabe (D) told the Daily News on Monday. “It’s very clear, as far as the role the governor has, when it comes to bills — whether he signs them, not signs them or vetoes them. To hold them for an arbitrary period of time doesn’t really work. He can’t rewrite the rules.”

“We were expecting him to act on these last Thursday when he was hanging out with [Republican presidential candidate and New Jersey Gov.] Chris Christie, but he seems to have gotten distracted by that,” McCabe added.

Included in the 19 or more bills is LD 369, which would permit asylum seekers to apply for assistance from the General Assembly. It was considered to be the most contentious bill of the legislative session.

LD 1013 seeks to prevent the shackling of pregnant women at Maine detention facilities, LD 1108 would ban electronic vaporizers in areas where traditional tobacco cigarettes are banned and LD 1185 would establish a municipal fund to support broadband development.

On Wednesday, the Daily News reported that the window for LePage to veto the bills had expired, “ensuring the bills become law.”

ACLU of Maine Legal Director Zach Heiden pointed out in a statement that the state Constitution was clear on the matter.

“The governor had 10 days to veto the bills, he did not veto them, and now the bills will become law. We do not have a government of one, and the governor cannot make up the rules as he goes along,” Heiden wrote.

Although most Republicans have reportedly had little to say about the botched vetoes, GOP consultant Lance Dutsoncalled the mistake a “substantial screw up.”

“Thanks to the gov’s screw up, asylum seekers will now receive GA [assistance]. Love to see the base’s reaction to this,” Dutson wrote on Twitter.

“Oops…knew I forgot something…”
~ LePage

“We were expecting him to act on these last Thursday when he was hanging out with…Chris Christie, but he seems to have gotten distracted by that,” McCabe added.



“Endless wars will always have their atrocities. And atrocities will always find a flag.”

via Three Good Links.

— Greg Grandin at Tom Dispatch. The Confederate Flag at War

(But Not the Civil War)

Cades Cove Great Smoky Mountains National Park – Sparks Lane by Dave Allen

via Cades Cove Great Smoky Mountains National Park -… – Chronicles of a Love Affair with Nature.

(Source: outdoormagic)


What to Do in Santorini, Part 2: Get Out to Sea

Everywhere Once

Nea Kameni at Sunset 2

Exploring volcanic landscapes has become a fairly frequent pastime during our travels, from Idaho’s Craters of the Moon to the Big Island’s Mauna Kea.

All of these places have their own starkly desolate beauty, and Greece’s Nea Kameni is no exception. Visible from Santorini, the uninhabited volcanic island looks like a black mass. Up close, its nuances come into focus.

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Pembient, a biotech firm, has mass-produced rhino horns that are genetically identical to, and indiscernible from, the ones cut off of rhinos–but instead, are grown in a lab. Then they flooded the black market with the fake horns, driving down the price and making rhinos an unappealing target to poachers

via Republican Idiots – today in RL superheroes.

They’re looking into ivory next. [source]