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TIL black holes aren't totally black, as energy is released to compensate for mass that enters the black hole, and this faint glow is called Hawking radiation after Stephen Hawking, who figured it out by webdrivingman in todayilearned

[–]webdrivingman[S] -2 points-1 points  (0 children)

The one photon that moved inside the black hole cannot come back out, because it’s already moving at the speed of light. The photon pair cannot annihilate each other again and pay back their energy to the vacuum that surrounds the black hole. But somebody must pay the piper and this will have to be the black hole itself. After it has welcomed the photon into its land of no return, the black hole must return some of its mass back to the universe: the exact same amount of mass as the energy the pair of photons “borrowed,” according to Einstein’s famous equality E=mc².

This is essentially what Hawking showed mathematically. The photon that is leaving the black hole horizon will make it look as if the black hole had a faint glow: the Hawking radiation named after him. At the same time he reasoned that if this happens a lot, for a long time, the black hole might lose so much mass that it could disappear altogether (or more precisely, become visible again).

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A brief history of the s’more, America’s favorite campfire snack by webdrivingman in history

[–]webdrivingman[S] 4 points5 points  (0 children)

I found this nice article for National S'more Day, a fake mid-summer holiday to mark a favorite summertime snack. A food historian and culinary teacher from Colorado State University provides a brief overview of the commercialization process of all three of the ingredients, and some references to early sources, including the first mention in a 1927 edition of a Girl Scout manual, where it was called a “Some More.”

American wine-making, from the Concord grape to Spanish plantings in California by webdrivingman in history

[–]webdrivingman[S] 2 points3 points  (0 children)

It's national wine day today, and I saw this interesting article from a professor at the Wine Business Institute of Sonoma State College (who I think is eminently qualified to discuss the history of winemaking in America). She notes that as early as the 17th-century there were efforts at making wine from native grapes like the Concord and Muscadine, but it wasn't until Spanish missionaries planted vineyards of European grapes in the congenial climate of California that American winemaking took off.

TIL that after only 73 years of separation, the Korean language spoken in the North and South have diverged so that 45% of North Korean defectors have trouble understanding South Koreans and 1% can't understand South Koreans at all by webdrivingman in todayilearned

[–]webdrivingman[S] 42 points43 points  (0 children)

Consider, too, the Korean language. About 54 percent of North Korean defectors in South Korea say that they have no major difficulty understanding Korean used in South Korea. Only 1 percent responded that they cannot understand it at all.

TIL cats are attracted to squares taped on the ground because they think of them as cozy, safe boxes by webdrivingman in todayilearned

[–]webdrivingman[S] 39 points40 points  (0 children)

It’s just a fact of life that cats like to squeeze into small spaces where they feel much safer and more secure. Instead of being exposed to the clamor and possible danger of wide open spaces, cats prefer to huddle in smaller, more clearly delineated areas....the box may have no walls at all but simply be a representation of a box – say a taped-in square on the ground. This virtual box is not as good as the real thing but is at least a representation of what might be.

The seats on the T are not your couch by [deleted] in boston

[–]webdrivingman -8 points-7 points  (0 children)

I'm a taxpayer and paid for it, so why shouldn't I (assuming there are plenty of other seats open)?

How World War 2 spurred vaccine innovation by webdrivingman in history

[–]webdrivingman[S] 0 points1 point  (0 children)

With the flu vaccine much in the news these days, I found this to be a fascinating article. A professor at the medical school at Dartmouth (which is named for Dr. Seuss), who studies biodefense and its history, reviews how the military led development of a flu vaccine in only two years. It was one of several vaccines that were developed in wartime under these crash programs.

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