A quick physics news update, on some stories that came out last week:<\/p>\n
“Thundercloud “accelerator” fires gamma-ray beam<\/a>:” A team of scientists in Japan has seen a 40-second burst of gamma rays from a thundercloud. This was presumably produced by electrons accelerated to extremely high velocities within the could coming to a sudden stop– a process with the fabulous German name “bremsstrahlung.” This was not associated with lightning, and indeed, one of the scientists quoted in the article says that lightning would be counterproductive, basically “shorting out” the multi-million-volt potential difference needed to produce gamma rays.<\/p>\n But, really, the main point of this is: “Dude. Gamma rays from thunderclouds!”<\/p>\n Matter-antimatter molecule makes its debut<\/a>: When a positron and an electron encounter one another, they form a sort of transient pseudo-atom, known as “positronium.” The two orbit each other for a time, and then collide and annihiliate. Now, a group at UC Riverside has managed to create a sample with a high enough positronium density to see interactions between neighboring “atoms.”<\/p>\n You can also read a press release<\/a>, which makes the faintly hilarious claim that this “could one day help develop fusion power generation as well as directed energy weapons such as gamma-ray lasers.” The Physics World<\/cite> piece says some more measured things about using gamma-ray lasers for nuclear-scale microscopy, which is more plausible.<\/p>\n Earth could survive a red-giant Sun<\/a>: It wouldn’t be pleasant, but if your retirement plans for five billion years from now involve real estate speculation, you’ll be happy to learn that observations of an extrasolar planet suggest that the Earth might survive having the Sun swell into a red giant. So, you know, there’s that to look forward to.<\/p>\n","protected":false},"excerpt":{"rendered":" A quick physics news update, on some stories that came out last week: “Thundercloud “accelerator” fires gamma-ray beam:” A team of scientists in Japan has seen a 40-second burst of gamma rays from a thundercloud. This was presumably produced by electrons accelerated to extremely high velocities within the could coming to a sudden stop– a… Continue reading Radioactive Clouds, Antimatter Molecules, and the Dying Earth<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"1","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-1744","post","type-post","status-publish","format-standard","hentry","category-physics","entry"],"_links":{"self":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/1744","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/comments?post=1744"}],"version-history":[{"count":0,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/1744\/revisions"}],"wp:attachment":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/media?parent=1744"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/categories?post=1744"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/tags?post=1744"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}