{"id":6996,"date":"2015-08-03T17:35:20","date_gmt":"2015-08-03T21:35:20","guid":{"rendered":"https:\/\/spinor.info\/weblog\/?p=6996"},"modified":"2015-08-03T17:35:20","modified_gmt":"2015-08-03T21:35:20","slug":"light-echo","status":"publish","type":"post","link":"https:\/\/spinor.info\/weblog\/?p=6996","title":{"rendered":"Light echo"},"content":{"rendered":"

Here is one of the most mind-boggling animation sequences that I have ever seen:<\/p>\n

\"\"<\/a><\/p>\n

This image depicts V838 Monocerotis<\/a>, a red variable star that underwent a major outburst back in 2002.<\/p>\n

Why do I consider this animation\u00a0mind-boggling? Because despite all appearances, it is not an expanding shell of dust or gas.<\/p>\n

Rather, it is echoes of the flash of light, reflected by dust situated behind<\/em> the star, reaching our eyes several years after the original explosion.<\/p>\n

In other words, this image\u00a0represents direct, visual evidence of the finite speed of light.<\/p>\n

The only comparable thing that I can think of is this video<\/a>, created a few years ago using tricky picosecond photography, of a laser pulse traveling in a bottle. However, unlike that video, the images of V838 Monocerotis required no trickery, only a telescope.<\/p>\n

And light echoes are more than mere curiosities: they actually make it possible to study past events. Most notably, a faint light echo of a supernova that was observed nearly half a millennium ago, in 1572, was detected in 2008<\/a>.<\/p>\n<\/fb:like>","protected":false},"excerpt":{"rendered":"

Here is one of the most mind-boggling animation sequences that I have ever seen: This image depicts V838 Monocerotis, a red variable star that underwent a major outburst back in 2002. Why do I consider this animation\u00a0mind-boggling? Because despite all appearances, it is not an expanding shell of dust or gas. Rather, it is echoes […]<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20,3],"tags":[],"class_list":["post-6996","post","type-post","status-publish","format-standard","hentry","category-astronomy","category-physics","category-20-id","category-3-id","post-seq-1","post-parity-odd","meta-position-corners","fix"],"_links":{"self":[{"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/posts\/6996","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6996"}],"version-history":[{"count":4,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/posts\/6996\/revisions"}],"predecessor-version":[{"id":7001,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/posts\/6996\/revisions\/7001"}],"wp:attachment":[{"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6996"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6996"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6996"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}