{"id":1283,"date":"2009-08-08T12:31:37","date_gmt":"2009-08-08T03:31:37","guid":{"rendered":"https:\/\/regex.info\/blog\/2009-08-08\/1283"},"modified":"2009-08-08T12:31:37","modified_gmt":"2009-08-08T03:31:37","slug":"pretty-and-mysterious-water-shadows","status":"publish","type":"post","link":"https:\/\/regex.info\/blog\/2009-08-08\/1283","title":{"rendered":"Pretty (and Mysterious?) Water “Shadows”"},"content":{"rendered":"\n\n\n
\nNOTE<\/b>: Images with an icon next to them have been artificially shrunk to better fit your screen; click the icon to restore them, in place, to their regular size.\n<\/div>\n\n\n
<\/a>\nNikon D700 + Nikkor 70-200mm f\/2.8 @ 135 mm — 1<\/sup>\/<\/big>400 sec, f<\/span>\/9, ISO 220 —\nmap & image data<\/a> — nearby photos<\/a><\/span>\nFreaky Water “Shadows”<\/span>\n<\/div>\n\n

While filling the kiddy pool mentioned in the previous\npost<\/a>, two blades of grass got into the water and made interesting\n“shadows” on the floor of the pool a foot<\/span> below.<\/p>\n\n

Here are some close-ups...<\/p>\n\n
\n\n<\/a>\n<\/td><\/td>\n\n<\/a>\n<\/td><\/tr><\/table>\n\n

Sometimes you see these in larger pools or fountains created by\ninvisible eddies on the surface. They're always pretty and somewhat\nmysterious because they seem to be shadows of nothing, or at least\nmuch larger than the thing that seems to be creating them.<\/p>\n\n

Of course, they aren't shadows at all. I'm sure someone<\/span>'s done all kind\nof research about them (and I'm sure the phenomenon must have a name<\/span>), but\njust putting a bit<\/span> of thought into it makes you realize that the very\nslight indentation in the surface of the water due to the weight of the\nblade of grass acts like a lens,<\/span> refracting the light off to one side or\nother. The dark “shadows” have bright edges, because that's where the bulk\nof the refacted light has been diverted.<\/p>\n\n

I wonder whether Richard Feynman ever contemplated them. He could<\/span> probably do the math in his head. Just thinking about someone thinking\nabout the math makes my brain melt. I'll stick with “hey, look,\npretty!”<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"

While filling the kiddy pool mentioned in the previous post, two blades of grass got into the water and made interesting \"shadows\" on the floor of the pool a foot below.<\/p>

Here are some close-ups...<\/p>

Sometimes you see these in larger pools or fountains created by invisible eddies on the surface. They're always pretty and somewhat mysterious because they seem to be shadows of nothing, or at least much larger than the thing that seems to be creating them.<\/p>

Of course, they aren't shadows at all. I'm sure someone's done all kind of research about them (and I'm sure the [...]","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,4],"tags":[],"_links":{"self":[{"href":"https:\/\/regex.info\/blog\/wp-json\/wp\/v2\/posts\/1283"}],"collection":[{"href":"https:\/\/regex.info\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/regex.info\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/regex.info\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/regex.info\/blog\/wp-json\/wp\/v2\/comments?post=1283"}],"version-history":[{"count":0,"href":"https:\/\/regex.info\/blog\/wp-json\/wp\/v2\/posts\/1283\/revisions"}],"wp:attachment":[{"href":"https:\/\/regex.info\/blog\/wp-json\/wp\/v2\/media?parent=1283"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/regex.info\/blog\/wp-json\/wp\/v2\/categories?post=1283"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/regex.info\/blog\/wp-json\/wp\/v2\/tags?post=1283"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}