{"id":8,"date":"2007-08-15T04:19:03","date_gmt":"2007-08-15T09:19:03","guid":{"rendered":"http:\/\/arxivblog.com\/index.php\/2007\/08\/15\/the-dark-matter-problem\/"},"modified":"2007-08-15T04:28:37","modified_gmt":"2007-08-15T09:28:37","slug":"the-dark-matter-problem","status":"publish","type":"post","link":"https:\/\/arxivblog.com\/?p=8","title":{"rendered":"The dark matter problem"},"content":{"rendered":"

It ain’t right, this dark matter business. The problem is these galaxies that astronomers are a-peepin and a-starin at: they’re just rotatin too quick for Newton’s beloved gravity to hold em together. So something has to be a-stickin and a-holdin them tight.<\/p>\n

Ya’ll bin told that dark matter provides the extra gravitational oomph to stop galaxies flyin apart. For some reason, the notion has stuck. Physicists have squandered more than their fair share of pocket money lookin for dark matter and wot have they got to show for it? Zilch.<\/p>\n

But it don’t got to be dark matter says John “Mohawk” Moffat at the Perimeter Institute<\/a> in Canada. Maybe gravity needs a-nudgin and a-kneedin to fit the data.<\/p>\n

The most famous attempt is a quick’n’easy rewrite of Newton called MOdified Newtonian Dynamics or MOND which was proposed by Mordehai “Mouse” Milgrom in 1981. MOND makes gravity stronger at large distances, which stops ’em galaxies a-rippin and a-tearin themselves apart without invokin dark matter.<\/p>\n

But MOND don’t work on much larger scales for clusters of galaxies, which also need something to stop em flyin apart.<\/p>\n

So Mohawk Moffat has dreamt up MOdified Gravity or MOG and now fitted it to the data. Works a treat, he says. MOG explains the motions of galaxies and clusters of galaxies without needin dark matter.<\/p>\n

What Mohawk needs now is a way a-measurin MOG on planet Earth. Cos ain’t nobody gonna believe him otherwise.<\/p>\n

Ref: arxiv.org\/abs\/0708.126<\/a>: Testing Modified Gravity with Globular Cluster Velocity Dispersions<\/p>\n","protected":false},"excerpt":{"rendered":"

It ain’t right, this dark matter business. The problem is these galaxies that astronomers are a-peepin and a-starin at: they’re just rotatin too quick for Newton’s beloved gravity to hold em together. So something has to be a-stickin and a-holdin them tight. Ya’ll bin told that dark matter provides the extra gravitational oomph to stop […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-8","post","type-post","status-publish","format-standard","hentry","category-stars-in-their-eyes"],"_links":{"self":[{"href":"https:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts\/8","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8"}],"version-history":[{"count":0,"href":"https:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts\/8\/revisions"}],"wp:attachment":[{"href":"https:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}