{"id":196,"date":"2008-01-01T00:38:35","date_gmt":"2008-01-01T05:38:35","guid":{"rendered":"http:\/\/arxivblog.com\/?p=196"},"modified":"2008-01-01T00:41:06","modified_gmt":"2008-01-01T05:41:06","slug":"the-top-posts-of-2007-number-1","status":"publish","type":"post","link":"https:\/\/arxivblog.com\/?p=196","title":{"rendered":"The top posts of 2007: number 1"},"content":{"rendered":"

Over the holiday period, the physics arxiv blog is re-running the most popular blogs (by page views) of 2007.\u00a0 This was the one ya like the most [cue drum roll]:<\/p>\n

Why our time dimension is about to become space-like
\n<\/a>9 October<\/p>\n

It don\u2019t get much weirder than this. The universe is about to lose its dimension of time says a group of theoretical astrobods at the University of Salamanca in Spain. And they got the evidence to prove it.<\/p>\n

The idea comes from the study of braneworlds: the thinking that the universe we see around us is a 4-dimensional cosmos called a braneworld embedded in a multidimensional universe. The \u201csignature\u201d of our universe is the number of space and time-like dimensions it has: in our case we got 3 space-like dimensions and one time-like dimension. It\u2019s what astrobods call a Lorentzian universe. So far so good: lots of astronutters think the same thing.<\/p>\n

But our universe may not always have been like this. Some theorists think it may once have had a Euclidean signature meaning that all the dimensions were space-like. Now Marc \u201cBars\u201d Mars and a few pals in Spain say that the Universe\u2019s signature might be about to flip from Lorentzian to Euclidean. In other words, our dimension of time is about turn space-like. Gulp!<\/p>\n

This ain\u2019t entirely bonkers and here\u2019s why. Bars Mars has calculated what it\u2019s like to be an observer in a universe that is about to flip and get this: it would look as if it were expanding and accelerating away from us. Sound familiar?<\/p>\n

Yep, it\u2019s exactly what astrobods have been observin over the last few years, a phenomenon they attribute to dark energy. If Bars Mars is right, dark energy ain\u2019t got nothing to do with it and we\u2019re all starin\u2019 down the barrel of a cosmic catastrophe.<\/p>\n

Still, maybe four space-like dimensions will be better than three. Who needs time anyway?<\/p>\n

Ref: arxiv.org\/abs\/0710.0820<\/a>: Is the Accelerated Expansion Evidence of a Forthcoming change of Signature?<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"

Over the holiday period, the physics arxiv blog is re-running the most popular blogs (by page views) of 2007.\u00a0 This was the one ya like the most [cue drum roll]: Why our time dimension is about to become space-like 9 October It don\u2019t get much weirder than this. The universe is about to lose its […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19],"tags":[],"class_list":["post-196","post","type-post","status-publish","format-standard","hentry","category-highlights"],"_links":{"self":[{"href":"https:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts\/196","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=196"}],"version-history":[{"count":0,"href":"https:\/\/arxivblog.com\/index.php?rest_route=\/wp\/v2\/posts\/196\/revisions"}],"wp:attachment":[{"href":"https:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=196"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=196"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/arxivblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=196"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}