Comments on: 267. Twitter updates for 2009-02-17 http://www.nonequilibrium.net/twitter-updates-for-2009-02-17/#utm_source=feed&utm_medium=feed&utm_campaign=feed For physicts by physicists Tue, 31 Jan 2012 20:24:03 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Dmitry http://www.nonequilibrium.net/twitter-updates-for-2009-02-17/comment-page-1/#comment-6071 Dmitry Tue, 17 Feb 2009 19:46:35 +0000 http://www.nonequilibrium.net/twitter-updates-for-2009-02-17/#comment-6071 That was pure wishful thinking - they wanted to find non-commutativity of spacetime so much and were unable to notice that they are dealing with the theory with torsion :-) That was pure wishful thinking – they wanted to find non-commutativity of spacetime so much and were unable to notice that they are dealing with the theory with torsion :-)

]]> By: Lubos Motl http://www.nonequilibrium.net/twitter-updates-for-2009-02-17/comment-page-1/#comment-6062 Lubos Motl Tue, 17 Feb 2009 16:56:55 +0000 http://www.nonequilibrium.net/twitter-updates-for-2009-02-17/#comment-6062 The DGR (degenerated general relativity) paper by Gibbons et al. is pretty interesting. They show that most attempts to reconcile DSR with general relativity are instantly inconsistent, and the consistent one is just a version of some old, mundane Einstein-Cartan theories with torsion, and when things are put together, it can be ruled out on empirical grounds. These are pretty simple arguments. What's amusing is that some not-quite-serious but still people have proposed DSR as emerging in loop quantum *gravity* - which is now shown to be impossible because gravity is exactly what DSR can't be compatible with. The DGR (degenerated general relativity) paper by Gibbons et al. is pretty interesting.

They show that most attempts to reconcile DSR with general relativity are instantly inconsistent, and the consistent one is just a version of some old, mundane Einstein-Cartan theories with torsion, and when things are put together, it can be ruled out on empirical grounds.

These are pretty simple arguments. What’s amusing is that some not-quite-serious but still people have proposed DSR as emerging in loop quantum *gravity* – which is now shown to be impossible because gravity is exactly what DSR can’t be compatible with.

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