PlaidX comments on Shock Level 5: Big Worlds and Modal Realism - Less Wrong

15 [deleted] 25 May 2010 11:19PM

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Comment author: PlaidX 26 May 2010 07:55:08AM 0 points [-]

I don't think you're right... isn't it broken down into plank lengths or something?

Comment author: AlephNeil 26 May 2010 04:03:25PM 1 point [-]

::Shrug:: There's something important about the Planck distance, but I don't know enough physics to be able to say much more. Like Hawking radiation, It's something that only crops up when you start trying to do 'quantum gravity'.

It's tempting to imagine that the universe is something like the "Game Of Life" but with Planck sized cells, but what little I know about string theory makes this idea seem extremely naive. (And anyway, space could be both discrete and infinite.)

Comment author: Nick_Tarleton 29 May 2010 05:21:06AM *  0 points [-]

IANAPhysicist, but I'm fairly sure that space and time are entirely continuous in standard QM or QFT, though they are discrete in loop quantum gravity and possibly other theories of QG.

Comment author: Douglas_Knight 29 May 2010 05:17:34PM 1 point [-]

Standard QFT doesn't have discrete space and QCD may make sense with continuum of space-time, but models with a Landau pole, like QED and the standard model, don't make sense at small length scales. The length at which the Landau pole appears in QED is smaller than the Planck length, so no one cares about it, since they expect bad things to happen already at the Planck scale.