[yor_on]

But there was some others too in the book?
Try this one too 'Can we probe planck-scale physics with quantum optics?' at http://backreaction.blogspot.se/

[JP]

It looks like all the arguments against making sub-Planck measurements use general relativity + quantum mechanics to "prove" that the energies required to probe sub-Planck lengths will create Planck scale black holes.  But that assumes GR and quantum mechanics both hold at that scale, which we don't expect to be the case...

[Æthelwulf (OP)]

That was so weird... a good while ago I couldn't even post here lol

[syhprum]

There is a technical difficulty reading this as it is much tooooooooooooooooooooooooooo wiiiiiiiiiiiiiiiiiiiiiiiiiiide

[yor_on]

It looks like all the arguments against making sub-Planck measurements use general relativity + quantum mechanics to "prove" that the energies required to probe sub-Planck lengths will create Planck scale black holes.  But that assumes GR and quantum mechanics both hold at that scale, which we don't expect to be the case...

That's the way I think of it too JP. As if we have 'phase transitions' of a sort, describing one thing at the macroscopic scale, another at QM level, a third under it. What will be interesting is the question of 'causality chains' and a 'arrow' there. I don't expect there to be any linear definition as our 'normal arrow' possible myself at/under Planck scale. But then again, what will 'exist' there? Bosons?

[yor_on]

Although I better point out one thing. As I think of relativity, from a point of 'locality', meaning that all reference frames are locally equivalent. Which simply stated please me by making a Planck length 'invariant' in any local measurement (that is, if we could:) no matter where you do it, or your relative speed. If looked at that way one does not have to consider a relative length of something, depending on mass/motion etc. So a Planck length will then be a Plank length. But I agree fully on that there will be something more after that, although I don't expect our current definitions to cope with describing it.
=

And I can do that by relate a 'arrow' to 'c', as well as define a length to never change for you 'locally'. You may find a twin experiment to be true, But there is no way you will find a 'changed length', as some rulers compared between frames of reference relatively,  to stand the final test of joining 'frames of reference'.

So what is 'real' to me is how you can put it to that test, and from the conclusions you get you will be able to define the 'properties' of whatever concept you're laboring with. Which makes the arrow locally equivalent to 'c', and a 'length' locally invariant.