Recent content by jarek

Doesn't it come from the simple fact that there exists the max speed, which module should be preserved in all inertial frames? Then a simple calculus shows what is the invariant element. Heuristically: (dx/dt)^2=c^2=(dx'/dt')^2 <=> (cdt)^2-dx^2=(cdt')^2-dx'^2 best, jarek

:puke: why are you attacking me with your silly entropy all the time :eek: I was rather referring to point individuation, as that would be an example how you get "kinematical" background (i.e. manifold itself, of diff class rather) from dynamics (Einstein Eq's). I KNOW that such schemes are...

I like a lot what you are saying re dynamics vs. kinematics. You got me once thinking with similar remark (all that orthomodular toys should really be dynamically determined, not rigid as they are right now). However the only theory with kinematics following from dynamics seems to be GR, as...

Erm, by superluminal signalling I mean transmitting information faster than c. And this you cannot do with entangled pairs. You can invent whatever waves you like (Gisin and co once even put experimental bounds on their velocities) which propagate between entangled pairs, but information...

No, I'm talking about orthomodular lattices more than about silly entropies :smile: You will call it kinematics and say that it should be dynamically determined etc and I will agree. But if you need quantum statistics per se, understood here rather abstracly like you can speak of classical...

Nah, Careful, please...Mackey put it in a very well defined form. If you don't accept other forms of statistics apart from the classical one (who was talking about thinking out of the box :rolleyes: ), then sure entanglement is magic, local realism is lost (at least on paper) and we desperately...

Would you care to briefly list them? I haven't had a live contact with GR for some years now and wanted to learn whazzup. best, jarek

Hi all, what would be your standard Ref. for algebraic approach to quantum theory (algebras, states, folia, etc.)? Haag or there is something better? Beyond the standard things, I'm interested in two aspects of algebraic theory when applied to non-relativistic MECHANICS: i) Classical...

The time will show :-p I didn't say that in one experiment, that's why the field is still active. There has been a proposal of Fry to do such an experiment (with Hg+ ions), but as far as I know he hasn't done it yet (I heard him in 2001, but I think the idea is much older). There are also...

Not equal, but cryptography (in the modern incarnation) *heavily* uses entanglement (like evesdropping detectiion, NOT POSSIBLE classically) and your objection concerned practical benefits from studying entanglement. It is QUANTUM ...:frown: I moved in the other direction :-p Not really...

Putting aside already aviable commercial quantum crypthographical devices (IDQuantique of N. Gisin and MagiQ), if you consider knowledge alone to be practical (at least in principle) then that's a bit of b-s what you are saying here, Careful. During the study of quantum information and...

Ditto! I went through all the thread before my first post, Kea. I do understand sheaf as a functor, but that's *MATH*. I simply spotted an unclear point in your *PHYSICAL* motivation. I find the topos approach intelectually appealing, that's why I'm trying to understand how to motivate this...

To Kea As far as I undertsand your line of reasoning is the following: (points unphysical according to Einstein) => (substitute point-defined objects by sheaves over M) => (abstract further and use cathegory-theoretical sheaves). I think the reason for abondoning points is not the Einstein...

A comment on Kea's sheaf argument in GR Hi all, just joined you. Sorry for poping up with an old post, but wanted to comment on that: If you look at the hole argument which is usually invoked here, then a subset of the spacetime seems just as unphysical as a point (you give it a physical...