- if time doesn’t exist at the quantum scale, how is it possible to run a quantum process?

That question barely gets off the ground for me, since I don’t see good evidence right now that “time doesn’t exist on the quantum scale.” Conventional QM has a perfectly-ordinary time parameter t, and AdS/CFT even gives you quantum *gravity* models where that’s upheld (i.e., where you can have a well-defined time-slicing, at least on the boundary, and there are no closed timelike curves or anything like that).

Of course, AdS/CFT doesn’t seem to describe *our* deSitter universe, so it remains conceivable that the true quantum theory of gravity, whatever it is, will have no time at a fundamental level, and will relegate time to an “emergent” status—a possibility that lots of deep thinkers indeed speculate about these days. But it seems to me that the burden is squarely on those deep thinkers to explain how to recover a sensible notion of time from their ideas, in the regimes where we *know* time makes sense! It’s not on the people like me who have no problem with time at the present time. 🙂 So you should really direct your question to Rovelli or Connes or someone like that.

Scientists like Alain Connes and Carlo Rovelli believe that time emerges out of large quantum systems, as the variable which best stabilizes their statistical equilibrium. In their view, time is just a consequence of our lack of knowledge about quantum systems. Alain Connes has coined the motto: “a non-commutative space generates its own time.” He refers to the non-commutativity of Von Neumann algebras of quantum operators.

In my personal view, computations can be seen, by contrast, as the natural opposite trend to disorder: an ordering factor which creates knowledge but also destroys time – since time can only emerge out of statistical disorder. An interesting parallel can be made between this quantum situation and the well-known opposition stochastic-and-efficient versus exact-and-slow algorithms in complexity theory. The established fact that randomness is a provider of efficiency in computer science might turn out to be a simple consequence of the true nature of time: quantum disorder, while being an obvious destroyer of accuracy, remains the only possible time engine. What do you think of this hypothesis?

]]>Aaah, ok, it’s equation (4).

Thanks for the links! ]]>

FWIW, reference 4 is available part 1 2 3. And a bunch of reviews (I’m surprised that google scholar doesn’t find them.)

]]>Thanks, that’s a really nice way of looking at it! ]]>

I read the paper, but they lost me at:

” The CHSH assumption is not true in Faraday’s model. Instead there is prior communication of orientation along phase vortices such as (4), communication which the CHSH calculation excludes by its explicit assumption.”

And (4) refers to

“GN Cantor and MJS Hodge.

Conceptions of ether: Studies in the history of ether theories, 1740-1900”

?!

But I like one of the two authors’ web page (Robert Brady).

http://www.cl.cam.ac.uk/~rmb4/

“Computer optimisation algorithms often reach an impasse. A typical example is the travelling salesman problem, […] Biological evolution encounters the same problem. But if you can out-evolve your competitors, you will win in the long run. There have been billions of years to solve this problem – and the answer is sex.”

We’re getting really close to finally tying up complexity theory and those recent controversial topics you’ve been exploring!

]]>(a) there must be signalling between the detectors in their model, perhaps smuggled into the “quadratic terms in Euler’s equation” (which would render the result uninteresting), or else

(b) there must be an error in their derivation.

I’ll be *extremely* grateful to any readers who want to look carefully, and explain to us whether (a) or (b) holds. But if Alice and Bob get to choose polarizations v and w independently, and there’s no communication between them, then they’re not going to produce independently-uniform random bits that are correlated with probability cos^{2}(v-w) and anticorrelated with probability sin^{2}(v-w). I’m as sure of that as I am that √2 is irrational.

“And yes, relativity encourages this perspective, by showing that different observers, moving at different speeds relative to each other, will divide up the 4-dimensional manifold into time slices in different ways, with two events judged to be simultaneous by one observer judged to be happening at different times by another.”

So why does everybody agree on the age of the universe?

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