Quantum Entanglement Drives the Arrow of Time

Post by madaxe_again » Fri, Apr 18, 2014, 7:11 AM UTC

im3w1l wrote: post #129

tim333 wrote: post #8

The reasoning sounds a bit iffy as in: “Finally, we can understand why a cup of coffee equilibrates in a room,” said Tony Short, a quantum physicist at Bristol. “Entanglement builds up between the state of the coffee cup and the state of the room.” I think you can understand coffee cooling quite well without any quantum stuff - the atoms in the coffee are moving faster than those in the room. There will be a tendency…

I think of the arrow of time like this. We started in an extremely exceptional state of very low entropy. The state space is very high dimensional. Therefore the entropy is much higher, pretty much everywhere we go. In this space we do a random walk. Now, the mystery that remains to be solved is: Why did we start with such an exceptional (low entropy) state?

Post by aufreak3 » Fri, Apr 18, 2014, 7:23 AM UTC

loup-vaillant wrote: post #57

cromwellian wrote: post #3

This Google Talk https://www.youtube.com/watch?v=dEaecUuEqfc uses entanglement and quantum information theory in a clear and understandable way to explain 'spooky' quantum phenomena, like the quantum eraser, de-coherence, the aspect experiment, and the measurement problem. Even if you don't know any QM, just basic algebra and calculus, it's really approachable. I used to be a fan of the Many Worlds interpretation, bu…

I must say, I'm not sure what he even means by this "zero universe" business. Sure, the classical illusion is bust, but the wave function itself, as far as we know, is real, is it not? While we're at throwing quantum explanation links, here is the Quantum Physics Sequence on Lesswrong: http://lesswrong.com/lw/r5/the_quantum_physics_sequence/ I'd say the math is even simpler there, yet the explanation go deeper. It's…

Post by Confusion » Fri, Apr 18, 2014, 9:22 AM UTC

stillsut wrote: post #139

Confusion wrote: post #85

Earlier quoted context omitted.

Whether the wave function is real depends on your answer to the question: is momentum real? You can't directly measure or observe momentum, you can't point to it in the world, but you can definitely feel its impact and it's a convenient measure for certain properties of objects. In that sense the wave function is just as real. But you can argue both those things are not as real as e.g. extension, force and energy, wh…

Can't I just weigh Galileo's cannon ball, then based on T from when I dropped it know its momentum? I think the difference comes on moving past the macroscopic world: say I drop a uranium atom into Shroedinger's box - I can't calculate at time T whether the cat is alive.

Post by loup-vaillant » Fri, Apr 18, 2014, 11:01 AM UTC

shasta wrote: post #116

loup-vaillant wrote: post #111

Earlier quoted context omitted.

You do not understand. Let me rephrase. You go on a space ship, on your way to the edges of the universe. Your buddy goes on a space ship, on his way to the other side of the universe. You will soon be outside each other's observable universe. Now, if you drop something in your ship (it spins, so you have gravity), you can "reverse time", and pull it back up. Can you do the same to you buddy's ship, should something…

> Maybe, just maybe, you could use the vanishingly small entanglement left with the other Everett Branch to directly communicate with your other self. I'm not even sure it can be done in principle. My understanding is that this would violate a physical law that we still believe to hold. You're right though, that I don't understand. At least I thought I understood your last post. With this one, I don't follow the conn…

Post by ars » Thu, Apr 24, 2014, 5:47 AM UTC

gameshot911 wrote: post #86

shasta wrote: post #83

Earlier quoted context omitted.

> The obvious answer in a classical universe is ... Since there is an obvious answer in classical physics, it's a bit disingenuous to claim that this solves a long-standing problem in classical physics, no? > With entanglement and de-coherence however, such reversal becomes impossible even in principle [...] So it does look like a better candidate for the arrow of time. That would be true if you could demonstrate by…

I'm on it. I've placed a broken egg on my table. I'll let you know the results.