[anindha]

Space and time are very macro concepts according to general relativity. It doesn't actually explain how time elapses differently on one atom vs. another atom only that it does.

I am traveling close to the speed to light how is my watching running slower? How do the atoms in my watch know to run slower?

I am not suggesting that current quantum mechanics is more than a model, but I think we are along the right path to figure out the answer to my above question.

[soVeryTired]

>I am traveling close to the speed to light how is my watching running slower? How do the atoms in my watch know to run slower?

I think in some sense this is the wrong question to ask. Your watch isn't running slower. The point is that if you're moving, you must be moving relative to something else. Their watch will appear slower to you, and your watch will appear slower to them. The counterintuitive part is that you're both correct.

The reason all this comes about is that both observers measure the speed of light as traveling at the same speed, but they can't agree on the path that the light has taken.

[anindha]

Yes, I should have been clearer. Running slower compared to a stationary observer.

Your last point doesn't explain why or how time dilation occurs, just that we know that the speed of light is a constant to all reference frames.

There is a famous experiment with three synchronized atomic clocks. Two were flown in opposite directions around the globe the other stationary. The eastward flown clock lost 59ns and the westward flown clock gained 273ns, both relative to the stationary clock. The reason is that the clock flown eastward is travelling faster since it is in the direction of the earth's rotation. Measurements are consistent with the theory of relativity.

https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experim...

[soVeryTired]

> Your last point doesn't explain why or how time dilation occurs, just that we know that the speed of light is a constant to all reference frames.

But that's what the light clock experiment [1] is all about. The two observers see the light moving at the same speed, but one observer thinks the light takes a longer path than the other observer does. If both observations are equally valid, the inevitable conclusion is time dilation.

[1] http://www.emc2-explained.info/The-Light-Clock/#.WBxO8vnLdPA

[pavel_lishin]

Isn't part of it the spacetime geometry, specifically your path through it?

It makes absolute sense for my gas tank to be lower if I take a long roundabout path from A to B while you take a short one, even though our cars have no idea about what the other one is doing.

[johncolanduoni]

Yes, general relativity is all about the "metric tensor" of space, which is just a fancy way of saying it's about assigning distances to paths. For paths you can actually physically take (i.e. movement slower than the speed of light relative to local space) this ends up corresponding to the time experienced along that path.

[anindha]

"quantum entanglement of whatever the underlying ‘atoms’ of spacetime are"

If we use this idea there are some space-time atoms, to explain entanglement. That same concept could explain space-time itself better.

It is similar to how Einstein used anomalies in the application of Newtonian physics to light to postulate a more accurate model. Explaining entanglement might be the gateway to explaining space-time more accurately.

[johncolanduoni]

That's not what they're doing at all though... they're looking to use entanglement to explain space time, not use space time to explain entanglement.

[johncolanduoni]

The ideas here lean heavily on entanglement, which is very macro (not to mention unexplained) itself. So I don't see a path forward as far as figuring out how pieces of the system "know" to do what they do via the it from qubit program.