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Gödel's solution to Einstein's field equations (2021)

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Re: Gödel's solution to Einstein's field equations (2021)

#31

Post by Jaygles »

jiggawatts wrote: post #26
superposeur wrote: post #4

Earlier quoted context omitted.

Yes, which is why sci fi scenarios in which ships whiz between star systems will never, ever, ever happen.

I’ve never quite understood why this is so certain. If I instantly teleported to Alpha Centauri, that wouldn’t put me in the future. Sure, if I turned a telescope back towards our system and watched Earth, I would see myself wandering around as I was four years ago and then… after four years… I could watch myself step into a teleporter. This is entirely consistent and in no shape, way, or form would this let me get s…

True teleportation would not hit the same limits. The idea is, in conventional travel, your velocity has a time and space component that are hard linked, the faster you are traveling through space, the slower you are traveling through time. The speed of light is the maximum speed you can travel through space, because you've run out of the time component you must take away from to get a larger spatial component. An object that has a spatial speed greater than the speed of light must have a negative time component, aka traveling into the past, which under current understanding isn't possible.

Re: Gödel's solution to Einstein's field equations (2021)

#32

Post by User23 »

shsbdncudx wrote: post #28
daxfohl wrote: post #5

So to solve physics, you don't just have to be smarter and more creative than Einstein, but than Einstein and Godel combined.

You don’t have to be smarter than them, no. Standing on the shoulders of giants etc.

Indeed, in fact indirect evidence suggests that Sir Isaac, the source of that quote, probably had more intellectual horsepower than anyone until von Neumann.

Re: Gödel's solution to Einstein's field equations (2021)

#33

Post by gnad_sucks »

mr_mitm wrote: post #30
jiggawatts wrote: post #26

Earlier quoted context omitted.

I’ve never quite understood why this is so certain. If I instantly teleported to Alpha Centauri, that wouldn’t put me in the future. Sure, if I turned a telescope back towards our system and watched Earth, I would see myself wandering around as I was four years ago and then… after four years… I could watch myself step into a teleporter. This is entirely consistent and in no shape, way, or form would this let me get s…

If you "instantly" teleported to alpha centauri, then there would be a frame of reference in which you arrive before you left. To another observer, you would travel back in time. It's not something you can disagree on. Instead, convince yourself by studying the spacetime diagram: http://www.physicsmatt.com/blog/2016/8/25/why-ftl-implies-ti... Note that "instantly" is ill-defined in SR. Simultaneity of events is obser…

Studying a spacetime diagram is hard work. It's a lot easier to just say "I never understood why it's so certain" and leave it at that.

Re: Gödel's solution to Einstein's field equations (2021)

#34

Post by avmich »

jiggawatts wrote: post #26
superposeur wrote: post #4

Earlier quoted context omitted.

Yes, which is why sci fi scenarios in which ships whiz between star systems will never, ever, ever happen.

I’ve never quite understood why this is so certain. If I instantly teleported to Alpha Centauri, that wouldn’t put me in the future. Sure, if I turned a telescope back towards our system and watched Earth, I would see myself wandering around as I was four years ago and then… after four years… I could watch myself step into a teleporter. This is entirely consistent and in no shape, way, or form would this let me get s…

> If I instantly teleported to Alpha Centauri, that wouldn’t put me in the future.

If the teleport is using a wormhole - a device which connect two points in space - we can consider this.

We have experimental confirmation of time dilation, if we have an accelerated motion. In other words, let's make the wormhole entry on Earth move for some time so that its time is behind, say, by 10 years from the Alpha Centauri.

Then, if you instantly teleport to Alpha Centauri by stepping from Earth into the wormhole, the time at Alpha Centauri is 10 years before. You may use, say, 7 years to fly back to Earth through "ordinary" space, with sub-light speed, and you'll arrive to Earth 3 years before you left.

Re: Gödel's solution to Einstein's field equations (2021)

#36

Post by jiggawatts »

shsbdncudx wrote: post #27
jiggawatts wrote: post #26

Earlier quoted context omitted.

I’ve never quite understood why this is so certain. If I instantly teleported to Alpha Centauri, that wouldn’t put me in the future. Sure, if I turned a telescope back towards our system and watched Earth, I would see myself wandering around as I was four years ago and then… after four years… I could watch myself step into a teleporter. This is entirely consistent and in no shape, way, or form would this let me get s…

You could do something on Alpha Centauri, instantly teleport back, and then make a bet on what’s going to be observed in 4 years time.

You'd be seeing Earth's past at Alpha Centauri. You have only the information you take with you through the wormhole (the present), and information that has been travelling through space for 4 years (the past). You have no information from the future, and I've never seen a convincing argument as to how it would be possible to cheat this via instant travel.

Re: Gödel's solution to Einstein's field equations (2021)

#37

Post by jiggawatts »

mr_mitm wrote: post #30
jiggawatts wrote: post #26

Earlier quoted context omitted.

I’ve never quite understood why this is so certain. If I instantly teleported to Alpha Centauri, that wouldn’t put me in the future. Sure, if I turned a telescope back towards our system and watched Earth, I would see myself wandering around as I was four years ago and then… after four years… I could watch myself step into a teleporter. This is entirely consistent and in no shape, way, or form would this let me get s…

If you "instantly" teleported to alpha centauri, then there would be a frame of reference in which you arrive before you left. To another observer, you would travel back in time. It's not something you can disagree on. Instead, convince yourself by studying the spacetime diagram: http://www.physicsmatt.com/blog/2016/8/25/why-ftl-implies-ti... Note that "instantly" is ill-defined in SR. Simultaneity of events is obser…

> there would be a frame of reference in which you arrive before you left

There would be a frame of reference in which you appear to arrive before you left.

The analogy is with a sonic boom, where an observer using only sound for sensing the world would hear the plane arriving before it left.

This does not allow closed timelike loops, the type that would allow you to predict the stockmarket.

The observers can't create paradoxes through via a third observer with a high celerity in the same way that QM "action at a distance" doesn't allow causality violations either, or how moving a laser pointer across the surface of the moon doesn't allow FTL motion either.

It just looks like it does, that doesn't mean that it actually does.

PS: I'm fully aware that in the SR/GR model, appearance is reality, and hence the paradox within the framework of relativity. Clearly, if FTL were allowed, then relativity would be falsified by that, and a new framework would be required. I'm saying that that framework could be consistent, allowing FTL and relativity without allowing travel backwards in time.

Re: Gödel's solution to Einstein's field equations (2021)

#38

Post by wiml »

__Joker wrote: post #7
n4r9 wrote: post #6

Earlier quoted context omitted.

Also, any kind of instantaneous communication. Unless the theory of relativity is superseded by something quite radically different.

High school educated talking here. Does Quantum Entanglement have any promise for instantaneous communication (theoretically) ?

It probably doesn't, but if it does, it could be used to send messages back in time. Relativity doesn't care how something goes FTL, it's just really clear there's no room for "FTL but not time travel" unless you introduce some odd and unphysical-seeming extra restrictions on the universe.

Re: Gödel's solution to Einstein's field equations (2021)

#39

Post by consilient »

phkahler wrote: post #24
BoiledCabbage wrote: post #22

Earlier quoted context omitted.

For someone who is trying to learn the basics of quantum entanglement, the distinction between local and non-local hidden variables isn't take that essential. Or make those "hiddens" in the code above globals. Problem solved.

Non-locality seems to be the least favorable way to resolve the Bell inequalities as far as most physicists are concerned. I'm not sure why though. I think they like exotic and unintuitive sounding stuff.

> I think they like exotic and unintuitive sounding stuff.

Exactly the opposite, nonlocality is by far the most exotic resolution here. It means losing existence and uniqueness of solutions to differential equations - i.e., causation.

Re: Gödel's solution to Einstein's field equations (2021)

#40

Post by NoThisIsMe »

consilient wrote: post #39
phkahler wrote: post #24

Earlier quoted context omitted.

Non-locality seems to be the least favorable way to resolve the Bell inequalities as far as most physicists are concerned. I'm not sure why though. I think they like exotic and unintuitive sounding stuff.

> I think they like exotic and unintuitive sounding stuff. Exactly the opposite, nonlocality is by far the most exotic resolution here. It means losing existence and uniqueness of solutions to differential equations - i.e., causation.

Could you expand on this, or provide a source? I don't see how physics could yield a pure math result like that.
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