Godel meets Einstein: Time Travel in Godel Universe by Yourgrau may also be of interest.
Time Travel: Probability and Impossibility
51–60 of 106 posts
Re: Time Travel: Probability and Impossibility
#52It all boils down to how the simulation was written. If we can make it crash, time travel being possible is very likely. If the parent universe is running an exploration of possible universes according to consistent laws of physics, upon crash it will probably backtrack the simulation to a previous timestamp, fiddle a little in the phase space, then continue forward. One way to make it crash is making the simulation…
That certain huh?
Re: Time Travel: Probability and Impossibility
#53It will be invented and it will become mundane like flying and having all knowledge in your pocket.
Re: Time Travel: Probability and Impossibility
#54This is like saying we will never fly a plane. Do you really think people in the 1200's could fathom a phone or the internet or access all information that ever has been on a device that fits on your phone? Its incredibly naïve to think that time travel isn't possible purely based on "laws of physics".
This is nothing like saying we will never fly a plane. Flight was always quite obviously possible, physically. Birds and other flying creatures did it all the time. Gliders existed long before powered flight, so the basics of aerodynamics were understood well ahead of powered flight.
Understanding time travel and its possibility is definitely purely based on the laws of physics. What else would it be based on?
Re: Time Travel: Probability and Impossibility
#55This is like saying we will never fly a plane. Do you really think people in the 1200's could fathom a phone or the internet or access all information that ever has been on a device that fits on your phone? Its incredibly naïve to think that time travel isn't possible purely based on "laws of physics".
Why do you you think that people in the 1200s will never be able to use the Internet? Likewise, why do you think that flying a plane will remain possible in the future or that we will have had computers in the past? Those things are all based on assuming "laws of physics."
Re: Time Travel: Probability and Impossibility
#56Earlier quoted context omitted.
You can't do on/off manipulation of entanglement. Side note: timelike entanglement is kind of funny to read about. It's a bit like describing "just leaving an atom in the same spot for a bit" as a "timelike quantum teleportation". It's applying fancy words to make the normal case sound like the strange case.
Why not? Read the particle as there/remove the particle. On/off.
You know, I've seen this discussion carried out any number of times, and the math just doesn't convince people this is impossible.
So, try this on for size: If this did work, it would be easy. It is every bit as easy as the idea sounds. Any lab set up for "quantum" experimentation could do this; entangling two things is step one in any experiment that you could call "quantum".
Yet this is not established, easy technology, with YouTube videos showing you how to set up your own FTL communication with your buddy on the other side of the planet, and off-the-shelf FTL networking equipment available for any ol' hedge fund or ISP who wants it.
This is because it's impossible.
If you're interested in why it's impossible, feel free to check out the many and abundant explanations of why it doesn't mathematically work.
But in the meantime, consider that if it hasn't been that commercialized, maybe that's because it's impossible. Because if it were just as easy as "entangle two particles and then poke one of them to send a message to the other", this would be trivial stuff. Nothing like quantum computing and its need for extreme isolation, this would just be a simple variant on stuff that really is off-the-shelf tech for quantum key distribution: https://infogalactic.com/info/Quantum_key_distribution#Quant... If FTL communication was just a matter of perturbing entangled particles, any of these existing, real-world, you-can-touch-them network setups could be turned into FTL networks with just a few small tweaks. No problem at all.
Re: Time Travel: Probability and Impossibility
#57Earlier quoted context omitted.
You can't do on/off manipulation of entanglement. Side note: timelike entanglement is kind of funny to read about. It's a bit like describing "just leaving an atom in the same spot for a bit" as a "timelike quantum teleportation". It's applying fancy words to make the normal case sound like the strange case.
Why not? Read the particle as there/remove the particle. On/off.
Both of those options have the same measurement statistics on the other side. You can't control whether the other side sees On or Off via entanglement.
Re: Time Travel: Probability and Impossibility
#58Is there any sci-fi story where time travel is possible, but the government has mandated that the only legal purpose for it is to offset the effects of time dilation from near-lightspeed voyages? Basically as you travel to your destination, you are also traveling backward in time so you can arrive at the same time you started relative to when you left, essentially making a sort of “warp drive”. To an observer on Eart…
This is a theme in Isaac Asimov's "Thiotimoline to the Stars"; in the story, starship pilots are required to travel through both space and time so as to cancel out the effects of time dilation.
Re: Time Travel: Probability and Impossibility
#59I did not see mention in the link of the problem of space. You might very well move through time, either forward or backward, but the solar system is moving through the galaxy is moving through the universe is still expanding. Therefore, maybe you moved in time, and when you’ve phased to no longer has the where you needed.
Re: Time Travel: Probability and Impossibility
#60I did not see mention in the link of the problem of space. You might very well move through time, either forward or backward, but the solar system is moving through the galaxy is moving through the universe is still expanding. Therefore, maybe you moved in time, and when you’ve phased to no longer has the where you needed.
This assumes some fixed, absolute "background" space through which the universe is moving; the idea being that you'll stay in the same position in "background" space but all of the things you care about (e.g the earth) have moved on.
Is space not relative?