11–20 of 70 posts
I simulate backward time travel all the time It's called my imagination...
Yah but have you set up a set of statically significant entangled bosons in a Hau array and then coupled those to your cerebral cortex to be able to meaningfully act upon the knowledge gained by said imagination?…
The letter discusses a theoretical framework to understand certain quantum phenomena, which includes simulating hypothetical constructs known as Closed Timelike Curves (CTCs). CTCs in the realm of general relativity are paths through spacetime that, if they could exist, would allow for time loops and, in that sense, "time travel." However, in this letter, CTCs are not being used to propose actual time travel, but are…
I’m always curious what in quantum mechanics is considered “canon” vs purely hypothetical ideas.
I suppose the actual paper is describing retrocausality and not time travel but maybe I'm perceiving that wrong?
Time Crystal: https://en.wikipedia.org/wiki/Time_crystal
/q discrete time crystal "retrocausality" https://www.google.com/search?q=discrete+time+crystal+%22ret...
Delayed choice quantum eraser: https://en.wikipedia.org/wiki/Delayed-choice_quantum_eraser
From https://news.ycombinator.com/item?id=28402527 :
> one must perform electrodynamic engineering in the time domain, not in the 3-space EM energy density domain.
And from https://news.ycombinator.com/item?id=35877402#35886041 :
> Physical observation (via the transverse photon interaction) is the process given by applying the operator ∂/∂t to (L^3)t, yielding an L3 output
... > FWIU electrons are most appropriately modeled with Minkowski 4-space in the time-domain; (L^3)t
Retrocausality > Physics: https://en.wikipedia.org/wiki/Retrocausality#Physics
Paper: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.13... > We construct a metrology experiment in which the metrologist can sometimes amend the input state by simulating a closed timelike curve, a worldline that travels backward in time. The existence of closed timelike curves is hypothetical. Nevertheless, they can be simulated probabilistically by quantum-teleportation circuits. We leverage such simul…
There is a nice explanation at the end of the letter: “While PCTC simulations do not allow you to go back and alter your past, they do allow you to create a better tomorrow by fixing yesterday’s problems today.”
Something I wonder is where is the line in quantum physics where there is no experimental evidence? Obviously things like wave-particle duality have been rigorously experimentally proven, but you hear things about quantum fields, virtual particles, quantum gravity, and others and to a layperson like my self it seems like there is much less — maybe even no — experimental evidence for some of these theories. I’m always…
Yes. And no.
Paper: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.13... > We construct a metrology experiment in which the metrologist can sometimes amend the input state by simulating a closed timelike curve, a worldline that travels backward in time. The existence of closed timelike curves is hypothetical. Nevertheless, they can be simulated probabilistically by quantum-teleportation circuits. We leverage such simul…
"Gedankenexperiment" sounds an awful lot like "thought experiment".
Layperson's read but the paper seems to say "this is weird we were accurate than should be possible" combined with "causal order wouldn't make sense here" Much less "we found time travel" and more "that was weird maybe it was time travel". Also note that to my knowledge there is no form of talking about entanglement that involves time before entanglement or any meaningful manipulation of the entangled particle. Thus…
PBS Space Time did an episode that posed the question as a delayed choice quantum eraser experiment where the “long” leg is farther away, like on the moon, and we somehow reflect a particle back and forth to delay the observation indefinitely. I also wonder if they can do something like this at CERN.
Their conclusion was, it would be possible theoretically, but you wouldn’t be able to read the result.
The sci-fi enjoyer part of me likes to believe CERN is a big delayed choice quantum eraser experiment used to receive messages from the future.
Layperson's read but the paper seems to say "this is weird we were accurate than should be possible" combined with "causal order wouldn't make sense here" Much less "we found time travel" and more "that was weird maybe it was time travel". Also note that to my knowledge there is no form of talking about entanglement that involves time before entanglement or any meaningful manipulation of the entangled particle. Thus…
> unlikely to make a meaningful difference at distances measured less than how far light travels in that time PBS Space Time did an episode that posed the question as a delayed choice quantum eraser experiment where the “long” leg is farther away, like on the moon, and we somehow reflect a particle back and forth to delay the observation indefinitely. I also wonder if they can do something like this at CERN. Their co…