3 hours ago
(This post was last modified: 3 hours ago by C C.)
The Seth Lloyd paper they mention isn't actually recent. It dates back to 2011. Quantum entanglement as a "test" is brought up eventually in the Neil deGrasse Tyson video at bottom.
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Physicists say it's possible to send messages backward in time
https://www.popularmechanics.com/science...d-in-time/
EXCERPT: Time loops may provide a mechanism for sending messages into the past like Cooper did in Interstellar. General relativity allows for a closed timelike curve (CTC), which occurs when an object’s trajectory through spacetime takes it to the future and then back to the past.
Another possible mechanism is quantum entanglement: If Cooper and Murph were quantum-entangled, they could share information backward through time. Particles that are quantum-entangled are always sensitive to each other’s state, so even if one gets catapulted through space so far and so fast that it ends up in the future, it’s still transmitting information to the one left behind in the past.
In fact, some physicists have suggested that the hypersensitivity between entangled particles actually comes from the one in the future sending messages back in time. Recently, Seth Lloyd and fellow researchers at the Massachusetts Institute of Technology wanted to make this very science fiction-seeming concept into a reality. While bending spacetime to build an actual CTC would require an almost unfathomable amount of energy, Lloyd had previously succeeded in using photons that were quantum entangled to simulate a CTC by sending one of them a few nanoseconds back in time. Now, inspired by Interstellar, they wanted to see if sending messages backwards was an option, too.
Though it may sound counterintuitive, the researchers discovered that for a CTC-like channel that’s full of noise—like the quantum mechanical version of phone static—it was actually easier to transmit a message to the past than to the future.
“Access to a noiseless CTC of one kind or the other has been shown to unleash stunning information-processing power,” they said in a study recently published in Physical Review Letters, adding that a CTC-like channel “[can be] represented by a quantum channel, in the sense that information traveling through the noisy [channel] effectively evolves as if passing through the channel, except for ending up in the past.”
Messages traveling through a noiseless CTC channel are being teleported to the past so long as no other actions are necessary to complete message transmission. It is because the channel is noiseless that the past and future versions of the time loop are the same. But in a noisy time loop, a message from the future is sent to the past through a channel whose noise affects its journey. The researchers see the communication channel between Cooper and his daughter as “some noisy mechanism” that defies the usual passage of time from the past to the future. What’s really surprising is that this is more efficient than using a channel that’s just as noisy to communicate forward in time... (MORE - missing details)
Star Talk Plus: "Does the future exist?" ... https://youtu.be/sdABj-mKNo8
https://www.youtube-nocookie.com/embed/sdABj-mKNo8
- - - - - - - - - - -
Physicists say it's possible to send messages backward in time
https://www.popularmechanics.com/science...d-in-time/
EXCERPT: Time loops may provide a mechanism for sending messages into the past like Cooper did in Interstellar. General relativity allows for a closed timelike curve (CTC), which occurs when an object’s trajectory through spacetime takes it to the future and then back to the past.
Another possible mechanism is quantum entanglement: If Cooper and Murph were quantum-entangled, they could share information backward through time. Particles that are quantum-entangled are always sensitive to each other’s state, so even if one gets catapulted through space so far and so fast that it ends up in the future, it’s still transmitting information to the one left behind in the past.
In fact, some physicists have suggested that the hypersensitivity between entangled particles actually comes from the one in the future sending messages back in time. Recently, Seth Lloyd and fellow researchers at the Massachusetts Institute of Technology wanted to make this very science fiction-seeming concept into a reality. While bending spacetime to build an actual CTC would require an almost unfathomable amount of energy, Lloyd had previously succeeded in using photons that were quantum entangled to simulate a CTC by sending one of them a few nanoseconds back in time. Now, inspired by Interstellar, they wanted to see if sending messages backwards was an option, too.
Though it may sound counterintuitive, the researchers discovered that for a CTC-like channel that’s full of noise—like the quantum mechanical version of phone static—it was actually easier to transmit a message to the past than to the future.
“Access to a noiseless CTC of one kind or the other has been shown to unleash stunning information-processing power,” they said in a study recently published in Physical Review Letters, adding that a CTC-like channel “[can be] represented by a quantum channel, in the sense that information traveling through the noisy [channel] effectively evolves as if passing through the channel, except for ending up in the past.”
Messages traveling through a noiseless CTC channel are being teleported to the past so long as no other actions are necessary to complete message transmission. It is because the channel is noiseless that the past and future versions of the time loop are the same. But in a noisy time loop, a message from the future is sent to the past through a channel whose noise affects its journey. The researchers see the communication channel between Cooper and his daughter as “some noisy mechanism” that defies the usual passage of time from the past to the future. What’s really surprising is that this is more efficient than using a channel that’s just as noisy to communicate forward in time... (MORE - missing details)
Star Talk Plus: "Does the future exist?" ... https://youtu.be/sdABj-mKNo8
