Consequences/applications of "negative time evidence" article in the news, like time-loop computers breaking most of current ciphers?

[Jarek]

Maybe let's discuss consequences/applications of this "negative time evidence" experiment: https://arxiv.org/pdf/2409.03680 currently in the news (e.g. Evidence of ‘Negative Time’ Found in Quantum Physics Experiment ) - clearly observing response before the impulse (diagram below).

Since 2009 I am expecting this kind of effects ( https://arxiv.org/pdf/0910.2724 ) using observation that absorption and stimulated emission equations seem CPT analogs , hence should have opposite signs of time delay - what seems also used in this "negative time evidence" experiment.

If so, we would need ~300 000 km delay line to send information back by 1 second, and laser beam able to survive such distance - what will need satellite networks, much more practical would be ~microsecond time delays (300m delay line for microsecond).

Microsecond negative time is sufficient to build time-loop computer: sending its output back to its input, what would already allow to solve NP problems, e.g. breaking most of current cryptography ...

What other consequences could you see?

 

[hitmouse]

Interesting, but… not yet peer-reviewed etc.

 

[Dave]

For any practical uses wouldn't you need to factor in the time taken to deliver the result to somewhere else. Electricity travels at around 90% of the speed of light, so fast, but not instantaneous, and possibly a significant drag?

 

[Jarek]

Team of one of the best experimentalists ( Aephraim M. Steinberg - Wikipedia Aephraim Steinberg ) clearly gets system response before the impulse - peer review will not change it.
I suspect many teams are now trying to recreate it, simplify for more practical realizations, e.g. https://arxiv.org/pdf/2409.15399

As this is SF forum, maybe instead of waiting for everybody already using it, let's discuss the consequences to prepare ...
Just think about SF story that let say in 2024 some famous experimentalist gets system response before the impulse, starting technology for sending information back in time - how would such SF story evolve? ;-)

E.g. a quote from https://arxiv.org/pdf/0910.2724 : "Finally, being able to send information back for macroscopic time differences (e.g. using systems of satellites for delay lines), could allow to prevent currently unpredictable unwanted events: there would be attempt to send back such missing information - creating inconstancy, hence action optimization should modify the weakest links of such reason-result chain (e.g. in quantum measurement level) to get self-consistent time loop (Novikov self-consistency principle ) -for example with satisfying outcome: not requiring to use such channel. In other words, just having access to such channel, we would enforce physics to make its best to prevent our bad choices, optimize randomness for outcomes preferred by us - like mentioned creation of contradictory NOT time loop for non-satisfying outcomes (easier to optimize if leaving freedom by making choices based on good HRNG). While there would be many dangers on the way, if well balancing strengths of such channels worldwide (between players of different/opposite goals), it might lead to a much more harmonic world based on trust and common goals, potentially without crime and various types of gambling (economy based on objective values), with choices made optimizing their actual future consequences - maybe also avoiding wars, suboptimal politicians, dangers of new technologies, etc."

 

[CupofJoe]

This feels like that time where people at CERN discovered particles that moved faster than light.

 

[Jarek]

This is completely different - that was extending by a fraction of percentage, forbidden by special relativity ( 2011 OPERA faster-than-light neutrino anomaly - Wikipedia )

Here we are talking about CPT symmetry required by physics: CPT symmetry - Wikipedia
"The CPT theorem says that CPT symmetry holds for all physical phenomena"
It says that if some process is possible, also its CPT analog is, for example
"laser causes excitation" <-CPT-> "laser causes deexciation"
both such causalities are used e.g. in STED microscopy ( STED microscopy - Wikipedia ).

T is time reversal, hence if causality of one is later, of the second has to be earlier ... exactly as observed in this "negative time evidence" - not by a fraction, but nearly symmetric time dependence (plots at the top).

Anyway, once again, as this is SF forum, maybe let's discuss the consequences as e.g. just a thought exercise, SF story discussion ...
Just think about SF story that let say in 2024 some famous experimentalist gets system response before the impulse, starting technology for sending information back in time - how would such SF story evolve?

 

[Tremendinah Rectiferus X]

This is completely different - that was extending by a fraction of percentage, forbidden by special relativity ( 2011 OPERA faster-than-light neutrino anomaly - Wikipedia )

Here we are talking about CPT symmetry required by physics: CPT symmetry - Wikipedia
"The CPT theorem says that CPT symmetry holds for all physical phenomena"
It says that if some process is possible, also its CPT analog is, for example
"laser causes excitation" <-CPT-> "laser causes deexciation"
both such causalities are used e.g. in STED microscopy ( STED microscopy - Wikipedia ).

T is time reversal, hence if causality of one is later, of the second has to be earlier ... exactly as observed in this "negative time evidence" - not by a fraction, but nearly symmetric time dependence (plots at the top).

Anyway, once again, as this is SF forum, maybe let's discuss the consequences as e.g. just a thought exercise, SF story discussion ...
Just think about SF story that let say in 2024 some famous experimentalist gets system response before the impulse, starting technology for sending information back in time - how would such SF story evolve?

I already have that story flashed out. It's called Intergalactic Calamity. It evolves along the usual trope lines of mad scientist via Intergalactic Council towards the inevitable happy ending post personal transformation.

 

[Venusian Broon]

This is, I believe, to do with group velocities of a photon and how the various frequencies that make up the photon interact with certain materials. A photon is a group of differently frequency light waves, peaking at one particular frequency. We normally detect this peak as being 'the photon'.

Basically what is happening in this experiment is that the material that the photon is travelling through amplifies the first part of the photon package but suppresses the second part. Therefore to an observer looking at the experimental set up can see the new frequency peak appear before the old frequency peak has completely gone through, making it look like the photon has 'jumped' ahead in an instant (hence the 'negative time' I suppose.)

But it's nothing to do with making time go backwards, changing causality or anything like that. It's just a consequence of EM waves interacting with a material. The photon has just been heavily manipulated by the material. I believe it's been observed before as well.

It does have a practical use as, understanding how this works well can be used to correct certain distortions in transmitting light in fibreoptic cables, making them more efficient in signalling, I guess.

 

[Swank]

could allow to prevent currently unpredictable unwanted events:

Did this fine piece of English actually come from a scientist?

 

[Swank]

This sounds like another effect of "what if we could break one law a little bit", like Alcubierre drives - all that's needed is "negative mass". Whatever the hell that is.

As to a story where information travels backwards - that's kind of the death of consequence. And what is a story other than consequence? The First Fifteen Lives of Harry August demonstrates how a network of negative time information loops would allow information to travel back in major blocks. But that's with people, not devices that don't insert choice.

 

[Jarek]

CPT symmetry says that if there is something, then its CPT analog is also possible - if there is causation forward in time, there needs to exist also backward.
So we are not talking about breaking any law, but accepting CPT symmetry of physics ( CPT symmetry - Wikipedia ).

It needs symmetric formulations: the least action principle, Feynman ensembles ... which need eternalism/Einstein's block universe philosophy of time: Eternalism (philosophy of time) - Wikipedia - in which we travel through some already found 4D solution.

Time-loops are possible, but they have to be self-consistent: Novikov self-consistency principle - Wikipedia
Time-loop computer would prepare situation that physics making time-loop self-consistent, would solve the given problem like cipher breaking ... all of them are already solved in the 4D solution we travel through.

 

[mosaix]

As @hitmouse says, not peer reviewed. Let's wait.

 

[Jarek]

Are you saying SF people have to wait for arrival of new technology before discussing/trying to understand its consequences, warning about dangers?

 

[Tremendinah Rectiferus X]

Are you saying SF people have to wait for arrival of new technology before discussing/trying to understand its consequences, warning about dangers?

Actually I did wonder about who expects Science Fiction to have scientifically accurate and workable aparatuses? I mean I know people like to quibble about how something could or couldn't possibly work but does anyone really enjoy reading fiction for the reliable factual information?

 

[hitmouse]

Are you saying SF people have to wait for arrival of new technology before discussing/trying to understand its consequences, warning about dangers?

No of course not. As long as we are clear that your speculation sits in roughly the same class as teleportation, lightsabers, the force, hyperdrives, triffids and time machines, then there is absolutely nothing to stop sf-style speculation. It is one of the things we do here.

 

[Jarek]

In the past SF people were inspiring many technologies - not accurately, but suggesting possibilities, discussing their consequences and dangers.
But indeed looks like the level has dropped - seems now it is mostly variations on old ideas ... famous experimentalist gets response before impulse - but SF people will not think about consequences before peer-review ...

Here is a much more powerful strongly related possibility with many peer-reviewed papers: non-orientable wormhole e.g. inverting time inside a rocket going through - great thought experiment, also allowing to send information back in time ... and missing SF stories: Google Scholar

 

[mosaix]

But this is posted in the Science and Nature forum not a writing forum, inviting comment on a non-fiction rather than fiction basis.

 

[Jarek]

Based on experimental observation of response before impulse by famous experimentalist ... consequence of CPT symmetry of physics.

 

[Christine Wheelwright]

Feedback loops, where a function of the current output is used as a factor in the input, are common in control technologies (eg proportional, integral, differential PID controllers). This can be a powerful technique when tuned well, but extremely unstable when not. I'm trying to imagine what would result if the output were time shifted backwards before being introduced as a factor in the input. I think stability would be impossible, and I'm not sure the machine would be able to perform any useful function.

 

[Dave]

Of course this is a subject that may be discussed on an SFF Forum, however not only is this in our Science and Nature subforum rather than say, the SF Lounge, but it isn't the first time you have mentioned it here: Discussion: approaches and thought experiment - consequences of being able to send information back in time?

So I'm sorry, but I don't think it is unreasonable that from the content of your fifteen posts here, that some members of the forum might get the impression that you were fixated on this particular subject, rather than on the greater range of SF-style speculations that we do regularly discuss here.

In addition, being able to send information back in time is not such a novel idea in science fiction stories - I can quickly think of the film Frequency (2000) and the Gregory Benford novel Timescape which both involve interpretation of messages from the future to change the course of the future. It is a sub-genre of Time Travel stories.

You also didn't answer my question, which I may not have made clear. I wasn't even making any point about whether this breakthrough was proven or not, but that the observations are not synchronous with the effect. In order to act upon the observation of the effect there must be a time lag which is likely to be longer than the time between the response and impulse themselves. It matters not how many thousands of times the delay is repeated to create a much longer delay, because the observational delay will also be increased on each occasion too.