It would be nice if photons from the past could be captured to take pictures of millennia ago.
Just imagine of all the plants that have absorbed photons…the memories would be corrupted…though photons do dispersed isotropically…
Time Warp: Delayed-choice quantum erasure
21–30 of 82 posts
Re: Time Warp: Delayed-choice quantum erasure
#22Earlier quoted context omitted.
If you could use a wormhole to travel 50 million light years away from earth instantly, then look back at earth with a sufficiently powerful microscope, I believe you could observe the dinosaurs.
There is this sci-fi book about this, but I forgot name/author. In the book a wormhole end can be positioned anywhere in space and time history. The tech starts as an ITER-like project and then becomes available in mainstream products, and all the dirty secrets of mankind come to light.
That is Arthur C Clark's last novel "The Light of Other Days", and it even has an Elon Musk like no ethics billionaire as one of the plot driving main characters.
Re: Time Warp: Delayed-choice quantum erasure
#23I am I crazy or do Feynman diagrams not explicitly show interactions of particles moving back in time?
Yes they do and that is the secret to the wave-particle duality manifested in the double-slit experiment. Information from future completely illuminates (pi) the paradox.
No it isn't. Please stop.
Re: Time Warp: Delayed-choice quantum erasure
#24I appreciate this article, as I agree with the author that the delayed-choice quantum eraser is a misnomer due to ignoring what we now know of quantum states. It's really frustrating learning modern quantum mechanics but then reading about the delayed-choice quantum eraser making conclusions from an older understanding. However, I still haven't seen anyone do the math about it. It shouldn't be too hard to keep track…
I don't think it has anything to do with what we know "now". It's just paying attention to the fact that the signal photon hitting the screen causes a collapse that affects the state of the idler photon. Which then explains the data via the collapsed state depending on the position of the hit, and one of the possible idler measurements being in a basis perpendicular to those variations. All quantum interpretations give the right answer for this experiment, and very few of them invoke retrocausation, therefore the experiment clearly doesn't require retrocausation.
I don't even think the delayed choice eraser is a "quantum" paradox. It involves quantum particles, but they're really just there for flair. They're not crucial. You can apply the same confusion to a classical experiment. Set up some basic correlation between A and B, with A revealed first and then a choice to reveal B or an unrelated C. Then describe the situation so badly that it sounds like choosing to measure B vs C is changing the probability distribution of A backwards in time (since if you condition on B you'll see the correlation vs A, but conditioning on C shows no correlation).
Re: Time Warp: Delayed-choice quantum erasure
#25It would be nice if photons from the past could be captured to take pictures of millennia ago.
If you could use a wormhole to travel 50 million light years away from earth instantly, then look back at earth with a sufficiently powerful microscope, I believe you could observe the dinosaurs.
You don't even need a wormhole. Light can "reflect" (ok more like slingshot) around a blackhole 25 million light years away, giving us a direct visual path to our own planet 50 millions years ago.
Of course our telescopes don't have anywhere near the resolution for this right now.
Re: Time Warp: Delayed-choice quantum erasure
#26Earlier quoted context omitted.
There is this sci-fi book about this, but I forgot name/author. In the book a wormhole end can be positioned anywhere in space and time history. The tech starts as an ITER-like project and then becomes available in mainstream products, and all the dirty secrets of mankind come to light.
That is Arthur C Clark's last novel "The Light of Other Days", and it even has an Elon Musk like no ethics billionaire as one of the plot driving main characters.
Thank you! Yes, that is the one. I actually found it on my bookshelf just now, but in searching for "that book with the wormholes" several times before I never thought to check this one. Great sci-fi story.
Re: Time Warp: Delayed-choice quantum erasure
#27I always enjoy reading about quantum optics, and the concept of entanglement is mind-blowing (I mean after all, no less than Albert Einstein went to his grave thinking we must be missing something in the theory.)
However, the quantum erasure experiments are really just a variation on other Bell Violation experiments (which also appear to violate causality at first glance.) At their heart the wave functions appear to say that particles are in multiple locations at the same time (so "touching" one particle must affect the state of the other particle instantly.) This information, though, isn't useful until all the results are brought back to one location (i.e., all the strangeness is buried in _some combination_ of the lists of results in the different locations, which can only be combined in a way that obeys causality.) Each list of results by itself looks random. So in this sense, "when" exactly you get your result won't tell you anything.
So no, you can't retake that picture you really wanted but flubbed on your last vacation.
Re: Time Warp: Delayed-choice quantum erasure
#28Earlier quoted context omitted.
If you could use a wormhole to travel 50 million light years away from earth instantly, then look back at earth with a sufficiently powerful microscope, I believe you could observe the dinosaurs.
You don't even need a wormhole. Light can "reflect" (ok more like slingshot) around a blackhole 25 million light years away, giving us a direct visual path to our own planet 50 millions years ago. Of course our telescopes don't have anywhere near the resolution for this right now.
Will they ever? Surely at some point there just wasn't enough light reflected off of dinosaurs skin to reconstruct anything more than scattered dots of light.
Re: Time Warp: Delayed-choice quantum erasure
#29Earlier quoted context omitted.
You don't even need a wormhole. Light can "reflect" (ok more like slingshot) around a blackhole 25 million light years away, giving us a direct visual path to our own planet 50 millions years ago. Of course our telescopes don't have anywhere near the resolution for this right now.
Will they ever? Surely at some point there just wasn't enough light reflected off of dinosaurs skin to reconstruct anything more than scattered dots of light.
Theoretically you'd just need an enormous telescope to collect enough light to resolve an image. Though based on the features that modern telescopes can resolve on the moon ~1 light second away, it'd probably need a telescope on the scale of a galaxy
Re: Time Warp: Delayed-choice quantum erasure
#30It would be nice if photons from the past could be captured to take pictures of millennia ago.
I'd personally appreciate it very much if photons from the future could be captured to take pictures from week and years ahead. Could be used to help with those awkward tasks like choosing the correct lottery numbers, choosing the correct stocks, choosing the horse that's definitely going to win, etc.
If you can't get photons from the future, just get a hold of some thiotimoline, a compound invented by SF master Isaac Asimov that dissolves slightly before it is added to water. After first describing it in a spoof chemistry paper, he returned to it several times, exploring its different applications and the new scientific field it created, "chronochemistry".
The best IMHO is "Thiotimoline and the Space Age" from 1960. You can read it on archive.org: https://archive.org/details/MerrilEdTheYearsBestSF05/Merril_...