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Time Warp: Delayed-choice quantum erasure

drgblackwell.substack.com

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Re: Time Warp: Delayed-choice quantum erasure

#41

Post by gpderetta »

bsenftner wrote: post #22
rapnie wrote: post #14

Earlier 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.

Asimov has written a somewhat similar novel called "The Dead Past". In fact from the description I thought parent was referring to this story.

Re: Time Warp: Delayed-choice quantum erasure

#43

Post by Filligree »

ziofill wrote: post #40

Quantum physicist here. My PhD back in the day was about the entanglement between downconverted photons. I've thought about this more than I like to admit. While I appreciate the blog post, it seems a bit disingenuous. I hope everyone understand that if you take two entangled photons A and B and detect A before B, then the outcome of the measurement of B must depend on the outcome of the earlier measurement of A, bec…

> I hope everyone understand that if you take two entangled photons A and B and detect A before B, then the outcome of the measurement of B must depend on the outcome of the earlier measurement of A, because measuring A causes the collapse of the joint state and determines the wavefunction of B undergoing the later measurement.

This bakes in an assumption that collapse happens, which I don't believe everyone agrees with...

Re: Time Warp: Delayed-choice quantum erasure

#44

Post by wasabi991011 »

EGreg wrote: post #35

I literally posted about this topic a few days ago! But for some reason it was flagged as a “Dupe” and buried by someone: https://news.ycombinator.com/item?id=43173195 It links here: https://chatgpt.com/share/67bde29f-a56c-800a-8e26-44a5a3ad23... I will summarize by saying that I think our current understanding of Faster-than-Light communication is wrong, and the no-go theorem about no information transmission faster…

I'm sorry but the chat format is a really poor way to share ideas.

It's long, meandering, and contains many instances of wrong and not-even-wrong assertions by you (expected, you don't claim to be an expert, but hurts your credibility) and by chatGPT (expected, hallucinations, but makes it impossible to believe any assertion without already knowing what makes sense).

If you believe you came up with something worth sharing, please take the 30 minutes to edit it into something coherent.

I tried to understand as much as I could from the conversation, but there was some much where I had to pause and consider if it makes sense or not that it's almost as much effort as if I had to come up with the idea myself in the first place, and that's too much effort for someone else's idea.

I'm sorry for the negativity, but I believe I am giving constructive criticism. You're clearly very curious and creative, but that's sadly not enough.

Re: Time Warp: Delayed-choice quantum erasure

#45

Post by xenadu02 »

AnotherGoodName wrote: post #33
LPisGood wrote: post #18

I am I crazy or do Feynman diagrams not explicitly show interactions of particles moving back in time?

They do. In fact i always thought this was the answer to the matter/antimatter imbalance. Feynmann diagrams literally show anti matter as the same particle as a matter particle, just travelling back in time (see election/positron interactions). So what happens when matter and antimatter are created in a big boom? Well the antimatter is in the past, we're here in the future.

Not sure how we could ever prove something like that but it's certainly an amusing and symmetrical view of the universe: big bangs create two universes, moving in opposite time directions from each other. Each seeing the other's particles as anti-particles.

Thinking about it though: photos are their own antiparticle. So I'd expect to see a lot more cosmic microwave background than we should because at least in the early days the antimatter universe would have been visible to us?

Side note: how can photos be their own antiparticle? Same reason they move at the speed of causality. They have no mass thus do not experience the flow of time themselves. So they do not annihilate with themselves. From a photon's POV a trip across the universe is instant.

Re: Time Warp: Delayed-choice quantum erasure

#46

Post by emaro »

EGreg wrote: post #35

I literally posted about this topic a few days ago! But for some reason it was flagged as a “Dupe” and buried by someone: https://news.ycombinator.com/item?id=43173195 It links here: https://chatgpt.com/share/67bde29f-a56c-800a-8e26-44a5a3ad23... I will summarize by saying that I think our current understanding of Faster-than-Light communication is wrong, and the no-go theorem about no information transmission faster…

Ah yes, ChatGPT, the tool famous for it's rigor and accuracy which can never be brought to agree with something untrue, no matter how hard you try. /s

Honestly, I think this is a horrible format to share ideas. It's a scratch pad with very elaborate but not necessarily true explanations why your ideas could be true. Either submit your ideas directly, so it's easier to point out mental leaps/errors and visible how hard you thought about it or do the fact-checking yourself and publish a blog post with sources.

Edit: 100% agree with wasabis reply and they criticized more constructive so take my comment with a grain of salt.

Re: Time Warp: Delayed-choice quantum erasure

#47

Post by wizzwizz4 »

xenadu02 wrote: post #45
AnotherGoodName wrote: post #33

Earlier quoted context omitted.

They do. In fact i always thought this was the answer to the matter/antimatter imbalance. Feynmann diagrams literally show anti matter as the same particle as a matter particle, just travelling back in time (see election/positron interactions). So what happens when matter and antimatter are created in a big boom? Well the antimatter is in the past, we're here in the future.

Not sure how we could ever prove something like that but it's certainly an amusing and symmetrical view of the universe: big bangs create two universes, moving in opposite time directions from each other. Each seeing the other's particles as anti-particles. Thinking about it though: photos are their own antiparticle. So I'd expect to see a lot more cosmic microwave background than we should because at least in the ea…

In the early days, the universe was opaque.

Re: Time Warp: Delayed-choice quantum erasure

#48

Post by wizzwizz4 »

itishappy wrote: post #39
thrance wrote: post #28

Earlier quoted context omitted.

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.

Scattered dots of light can tell us a lot! If you find a photon of a frequency that's only produced by, say, a CO2 molecule, you can prove that CO2 existed 50 million years ago. Ok wow, probably not too useful. Collect a bunch of photons, count how many indicate CO2 and how many indicate O2, and you can figure out the composition of Earth's atmosphere. All of this using single photon detections!

This would be a very expensive way to get a very noisy copy of data that we can more easily extract from the geological record.

In other words: it's awesome, and we should totally do it.

Re: Time Warp: Delayed-choice quantum erasure

#49

Post by gitfan86 »

FollowingTheDao wrote: post #38

No, and Yes, because there is no "back in time", nor "forward in time". Time is just a useful illusion we create to navigate space. This idea is set up on a false premise. But I was extremely happy to read; "There’s no such thing as wave-particle duality" "Light only ever travels as a wave". Everything is only fundamentally a wave. Please take a look at "The end of time : the next revolution in physics" by Julian Bar…

This seems like the most likely answer to the Fermi paradox. Our assumptions about time and space are wrong.

If we understood them we wouldn't be looking this way

Re: Time Warp: Delayed-choice quantum erasure

#50

Post by wnmurphy »

Our understanding of the world is overfit to the macro level, where we project concepts onto experience to create the illusion of discrete objects, which is evolutionally beneficial.

However, at the quantum level, identity is not bound to space or time. When you split a photon into an entangled pair, those "two" photons are still identical. It's a bit like slicing a flatworm into two parts, which then yields (we think) two separate new flatworms... but they're actually still the same flatworm.

Experiments like this are surprising precisely because they break our assumption that identity is bound to a discrete object, which is located at a single space, at a single time.

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