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Can a Human See a Single Photon? (1996)

math.ucr.edu

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Re: Can a Human See a Single Photon? (1996)

#51

Post by phailhaus »

mensetmanusman wrote: post #38
lebubule wrote: post #15

Recent experiments have put the claim to test Overview https://www.nature.com/articles/nature.2016.20282 The actual work https://www.nature.com/articles/ncomms12172 > Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance.

Would be fun to see if it’s possible to set up the experiment as a double slit. Would humans sense an interference pattern? Is the back of an eye a sufficient observer? :)

Yep! Any interaction counts. If something interacts with a photon, and that interaction can only happen if it goes through one of the two slits (i.e., it tells you "which way" the photon went), then the interference pattern will disappear.

Re: Can a Human See a Single Photon? (1996)

#52

Post by jiveturkey »

danbruc wrote: post #34

On a related note, you can hear sounds that displace your eardrums on the order of an atomic diameter. At least that is something I heard years ago, a quick search turned up this StackExchange question [1] so there may be some truth to this, I did however not read the answers too carefully. They actually seems to suggest that the threshold is even quite a bit smaller which makes me somewhat cautious of the claim, but…

> something I heard

Re: Can a Human See a Single Photon? (1996)

#53

Post by danbruc »

jiveturkey wrote: post #52
danbruc wrote: post #34

On a related note, you can hear sounds that displace your eardrums on the order of an atomic diameter. At least that is something I heard years ago, a quick search turned up this StackExchange question [1] so there may be some truth to this, I did however not read the answers too carefully. They actually seems to suggest that the threshold is even quite a bit smaller which makes me somewhat cautious of the claim, but…

> something I heard

Pun not intended but noticed while typing.

Re: Can a Human See a Single Photon? (1996)

#54

Post by mlindner »

jonplackett wrote: post #23
pavlov wrote: post #9

Earlier quoted context omitted.

Maybe seeing in the dark is simply so valuable that evolution has created extremely light-sensitive eyes for many species? If there was a molecule whose detection in tiny amounts would give a species a competitive edge, we might have noses capable of detecting 5-molecule amounts of this substance.

Weird that humans can do this when our eyes aren’t even that great at night vision compared to a lot of other animals.

Unless there's something else involved, most other animals that have good night vision is simply because they have bigger eyes that collect more photons. A single photon test would be the same with those animals eyes versus our own. I think the bigger determining factor is visual acuity as that corresponds to how easy it is to activate a photo receptor area which is easier to do the smaller those areas are.

Re: Can a Human See a Single Photon? (1996)

#55

Post by mlindner »

LastTrain wrote: post #45
vjulian wrote: post #40

Genuine question: I’ve never taken LSD, but could some of its purported visual effects be explained as seeing photons via a depressed neurological filter?

It is too bad the risks (criminal) are so high, LSD is an interesting enough experience that is worth trying at least once.

As someone who's never taken LSD and have talked to people who have, the number of times people express irreversible changes in how they think about things just from trying things once makes me think that it is not a very good idea to even try once. A chemical that causes irreversible random brain chemistry changes from a single use sounds like damage has happened and the user simply interprets that damage as an improvement of some sort. In the same way we used to cut out pieces of people's brains in the early 1900s and they would report more comfortable lives.

Re: Can a Human See a Single Photon? (1996)

#56

Post by [deleted] »

superposeur wrote: post #6

I’ve been aware of this fact as Feynman points it out in the course of the lectures, but find it totally nuts — there is some sense of scale I’m missing. Matter consists of discrete chunks, atoms, but these chunks are so infinitesimal and numerous that there is no question of seeing them and any effect involving a handful of them is far, far below the human scale. Light also comes in chunks, and the number of these c…

[deleted]

Re: Can a Human See a Single Photon? (1996)

#57

Post by hgsgm »

mjburgess wrote: post #16
superposeur wrote: post #6

I’ve been aware of this fact as Feynman points it out in the course of the lectures, but find it totally nuts — there is some sense of scale I’m missing. Matter consists of discrete chunks, atoms, but these chunks are so infinitesimal and numerous that there is no question of seeing them and any effect involving a handful of them is far, far below the human scale. Light also comes in chunks, and the number of these c…

Its my understanding that the human finger, run across an extremely flat surface, can detect a (via a quick google: https://www.newscientist.com/article/2276384-your-finger-can... )

Not true.

It's one atom per molecule, changing the friction.

> those who touched the surfaces could differentiate them based on chemical differences, including the substitution of one atom within each silane molecule for another, because of subtle changes in friction

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