Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Routledge eBooks

ADVANCED FURTHER PROBLEMS OF NATURAL PHILOSOPHY

Martin Cohen

Published Jan 4, 2002• 0 citations
Publisher

Abstract

If we turn down our light source from 100 million whatever photons a second to, say, just ten a second, we see the problem, if not the screen, very clearly. These last few photons of light head off, one by one, for the screen, some of them hitting the piece of card but the odd one going through a slit. Now, according to common sense, each should be able to land on the screen unaffected by whether the other slit is there – or not.

DOI
10.4324/9780203029893-93

Related papers

Advanced further problems of natural philosophy

Martin Cohen

If we turn down our light source from 100 million whatever photons a second to, say, just ten a second, we see the problem, if not the screen, very clearly. These last few photons of light head off, one by one, for the screen, some of them hitting the piece of card but the odd one going through a slit. Now, according to common sense, each should be able to land on the screen unaffected by whether the other slit is there-or not. But none of them, no matter how long we wait, will try to land on the dark areas seen in the interference pattern with lots of light. After all, if an individual photon could behave in this way, it might take a long time but, eventually, the screen would record a picture more like the one-slit experiment with the light diffusing evenly, than the interference one. And the individual photons recognise the contradiction. They continue to behave individually as ‘waves’ all on their own. Points where the light particle could go when just one slit is open become unavailable when the other slit is open. (Incidentally, the same thing, scientists have observed, will happen with any small particle-electrons, whole atoms or even molecules will do just as well.) In experiments, the individual particles of light seem to know about the other slit on the piece of card, indeed what is going on elsewhere in the universe. For, in principle at least, the distance between the slits can be any size, and the same interference effect will apply. (Although if the slits were even a metre apart, the screen might need to be on the moon before the deflected light begins to converge.) Suppose we asked our neighbour if we could borrow their particle detector to check whether the light energy is still travelling in ‘whole photons’, rather than splitting into two and going through both slits and thereby getting in and out of phase with each other. We would find, indeed, that it was still travelling as a whole photon, and that this attempted explanation does not fit with observation. But we would find something else too. The mere act of putting the particle detector next to one slit causes the wavy pattern, the ‘interference’ effect, to disappear!

Routledge eBooks•Nov 1, 2002•0 citations

The secret lives of photons revealed

In the classical double-slit experiment, a beam of light is shone onto a screen through two slits, which results in an interference pattern on the screen.

Physics World•Jul 1, 2011•0 citations

Double Slit Experiment

Jac L. Williams

Sir Arthur Conan Doyle once said, and I am paraphrasing (once you remove all that's false, whatever remains has to be the truth. No matter how strange or ridiculous it may seem). I am going to assume that a photon will turn into a wave just because it goes through a double slit in a piece of paper is a false statement. I will then demonstrate that whatever is left can explain the four bars of light that form when light travels through the double slit.

•Feb 1, 2017•3 citations

If a Photon Falls in the Woods: An Aristotelian Answer to a Quantum Question

Andrew Younan

The Heythrop Journal•Jul 13, 2017•2 citations

A Possible Resolution of the Enigmatic Double Slit Experiment

Shlomo Barak

We dispel the need to attribute a dualistic nature to single photons that arrive, in a double slit experiment, at the screen one at a time. Interference is explained in a novel way based on known and accepted physics. The photon, being an excitation of the electromagnetic field, is regarded as kind of a “particle”, not yet modeled, of a defined size, and not a wave.

•Jan 1, 2026•0 citations

Introduction: The photon

R. Loudon

Abstract The use of the word ‘photon’ to describe the quantum of electromagnetic radiation can lead to confusion and misunderstanding. It is often used in the context of interference experiments, for example Young’s slits, in such phrases as ‘which slit does the photon pass through?’ and ‘where do the photons hit the screen when one of the slits is covered up’. The impression is given of a fuzzy globule of light that travels this way or that way through pieces of optical equipment or that light beams consists of streams of the globules, like bullets from a machine gun. Lamb has even argued that there is no such thing as a photon [11 and he has proposed that the word should be used only under licence by properly qualified people! It is, however, difficult to disagree with some of his concerns.

•Sep 7, 2000•2 citations
If we turn down our light source from 100 million whatever photons a second to, say, just ten a second, we see the problem, if not the screen, very clearly. These last few photons of light head off, one by one, for the screen, some of them hitting the piece of card but the odd one going through a slit. Now, according to common sense, each should be able to land on the screen unaffected by whether the other slit is there – or not.
If we turn down our light source from 100 million whatever photons a second to, say, just ten a second, we see the problem, if not the screen, very clearly. These last few photons of light head off, one by one, for the screen, some of them hitting the piece of card but the odd one going through a slit. Now, according to common sense, each should be able to land on the screen unaffected by whether the other slit is there-or not. But none of them, no matter how long we wait, will try to land on the dark areas seen in the interference pattern with lots of light. After all, if an individual photon could behave in this way, it might take a long time but, eventually, the screen would record a picture more like the one-slit experiment with the light diffusing evenly, than the interference one. And the individual photons recognise the contradiction. They continue to behave individually as ‘waves’ all on their own. Points where the light particle could go when just one slit is open become unavailable when the other slit is open. (Incidentally, the same thing, scientists have observed, will happen with any small particle-electrons, whole atoms or even molecules will do just as well.) In experiments, the individual particles of light seem to know about the other slit on the piece of card, indeed what is going on elsewhere in the universe. For, in principle at least, the distance between the slits can be any size, and the same interference effect will apply. (Although if the slits were even a metre apart, the screen might need to be on the moon before the deflected light begins to converge.) Suppose we asked our neighbour if we could borrow their particle detector to check whether the light energy is still travelling in ‘whole photons’, rather than splitting into two and going through both slits and thereby getting in and out of phase with each other. We would find, indeed, that it was still travelling as a whole photon, and that this attempted explanation does not fit with observation. But we would find something else too. The mere act of putting the particle detector next to one slit causes the wavy pattern, the ‘interference’ effect, to disappear!
Abstract The use of the word ‘photon’ to describe the quantum of electromagnetic radiation can lead to confusion and misunderstanding. It is often used in the context of interference experiments, for example Young’s slits, in such phrases as ‘which slit does the photon pass through?’ and ‘where do the photons hit the screen when one of the slits is covered up’. The impression is given of a fuzzy globule of light that travels this way or that way through pieces of optical equipment or that light beams consists of streams of the globules, like bullets from a machine gun. Lamb has even argued that there is no such thing as a photon [11 and he has proposed that the word should be used only under licence by properly qualified people! It is, however, difficult to disagree with some of his concerns.