Do photons exist or not

  • I
  • Thread starter ftr
  • Start date
  • Tags
    qft
  • #1
ftr
623
47
from wiki
"Although the photoelectric effect and Compton scattering strongly suggest the existence of the photon, it might alternatively be explained by a mere quantization of emission; more definitive evidence of the quantum nature of radiation is now taken up into modern quantum optics as in the antibunching effect.[30]"

That suggest that no individual photon has actually been observed. Is that correct?
 
Last edited:

Answers and Replies

  • #4
Demystifier
Science Advisor
Insights Author
Gold Member
10,947
3,656
That suggest that no individual photon has actually been observed. Is that correct?
It's not correct.
 
  • #5
ftr
623
47
It's not correct.
I remember from many years ago in the research institute I used to work for had a million dollar ccd camera that was supposed to count photons. Do you know of an actual experiment.
 
  • #6
DrChinese
Science Advisor
Gold Member
7,358
1,150
I remember from many years ago in the research institute I used to work for had a million dollar ccd camera that was supposed to count photons. Do you know of an actual experiment.
Not sure what you would call suitable for proving the existence of photons, but this is something I consider to be good:

Abstract:
"... For example, while well-known phenomena such as the photoelectric effect and Compton scattering strongly suggest the existence of photons, they are not definitive proof of their existence. Here we present an experiment, suitable for an undergraduate laboratory, that unequivocally demonstrates the quantum nature of light. Spontaneously downconverted light is incident on a beamsplitter and the outputs are monitored with single-photon counting detectors. We observe a near absence of coincidence counts between the two detectors—a result inconsistent with a classical wave model of light, but consistent with a quantum descriptionin which individual photons are incident on the beamsplitter. ..."

http://people.whitman.edu/~beckmk/QM/grangier/Thorn_ajp.pdf
 
  • Like
Likes vanhees71, ftr, Delta2 and 1 other person
  • #7
PeterDonis
Mentor
Insights Author
2019 Award
30,686
9,691
That suggest that no individual photon has actually been observed. Is that correct?
No. We have instruments that can detect individual photons in experiments. See the paper @DrChinese referenced for an example.
 
  • Like
Likes vanhees71
  • #8
Richard Feynman has been clear that photons exist as particles. We can hear them hitting the detector, click, click, click.
 
  • #10
34,661
10,802
You can find opinions for every nonsense you like. That doesn’t mean they would be relevant.
It is possible to describe the world without using the word “photons”, but you would need entities that every reasonable physicist would just call photons.
from wiki
"Although the photoelectric effect and Compton scattering strongly suggest the existence of the photon, it might alternatively be explained by a mere quantization of emission; more definitive evidence of the quantum nature of radiation is now taken up into modern quantum optics as in the antibunching effect.[30]"

That suggest that no individual photon has actually been observed. Is that correct?
No, it suggests some experiments from the 1930s and earlier can be described without photons. We don’t live in 1930 any more.
 
  • Like
Likes vanhees71
  • #11
Cthugha
Science Advisor
1,955
317
from wiki
"Although the photoelectric effect and Compton scattering strongly suggest the existence of the photon, it might alternatively be explained by a mere quantization of emission; more definitive evidence of the quantum nature of radiation is now taken up into modern quantum optics as in the antibunching effect.[30]"

That suggest that no individual photon has actually been observed. Is that correct?
So what is wrong about antibunching as solid evidence that it is possible to prepare single photon states? It has been demonstrated in experiments over and over again.

A quote from that text "Photons do not exist, according to Geoff Jones of the University of Sussex. Jones believes that it is ‘wrong, and unnecessary’ to describe light in terms of small, localised particles."

Of course it is wrong and unnecessary to describe light in terms of small localised particles. But photons are NOT small, localised particles. There have been people such as Willis Lamb who stated the opinion that the term photon is often used incorrectly and thus the terminology should be changed, but these people also clearly stated that the quantum theory of radiation is the right tool to analyze problems in quantum optics. They just think that the term "photon" is giving people a wrong bullet-like intuitive picture of what photons are - which is exactly what they are not.
 
  • Like
Likes vanhees71 and Demystifier
  • #13
PeterDonis
Mentor
Insights Author
2019 Award
30,686
9,691
you can find many opinions like that.
The responses to your question in the OP were not "opinions". You have been given references to actual experiments that detect photons.

Question answered. Thread closed.
 
  • Like
Likes vanhees71 and StevieTNZ

Related Threads on Do photons exist or not

Replies
12
Views
4K
  • Last Post
Replies
3
Views
2K
Replies
10
Views
1K
  • Last Post
Replies
8
Views
1K
Replies
39
Views
10K
Replies
1
Views
1K
  • Last Post
Replies
3
Views
3K
Replies
95
Views
20K
  • Last Post
Replies
13
Views
1K
Top