Is it correct to state that all measurements count photons?

Click For Summary
SUMMARY

The discussion centers on the assertion that all measurements count photons, with participants debating the validity of this claim. While it is acknowledged that many measurement devices, such as thermometers and balances, utilize light for reading, the consensus is that they do not necessarily count photons. Participants highlight that measurements can occur without photon counting, citing examples like tuning forks and braille. The conversation emphasizes the distinction between using photons and counting them, ultimately questioning the credibility of the original source of the claim.

PREREQUISITES
  • Understanding of basic measurement concepts
  • Familiarity with electromagnetic interactions
  • Knowledge of quantum mechanics principles
  • Awareness of various measurement devices and their functions
NEXT STEPS
  • Research the role of photons in measurement techniques
  • Explore the principles of quantum mechanics related to measurement
  • Investigate the differences between using and counting photons
  • Examine various measurement devices and their operational principles
USEFUL FOR

Physicists, engineers, and anyone interested in the principles of measurement and the role of light in various measurement techniques.

Chiara
Messages
6
Reaction score
2
A text I read some weeks ago claimed that all measurements count photons. Indeed, even a thermometer requires light to be read off, and also a balance.

Is there a type of measurement or a measurement device that does not count photons?
 
Physics news on Phys.org
Measurements of weight or sound come to mind.
 
Chiara said:
A text I read some weeks ago claimed that all measurements count photons. Indeed, even a thermometer requires light to be read off, and also a balance.

Is there a type of measurement or a measurement device that does not count photons?
There is a very big difference between using photons and counting photons.
 
  • Like
Likes   Reactions: nasu, pines-demon and FactChecker
Chiara said:
A text I read
What text? Please give a specific reference.
 
  • Like
Likes   Reactions: gentzen and Lord Jestocost
Dale said:
There is a very big difference between using photons and counting photons.
Indeed. But is there a really precise measurement device that does not count photons?
 
Chiara said:
is there a really precise measurement device that does not count photons?
Almost all measuring devices do not count photons.

For example, you mention reading a thermometer, which requires light to see its reading. But the process of you seeing the light that tells you what the thermometer reads does not involve counting photons.

In short, whatever source you read seems highly questionable. But we can't say anything more about that unless and until you tell us specifically what that source is.
 
  • Like
Likes   Reactions: pines-demon, FactChecker and Dale
Chiara said:
Indeed. But is there a really precise measurement device that does not count photons?
Most do not. Even measurements based on quantum phenomena, such as an atomic clock.

I agree that it would be good to know the source of this claim
 
  • Like
Likes   Reactions: Lord Jestocost
Using a tuning fork to measure whether a piano is in tune counts zero photons.
 
  • Like
Likes   Reactions: PeroK
Chiara said:
Is there a type of measurement or a measurement device that does not count photons?
Reading a sign in braille. Tasting whisky. Tuning a piano. Feeling how sensitive a sore tooth is.
 
  • #10
Electromagnetism is a fundamental force that is hard to avoid and has few alternatives. That does not mean that photons are counted every time that force is involved. There are the weak and strong force at the subatomic level. Gravity is a force relevant to a lot of measurements.
If a balance says that 2 lbs is heavier than 1 lb, does that "count" photons?
 
Last edited by a moderator:
  • Like
Likes   Reactions: Dale
  • #12
After moderator review, the thread will remain closed. As @FactChecker points out, the fact that the EM interaction is involved in some way, shape, or form in most measurements does not mean those measurements count photons.

@Chiara you were asked more than once for a specific reference, and did not give one. If you post something like this again without a reference, it will be warned/deleted. We can't spend time discussing vague intimations with no source. Please be advised.
 
  • Like
Likes   Reactions: AlexB23, renormalize, FactChecker and 1 other person

Similar threads

  • · Replies 58 ·
2
Replies
58
Views
5K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 24 ·
Replies
24
Views
3K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 8 ·
Replies
8
Views
2K