High School Is it correct to state that all measurements count photons?

[Chiara]

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?

 

[Algr]

Measurements of weight or sound come to mind.

 

[Dale]

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.

 

[PeterDonis]

A text I read

What text? Please give a specific reference.

 

[Chiara]

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?

 

[PeterDonis]

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.

 

[Dale]

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

 

[DaveC426913]

Using a tuning fork to measure whether a piano is in tune counts zero photons.

 

[PeroK]

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.

 

[FactChecker]

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?

 

[PeterDonis]

Thread closed for moderation.

 

[PeterDonis]

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.