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Comment by throwaway8503 | Hacker News Reader

Purely as a matter of esoteric interest, does anyone know of any affordable photon counting devices?

I think you’re looking for a lux meter. Precision is far rougher than single photons, but good enough for any human-scale use. It’s what you’d use for things like calibrating indoor lighting, quantifying the difference between a sunny day and moonlit night, or testing flashlights. Last I checked a good basic one was under $40.

Only for high energy photons.

https://gammaspectacular.com/

Do you mean a camera?

If there's a way to get an integer value on the number of photons per cell in a camera sensor, let me know

No but there is a way to get integer values for the photo-electrons per pixel.

I suppose there would be a rough conversion between that value and photon count (at some wavelength range). I just imagine the error bars to be very wide.

Not really, it depends from the application. Even something like 20 years ago the CCDs available at the time were capable of astrometric measure of star magnitudes with 1/100 of magnitude precision using some control stars.

You realize that light is actually electromagnetic radiation and there is no such thing as a physical photon right?

I think you're sort of half right

Aren't you being very particular? Just wave the mistake off, I say.

Everything in our universe is made up of waves. Does it really matter whether it's an oscillation in one field or another? Photons are discrete systems, can you clearly differentiate why anything else in the universe is "physical"?

Photons as an idea can make simulation easier, but it matters if someone is trying to 'count photons' and they don't exist.

How so? My understand is that a photon is a discrete packet of energy. Why can't I count those? If there is an excitation in the electromagnetic field, and then there is not, and then there is one - why are those not separate, countable photons?

You realize you're now just making up your own definition for a photon on top of what actually exists right?

No, I'm asking questions. I literally said (albeit with a typo) "my understanding is". Where am I making up a definition?

You're free to show everyone my stupidity by answering my questions.

I already told you that photons don't exist, I think you just didn't accept it.

My understand is that a photon is a discrete packet of energy.

There is no such thing in the physical world as a 'discreet packet of energy'. This is an abstraction for simulation.

Would you be so gracious as to answer my questions, instead of just repeating what you previously said? I'll copy and paste:

> Why can't I count those? If there is an excitation in the electromagnetic field, and then there is not, and then there is one - why are those not separate, countable photons?

You can call and count things however you want. If you have a steady light source I'll go one better and count it for you - one, because electromagnetic radiation is not somehow switching on and off automatically.

That would be like you turning your stereo on and off and declaring the sound to be sound particles. You can do it, but you're ignoring physical reality.

Computers work with alternating voltages, but that doesn't make them 'electricity packets' or 'electricity particles'.

Electromagnetic radiation is going to be a magnitude at a certain frequency over time.

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