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.
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"?
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?
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.
