What do photons carry information about?

[cap.r]

hey, I am in a course that's building special and general relativity with logic and is non mathematical. I have done some E&M before and covered maxwell's equations...

the question that I am trying to answer is "what do photons carry information about"?

my quick response was the electric and magnetic fields that produce them. and since they are the force carriors of the E&M force they carry information about the strength and direction of these fields...

can you guys help me build on that? or add something to it I haven't. I am thinking about light, and well when you see colors they those photons carry information about the color of the object they were just in contact with or the shape of it...

am i on the right track?

 

[Carid]

You didn't use the word "polarity".

 

[cap.r]

i talked about fiber optics virtual photons and Mram... also included polarization. anything else you guys can think of?

 

[Carid]

Young's 2 slit (interference, diffraction), EPR, curvature of space demonstrated by bending of light from distant astronomical objects, emission and absortion lines in spectra...