Help on the photon

[Phys_Student]

I am very sure this has been and will be discussed time and again but i hope you have enough patience to please answer this one more time.

If the photon is masless, how can it possess momentum and energy ? The 2 things just seem to go together. When they say massless they do mean mass = 0 right ? And when AH COmpton derived the formulas to calculate momentum of a photon, he used the equation E=mc^2 right ? So therefore, the photon must have a mass, because E / C^2 = never 0 ...

I am a really confused high school physics student, please help me out, dont let me rot in the darkness.

thank you

[[Tycho?]]

http://en.wikipedia.org/wiki/Photon#Photons_in_matter

I'm sure if you use the search function you will get some of the time this has been discussed before.

[swansont]

The whole equation is E2 = p2c2 + m2c4 , where m is the rest mass.

For a photon, m = 0 so p = E/c

[Klaynos]

Just to take what swansont said one step further.

E=hf, so p=hf/c=h*Wavelength