Why is photon quantized in vacuum?
30422
Are photon energies universally quantized?
10504
What are the reasons to expect that gravity should be quantized?
3909
Does $E = mc^2$ apply to photons?
69983
Photon energy - momentum in matter
82218
Do we really not know why atoms 'decide' to produce a photon?
82894
Why cannot fermions have non-zero vacuum expectation value?
82492
How does a photon released from particle A interacting with particle B, entangle them?
152528
Bound states in QED
53259
Do photons have mass?
8048
How does one account for the momentum of an absorbed photon?
58728
Why does the speed of light in vacuum have no uncertainty?
28165
Why can't a single photon produce an electron-positron pair?
57502
Do electrons really perform instantaneous quantum leaps?
41889
Why is the $S_{z} =0$ state forbidden for photons?
97466
what is the relationship between the dynamical casimir effect and virtual particles?
52418
What exactly is a quantum of light?
138161
Why is space a vacuum?