All fundamental particles in nature are, as far as we can tell, identical to one another. Two photons, the particles of light, could have the same frequency, the same polarization and could travel in the same direction, i.e. all of their features could in principle be identical.
Entangled Identity of Quantum Indiscernibles
Entangled Identity of Quantum Indiscernibles
Entangled Identity of Quantum Indiscernibles
All fundamental particles in nature are, as far as we can tell, identical to one another. Two photons, the particles of light, could have the same frequency, the same polarization and could travel in the same direction, i.e. all of their features could in principle be identical.