How does light interference occur when EM radiation interacts with itself?

AI Thread Summary
Light interference occurs when electromagnetic (EM) waves interact with each other, leading to superposition where waves can either amplify or cancel each other out. This phenomenon is explained by the vector nature of classical electromagnetic waves, which combine based on their amplitudes and phases. When two EM waves are out of phase, they can create a net effect of zero at certain points, resulting in destructive interference. Conversely, when in phase, they can enhance each other, leading to constructive interference. Overall, light can interfere with itself through the principles of superposition and vector addition.
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How can light interfere with other light? I thought EM radiation only interacts with charges?

Is it because, at your eye, the EM waves are out of phase? So the EM waves don't 'delete' each other, they both exist in superposition with each other, and one EM wave is pushing the electron one way, and the other pushing the other way, so the net effect is 0?
 
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Classical electromagnetic waves are vector quantities, which add in a vector fashion. So yes, interference is due to multiple waves superimposed, with the proper amplitude and phases such that the net field at a particular position is zero.
 
dipole said:
Classical electromagnetic waves are vector quantities, which add in a vector fashion. So yes, interference is due to multiple waves superimposed, with the proper amplitude and phases such that the net field at a particular position is zero.
Thanks
 
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