MadSci Network: Physics |
If by "intersect each other" you mean the two beams intersect each other, then the white beam is still white after the intersection, and there will be a white spot when it hits the wall. This is because light (electromagnetic wave) obeys Maxwell's equations which are linear, therefore the existence of red light in a region where the white light passes does not affect the white light, as if the red light does not exist at all.
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