Quick revisit of how we know that light is a wave (after all, Newton had decided that light was particles moving with c): Thomas Young (1801) was skillful enough to see interference from two slits:
Quick revisit of how we know that light is a wave (after all, Newton had decided that light was particles moving with c): Thomas Young (1801) was skillful enough to see interference from two slits:
a recent improvement is a fast switch that can send light from one slit to a detector,
after it has gone through the slit