Why, if you get a 100 mW laser, you should never watch it directly. If you look at the diffracted light off this expired matchhead, you can see the bloom from the sensor (the six-pointed star), but also the interference fringe (the ringed nature of the aura) and even diffraction grain (single-pixel spots) - both indicative the reflected light is potentially damaging to the eyes. ALWAYS do these experiments through a webcam, with something solid blocking the direct view!!!
Why, if you get a 100 mW laser, you should never watch it directly. If you look at the diffracted light off this expired matchhead, you can see the bloom from the sensor (the six-pointed star), but also the interference fringe (the ringed nature of the aura) and even diffraction grain (single-pixel spots) - both indicative the reflected light is potentially damaging to the eyes. ALWAYS do these experiments through a webcam, with something solid blocking the direct view!!!
merlinjim 3 years ago