Offline scomato

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Re: Help me understand how light rays travel
« Reply #40 on: May 23, 2021, 08:18:33 PM »
Everyone likes to talk about how light works above the surface of the water, but I don't think I've ever seen someone bring up the behavior of light under the water.

One of the coolest things I've ever done is cenote diving in Mexico. The best part of the whole experience, is that you get spectacular sun rays through the cracks and crevices to the surface above.

This quite aptly disproves the diagram here ( and the possibility that light is refracted horizontally as it approaches the surface of the Earth. Which makes sense - the water level is kind of an arbitrary line, there's nothing special about it, and diving under water proves that light continues to travel in a straight line path regardless of whether you're above or below the water level.