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Light transmission experiment

Light transmission experiment

Light transmission experiment

Could anyone explain what happens in the following light transmission experiment. Take two corrugated roof tiles and make a 5 to 6 inches hole on the center of each tile. The first tile you use just with the plain hole . In the second tile you adapt a transparent PET 2 litres COKE bottle, so that the bottle has its upper half left to the outside and the bottom half to the inner side. You cement the bottle with epoxy firmly to the tile, and fill it with tap water. Mount the tiles on a roof of an enclosed room/area covering any oyher source of light. Observing both tiles side by side, from the enclosed side we get the impression that the tile with the bottle transmitts say twice the light as the tile with bare hole. The bottle without water transmitts less light.

RE: Light transmission experiment

This experiment is simular to Michaelson experment for measuring the speed of light.  He is the one who is responsible for being first to measure the speed of light, but he used a an optical prism intead of a water filled coke bottle.  The speed of light in air and a vacuum, with an index of refraction of 1 (n=1) is the standard value and is 186281 miles per second. In a prism it approximately 1.5 (n=1.5) times faster. In water it is 1.33 times and through the plastic coke bottle perhap 1.3 to 1.5 times faster.

Because of the shape and size of the coke bottle and the water, its external surface area become a light collector/gather just like a optical lens. The numerical aperature is increased proportionally to approximately 1.3 to 1.6 to 1 as compared to the plain hole.

regards jerre

RE: Light transmission experiment

Hi Jerre
Is there any other inexpensive way to further increase the light transmition? Changing the shape of the bottle to what form? Changing the liquid ?
Thanks for your kind help

RE: Light transmission experiment

yes, the more surface area, the more light gathering power. Longer and/or wider is better.  increasing the refracting index will also help.   

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