# How can light pass through some solid objects but not others?

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How can light pass through some solid objects but not others?

In: Physics

as far as i’m aware it’s a question of absorption and reflection/refraction. if a medium does not absorb the light and simply bounces the light, the average of every photon’s combined path will tend towards what you see when light is refracted or reflected through a window. the windows in your house, which you can almost completely see through without refraction, have their particles tuned in such a way that they bounce photons minimally compared with their entry angle.

if light is partially absorbed then that will give your object a visible, or invisible, colour. this is because every wavelength of light that is NOT absorbed will bounce (refract or reflect).

Imagine people in line to apply for a job at a warehouse. One by one, they go in and the boss asks them to lift a box and put it on a shelf. If a person is tall enough, they are permitted to stay. If they are not tall enough, they are sent out the door on the other side.

If the warehouse has a very high shelf, almost everyone who goes in will come out. If the warehouse has a low shelf, everyone can stay.

Photons are like the workers. Purple photons are very tall and red photons are short. Boxes are like electrons, and the warehouse is like the solid.

In glass, the shelf is so high that even the purple photons can’t lift the box all the way up. So all the photons come out the other side. In wood, the shelf is so low that even the red photons are tall enough, and they all stay.