I could be way off base with my original assumption, but if light is shined in space it travels straight forward indefinitely (in theory). But if it is shined on something, it illuminates that object then goes away. So what happens to the light particles/energy. I hope this makes sense, I am struggling to find the words for my question.
Just wanted to throw in an edit and say thank you for the responses. It was very informative and I greatly appreciate that!
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Light will bounce off objects. It is the Light bouncing 9ff an object and then reaching your eyes that allows you to see the object. It can either bounce off the object fully and you see white, partially and you will see a colouror not at all and you will see black.
Light doesn’t go away when it illuminates an object, and you can tell because the object is illuminated.
What you’re seeing is diffuse reflection. Unlike a mirror that reflects light at the same angle it came in, most objects reflect light a bit in every direction. That’s why the object appears lit up no matter where you’re seeing it from, there’s always a bit of reflected light in the direction of your eye. It’s also why you don’t see an image like in a mirror, because you’re seeing a jumble of reflections of light that originally came from a bunch of different directions.
It’s either absorbed or reflected. If it is absorbed, it turns into a different form of energy or helps an atom move into a higher energy state. If reflected, it simply bounces off.
that light goes into your eye, and the energy of that light is used up by molecules in your eye cells to send a signal to your brain!
When light hits an item it shakes the atoms. The atoms shaking sometimes makes more light (nearly instantly) and you see it as reflected light. Sometimes the atoms shake other atoms or the shakes other parts of the same atom. When that happens the atom doesn’t make more light and the light is absorbed.
When the light hits something, it’ll do one of 4 main things.
1. It’ll reflect off of it, which is what you see with your eyes.
2. It’ll be absorbed by it, converting to thermal energy. This is why standing in shade makes you cooler than in direct sunlight, even if the air temperature is the same both places.
3. It’ll pass through, and might be somewhat altered in the process. Windows are an obvious example, but prisms are another example where what you see is different than if it went through unimpeded.
4. Is rarer, but is when light is absorbed, but then re-emitted in some way. This is the cause of both fluorescence (things under a black light showing up more) and phosphorescence (things that glow in the dark).
EDIT: To add a bit more clarity to the “why,” light interacts with the electrons surrounding an atom. Exactly how depends on the atoms being hit, and the energy of the light particle (photon) hitting them.
It either gets absorbed, reflected, or refracted.
If it gets absorbed, the energy is imparted to an atom or molecule in the material, and it usually gets released as heat, but it can also break down molecules in the material.
If it gets reflected, it can either be a perfect reflection (like a mirror) or it can be scattered (like every other object). Ie, green objects reflect frequencies of light that our eyes perceive as green.
If it gets refracted, it passes through the material and gets bent due to changing speed. This is why a straw in a glass of water looks bent. The electric fields of the surrounding atoms simply slow down the propagation of light. The index of refraction is the factor of how much it’s slowed down and snell’s law tells us how much it gets bent.
The photons will hit an object and excite the electrons of the atoms into an unstable state. In this state, the electrons will “hold” more energy. It’s unstable, though, so it will want to return to its stable state, which “holds” lower energy. In order to do that, it will need to release that energy by releasing photons. The wavelength of the light released will determine the color of the object we perceive it as.
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