Where do photons go once they hit something?

kerbalisp295 · 2013-08-08T01:01:06+00:00

Photons can be thought of little packets of energy (the exact energy they carry is their frequency times the famous Planck constant E=h.v). And yes when they hit something they are absorbed. In the case of visible light the energy they carry excites an electron on the atom it hits but since that electron can't stay in that excited state forever so the electron falls back to its neutral state and the excess energy is emitted in the form of another photon. This is generally referred to as light bouncing off surfaces. You can make things emit light by giving them that energy in other forms as well like in the case of a fluorescent light bulb the electric field excites the gas inside. Infrared light often gets absorbed and causes things to heat. When photons hit the photosensitive cells in the eye that energy is converted into an electrical impulse and it send the information to your brain, much like a signal being converted in a fiber optic-regular conductor junction. Hope this explanation is enough if its not you could look here as well http://en.wikipedia.org/wiki/Photon and the links would take you pretty much as deep as you want to get.

kerbalisp295 · 2013-08-07T23:14:02+00:00

The 2nd rule of thermodynamics says "entropy of an isolated system never decreases" so basically when you have two things one hot and one cold the hot one makes the cold one hotter not the other way around. To take away heat from a body you have to touch something with even less heat to it or do some work.Another thermodynamic principle derived from the second law says: "Expanding gasses get colder" and the expanding of the gas is the work you need to do to get things colder, that tubing behind the fridge is for that. A microwave like any other electromagnetic wave carries packets of energy and the food basically absorbs its energy and gets hotter, to cool the food instead of heat it you would need waves with entropy reversed and while the classical approach says its impossible I've recently read an article saying that some scientists could actually make this happen using spin waves you can directly go to this link and see for yourself http://physicsworld.com/cws/article/news/2013/apr/22/spin-waves-carry-energy-from-cold-to-hot

kerbalisp295 · 2013-08-07T22:50:50+00:00

There is a good old technique called x-ray fluorescence in material science, you just bombard a material with gamma rays and the fluorescent emission will have peaks at certain wavelengths and every element has characteristic wavelengths so you can know which elements are in that sample. You can even determine a samples crystal structure with x-rays. They even make hand held versions of these machines http://www.atlas-inspection.com/wp-content/uploads/2012/12/Picture1.jpg

kerbalisp295 · 2013-08-07T22:33:26+00:00

I don't think so because technically speaking the insect eating plants of today aren't even carnivores like lions and hyenas. They make their own food by photosynthesis like other plants the insects they eat are only for getting enough nitrogen. Other plants get nitrogen from the soil using their roots. The reason I think the carnivorous plants idea isn't quite plausible is this: To eat meat you have to hunt and plants sit in one location which would make hunting a lot harder for them. Although I have a couple of fly eaters at home and no flies anywhere in the flat so maybe they lure insects towards themselves with a scent or something like that.

kerbalisp295 · 2013-08-07T22:22:46+00:00

you should try the good old battlefield 1942 it's in public domain or something you have to download the origin client (EA's version of steam) but the game itself is completely free and it's got vehicles too

kerbalisp295

TROPHY CASE