Why is the light hot?

Question

Natural or not. The sun or a light bulb. Is light just a by product of a burning substance?

Answer 1

No. Light is a form in which energy is released - that's all.
Consider 2 oppositely charged plates at high potential.
If they are brought sufficiently close together, then light will be produced clearly this is not by heating. In this case it is due to the formation of ions of air molecules between the plates.

Answer 2

We do have light sources with such a high efficiency of converting almost all the energy into light that the housing stays cool. Burning substances do give off light but the efficiency is low, about 4% or so like in the case of the tungsten filament based bulb. CFLs on the other hand are much more efficient and the housing of the lamp stays cool. LEDs are another example of a high conversion efficiency. Fire flies are nature's example of chemiluminiscence where chemicals join to produce light and no heat (or very little heat) is produced.

Answer 3

You can also look at it as Potential & Kinetic energies. You may do this experiment sometime in school...where you burn a peanut and have to figure out how much energy it contained (in calories or Kcals). So anything made of matter contains energy, and when that energy is released (burning a piece of wood, or an atomic reation), that matter gets converted to other types of energies, whether it be heat or light...or other radiation (subatomic particles & rays). All this is from Einstein's E=mC2, but that is another question altogether!

Answer 4

short answer = radiation.

When certain chemical reactions occur, energy is sometimes a byproduct. That energy can come in many forms: atoms moving, molecules vibrating, subatomic particles shooting off.

The sun, light sources, and fire all emit radiation in the form of photons and electromagnetic waves. These particles and waves have lots of energy and move very fast (speed of light in fact). When they encounter another object, such as your skin or a thermometer, they transfer their energy to that object. This raises the energy of the object making it "feel hotter." But really all that's saying is that the atoms and molecules of the object are moving at a faster speed than normal, because they were bombarded with a million subatomic bullets.

Answer 5

yes. but it is also the byproduct of other stuff.
light is essentualy energy. so intense light can be felt as heat. also burning stuff lets off lots of infrared light, which is felt more as heat than visible light.

Answer 6

It has energy in it.