How does incandescent produce light

The University of Colorado has graciously allowed us to use the following Phet simulation. Explore this simulation to see changing temperature changes the amount of radiation given by a light bulb filament.

All of the radiant energy to the right of the rainbow in the simulation is energy coming off as heat infrared radiation :. Fossil Fuels. We begin our service team training by covering the most basic idea of all in the lighting world: How does a light bulb produce artificial light? Basically, an incandescent light bulb is a controlled fire on display. When electrical current makes contact with the base of the bulb, electricity enters and heats the tungsten filament housed inside.

You would see this same effect in a burning log or coal. The light in an incandescent light bulb is really just that effect occurring in a contained, controlled environment. As the filament continues to burn, particles fly off the filament. And when there are no more particles to burn, the light bulb burns out, which typically takes place , hours into the life of the incandescent light bulb.

It also produces heat. Incandescent light bulbs, in fact, produce 90 percent heat and 10 percent light. Those bulbs are hot! Depending on the color palette in your home and your goals — energy efficiency vs. Instant Rebates are available to businesses Click to find out about your location. BulbFinder Our easy-to-use BulbFinder will let you find the correct bulb, step by step. Worcester, MA Tel. Get to know your light bulbs with our comprehensive type guides.

Where did they come from? Diagram showing the major parts of a modern incandescent light bulb. The chance of any one of those atoms emitting a nm photon instead of a nm photon is incredibly tiny, but the chances that some atom from within that vast mass will do so it pretty high.

And once it has, that long-wavelength photon has a much better chance of making it out without getting absorbed than a nm photon, which likely won't travel very far before another atom absorbs it. And that new atom has a tiny but non-zero chance of emitting a nm photon, and so on. As light slowly makes its way out of a gigantic collection of atoms, then, the nm photons that the atoms like to absorb and emit end up converted into longer-wavelength visible photons.

The broad spectrum we see coming from a light-bulb filament or from the Sun is the result of a vast number of events that are individually incredibly improbable but collectively inevitable. And when you work out the details of the process, taking account of the energy available in the thermal motion of the atoms, what you end up with is a black-body spectrum. So, just like the alarm clock on my nightstand , the operation of something as ordinary as an incandescent light bulb turns out to involve surprisingly deep and amazing physics.

Not only is it historically important as an example of the phenomenon that kick-started quantum physics, the very behavior that led to Planck's quantum trick is the result of bizarre and amazing quantum physics.

If you would like to see this worked out with a whole bunch of math, this paper from the American Journal of Physics is very nice, and provides the basis for much of this post. I was pointed to that after thinking out loud about this process a few years ago over at ScienceBlogs. This is a BETA experience. You may opt-out by clicking here. More From Forbes. Jul 23, , am EDT. Jul 15, , am EDT. Jul 8, , am EDT. Jul 1, , am EDT.