# Question: Slowing Down Light

## Main Question or Discussion Point

By sending light through bose-eistein condensate ( hope I spelled it right, and im going to use BEC instead from now own) the light slows down. Do the particles have a traffic jam at the BEC or do they move closer to gether.

normal light BEC slow light close together
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like this or like this
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normal light BEC slow light with traffic jam

I base this off of cars on the interstate. If one was to slow down there would be a trafic jam and the cars would all be close together. Also, if the car stays slow for to long, the trafficjam backs up farther. If given long enough, it will back up to where the interstate begins.(This is based on a one lane interstate.

Instead of cars, use photons. Will this happen or is there some fact im missing?? ??

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And if I am in the wrong thread, im sorry. Please then tell me what thread to post in

pervect
Staff Emeritus
You can more or less think of the photons themselves always travelling at 'c'. (A purist might argue that photons don't actually have a position or follow a path). So what happens is that the photons don't slow down - they get absorbed. The fact that 'c' is low means that almost all photons get absorbed, and stay that way for a long time, and spend only a very small amount of time actually moving. Most of the time they are just being "carried around" by some excited atom in the BEC.

pervect said:
You can more or less think of the photons themselves always travelling at 'c'. (A purist might argue that photons don't actually have a position or follow a path). So what happens is that the photons don't slow down - they get absorbed. The fact that 'c' is low means that almost all photons get absorbed, and stay that way for a long time, and spend only a very small amount of time actually moving. Most of the time they are just being "carried around" by some excited atom in the BEC.
excited electrons, to be exact.

Regards,