What Slows Light Down ?

A number of things slow light down. Here's a partial list:

• Light through a gravitational field - See http://en.wikipedia.org/wiki/Introduction_to_general_relativity for details.
• Light through a lense - See http://en.wikipedia.org/wiki/Lens_%28optics%29 for details.
• Light through a Bose-Einstein condensate - See http://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_condensate for details.

Could these be all the same effect? Probaby. The photon is interacting with the gravitational field of a nearby object.

Quantifying The Above Examples

If we take empty space and add the gravitational effect, UFT refers to this as a Gauge Field. The stronger the Gauge Field, the slower items can propogate through it. In the first example, we are dealing with planets and vast distances so we see the effect. In the second and third examples, we pass close to an object in the lense.

Possible Why's

Why would this be so?

• The Gauge Field interfears with the transmission of the photon, thus slowing it down. Consider the example of a bowling ball. When it strikes the pins, it slows down. Or, the photon may excite the Gauge Field and this takes more time than if the field were not present in the first place. Once light emerges, information is preserved.
• Local space is warped in such a way that light has to travel farther, but it really doesn't slow down. Suppose we suspended millions of tiny mirrors in transparent plastic. Light would essentually get caught for a while in the maze, but eventually make it out the other end.
• Time slows down in larger Gauge Fields.
• Stronger Gague Fields might be like molasis, things just take longer to get through. Sound travels faster in water than it does in air.
• The Gauge Field could be non-linear with respect to gravitation.