

What is Light anyway? - djshah
http://gizmodo.com/5985559/what-is-light-anyway

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lutusp
Light is an example of an electromagnetic field, a field whose carrier
particle is the photon. Gravity is a field whose carrier particle is the
graviton. In the same way, and generally:

<http://en.wikipedia.org/wiki/Force_carrier>

Quote: "In particle physics, quantum field theories such as the Standard Model
describe nature in terms of fields. Each field has a complementary description
as the set of particles of a particular type. A force between two particles
can be described either as the action of a force field generated by one
particle on the other, or in terms of the exchange of virtual force carrier
particles between them."

And to think --we could learn this in school along with who was president in
1801. The latter is interesting and useful, but the former is very, very
interesting and useful.

When I was in school (long ago), at age 12 I wanted to know what made lenses
work. I had a bunch of lenses and I was building little microscopes and
telescopes, but I wanted to know how glass bent light. No one could tell me.
They could tell me who was president in 1801, but nothing scientific or
interesting.

Much later I learned that lenses bend light by slowing it down -- the thick
part of the lens slows the light more than the edges, and this makes the light
converge to a point. How hard is that?

<http://arachnoid.com/example/index.html#Lens_Example>

