How Light Moves
Light is made of photons. Many, many photons make up the light you see around you. This is one photon.
a little photon
B
C
D
A
E
where it could
have ended
a medium photon
B
C
D
A
E
where it could
have ended
a big photon
B
C
D
A
E
where it could
have ended
A photon zooms along and hides some space behind it as it goes. It always goes in a straight line.
But as we saw before, space it goes through can get bent. If space gets bent from two directions it can get squished for some time.
Where it is squished the photon can pick a nearby way out.
That leaves only a few ways out, depending on how big the photon is.