There is no operational sense to the question:
| One question was, what does the world look like from the frame of a
| photon ?
One can, however, fruitfully consider what happens to observations of a pair of
given events made by observers moving with incrementally increased relative
speeds - approaching, but never achieving, the vacuum speed of light . If DeltaX
and DeltaT are the space and time intervals as measured in an unprimed frame,
then the Lorentz transformation gives these quantities as measured in some
primed frame:
1) (DeltaX)' = g(DeltaX - v DeltaT)
2) (DeltaT)' = g(DeltaT - [v/c^2][DeltaX]),
where v is the relative velocity of the two frames and
g = 1/(SQRT[1-(v/c)2]).
Propose a pair of events, described by DeltaX and DeltT, and see what happens as
v increases toward the value c.
NB: These relations assume the relative motion of the two frames is in the X
direction.