[petercooper]

Just to prove I never took physics, where are the photons actually going in a long distance undersea cable that makes it impossible to just flash a signal across an ocean sized length of fiber? (As I had assumed was the case.) Is it more a loss of clarity/resolution in terms of wavelength rather than the photons going astray?

[drcoopster]

Think of it as the same as the internal resistance of a conductor. Some of the photons are effectively absorbed by the fiber and turned into heat.

[petercooper]

Thanks! I am embarrassingly so much a 'software' kind of person that this didn't occur to me, but I get the idea a bit better now.