[hylaride]

Over long distances, fibre optic would have lower latency so it'd be shorter if taking the same path today. But these signals would likely have been morse code and sent one-way at a time, so latency wouldn't have been noticed unless the repeaters were people rebroadcasting the signal (no idea how that was done).

[joecool1029]

> Over long distances, fibre optic would have lower latency so it'd be shorter if taking the same path today.

Source that claim, it's well understood the speed of light is around 66% due to refractive index in glass.

It gets weird with telegraph cables and capacitance, wikipedia at least touches on it here: https://en.wikipedia.org/wiki/Speed_of_electricity

[hylaride]

I should have definitely qualified that statement. Technically, electrical signals over copper are "slowed down" less than light through fibre optic cables. However there's attenuation, electromagnetic interference, and other signal loss for electrical signals that (for long haul cables) will mean you will need repeaters that add significant amounts of latency. On top of that, the higher you try and up the frequencies, the worse these problems get.

For some medium-haul stuff, it wouldn't surprise me if you saw copper still being used for lower latency (eg between datacenter sites for flash-trading), but otherwise it's just not economical.