3 ms·

Typically the speed of light in copper/fibre is about 2/3rds of lights speed in a vacuum. Hence the discrepancy.

• samdoidge 10y ago
  Typically the speed of light in copper/fibre is about 2/3rds of lights speed in a vacuum Does light travel through copper?
  • dest 10y ago
    Both light (air, fiber) and electricity (copper) lead to a propagating electromagnetic field.