Don't photons (in a perfect vacuum), by definition, travel at the speed of light (3 × 10^8 m/s)? Radio waves also, right?
That's very fast, but given the vast distances of space, it still takes time for light to get from one point to another. The Earth is about 150 × 10^6 km (or 1.5 × 10^11 m) from the Sun.
(1.5 × 10^11 m)/(3 × 10^8 m/s) = 0.5 × 10^3 s = 500 s = approximately 8 minutes and 20 seconds.
So we're 8-1/3 light-minutes from the Sun, but about 4-1/2 light years from the closest star (i.e. next closest sun). It's all a bit mind-boggling!
Light in glass (e.g. fibre optic strands) travels at just over 2/3 the speed of light.
That's very fast, but given the vast distances of space, it still takes time for light to get from one point to another. The Earth is about 150 × 10^6 km (or 1.5 × 10^11 m) from the Sun.
(1.5 × 10^11 m)/(3 × 10^8 m/s) = 0.5 × 10^3 s = 500 s = approximately 8 minutes and 20 seconds.
So we're 8-1/3 light-minutes from the Sun, but about 4-1/2 light years from the closest star (i.e. next closest sun). It's all a bit mind-boggling!
Light in glass (e.g. fibre optic strands) travels at just over 2/3 the speed of light.