I was always confused by the speed of light expressed in miles per second.
Well, not confused, more that I can’t picture how far that is. I know light travels more than halfway to the moon in a second, but I don’t have a picture of how far away the moon is. It’s just that thing in the sky.
Light travels at 186,282 miles per second, which is 186 miles per millisecond.
It take about 300 milliseconds to blink.
The circumference of the Earth at the equator is 24,874 miles.
So in the time it takes to blink, light travels more than twice around the Earth.
That’s something I can picture.