SPEED OF LIGHT
We've been talking about the speed of light in Physical Science.
It's always hard to get the concept across as it's faster than our
minds can really comprehend. I ran across a passage in a book I'm
currently reading - E=MC*2, A Biography of the World's Most Famous
Equation by David Bodanis - that helps put it in perspective.
670,000,000 mph (speed of light) (rounded off).
"To emphasize how big a number this is, at 670,000,000 mph,
you could get from London to Los Angeles in under 1/20th of a
"Mach 1 is the speed of sound, about 700 mph. A 747 jet travels at a
little under Mach 1. The space shuttle, after full thrust, can surpass
"The number of 'c' is Mach 900,000."
"This vast speed leads to many curious effects. Let someone
irritatingly speak into a cell phone just a few tables from you in
a restaurant, and it seems as if you're hearing his voice almost as
soon as the words leave his mouth. But air only can carry a sound
wave at the lowly speed of Mach 1, whereas radio signals shooting
upward from the cell phone travel as fast as light. The person on
the receiving end of the phone - even if she's hundreds of miles
away - will hear the words before they've trundled the few yards
through the air in the restaurant to reach you."