Light is fast! It can reach the universal speed limit — 186,000 miles per second. (If you could travel as fast as light, the universe would look very different.) Because it moves so quickly, light can seem to appear instantaneously. Think about when you turn on a TV... images pop up right away.
How does the speed of light affect our lives and what we know about the universe? To shed some light on the subject, power up this thought experiment:
Question: What if light could only travel 1 foot/second?
