The speed of light in a vacuum is the absolute speed limit of the universe. Nothing will go faster than 299,792 kilometers ...

That's six minutes and four seconds for a light-speed round-trip. But on average, Mars is about 158 million miles from Earth — so the average round-trip communication takes about 28 minutes and ...

As I watched shooting stars from our campsite in the Virgin River Canyon south of St. George, Utah, I could not get my mind ...

There's no possibility of time travel. I asked Wang why light goes 186,282 miles a second (299,792 kilometers per second) and not some other speed. "That's just the way nature is," he said.