101 Amazing Facts of Earth

For the science geek in you. Here's just the first 5 facts.

1. What is the hottest place on Earth?
	Count one wrong if you guessed Death Valley in California . True enough on many days. But El Azizia in Libya recorded a temperature of 136 degrees Fahrenheit (57.8 Celsius) on Sept. 13, 1922 -- the hottest ever measured. In Death Valley , it got up to 134 Fahrenheit on July 10, 1913 .
2. And the coldest place around here?
	Far and away, the coldest temperature ever measured on Earth was -129 Fahrenheit (-89 Celsius) at Vostok, Antarctica , on July 21, 1983 .
3. What makes thunder?
	If you thought, "Lightning!" then hats off to you. But I had a more illuminating answer in mind. The air around a lightning bolt is superheated to about five times the temperature of the Sun . This sudden heating causes the air to expand faster than the speed of sound, which compresses the air and forms a shock wave; we hear it as thunder.
4. Can rocks float?
	In a volcanic eruption, the violent separation of gas from lava produces a "frothy" rock called pumice, lo aded with gas bubbles. Some of it can float, geologists say. I've never seen this happen, and I'm thankful for that.
5. Can rocks grow?
	Yes, but observing the process is less interesting than watching paint dry. Rocks called iron-manganese crusts grow on mountains under the sea. The crusts precipitate material slowly from seawater, growing about 1 millimeter every million years. Your fingernails grow about the same amount every two weeks. You can see the rest of the list here.