Even though it's tiny compared to the rest of the universe, Earth is a complex planet that, so far, is the only one we know of that sustains life.| HowStuffWorks
The light bulb hasn't changed a whole lot in its 120 years -- the original design was just that good. Apparently, you can throw together a filament, a glass mount, an inert gas and a bit of electricity and change the world. Learn what happens when yo| HowStuffWorks