The greatest need modern civilizations have is energy. Learn about oil, electricity and newer forms of energy like solar and wind power.
One way to store energy is to use a battery, like a lead-acid battery or a nickel-cadmium battery, but are there lighter or longer-lasting ways to store energy? There must be a better way!
Let's say you have a nice fire going, and it's reduced down to a pit of hot "glowing embers." If you now toss a piece of wood, or even a sheet of paper, onto this fire, you see a huge puff of smoke as it heats up.
An oscilloscope measures the voltage and frequency of an electric signal. A machine uses "sweeps" and and an input signal. See how it all comes together.
On the Flintstones, a small bird sits inside the light and turns it on every night before he goes to bed. In a modern streetlight, a small circuit replaces the bird.
You've probably never noticed how many of these you use everyday, but HowStuffWorks took the time to count them and take them apart to see what's inside!
Electrical power is a little bit like the air you breathe: You don't really think about it until it is missing. There are good reasons the power grid distribution system works the way it does, though it can lead to some big problems.
You've probably seen solar cells on calculators, call boxes, road signs, homes and businesses. But how do solar cells work?