I have a healthy respect for electricity. After all, it is both deadly and wondrous at the same time. One of the benefits of studying science at this level is that you get to learn about how ordinary, everyday things work at the most basic level. So what is electricity? We all use it, but how does it work? All you scientists out there can maybe skip this post, as you already know all this, but knowing you guys, you will read it anyway out of curiosity to see if you disagree! To start with, electricity only happens in stuff with free electrons. An electron is part of an atom, the part that encircles the nucleus. In some stuff, electrons are rather free, as opposed to being bound in atoms. The latter, we call Insulators, the former, Conductors and Semi-conductors. Electricity is basically the movement of these electrons from one end of a piece of stuff (usually called a "wire")to the other. But what makes them move? Scientists like to call it "electro-motive force." Fancy name for a simple concept! Actually, the concept boils down to holding another piece of stuff to one end of our "wire." This other piece of stuff has lots and lots of extra electrons on it, and since electrons are repelled by each other (as they are all ugly), the free ones in our wire try to get away by moving along the wire. This movement is called "current." Sounds simple? Well, it is. However, one thing puzzled my young mind. I discovered that the drift velocity of the electrons in the wire was only about 0.5 cm per second. Huh? But when I flick the light switch, the light comes on IMMEDIATELY! What is that all about?!?!?!? I had to figure this out for myself. And I reckon I should give my readers (I know I have them!) a chance to try and figure out the answer for themselves too, given my information above. Oh, and you will need one other snippet of information ~ the density of electrons in conductors is at least 1,000,000,000,000,000,000,000 to the cubic centimeter. Good luck and watch out for future posts.