 Thomas Edison, who's the inventor of the light bulb, the phonograph, he was a pioneer of motion pictures, but did you know he was also an elephant killer? It's true. In 1903, Thomas Edison oversaw the execution of Topsy, a circus elephant from Coney Island. Now you might be asking yourself, why would Thomas Edison do something like this? Well, before we can talk about that, we need to talk about some ACDC. No, not that ACDC, alternating in direct current. An electrical current is the flow of electrically charged particles, like electrons. In a direct current, all of the electrons flow in the same direction. Think about a flashlight. You have your battery, and the electrons flow from the negative end of the battery to the light bulb, then back to the positive end of the battery to complete the circuit. Circuits like these are the kind that Thomas Edison used in his lamps and motors. So when it came time for municipalities around the country to start building electrical grids, Thomas Edison had a financial incentive to make sure those grids used direct current to power his devices. But see, there was a problem with Edison's plan. Direct current isn't very good for transmitting a large amount of energy over a vast distance. As the electrons move through the wire, they encounter resistance. This can cause the wire to overheat, and even spark in a process known as line loss. What's the amount of available energy is the product of volts, the electrical pressure, and amps, the current. You don't have to be a scientist to know high voltage is dangerous. The signs are everywhere. So in order to be safe, you want to keep your volts low. But if you want to keep the same amount of available electricity, you have to increase your amps. The problem with this is that as you increase your amps, you increase the resistance in the wire, leading to more line loss. The solution to the line loss problem would be found by a former employee of Edison, a Serbian immigrant, Nikolai Tesla. Tesla had left Edison's employment after Edison failed to pay him $50,000. Keep in mind, that's like a million dollars in today's money. Edison claimed that he never made the promise and that Tesla didn't understand American humor. Tesla would go on to found his own company and develop his own means of electrical transmission, alternating current. Unlike a direct current where all of the electrons flow in a single direction, in an alternating current the flow of electrons periodically switches directions. This allows for the transmission of energy with very low currents, meaning you can send the electricity over long distances without line loss. Tesla was also able to develop step up and step down transformers, meaning he could send high voltage energy over long distances, but then step down to a lower, safer voltage closer to the customer. George Westinghouse, an entrepreneur and engineer, took notice of Tesla's alternating current. He worked with Tesla to license Tesla's ideas into lamps, motors and home goods. This led to a huge marketplace rivalry between Westinghouse and Edison. Edison attempted to frame alternating current as the more dangerous of the two. He tried to coin Westinghouse as a term for when someone gets electrocuted. He hired two men to work on the first electric chair and make sure it ran on alternating current. He even went as far as public executions of animals, which brings us back to topsy. Edison hoped that demonstrations like these would scare people away from using alternating current. But all the scare tactics in the world couldn't make up for the fact that alternating current was the better, more efficient way of transferring energy over long distances. Want to learn more about alternating than direct currents? Thomas Edison, Nikolai Tesla, Elephants, CheckoutSailor.org, like this video? Check out some of our other videos. They're all equal to or better than this one. Tesla was also able to develop transformers. Now I can think of transformers like Optimus Prime coming in here, should be right there.