Rube Goldberg Machine - What's that?

Have you ever seen the band OK GO's music video for their song "This Too Shall Pass"? One of the members of the band used a car to knock down a set of dominos, which leads to more and more convoluted things happening, like balloons being let out of a cage and, in the end, the members of the band being paintballed. Cool, right?

So, why couldn't the band members just set up the paintball guns to shoot automatically? Why all the crazy processes in between? That's the whole concept of the Rube Goldberg machine, named after a cartoonist and inventor who was famous for his silly cartoons where a complicated machine would do a very simple job, like wipe someone's face. The whole concept of a Rube Goldberg machine is to do a simple task in a very complicated way using a chain reaction.

So what's the science behind it? Why does this chain reaction work? Well, the whole process works due to the law of conservation of energy. This law states that energy can not be created nor destroyed, but it can change form. So, when the car hits the domino in the video, the energy from the push that the band member gives the car is transferred to the domino. The energy is too much for the domino to handle, so it falls down and hits the next domino, transferring the energy again. The same energy keeps moving through the system in different forms, like spinning a tire or pulling a string, until it reaches the end and sets off the paintball guns. 

So, what happens at the end of the process? We just said that energy can't just disappear. What happens to the energy once the paintball guns are set off? Over the process, there's some loss of energy due to different factors. Some energy's lost in heat, some due to friction (like when the marbles roll through the frame), and countless other reasons. At the end, the energy transfers to the paintballs, and the last left amount of energy is enough to propel the paintballs at the band members and hit them.

Now that you know the basics of how a Rube Goldberg machine works, it's pretty simple to make one yourself! Pick a simple task, like ringing a bell or dropping a ball in a cup. Then, use any materials that you have lying around (the sillier, the better) and try to put as many steps in your chain reaction as possible. The more transfers of energy, the better! The genius of the Rube Goldberg machine is that you can be as creative as you want to be; there's no wrong way to do it. Good luck!