Self-Balancing Machines are Some Satisfying Engineering

Here are two machines, both capable of balancing themselves using the power of reaction wheels. First, it's kind of amazing that people do this every day without even thinking about it. Second, it's really amazing that someone figured out how to engineer self-balancing machines out of a few motors and strategically placed wheels. For some funny engineering, here's a dude who kicked up his video game rumble several notches.