Buh-bum. Buh-bum. Buh-bum. We all have our own interpretations of what a heartbeat sounds like but here is what it looks like during heart surgery. It looks like it's rolling in place inside your chest. Pretty amazing.
You gotta love it when science goes goth. Gallium, a silvery metal, can be made to pulse like a living heart when touched with an iron nail. Take a look at a robot's heartbeat, and find out how this metal heart works!