I recently picked up Battlefield 1 for PlayStation 4 and have been having a great time playing through the story modes and jumping into multiplayer matches. For those who don't know, Battlefield 1 is a first person shooter set during World War I, so you're playing with some of the first automatic weapons, tanks and fighter planes.
When I was a kid, one thing I always had trouble wrapping my head around was how fighter pilots with propeller planes would shoot their machine guns through the propeller. I later learned it was all about timing the shots so they wouldn't interfere with the propeller by syncing up the gun and propeller mechanically. But knowing something is a lot different from seeing it.
Fortunately, a video is trending on YouTube right now on that very subject from the Slo Mo Guys. They built a replica of a WW1 fighter fuselage with a propeller and mounted a M60 machine gun on top. Once you see it in action, it's easy to see how it all worked.
Check it out: