Just for the fun of it, here's some melt-your-eyeballs chain reactions! Amazing creativity!
The Cake Server - Watch this insane machine do its job while the guy peacefully eats his dinner!
How to Pass the Salt While Maintaining Social Distancing - Carrots, marbles, and other random wackiness gets the job done! The Cake Server guy puts his mind to work helping with dining safety during the pandemic.
250,000 Dominoes: The Incredible Science Machine - This will totally wipe you out! It's 15 minutes, but the incredibly well-planned complexity of this gigantic domino reaction is worth the watch!
This Too Shall Pass - OK Go is a rock band that created a wacky chain reaction as a music video. Pro Tip: If you don't like the music, or find it distracts from watching the chain reaction action, just mute the sound!
The Way Things Go - This is one of the earliest chain reaction creations to send random items careening into each other to accomplish a task! The link opens a compressed 3-minute version of the chain reaction, which took longer to unfold in reality. See the full (29 minutes) version here.
A Better Mousetrap - The creative history of chain reaction machines, of course, must include Rube Goldberg, whose amazing chain reaction machines dominated the comics pages of newspapers back in the day. Indeed, his name has now entered the Oxford Dictionary: Rube Goldberg: adj. (of machines and devices) having a very complicated design, especially when used to perform a very simple task. Check out his wonderful inventions!
Guinness World Record for Largest Rube Goldberg Machine - The 5-minute video greatly compresses everything that happens in this mammoth chain reaction, so you miss details, but the complexity is marvelous as it "gets the job done."