The Surprising Secret of Synchronization

Veritasium · 27.9M views · 2021 · 19:29

Open on YouTube

Everyday physics & science demosFundamental physicsexplainer

Why Hacker News recommends it

Cited as an intuitive illustration of synchronization, particularly the metronome demonstration.

What it is

Veritasium explores how synchronization arises spontaneously in nature, with metronomes, fireflies and bridges, drawing on Steven Strogatz's work on chaos and complexity.

Recommended by 1 HN commenters across 1 different months, 2021 to 2021.

What Hacker News said

Recommends sphericalgames · 2021-08 · on “Train Wheels Are Cones”

This video explains the problem - it is worth watching the entire video. If you are pressed for time jump to 15:00 mark [this video]

Cites juhatl · 2021-05 · on “Longest pedestrian suspension bridge opens in Portugal”

Apparently an incident took place in 1831 where a bridge collapsed under soldiers marching, but the Wikipedia article [1] notes that "The conclusion of the investigation was that the vibration caused by the marching precipitated the bolt's failure, but it would have failed eventually anyway". There's more interesting information on synchronization and bridges on Veritasium's video, The Secret of Synchronization [2]. [1] [LINK] [2] [this video]

Cites LeifCarrotson · 2021-09 · on “When listeners pay attention to stories, their heart rates rise and fall in sync”

There's some synchronization effects in metronomes and in industrial equipment. If you have several things that can oscillate, perhaps not at precisely the same rate but close, and the motions reinforce each other when they do achieve the same rate, you can get surprising synchronization. For an intuitive example, see this Veritasium video, starting at around 4:50: [this video] . This happens in crowds of people, for an example, the London Millenium pedestrian bridge wobble: [LINK] . I was initially curious how this could happen with a heart rate; I could imagine some shared feedback mechanism for walking, or breathing, but a shared feedback for heart rate was surprising. Perhaps if they were tou