Saw Stop - This guy puts a finger into an active table saw blade & comes away without a scratch!
Why Hacker News recommends it
Linked as the canonical demo of a safety technology that stops a blade before it injures a finger.
What it is
A short clip showing a person touching an active table saw blade with a finger and walking away unharmed, thanks to SawStop's system that stops the blade within milliseconds of skin contact.
Recommended by 2 HN commenters across 2 different months, 2015 to 2018.
What Hacker News said
Strong rec nickpsecurity · 2016-12 · on “The Resurgence of C Programming”
Case in point: [this video] Maybe we need to use your sharp tools point with that video. It drives the point home with even experienced people losing fingers to their tools followed by tech modified to prevent it. The demo also never gets old. Just too badass.
Recommends toothbrush · 2015-05 · on “The View from the Front Seat of the Google Self-Driving Car”
Wow, that's super neat, i'd never heard of it. Seems like something that should be absolutely mandatory for all factories equipped with such devices! Go technology! Here's a demonstration, it's very fluffy but it gets the point across. [this video]
Cites ljf · 2018-11 · on “Uber says air transportation drones are closer than we think”
/some/ power saws can stop instantly - if you try and touch this one with a finger it will stop before it can do damage: [this video]