How does a whip break the sound barrier? (Slow Motion Shockwave formation) - Smarter Every Day 207
Why Hacker News recommends it
Recommended as the clearest footage of a whip tip going supersonic, and cited in shockwave discussions.
What it is
Smarter Every Day uses high-speed and Schlieren photography to show how a whip crack is a supersonic shockwave formed at the tip. It references academic papers on whip physics.
Recommended by 2 HN commenters across 2 different months, 2019 to 2023.
What Hacker News said
Strong rec wolfram74 · 2019-03 · on “Nasa captures images of supersonic shockwaves”
As mentioned by others, the photography technique looks like (and apparently is a software enabled variant of) Schlieren photography. This(1) is a neat example of an old school Schlieren set up capturing shockwave formation during whip cracks. I highly recommend it. (1) [this video]
Strong rec nuccy · 2021-12 · on “Supersonic Trebuchet”
Fun fact, you can accelerate an almost-everyday object to supersonic speeds: whip tip [1,2]. 1. [LINK] 2. [this video] (very much recommended)
Cites maxbond · 2023-04 · on “Sabine Hossenfelder: I think faster than light travel is possible. Here's why”
Point taken. Thanks for the explanation, that helped me a achieve a deeper understanding & blew my mind. This animation of a tachyon goes well with your explanation: [LINK] If you look for it, you can observe this effect in the high speed Schlieren footage of a whip in this video [this video] (you can skip to around 8 minutes) It starts to disturb the air, then the shockwave overtakes the disturbance, so you can observe them in the flipped order if you're in the sound universe.