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Comment by daemonologist | Hacker News Reader

Also (mentioned by Tom), this elastic-powered supersonic trebuchet is an excellent video: https://www.youtube.com/watch?v=gdXOS-B0Bus

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That device is so much more scary! Both really demonstrate the ridiculous amount of energy stored in a pinch of gun powder. And I presume gun powder is quite inefficient at driving the projectile, too.

I’m not sure dropping 50 kg 4 feet… is my idea of demonstrating the ridiculous amount of energy stored in something…

Well, let that drop on your feet. Or have those fat rubber bands slap you in the face... The small pinch of powder in a cartridge got the same punch.

It's not a nuclear bomb obviously, but I feel you would be just as dismissive, anyway.

This would qualify more as a Ballista than a trebuchet

https://en.wikipedia.org/wiki/Ballista

No it wouldn't... the projectile is still launched by the same angular motion of an arm and a sling basket the power for the rotation just comes from a different source.

the "shot you've been waiting for" was sort of anticlimactic, but the two plywood arm shots after show what it actually sounds like. I think the grass and tree dulled the sound a lot on the metal arm.

I actually have a camera that can shoot that at high speed (1200fps), but i'm sure other people have better cameras these days, mine has very low resolution.

Scientific research systems like the SCARF achieve 156.3 trillion fps but at greatly reduced spatial resolutions.

Is that the "nuclear potato cannon" one?

Slow Mo Guys have a Phantom that rocks up around 1.5 million FPS. They've used it to show how glass cracks etc. when you get to that speed though, you need a LOT of light, and a very low resolution.

i dont imagine the low resolution is per se essential the same way the light is. you could maybe figure out ways of syncing the data collection to match each other at that high of speed

It is because the main limitation for high speed digital video is the bandwidth of the pipeline from sensor to storage. Lowering the resolution increases the number of frames you can shove through the X Gbps pipe between the photons hitting the sensor and the highspeed memory the camera is buffering into.

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