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websterhamster t1_j98s3tz wrote

I love how they used the extremely technical and scientific benchmark of Rice Krispies to compare the noise level of the Artemis I launch.

I mean, forget explaining decibels. Rice Krispies is something everyone can understand.


evanc3 t1_j99dk3g wrote

So if you're at postion, and you change position, we call that velocity. If you change between two velocities we call that acceleration. If you learned this in school you would call these derivatives. Well when you take the derivative of acceleration, you get something called jerk. And the derivative of jerk is called jounce.

But jounce is a horrible name, so they started calling it "snap". Naturally this lead to the next two derivatives being called "crackle" and "pop".

These aren't the official names, but they don't have official names so "position, velocity, acceleration, jerk, snap, crackle, pop" is officially unofficial


marketrent OP t1_j98sh5l wrote

From the linked release:^1

>At 1.5 km from the pad, the maximum noise level reached 136 decibels. At a 5.2 km distance, the noise was 129 decibels, nearly 20 decibels higher than predicted by a prelaunch noise model.

^1 The Roar and Crackle of Artemis 1, AIP Publishing, 14 Feb. 2023,


RollinThundaga t1_j990ccl wrote

For general reference; a 10 decibal increase in sound intensity is an apparent doubling of the loudness.

130 decibels is the human pain threshold. A lawn mower is around 90 decibels. A normal conversation is about 60 decibels.


marimbawarrior t1_j9b6arb wrote

Key word: apparent. Actual doubling of sound pressure levels is every 3dB. Every 10dB added is 10x the energy. (Sound energy and volume are two different things but they’re directly proportional)

Honestly surprised that it’s only 136 dB around the rocket. Also surprised that they didn’t also state the C-weight, as that would highlight more of the low end you get from the rocket itself. There’s a ton of low end that’s being tossed out (for good reason) when they A-weight.


mmgoodly t1_j9dkgev wrote

No bone to pick with most of what you wrote... but

> around the rocket

1.5 kilometers from the rocket.

IMMEDIATELY around the rocket (which is what I'd mean if I said simply "around the rocket") would be a different story. Obvs.


marimbawarrior t1_j9dtbw4 wrote

True! Inverse square law can help us out here.

Just punched the numbers in, 26 dB louder if you were located 80 meters away from the rocket, or roughly 162 dB. So yeah, 136 dB from 1.6 km would make total sense.


Raed-wulf t1_j9a9jew wrote

Yeah but 40 million is a hard number to grasp.

If they were being true Americans about it, they’d say it sounded like being 2 football fields away from a machine gun firing full auto into the side of a tractor trailer.