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Comment by lake_vincent | Hacker News Reader

Wait, meaning the third derivative of the what is already the second derivative of position - so snap = 5th derivative of position? Is there an intuitive explanation for this?

Just checking my understanding.

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Linked elsewhere, the Wikipedia page is pretty good: https://en.wikipedia.org/wiki/Fourth,_fifth,_and_sixth_deriv...

The Wikipedia page on Jerk also has a good explanation for the how people feel that: https://en.wikipedia.org/wiki/Jerk_(physics)

I'm unsure if we can really feel Snap and beyond.

Snap, or jounce, is the fourth derivative of position.

I thought that was called "jerk".

0th derivative = position

1st derivative = velocity

2nd derivative = acceleration

3rd derivative = jerk

4th derivative = snap

5th derivative = crackle

6th derivative = pop

I just learned the last 3 due to this discussion and Wikipedia[1][2].

[1]: https://en.wikipedia.org/wiki/Fourth,_fifth,_and_sixth_deriv...

[2]: https://en.wikipedia.org/wiki/Snap,_Crackle_and_Pop

Thanks! Very enlightening.

It gets crazier:

−7th: absop

−6th: absackle

−5th: absnap

−4th: abserk

−3rd: abseleration

−2nd: absity

−1st: absement

https://en.m.wikipedia.org/wiki/Absement

Jerk is the third derivative of position and is very familiar to anyone who has ever ridden a bus or other vehicle with not-so-smooth acceleration curves.

Are there intuitive examples of snap, crackle and pop?

What are they used on?

(Very nice to think about)

Intuitively I think you would be able to tell the difference between a jerk and a snap. In a car experiencing jerk, you would find yourself no longer able to balance against acceleration and you would sway. In a snap, you would not just sway, but really bounce around. Think the difference between hitting the gas pedal in ludicrous mode vs hitting the gas pedal while driving over potholes.

Crackle and pop, I have no idea if you could tell the difference.

An interesting fact: it has been shown ([0], [1]) that human body movements are performed in such a way as to minimize the jerk, so the jerk is used in robotics to make humanoid robot movements look more natural.

[0] https://doi.org/10.1109/TAC.1984.1103644

[1] https://doi.org/10.1523/JNEUROSCI.22-18-08201.2002

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