4 ms·
Yes, "Truth quark". Because they don't exist naturally it lead my physics prof to say "There is no truth in the universe". Also, Some physicists call the fourt
by reedf1 6y ago
Yes, "Truth quark". Because they don't exist naturally it lead my physics prof to say "There is no truth in the universe".
Also, Some physicists call the fourth, fifth, and sixth derivative of position, "snap, crackle, and pop" respectively. Physicists are a fun lot aren't they?
- lovemenot 6y agoT and B retained. They clearly like symmetry, even through terminological adjustments. Not defending BBC's using non-prescribed terms, but quarks were always named whimsically. The word quark itself having been taken from Ulysses. It's hard to argue with snap following jerk, then acceleration then velocity. The next two follow snap, if not physically then at least historically.
- jcims 6y agoAlso jounce, flounce and pounce lol https://en.wikipedia.org/wiki/Fourth,_fifth,_and_sixth_derivatives_of_position https://en.wikipedia.org/wiki/Fourth,_fifth,_and_sixth_deriv... I thought were all useless terms but apparently snap is quite commonly used in quadrotor motion control.
- rocqua 6y agoSnap is that feeling you get when a train is braking and comes to a halt. The breaking force suddenly falls of, which is noticeable. In general, snap shows how smoothly the acceleration occurs. This allows anything that flexes (like flesh) to slowly take-up the slack. I've also heard this is important for self-driving convoys. You want the cars in the convoy to all accelerate and brake smoothly rather than jostle all the things inside them.
- b3orn 6y ago> In general, snap shows how smoothly the acceleration occurs. That's third derivative of position and called jerk.
- ragebol 6y agoNot just quadrotor motion control, it applies to precision machinery as well. Eg. it's used in those big ASML wafer stepper machines that help power Moores Law for example, but also 3D printers etc. Low values for these derivatives help reduce vibrations in the machines IIRC.
- DrBazza 6y ago> Physicists are a fun lot aren't they? Atomic cross section is measured in barns. As in "you couldn't hit a barn door".
- quchen 6y agoIn particle physics a barn is a huge area though, so the joke kind of makes sense there.