What do an egg and a paintball have in common?

[Star_Base_CGI]

The answer is angular momentum.

http://physics.iop.org/IOP/Press/PR2102.html

http://www.ecst.csuchico.edu/~kend/potw/archive/000428sol.html

Dying eggs but cant remember which ones are cooked?

A soft boiled egg will spin faster than a raw egg..

"How do I tell if an egg is raw without breaking it?
Spin a cooked egg on a table and when you gently touch it, it comes to a complete halt; do the same with a raw egg and when you gently touch it and let go, it carries on spinning. When you spin the egg-shell of a boiled/solid egg, all of the egg - from the eggshell to the yolk - should immediately start spinning. When you touch the boiled egg to stop it, everything on the inside of the egg should immediately stop and stay stopped when you let go. When you spin the raw egg, the eggshell will spin, but the jelly-like insides will lag behind a little, energy will be wasted in the form of friction and the egg will probably spin a little slower. When you touch the raw egg to stop it, the soft jelly-like insides are still spinning, and the friction force slowly starts the egg spinning again if you let go of the shell. An eggs-periment to try at home. "

[FooTemps]

That's why rifling doesn't work with a paintball. The liquid prevents the paint from spinning enough for it to be effective... I forgot where Tom posted it but there was an insane amount of RPM required for paintball spinning to work well.

[bjjb99]

Has anyone actually spun a raw egg and a paintball to see how each behaves, or is all this just talk?

I ask this because I have done both, and paintballs behave nothing at all like raw eggs at the spin rates generated by a human hand. If spinning a paintball were as difficult as people claim, then the backspin-inducing systems (Z-body and Flatline barrel) generating spins of approximately 10,000 rpm would not work either. Since they do work, it logically follows that spinning a paintball at those rates is not difficult.

What Tom said (I believe, since I too am working from memory here) is that the axial spin induced by rifling does not affect the accuracy of a paintball in any significant way, even at obscene spin rates. What he did not say (I believe, since I too am working from memory here) is that spin is not achievable because the fill prevents it.

BJJB

[hitech]

Originally posted by bjjb99
What Tom said (I believe, since I too am working from memory here) is that the axial spin induced by rifling does not affect the accuracy of a paintball in any significant way...

What Tom said is that spin under 6000 RPM has little effect. I believe that he was unable to produce "side spin" that was greater than that with "rifling".

BTW, the insides of an egg and the insides of a paintball have very little in common. The both have a hard shell with some liquid inside. However, that is where the similarities end.

[Wat]

There is a huge difference between back spin and axial/rifled spinning.

In an axial rifle spinning, the effect we are wanting is a gyroscopic effect to make the projectile want to stay in its current orientation. A liquid fill screws this up because gyroscopic effect is all about your rotational inertia so if your mass is not rotating but your surface is rotating then you don't get your desired effect. Tom Kaye spun a barrel up to a lot of RPM's and gave the paint enough time so the liquid would spin also before being fired and noticed nothing worthwhile. Thats because spheres are perfectly symetrical and thus the moment of rotational inertia is the same regardless of the axis you choose. I would bet that if you took one of those sniperballs or AGD non lethal rounds it would make a bigger difference.

Now, backspin has nothing to do with rotational inertia, all that is important is the surface effects of the fluid flow. It makes no difference if there is a liquid fill or solid fill as the rotational inertia or angular momentum is not the property relevant to the effect we're looking for with backspin.

Eggs and paintballs are both edible and both in large quantities will shorten your lifespan.