Screwball

[_MIA_]

pattar, how about some knuckleball science?

Lol..I am off the clock. Maybe later..

 

[_MIA_]

pattar, how about some knuckleball science?

This is just a guess...

First thing to note is that balls without seams knuckle, for example soccer balls so one can assume that it isn't (predominantly) a seam effect. So with that assumption, the fluid dynamics of non-rotating smooth spheres is pretty well known. For a certain range of Reynolds numbers (a non-dimensional number which combines velocity, diameter and air viscosity) unsteady vortex shedding occurs. Here is simulation of that effect over a cylinder (same idea):



This causes unsteady (e.g. time-dependent) forces to be generated on the ball which is why you see the ball dart in different directions..the force is not constant and is changing in time.

This same physics actually caused this:





Edit: Whether that phenomena caused that is still up in the air actually..some other physicists give a valid explanation why it wouldn't be the cause..in any case luckily they know not to design bridges like that anymore

 

[Rolling Hard]

This is just a guess...

First thing to note is that balls without seams knuckle, for example soccer balls so one can assume that it isn't (predominantly) a seam effect. So with that assumption, the fluid dynamics of non-rotating smooth spheres is pretty well known. For a certain range of Reynolds numbers (a non-dimensional number which combines velocity, diameter and air viscosity) unsteady vortex shedding occurs. Here is simulation of that effect over a cylinder (same idea):



This causes unsteady (e.g. time-dependent) forces to be generated on the ball which is why you see the ball dart in different directions..the force is not constant and is changing in time.


This same physics actually caused this:

Awesome stuff. Dog Lives Matter? You have to watch the whole bridge video to get it.

 

[efastball]

FYI, baseball curve/slider looks different to the hitter depending on the initial 2S or 4S grip. (It's not always a dot)

(I taught my son to use both grips on curve/slider, and suggested that he reverse the grip if he threw a back to back curve)

 

[radness]

This is just a guess...

First thing to note is that balls without seams knuckle, for example soccer balls so one can assume that it isn't (predominantly) a seam effect. So with that assumption, the fluid dynamics of non-rotating smooth spheres is pretty well known. For a certain range of Reynolds numbers (a non-dimensional number which combines velocity, diameter and air viscosity) unsteady vortex shedding occurs. Here is simulation of that effect over a cylinder (same idea):



This causes unsteady (e.g. time-dependent) forces to be generated on the ball which is why you see the ball dart in different directions..the force is not constant and is changing in time.

This same physics actually caused this:





Edit: Whether that phenomena caused that is still up in the air actually..some other physicists give a valid explanation why it wouldn't be the cause..in any case luckily they know not to design bridges like that anymore

again with the pink floyd video's
Like it!

The bridge one reminded me of the mothman prophecies...
Guess thats where my brain was in class