Magic Spheres

Spoiler! Highliight to read:

The balls are quite dense. They are running on rails, which means they are rotating much faster than their movement would indicate. There's a lot of angular momentum stored.
That angular momentum is not lost when they collide and bounce off each other. In effect, as they move apart, they are "skidding" - they've lost traction, but are still rotating. Eventually the rotation gains traction on the rails and the spheres accelerate toward each other again.


Reviewing the video again, I can see confirmation that I am right. The balls are not perfect; there is an arrow marked on each of them which shows how they are rotating. You can see the arrows in the closeup (as a matter of fact, you can juuuust catch them at the start of the closeup - at 0:19 juuuuust as they disappear into the black reflection at the bottom.) They are rotating the same direction both before and after the collision.

 

Gee, that's complicated. I would have just filed a low spot in the rail.

 

:D The first post I made, which I deleted as superfluous, suggested the rails might simply be bowed in the center. But after more examination, I decided the demo was legit, not just a trick.

 

You're probably right. My eyes aren't that good any more; I can't really see the spin.

 

Hard to say without more data. Is it certain that balls/spheres are made homogeneous ?

 

Look at the sky reflection, right when they collide.

 

The density distribution seems symmetrical, given how uniformly they roll.

 

Okay, I've got it now. When I first looked at it, that arrow thingie just didn't quite register in my brain. It took half a dozen more viewings before it did. (I saw it; I just couldn't figure out what it was doing.) Maybe temporal dyslexia affects visual things as well as spoken ones.

 

I'm not sure why I only saw the arrows appear one time ?

 

Maybe there's sidespin as well, so they weren't in a visible spot earlier. Originally, once I realized that they were arrows, I suspected that they might have been digitally added to indicate spin, but that doesn't seem to be the case.

 

Because they cross the upper bright part only one time. But you see them also at 0:17 on the left ball, in the lower right part.

 

Thanks, yes:)

 

Did no one read my spoiler? It describes the arrows.

 

I just read the OP's "are they magnetic?", watched once, then read your spoiler, then watched again and it all made sense.

Once I realised the balls were rolling on rails the dramatic pushes and attractive reactions all fell into perspective.

 

I read it, and once I actually realized that they were physically present as opposed to CGI it made sense.

 

I can't understand what highlight to read, is supposed to do ?
Your next post said you deleted the first one.
Now you ask if no one read it ? I'm confused other than to say post #4 you say it's not a trick :)

 

I didn't get it at first either, just click and drag the mouse like you are selecting text to copy or quote.

 

Thanks, I finally figured it out :) I'm pretty simple minded when it comes to finding text that's not visible. :D
I did slide the mouse on the text that was visible and all that came up was +quote or reply

 

I believe this man is right. ( and I didn't say that because he looks like moses.)