Spool Trick

Today I'm doing a two-part experiment involving a spool. I've wrapped some nylon rope around the spool, and right now it's coming over the top, as you can see. I'm going to place the spool down beside me, and I'm going to pull the rope horizontally towards me.

I want you to make a prediction: what's going to happen when I pull the rope? Will it move to the right or to the left? Or does it depend on how I pull the rope?

It will go this way; it'll go to the left. I don't know why, but it will. I think it'll go to the right. It depends on how you pull it. What do you reckon?

If it's loose, yeah, it's just going to spin around on the sp—on the blue bit. But if it's tight, it's going to come toward—no, it's going to stay where it is; it's going to unwind.

I'd like you to make your prediction now by clicking on one of the annotations. Now, I should point out that this is only the first part of the experiment, so try not to overthink it. If you're on a mobile device, you can find the links in the description below.

All right, are you ready? 3, 2—[Applause]—1.