Dirac's Belt Trick demonstrated with long hair

Demonstrations of the fact that spinors have symmetry under 720 degree rotation but not under 360 degrees.

This is an area of mathematics called Topology. The formal definition of what i've explained is that SU(2) (which double-covers SO(3)) is simply connected.

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[WSallai]

Your demonstration utilizing the water-filled glass had me repeat that section of your video 3-times! Fun!

[SCDarkZide]

I have been dealing with QM for a while, but this is the first time I see this kind of trick explaining how spinors work. I have been quite in awe for several minutes and cut one of my sheets just to really believe it. This is amazing. Thanks for the explanation!

[kamilpeteraj]

That was a better explanation than the dozens I’ve seen given by physicists! Bravo!

[RyanRidden]

Great video! Who knew you could demonstrate so much with hair. Looking forward to your next video!

[fuseteam]

the spinor is so mind boggling yet so natural D:

[tombufford]

We are able to enjoy your beauty and mathematics Toby !

[wyocoloexperience]

What a great video. Are you teaching at a University yet. I think you would make a great professor.

[greywolfwalking]

Thank you for your illustrations.. I do believe that you have a great way of communicating your intended lessons.. I happen to find your technique very intetesting!!
Thanks!
GWW... Ooouuuttt!!!

[martm]

A voice to lull one into sweet dreams. Not that I mean you send me to sleep! Far from it. Your explanations are always as clear as possible and render these often arcane topics understandable, or almost understandable, and fascinating even to a sciences dunderhead like me. And I wish I could smile as I speak the way in which you do. But when I try it comes out like some extremely obscure dialect of Chinese. 😳

[lokmanmerican]

Are there objects that need even more rotations to come back to the original state? This presentation is excellent!

[jaimeduncan]

Notice that the system can be defined eminent each case si that a 360 rotation and a 720 are equal. All the systems shown are conectes to an external system and that brines the symmetry, but this is a characteristic of the systems shown as examples l.

[seanscon]

Good afternoon.
I came here from Dirac Belts, and as a physicist, I enjoyed this thoroughly . May I make a suggestion to use a darker background next time, as your hair is fair in color?

Besides your beautiful hair, you seem to really enjoy physics, as much as I do :) I see you have used it for many a description about QM. I wish I met you when I was a student myself. It would have made the QM lessons more enjoyable :) and the gruelling hours self inflicted study of representation theory something to look forward to ;)

Good luck for the time being and stay in touch.

[billm]

Another wonderful video! I'm not sure which is more adorable, your eyes, your freckles, or your amazing hair. Rock on! ♥

[NotTheSharpestKnife-mh]

To be clear, this is about rotating part of a connected object without rotating the other connected part. The connections to a non-rotating part are the catch.

[massecl]

The first one with the bowl is not a belt trick. Observe that the two halves of the rotation are in reverse direction, they seem to be in the same direction because the axis is the one in the inverse direction.

[tombufford]

Setting up a rotation framework for a Rubic Cube program. I have written this before, however the computer failed ! Not as exciting as your demonstration. I would not usually watch this, however I trust you Toby. 720 degrees rotation to reset with out further rotations. My cube blocks may require 3 repeat sequences to reorientate individual faces.

[geraldhiller]

Wonderful video! May I ask where that last animation is from? That’s probably the most enlightening visualization of a spin half particle I’ve ever seen - even though the water glas is the most fascinating.

[RichMitch]

Ooooohhhh. Any plans for a Dirac video? Explaining the equation Bob Ross-esque

[massecl]

It's not that mysterious, it can be understood with good ol' Euclid geometry. The angle to two points on a circle is twice as large from the center than from another point of the circle, taken on the largest arc. Rotate one point a full turn and observe what happens.

[koheiendo]

Thank you for uploading videos these days!! You have beautiful hair! Do you plan to get your haircut? I don't want you to get your haircut:)