Spinor rotated twice

Most people don't understand the difference between vectors and spinors. Both are directed entities. They have feet and a head. What are you, reader, a vector or a spinor?

You might think that rotating your body by 360° or 2 pi would return it to its former position. Reader, you're wrong. You must rotate your body twice, i.e. by 720° or 4 pi, before your initial position is retrieved.

Vectors need a single rotation. Spinors, by contrast, require a double turn. Reader, you are a spinor!

In this movie, your body is represented by a plastic can formerly filled with milk powder. The can becomes spinor when it is connected to its environment via elastic ribbons. In this movie, the environment is represented by students on the left- and right-hand sides. They hold the ends of the ribbons. The student in center rotates the can twice. Finally he demonstrates that the ribbons, apparently being twisted, can be disentangled without any rotation.

After a single rotation, disentanglement is not possible. This is shown in a companion movie:

For an example showing that each palm of yours is a spinor, too, watch

Instead of the elastic ribbons it is now your arm which connects the palm with its environment.

All parts of your body, reader, consist of electrons, protons and neutrons. They all have magnetic moments and are connected to their surroundings via magnetic field lines. They all are small spinors combining to make you a gigantic spinor.

The basic idea that the difference between vector and spinor comes from a stronger binding of the spinor to its surroundings was probably frist pronounced by P.A.M.Dirac. However, that a spinor and its binding to space can be visualized using trash materials, was first demonstrated in a lecture on quantum electrodynamics in 2009, see

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Ulrich Brosa