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I am confused about the directions of states and normal coordinate system Can somebody help me ?

Thanks

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- Thread starter Quarlep
- Start date

- #1

- 257

- 4

I am confused about the directions of states and normal coordinate system Can somebody help me ?

Thanks

- #2

mfb

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What does that mean?In The Theoritical Minimum

If you measure the spin direction of a particle with spin 1/2, the only possible measurements are "up" and "down". If the particle has a different spin, the options are different.

Which normal coordinate system?

- #3

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Therefore you can have spin directions in each and any direction. The theory is perfectly well developed and used e.g. in neutron diffraction.

https://www.ill.eu/en/instruments-s...-it-works/spherical-polarimetry-with-cryopad/

- #4

Nugatory

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In The Theoritical Minimum we shown all spins states use just two states up and down. How can we do that.?

Think of spin-up as a vector pointing east and spin-down as a vector pointing north. We can write any vector as a linear combinations of those two. For example, north-east would be the vector sum of north and east, southeast would be their east minus north, and so forth.

The confusing thing is that the "directions" these vectors point in their abstract vector space isn't the same as the direction that the spin angular momentum vector points in the real world. Spin-up and spin-down are represented by orthogonal vectors in the abstract vector space, even though up and down are opposite directions.

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