So I understand the commutation laws etc, but one thing I can't get my head around is the fact that L^2 commutes with Lx,y,z but L does not.(adsbygoogle = window.adsbygoogle || []).push({});

I mean if you found L^2 couldn't you just take the square root of it and hence know the total angular momentum. It seems completely ridiculous that you could know the square of the total angular momentum is 100, but not know that the angular momentum is therefore 10. Either that, or the textbook explains it horrifically and you can know the total angular momentum squared which is a scalar and hence you can know L scalar but L generally has direction, so they use L^2 to be explicit that it's a scalar.

Please elaborate. Cheers.

**Physics Forums - The Fusion of Science and Community**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Angular momentum Operators and Commutation

Loading...

Similar Threads - Angular momentum Operators | Date |
---|---|

I Measurement Values for z-component of Angular Momentum | Nov 18, 2017 |

I Adding types of angular momenta | May 14, 2017 |

I Angular momentum operator commutation relation | May 10, 2017 |

I Angular momentum raising/lowering operators | Mar 23, 2017 |

A What are L+ and L- matrices for l=3 ? | Jan 9, 2017 |

**Physics Forums - The Fusion of Science and Community**