@Peter Breuer

Suppose two matrices commute . How you will say that physically ?

B.Rath

@Peter Breuer

My question is related with quantum physics and uncertainty relation . Your

answers look nice for fun but not to write a paper in physics . My feeling is that one can measure simultaneously

violating uncertainty principle . Do you

agree with me ?

Reply.

B.Rath

@Wulf Rehder

Thank you for sharing your idea.

What happens in finite dimension ? In my view two matrices (N ×N ) dimension N=finite or infinite have one eigenfunction provided [A , B]=0 .

The order of measurement makes no sense as the eigenvalues remain invariant .

Thank you .

B.Rath

The way for multiply two matrices gives that are not valid for two matrices such (A) and (B) with order of (A) is 2*3 and the order of (B) is 3*5.

Here A*B is exist but if we take B*A we will not find an answer (not exist).