# Does all measured quantities by Hamiltonian operator should be real valued? [duplicate]

am not familiar with QM , and i have checked web many times to know wether all measured Quantities of any arbitray system should be real since it is Hermitian ?

• Yes, we use Hermitian operators because everything we measure (positions, velocities, momenta, accelerations, forces, energies, etc.) is real, not complex. So we need the eigenvalues to be real. – G. Smith Aug 12 at 23:04
• – AccidentalFourierTransform Aug 12 at 23:10
• Your question is kind of convoluted and the wording is difficult to decipher. The possible measurements of a QM system will be the eigenvalues of the Hermitian operator and these are real. The requirement of a real valued observable forces the operators to be Hermitian. – ggcg Aug 13 at 3:00