#### Alladi Ramakrishnan Hall

#### Time in classical and quantum physics.

#### Prof N.D. Hari Dass

##### TIFR-TCIS, Hyderabad.

*Abstract: I examine a number of subtle issues concerning time in both*

classical and quantum physics. These are: parametric vs physical time,

meaning of absolute time in Newton’s mechanics and Galilean relativity,

parametric vs physical time in quantum theory, time-energy uncertainty

relations, difficulties with operator time, Pauli’s theorem, Aharonov-Bohm time

operator, time and measurements in quantum mechanics, time of occurrence

vs time duration,quantum clocks, consistent treatment of lifetimes in

quantum theory etc. I shall conclude by discussing the very interesting

Page-Wootters formalism which appears to remove many of these difficulties.

Done