timesymmetry
Timesymmetry, or time-reversal symmetry, is the invariance of physical laws under reversing the time coordinate t to -t. If a process described by a set of equations evolves as x(t), the time-reversed trajectory x(-t) should also satisfy the same laws. This concept appears in classical mechanics, quantum mechanics, and statistical physics, though its presence and meaning can vary by context.
In classical mechanics, Newtonian dynamics with conservative forces is time-reversal invariant: a trajectory that is allowed
In quantum mechanics, time reversal is represented by an antiunitary operator T. A Hamiltonian H is time-reversal
In statistical mechanics, microscopic dynamics are typically time-reversal symmetric, but macroscopic irreversibility arises from entropy and
Timesymmetry remains a foundational idea for formulating physical laws and interpreting experiments. Its study helps distinguish