No, not all laws of physics work if time is reversed. The behavior of physical systems can depend on the direction of time, and reversing the direction of time can lead to different outcomes in various processes.
In classical mechanics, the laws of physics are generally time-reversible. The equations of motion, such as those described by Newton's laws, are symmetric under time reversal. If you reverse the direction of time in a classical system, the system will follow the same trajectory backward.
However, when we move into the realm of quantum mechanics and statistical mechanics, time reversal symmetry is not always preserved. The fundamental laws of quantum mechanics, such as the Schrödinger equation or the equations of quantum field theory, are typically time-reversible at the microscopic level. However, the statistical behavior and the interactions between particles can break this symmetry.
For example, certain processes involving the weak nuclear force violate time reversal symmetry. These processes, known as weak interactions, exhibit a phenomenon called "CP violation" (violation of combined charge conjugation and parity symmetry), which implies a violation of time reversal symmetry as well. These violations were experimentally observed in studies of particle decays and have been a subject of extensive investigation in particle physics.
In cosmology, the arrow of time is linked to the second law of thermodynamics, which states that the entropy (a measure of disorder) of a closed system tends to increase over time. This increase in entropy is what gives rise to the distinction between past and future in our everyday experience. The behavior of macroscopic systems, subject to statistical mechanics, is irreversible and not symmetric under time reversal.
In summary, while some fundamental laws of physics are time-reversible at the microscopic level, the statistical behavior of systems and specific interactions can break this symmetry, leading to irreversible processes and the arrow of time that we observe in our macroscopic world.