Time symmetry is a concept in physics that suggests the laws of nature are the same regardless of the direction of time. This means that processes in the universe can occur equally well forward or backward in time. For example, if you were to watch a video of a glass breaking, the reverse video of the glass reassembling would not violate any physical laws, even though it is not a common occurrence in everyday life. In the realm of quantum mechanics, time symmetry plays a crucial role in understanding particle interactions. The principle implies that the fundamental equations governing particles, such as electrons and photons, remain unchanged whether time moves forward or backward. This symmetry helps scientists explore the nature of time and its relationship with other physical dimensions.