Does anyone know Science Phenomenon

Phenomena can be defined as “observable events that occur in a natural or designed system.” They are everywhere around us, but some are easier to notice than others. Common examples of natural phenomena include lightning, earthquakes, tsunamis, volcanic eruptions, tornadoes, and similar.

i think it because equal matrices have equal dimensions, only square matrices can be symmetric. for all indices and . every square diagonal matrix is symmetric, since all off-diagonal elements are zero. in linear algebra, a real symmetric matrix represents a self-adjoint operator over a real inner product space.