<human>:  Why is the metric tensor a symmetric function in the work of Hermann Minkowski?
<bot>: Because the metric tensor is the metric of the Minkowski spacetime. Minkowski was a mathematician who worked on special relativity. He discovered that the laws of physics are invariant under Lorentz transformations, which are transformations that preserve the speed of light. He also found that the laws of physics are invariant under the group of transformations that preserve the metric of the Minkowski spacetime. The metric tensor is a symmetric function because it is a function of the four-dimensional spacetime coordinates.