what is a spacetime

Answer 1

Spacetime is a theoretical concept in physics that combines the three dimensions of space with the one dimension of time into a single four-dimensional continuum. It is the framework in which events and physical phenomena are described in the theory of relativity, both the special theory of relativity (which deals with objects moving at constant speeds in straight lines) and the general theory of relativity (which deals with accelerated motion and gravitational fields). Spacetime is considered to be a flexible and dynamic structure that can be curved and warped by the presence of mass and energy, as described by Einstein's equations of general relativity.