Spacetime has two meanings. For a mathematician, spacetime is just a set of four coordinates. (Actually, they are not coordinates, but numberlines.) For a mathematical ‘physicist’, spacetime is a four dimensional object or manifold which he invokes in his vain attempt to provide a physical interpretation to gravity.
Essentially, spacetime is an unimaginable four-numberlined object, presented as a three-dimensional warped canvas projected onto a two-dimensional platform. Mathematical ‘physicists’ invoke this surrealisitc contraption to explain gravity.
Laymen are urged to visualize a mathematical concept known as ‘mass’ warping a fishnet ‘downwards’. Any object sitting on the canvas is seen falling into the depression. This is the physical interpretation that mathematical ‘physicists’ offer for gravity.
NASA illustrates this amusing mechanism of gravity on its website. It shows the Earth weighing down a fishnet.
the Earth bending down an unidentified object that looks like a fishnet. The question is: what medium provides background and shape to the fishnet if the fishnet is space + time?
A rational human being instantly questions the surrealistic claims made by relativists:
Whether there are anything other than three-dimensional objects (i.e., four-dimensional objects).
Whether spacetime is a physical object or a mathematical concept.
Whether the roulette-like mechanism is a valid analogy for gravity and has any merit. (i.e., Whether the Earth rolls around a depression that physically prevents it from flying out of the Solar System.)
Whether the spacetime depression is an explanation of a physical mechanism or a mathematical description.
Why can the Moon can go in and out, through the curved wall that impedes the Earth’s exit out of the Sun’s gravity well?
Whether the Earth can drag space around itself as claimed by NASA’s Gravity Probe B theorists. (Is space a physical object?)