What is movement and velocity ?

Hi there,Modern physics is described by two theories: gravity is described by general relativity, and everything else by quantum field theories in the standard model.In general relativity, the ‘gravitational field’ caused by massive objects defines the geometry of space-time. This geometry is encapsulated in how we measure distance.For example, imagine finding the distance between two points (x1,y1) and (x2,y2) on a 2D plane (The Distance Formula | Purplemath). The distance s is given by pythagoras theorem in ‘every day’ geometry:S^2 = (x2-x1)^2 + (y2-y1)^2However, general relativity tells us that this formula changes in the presence of massive objects. So we put the distribution of matter and energy in to general relativity, and it tells us what formula to use to calculate distance. If we can solve all the equations...I hope that helps, but bear in mind that general relativity deals with 4 dimensions not just 2. Also, I don’t know how much maths you’ve done, so apologies if this is too hard or too patronising!OliEdit: so in the presence of massive objects all the effects described by Son Goku occur on the background of the different geometry. But no one knows how quantum mechanics works with general relativity (least of all me).Edited by Oli, : Just saw post by Son Goku.Edited by Oli, : No reason given.