we say massive object bends spacetime, but space is same in all direction, then how do u decide which direction it will bend spacetime, for showing the movement of planet around sun is ok, wat about bending of space time due to earth mass because of which we are attracted towards it, if i use ur visual examples, then considering the earth is bending spacetime keeping south portion of itself to the downside, in that case people who are staying in the bottom most part of the earth should fall down to the bent of space time instead of coming towards earth center. Is there something which i m not able to imagine, can anybody help me with that?
1 Answer
The "rubber sheet" picture of spacetime is not an accurate one because (a) it only shows two dimensions whereas spacetime actually has four dimensions and (b) it shows the rubber sheet as being bent in a third external dimension ("extrinsic curvature") whereas the curvature of spacetime is actually internal to spacetime itself ("intrinsic curvature").
It is difficult to visualise the intrinsic curvature of spacetime, but you could think of large masses such as the Earth or the Sun as bending spacetime inwards, towards themselves.