Thanks Noel. If you can get to visualize SpaceTime then it starts to make “sense” (unlike QM on the smaller scale). Any object with Mass is sitting in a “field” of Spacetime, like a fabric made up of millions of threads which vibrate with different Energies which travel along them as Waves. This “fabric” is stretching because the Universe is expanding and stretching out in all directions, like an ever inflating balloon. This expansion is still accelerating, 13.8 billion years after it began.
When an object “sits” into this fabric of Spacetime it warps it. I think of a boeling ball sitting on a huge pool table and its base is made of sponge. You can see the dent it makes. Then think of a pool player at the edge trying to shoot a pool ball past the bowling ball. It will travel most of the way in a straight line but when it “falls” into the bump made by the pool ball it gets trapped and spins around it.
Newton would have described this as the Mass of both objects attracting each other, the effect known as Gravity. However Einstein explains that what is really happening is that because Spacetime is warped by the bowling ball, the pool ball is captured in warped SpaceTime around it. Both the bowling ball and the pool ball “think” that they are still travelling outwards in a straight line. The pool ball is not aware that it is trapped in the orbit of the bowling ball.
All this “time” the “space” between the two balls is being stretched further. The 2 planets are not moving away from each other but rather the “field” or fabric of SpaceTime between them is expanding so they appear to be moving away from each other. The Earth and Moon are like this. The field between us is expanding so the curvature will decrease. This is happening at a rate of about three inches ever ten years (needs confirmation). We can tell this by firing lasers at mirrors we left on the moon!!
At some point in the future they will move far enough apart because Spacetime will have straightened out the “dent” in its fabric. Then what we observe as Gravity (the warping of Spacetime) will not see either object have any force exerted upon the other and the pool ball will continue to travel towards the corner pocket.
This is the fate of the Universe. At some future point if Humans still exist, we will look up at the “night” sky and see no lights. The spaces between all objects will have expanded so much that Spacetime will exert no influence for there will be nothing “nearby”. There will be no night or day. Everything will be just a flat field of waves doing no-thing!!
Unless……something happens to a wave in that field and causes an explosion of happen….and off we go again…..so keep an eye out for any new theories about Loop Quantum Gravity!!
Reg the Fronkey Farmer 7 years, 3 months ago.