3 ms·
Right, but what's actually special about matter/energy that it causes the spacetime to bend? In your analogy the basketball is accelerated through the blanket
by quux 16y ago
Right, but what's actually special about matter/energy that it causes the spacetime to bend?
In your analogy the basketball is accelerated through the blanket by gravity, and thus deforms the blanket, but in the real world we don't know what the mechanism is that causes spacetime to bend.
- Herring 16y agoIm not sure "mechanism" is the best approach here. If you start at special relativity (c is constant), you can use the equivalence principle to show that time runs differently in gravitational fields. Then its only a small step to light bending & all paths bending.
- ck2 16y agoDoes energy cause space/time to sag? Or just matter? If the universe had no matter, only "empty space", there would be no gravity. I see it as space/time WANTS to be perfectly flat but any existence of mass causes it to warp/sag. Blackholes cause super-sags to the point of infinity (some say it can tear space/time at the final point) and wormholes in theory can connect two points of the space/time "blanket". The problem is people want to see gravity as some kind of particle or wave like light but it's not, it's an effect, a result of mass itself. It's not that we are being pulled, we are actually "falling" into the sag itself because we are supported by the evenness of space/time and without it, we "fall". In empty space where there are no big bodies of mass close enough, there are no nearby sags in space/time, hence no gravity, hence no "falling into space/time" or at least the effect is very very weak.