And we tend to think its not possible because we dont actually do it.
But, mathematically, it is possible.
In general relativity, curvature of space-time account for the curved orbits of the planets.
If space-time was not curved, planets and stars would move in straight lines.
The time direction of space-time surface also shows curvature, Mr Tippett says.
There is evidence showing the closer to a black hole we get, time moves slower.
That circle takes us back in time.
source: www.techworm.net
