, exact phrase.
Gravity's Lens - V2
A black hole is an object so compact - usually a collapsed star - that nothing can
escape its gravitational pull. Not even light. On Earth an object needs to be
launched with a speed of 11 km/s if it is to escape the planet's gravity and go into
orbi...
Keywords:
... avitational, gravity, lens, Relativity, swirl,
warp, wormhole ...