Relativity Lite

Gravity Lite | 55 In 1935, SubrahmanyanChandrasekhar showed that amassive enough star that has exhausted its nuclear fuel will collapse inward, and even the quantummechanical repulsive degeneracy force of the neutrons is insufficient to stop the star’s collapse. Such a star has no way to counter the grav- itational collapse so it will continue to collapse until all the mass—of a star that was more than 100 million times bigger than the Earth—is concentrated in an area of space smaller than the smallest area you can make by holding your thumb and two fingers together. You might expect that stuffing so much mass into such a small area of space might have some pretty weird results. Indeed, for a collapsed star, spacetime is warped infinitely deeply into the time dimen- sion, as depicted in figure 8. Put another way, it would take light an infinite amount of time to travel up out of this hole, and since we do not have an infinite amount of time at our disposal, we would see no light coming out. It would be black. Hence the name. Note that a planet circling such a star before its collapse would simply continue on as if nothing had happened, aside from the inconvenience of having its atmosphere blown away in the supernova that accompanied the collapse. So black holes do not suck up every- thing in sight, only items on a collision course with them. Figure 8. Spacetime is warped infinitely deeply into the time dimension for a collapsed star so that light would take an infinite amount of time to travel up out of this hole. Here, a planet is depicted still circling the collapsed star in its unchanged orbit, though having had its surface baked and irradiated to bare rock. So what happens when someone starts falling down the spacetime funnel shown in fig- ure 8? It is intuitively obvious that they fall to the bottom and cannot get back out. Careful application of mathematics confirms this.