
The basic idea is that we can imagine a bunch of photons of light, all moving in a sphere towards the centre, getting smaller and smaller. Using the general theory of relativity, physicists have shown that eventually this perfect sphere of infalling photons would in fact form a black hole.
The event horizon would actually start out infinitesimally small, and very quickly grow outwards, as the light photons fall inwards. This would happen until the event horizon gets to the same size as the infalling photons. Once the photons cross the event horizon, the horizon will not continue to grow and the black hole will be fully formed.
The trouble is, someone inside the final event horizon has no way of knowing that they’re about to be in deep trouble, because the event horizon growing on one side of them grows super quickly and can’t be seen anyway, and they won’t see the photons until the photons cross their path
#scary #physics #parthg #blackhole #understandingphysics #fallingintoablackhole #intoablackhole #spaghettification