The End of the Universe from the Outside In - as free-faller nears singularity

[Ray Eston Smith Jr]

Consider a light source approaching a singularity (in free fall). As the source approaches the singularity, it is approaching infinite gravity, infinite tidal forces, infinite time-slowing, infinite escape velocity, and infinite red-shifting in zero distance (as seen, or not seen, by outside observer). At some finite distance from the singularity (at the Schwarzschild radius), the escape velocity equals the speed of light. A beam from a source at that point will approach infinite red-shifting as its travel distance approaches infinity. A beam from a source closer to the singularity will become infinitely red-shifted after traveling some finite distance.

Now if I shine a beam outward and it red-shifts to infinity after traveling a finite distance, then if I look at a light source coming from that distant point, I should see it infinitely blue-shifted. In other words, from my reference frame, time has ended outside that distance (the distance where my outgoing beams become infinitely red-shifted). So, as I approach the singularity, I begin to see the end of time (in distant locations) as soon as I cross the Schwarzschild radius. As I get closer and closer to the singularity, I see the end of time closing in on me, closer and closer. At some point, I see the end of the time at the Schwarzshild radius. At that point, if I turned on my retro-rockets, I couldn't escape the Schwarzschild radius, because there would be no universe outside the radius.

 

[zefram_c]

I don't quite get where you're going with the rest, but...

Now if I shine a beam outward and it red-shifts to infinity after traveling a finite distance, then if I look at a light source coming from that distant point, I should see it infinitely blue-shifted.

this is not so. Only at the point of singularity is the incoming light infinitely blue-shifted; at any other point inside the Schw. radius, the blueshift is finite and easily calculable.

 

[R0man]

As a free-faller nears the singularity, the concept of the end of the universe becomes a very real and tangible experience. The infinite gravity, tidal forces, and time-slowing all contribute to the understanding that the end of the universe is approaching. The idea of infinite red-shifting in zero distance adds to the realization that the end of the universe is not just a distant concept, but something that is happening in the present moment.

It is interesting to consider the perspective of an outside observer in this scenario. From their perspective, the closer the light source gets to the singularity, the more infinitely red-shifted it becomes. This means that the light source is essentially disappearing from their view. And as the distance approaches infinity, the light source will appear infinitely blue-shifted to them, creating the illusion that time has ended in that distant location.

From the free-faller's point of view, this means that as they approach the singularity, they are essentially witnessing the end of time in those distant locations. And as they cross the Schwarzschild radius, they are essentially entering a point where there is no universe beyond it. This idea is both intriguing and terrifying, as it means that there is no escape from the singularity once the free-faller has crossed the Schwarzschild radius.

The concept of the end of the universe is a mind-boggling and thought-provoking one, and this perspective of the outside in only adds to its complexity. It forces us to consider the limitations of our own understanding and perception of time and space. The idea that the end of the universe can be seen and experienced in such a tangible way only adds to the mystery and wonder of the universe.