Is the Universe a Black Hole? - Comments

[Multiple_Authors]

Multiple_Authors submitted a new PF Insights post

Is the Universe a Black Hole?

Continue reading the Original PF Insights Post.

 

[bcrowell]

I've previously requested that Greg stop recycling my old posts as Insights blog posts. It suggests that I'm interested in the Insights blog, which I'm not. Also, it makes me feel as though I'm obliged to respond to a flurry of new discussion on some post that I wrote years ago and that was discussed then. Although this post has multiple authors, I basically wrote it. I've repeated my request to Greg that he stop doing this.

 

[Stephanus]

Good reading. I have a thread
https://www.physicsforums.com/threads/big-bang-vs-black-hole.827828/
Which was already closed.

 

[RUTA]

Here is a paper on this subject I wrote for Am. J. Phys. some years ago: http://users.etown.edu/s/STUCKEYM/AJP1994.pdf

 

[GeorgeDishman]

Nice summary, and it's something I'd like to point people at when this question comes up in other forums. Before doing that, can I just check one point which surprises me, I think I'm mis-reading it perhaps:

"The singularity is a point at which the world-lines only extend a finite amount of time into the future."​

I thought the singularity was where world-lines finished and that they only extend a finite amount of time into the future from the event horizon before reaching the singularity? Some clarification would help me here.

https://www.physicsforums.com/insights/universe-black-hole/

 

[PeterDonis]

I thought the singularity was where world-lines finished and that they only extend a finite amount of time into the future from the event horizon before reaching the singularity?

This is correct, and I think it is the same thing that the article was trying to say (though the wording was apparently somewhat confusing).

 

[GeorgeDishman]

Would it be possible for someone to clarify that sentence?