Hi Son, I thought that regardless of the Mass of a black hole it was still being compressed into a singularity with a theoretical volume of zero.
So I guess if we were in a universe inside a black hole, our universe would have to end with some sort of a Big Crunch. But if it was a really big black hole of low density, that might take a very long time to actually happen.
What I mean by saying the universe is expanding toward a singularity is basically that the Big Bang and the so-called Big Crunch are the exact same thing. The image I used to describe this in the original blog post was an apple.
The skin of the apple represents spacetime. The core of the apple represents a singularity out of which the universe--you, me, all the stars and galaxies--emerged. One can imagine a galaxy, sometime after the Big Bang, moving out and away from this singularity according to Hubble's law, eventually crossing the "equator" of the apple/universe, and finally winding up right where it started.
In which case when it crossed the equator it would be contracting towards a singularity. You see why I was puzzled?
It's puzzling because 4-dimensional objects are puzzling. But I must insist that this is an expansion, or at least looks like one. From the perspective of an observer anywhere on this apple/universe all the galaxies, everything, will appear to be moving away at an accelerated rate in all directions.
Not after the "equator" has been passed. Then it'll look like it's contracting. 'Cos it'll be contracting.
In order for there to be a Big Crunch, in order for the universe to end up "finally winding up right where it started", it has to contract. Then we will not observe it expanding. We'll observe it contracting. The stars will appear blue-shifted to an observer. They will be getting closer together.
This is why we know that this isn't happening now.
So I must ask you again, because this is the question you’ll dodge to save face: Where would an observer need to be positioned for the universe to “look like it’s contracting”?
Anywhere inside it, during the phase in which it is in fact contracting.
A gravitational singularity, yes, at the center of earth. This is gravity 101.
Apply palm liberally to face.
In Einstein’s theory the main features of gravity around the Earth are exactly the same as they would be if our planet were hollow, with a faked-up papier-mâché surface of mountains and seas, but having a black hole at the centre with the same mass as Earth.
But the Earth is not made of papier-mâché. You see that word "if", just after the words "would be"?
Even if an observer was “embedded in the paper”—a scenario completely of your own invention ...
If the paper is an analogy for spacetime, then we are all embedded in the paper.
—in this analogy there’s no conceivable way the universe would appear to be contracting. An observer buried or “embedded” anywhere in “the paper” of this analogy—the skin of the apple—would observe an expanding universe according to Hubble's Law.
If only saying things made them so, your argument would be a lot more convincing. Also it would be an argument.
If I’m wrong please paste a picture with a point on the apple where an observer sees a contracting universe…
If time progresses from the bottom to the top of the apple, then anywhere above the equator of the apple. You know, in the bit where the universe would be contracting.
Since the singularity—in this clearly inadequate 3-dimensional representation—is omnipresent (the core of the apple)
* sighs deeply *
If the skin of the apple represents the universe, then the Big Bang singularity is at the bottom of the apple, and the Big Crunch singularity is at the top of the apple. There is no singularity at the center of the apple, and the notion of a singularity being there is completely meaningless, since there is no "there" there.
Time does not progress from the bottom to the top of the apple.
What do you think it's an analogue for?
According to the BHUM time is essentially unreal ...
But don't throw away your clocks just yet.
The point of the apple analogy was to show that the Big Bang and Big Crunch singularity are the same thing. The universe both originates from and collapses into the same point—the singularity at the center of the apple.
But that's meaningless. The center of the apple is not an analogue of anything.
NoNukes, if you are tickled pink by these explanations, well, no problem for you then. Alfred Maddenstein is not. That is all. Horses for courses and courses for horses. Then the satisfaction goes like: Light is a wave in vacuum. What is it exactly that is waving? Space-time which is a field metric. Got it. Lovely and very instructive!!!! The Universe is expanding. Where could it be possibly expanding into being everywhere already? Nowhere. It's JUST expanding. Everywhere itself is expanding. Got it. Illuminating!!!!
Translated from woo-woo into English: Alfred Maddenstein still doesn't understand physics. Which proves that physics is still stupid.