I have to wonder how this slowing down of time affected the Universe when it was still an inconceivably dense point that suddenly went into inflation mode, where and when time dilation must have been nearly as extreme as in the immediate proximity of an event horizon.
And how has any black hole in the Universe grown in mass at all in the past 13 billion years if time stops there? Any matter within the event horizon should be falling towards the singularity but frozen in time, frozen in its’ fall, never quite making it there.
How does any supernova ever even finish collapsing into a singularity?
The way I understood it way back when I was taking basic physics in college was thus (simplified): Time for the particle at relativistic speeds / gravities moves slower compared to a far away observer unbound by such influences. Like the twin siblings paradox. So a particle past the event horizon of a black hole would basically cease to experience time, but if we could see it, it would move otherworldly fast into it.
Let me stop you right there: a ray can’t emanate from a black hole, that’s why it’s a black hole, not even zero-mass light-speed photons can get out.
We know about black holes rotating, because we can detect frame dragging around them, which means whatever mass is in there, has an average rotation.
The thing is, an absolute “singularity” doesn’t even make sense for a black hole. From what we know of how they get formed, they’re just a bunch of star that gets compressed so tight that its own gravity doesn’t let anything escape… but that doesn’t mean every particle goes straight to the center of mass. Forming a singularity would require the initial star core to be kind of perfectly symmetrical, at absolute rest and 0K, which definitely is not the case. What’s more likely, is that at the center of a black hole, there is a star worth of particles “orbiting” the center of mass at speeds close to the speed of light, sometimes bumping into each other, but since not even mass-less photons can escape the black hole, nothing can get bumped out like it would in normal stars, atmospheres, and so on.
From a mathematical point of view it makes sense to say there is a “singularity”, since for most purposes it behaves like one… but it really isn’t one. It’s also easier to think of the event horizon to be “empty” inside… but it also really is not, it’s going to be full of recently trapped particles on decaying orbits, with a lot of them being still right on the other side of the event horizon (more particles will be entering at a shallower than a steeper angle).
Also, being an actual singularity would make evaporation due to Hawking radiation kind of impossible.
When I said “ray” I just meant an imaginary line that could be drawn to extend in a given direction, not a literal particle escaping. It was mostly to think of a way you might conceptualize an orientation of an object that may not have any dimension. As in, if the matter just outside a singularity rotates, perhaps you could consider it to rotate? But I’m not sure that would be accurate to say anyway. My grasp of the physics of black holes is obviously pretty loose. :)
an orientation of an object that may not have any dimension
The thing is, if it had no dimension, then there would be no way for it to have any orientation in some dimensions, it would have to be perfectly identical regarding all dimensions.
if the matter just outside a singularity rotates
It’s a bit more fun, because it would be normal for matter to orbit around before falling in, but “frame dragging” means that not just matter, but also light outside it rotates with the black hole, and time gets stretched.
The idea that somewhere inflation is continuing to produce new universes is intriguing. Will they be similar to our universe or have less energy because inflation continued for longer?
Also, the article says we can’t reach them because inflation has pushed them too far away from us. But what if we tried to go there anyway? What exists between us?
The universe is expanding faster than the speed of light. So what exists between us and distant objects is the future distance between us and distant objects.
Imagine chasing a balloon floating north on a long airport treadmill pulling you south. It’s faster than you could ever hope to run, so the distance between you and the balloon will only ever grow.
This is a sort of analogous metaphor for what would happen if you tried to go to distant objects.
Will they be similar to our universe or have less energy because inflation continued for longer?
Likely similar to ours. The energy from inflation came from energy that is inherent to the fabric of space - dark energy. So it was not diluted.
But what if we tried to go there anyway? What exists between us?
First there is distance. New space would be created faster than we could travel there. There would likely be other problems. For example, matter would not be stable enough to form atoms and probably wouldn’t exist at all. In the inflation universe, the particles are hypothetical “inflatons”, not the particles we have.
Is there any part of our universe where this inflationary region is visible? Even if it’s too far for us to ever reach, I’m just curious what the edge of our universe is like and what we would see beyond it.
No. Our observable universe would be way to small to be connected to the inflationary region. Also, the inflationary universe probably doesn’t have any of our particles so it would not have any light photons. It would probably just look like a mysterious dark area to us.
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