Ask HN: Is it black holes all the way up?
People recently have been positing that the big bang occurred as result of a black hole (i.e. black hole sucks up more and more material, gains more mass, until it explodes in a big bang into a new universe).
My question is, if this is the case, is there (1) another universe "above"? And is there another universe "above" that eternally? Or is it (2) more the case that our existing universe expands, it reaches an edge of maximum expansion, and a gravity-like counter force causes it to collapse in on itself, until it again repeats the big bang process (eternal recurrence)?
Take the first example. If the conditions at the bottom of two black hole "singularity"s are the same - you would expect parallel, equal universes to be generated each time. Copies of the same universe generated over and over again with each black hole. If the conditions were slightly different (i.e. one black hole has slightly more quarks than another), you might have a "parallelish" universe arise where with slightly different initial conditions you experience vastly different results (chaos theory, small changes in initial conditions).
If the second were true, given no energy / mass would be leaving the system, you'd expect the same situation to recur eternally. The "universe" as we experience it would be bounded on one side in time by the "singularity" and on another side in time by the "edge" (the point of maximum expansion) creating a fixed, spatiotemporal object. Why does this spatiotemporal universe marble exist and what exists outside of it?
I can't wrap my head around this. Which scenario is more likely? Does any of this make any sense? If the answer is "we don't know", do you think there is a way to ever answer these questions?
It seems like we're trapped in some sort of strange, fractalian experiment.
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[ 4.8 ms ] story [ 73.0 ms ] thread[1] - https://www.youtube.com/@pbsspacetime/search?query=black%20h...
[2] - https://www.youtube.com/watch?v=MH_QCIhSHLs
The jump from matter / elements to RNA also doesn't make sense to me - so maybe there's a drop in the petri dish to explain life arising from nothing.
It's overwhelmingly mysterious & confusing :(
My fun answer for this one is that there is a future civilization facing collapse / extinction / "great filter" and they're (humans or AI) running infinite life simulations to try to determine what actions will give them the greatest probability of escape / survival. We're living in one of those simulated worlds. But that's very human / AI centric, and doesn't answer any of the same questions higher up. Maybe they know.
I have some fun thoughts around this problem which is maybe just as a lonely sculptor might sculpt a human-like figure that they can converse with to feel less alone (and from "one" make "two"), maybe a universal consciousness decided to create something & the illusion of "separatedness" (from one, many) in consciousness to feel less alone. Hence make a universe with lots of manifestations of consciousness to observe and interact with one another, and keep any true knowledge of itself a mystery to preserve the illusion.
But that's not a very scientific perspective, and all the questions above still remain.
Krang inputs 'teletubbies having tea with elon musk in the style of milo manara' and somewhere on deviantart someone makes it and the universe has a reason to be kept going.
It does align w/ the "eternal recurrence" concept.
Alternative hypothesis the OP seems to refer to is the one of Lee Smolin in which a black hole from a previous universe creates a new universe. Smolin wrote a book about his theory, The Life of the Cosmos. I haven't read it nor do I know / understand his theory fully, so interested to learn others viewpoint on this theory.
As best I understand, he's proposing that the universal will not ever fully collapse into a black hole. On the contrary, it will continue to expand and diffuse, eventually reaching a state in the far future—and here is where the details exceed my understanding—somehow physically/mathematically identical to the conditions that were present at the Big Bang. Or in other words, if you run time out to an infinity in one direction, it sort of "wraps back around" on itself.
https://en.wikipedia.org/wiki/Conformal_cyclic_cosmology
I'm sort of leaning towards LinuxBender here in thinking this is all some infinite movie on loop generated bc consciousness was bored by itself in the dark.
On the contrary, due to the expansion of the universe, stuff tends to move further and further away from other stuff over time, so the chances of things colliding with a black hole get smaller and smaller with the age of the universe. At some point all black holes evaporate (at least according to current theories) because so little stuff falls into them that the tiny amount of hawking radiation that they radiate is enough to evaporate them over trillions of years.....
Also, the question whether "a universe before the big bang" (if such a thing exists) is "the same" as ours, or "different", doesn't really make sense. If you take all matter in the universe, heat it up so that only high-energy radiation is left, and then let it "create another universe"... . how would you define if it's "the same" or "different"? All matter has been removed and recreated. It's similar to the idea that you take a ship, any ship, and piece by piece replace every single part of the ship one by one. At the end, is it still the same ship or a different one?
To take a more traditional scientific stance, asking "what happened before the big bang" is meaningless because time didn't exist, it was created by the big bang. It's tricky to wrap your head around the concept, the same way that it's tricky to wrap your head around the concept of an "expanding universe" that seems to expand "away" from us in every direction, yet we are not in the center of it. Or that the universe might be infinitely large or even wrap around, yet we will never know because we can only ever "look" 14 billion light years far into the universe. It could be that after travelling for 20 billion light years we wouldn't reach the end of the universe (because it has no end) but instead land back on earth.
Some questions can never be answered because of physics. They will forever be unknown because answering them either makes no sense, or none of the answers you could give could ever be verified/falsified. So: does asking these questions even make sense?
By the "sameness" point - I mean that in a deterministic universe where initial conditions are precisely the same, that the same universe structure will continue to arise and play out over and over again (putting aside quantum uncertainty). While the "ship" may not be the "same" ship, it will still be a ship and not a refrigerator.
That's a strong no (for any sufficiently complex physical setup with moving parts, falling glasses won't shatter the same way twice).
Two things here are relevant:
1) Lorentz (Butterfly) and Smale (Horseshoe Map) both proved that in some physical systems you can always find initial conditions that are very close (for any arbitary epsilon of "close") that none the less end up far away from each other as time passes.
ie: Unless the initial starting points are absolutely precisely identical without question, then "close enough" isn't good enough to guarentee an identical outcome in the presence of "strange attractors"
2) The Uncertainty Principle tells us that at a fine enough grain (within a certain epsilon) initial conditions are like jelly - you cannot nail them to the wall and declare two systems identical.
I think, in the black holes example this outcome is unlikely given even slightly more matter or quarks absorbed would differentiate the system. This would be the "parallelish" outcomes where slightly differences would compound over time. But if there's a limiting condition that only allows for one starting point, then you get the same duplicate outcomes.
In the same way that certain elements consistently arise as a result of fusion in a star, perhaps the same types of universes might arise here. You might have a "Hydrogen" universe, a "Helium" universe, an "Iron" universe dependent on the threshold that initiates a certain "big bang" / that create initial starting points that are "absolutely, precisely identical without question". This is a bit out there, probably wrong. I have no idea.
I'm not sure I'm explaining my thinking very well, but if only so much energy / matter can break through the other side of a black hole and it breaks through in the same way every time then you would get parallel, equal universes.
I am a huge fan of your usage of chaos theory to address this question - I appreciate it.
Another point of interest is that our specific universe formed in a manner that left a "chaotic" biased imprint of early intial turbulence imprtinted across our sky in the Cosmic Microwave Background clumping.
While the variations are tiny deviations from uniformity they do exist and are thought to be random quantum fluctuations that expanded to a much larger size during inflation.
There is further conjecture about how these early random forces went on to seed the distribution and pattern of stars and galaxies.
In other words, the tiniest roll of dice during the seeding moments appear to have held sway over the form of entire galaxies.
So like physics appears to have uncertainty but if you are outside it you can see that it's just playing back according to the map.
Then
- how do you measure with sufficient accuracy to (well) beyond the Heisenberg limit, everything within a relativistic radius in order to counter chaotic turbulence
and, then, once you have done so,
- how do you compute forward the rather large number of "grains" just measured in the fine time steps required to counter chaotic turbulence?
Leaving aside just how difficult (against the scale of the universe) such exercises are, let's return to the mathematical certainty of proof by both Lorentz and Smale ... any tiny deviation, even magnitudes of order finer than Heisenberg will eventually bite any claim to the certainity of determinism hard in the arse.
But it is not that black holes explode into the universe, it is that the knowable universe is in a black hole. like I said science fiction, the part I like is it explains(It does not really, again I repeat no actual science) why time as a dimension only goes one way. just like once you pass the event horizon of a black hole there is no "out", you have lost half a dimension, inside the event horizon we call the universe, the half dimension we are missing is the out direction of the dimension we call time.
I feel for you; I wish I had a trigger warning on existential questions this AM too.
Melodysheep (the creator) has some great stuff on the topic.
Very cool - thanks for sending.
Whil in reality it’s nothing but purely theoretical mathematical models operating on such a high level of abstraction and uncertainty that it is even hard to decide whether some of your questions make any sense or not.
That said - I agree w/ the point about whether or not these questions even make sense to ask when we (collectively) ultimately know so little. This is why I wanted to ask it in a public forum in the first place - to test my understanding and to see if there are others I can learn from who might have a more advanced understanding. These aren't exactly questions that people will leap to answer in the office or in daily conversation. That's why I wanted to bring it here, where I feel people are generally more thoughtful and insightful concerning existential topics.
I've appreciated a lot of the links to other resources, and pushback on some of the assertions. They have been and are helpful!
I tend to think we are a hologram generated from the surface of a black hole, and yes, probably black holes all the way "up".
Of course, it still leaves the question of the first black hole, and why anything at all instead of just nothing.
It's turtles all the way down.