These mfers are like glitches in reality. Even trying to wrap my head around wtf they are freaks me out. How the hell can there be a thing in this universe that has infinite density? That doesn't even make sense.
Ugh
These mfers are like glitches in reality. Even trying to wrap my head around wtf they are freaks me out. How the hell can there be a thing in this universe that has infinite density? That doesn't even make sense.
Ugh
Black holes are not infinitely dense because physical infinities do no exist, you are correct that it doesn't make sense and anyone claiming this is wrong.
The foundation of quantum mechanics is that the universe is quantum, which is to say, it is made up of a finite quantity of discrete "bits." An area of one Planck Length by one Planck Length contains one bit of information, either it contains mass or it doesn't. The concept of infinite density violates this by claiming that an infinite amount of information can be stored in an area smaller than that, which contradicts our understanding of quantum mechanics on a very fundamental level. The highest density something can have is to contain one bit of mass in every Planck area.
The reality is that black holes come from stars, with finite mass, and they occur when the force of gravity becomes so great that it overpowers the nuclear forces holding an atom together, causing electrons to collapse into the nucleus, and even for the subatomic particles to break down. However, the mass still occupies a discrete area, incredibly small but not infintismally so.
Now having said that, black holes are currently a controversial and unresolved subject because no consensus has formed around a satisfying resolution to what's called the Black Hole Information Paradox, which pits several fundamental principles against each other.
Information, in the context of physics, cannot be destroyed, because the destruction of information would mean reducing the complexity of the universe, reducing entropy and violating the second law of thermodynamics. What this means is that it's hypothetically possible, given sufficient knowledge of the physical world, to reconstruct everything that has ever happened. Every event that occurs leaves behind evidence, and that evidence can be jumbled up and garbled beyond recognition, but never completely erased from history.
For this to be true in the context of black holes, it is necessary for there to be some method of extracting information from a black hole - but there isn't. Or at least, nobody has been able to explain how that would work. Some have speculated that the information is emitted in Hawking radiation, but this doesn't really make any sense because of what Hawking radiation is. Others have speculated that the information could be stored on the event horizon, but this has been rejected as the event horizon is just a mathematical abstraction (this is sometimes referred to as a question of whether black holes have "hair," with most physicists agreeing that "black holes have no hair"). Various other hypotheses have been proposed over the decades, but all of them seem to contradict some principle that we have very good reasons for believing in, and we can't overturn any of those principles without solid evidence, which we don't have.
To restate the problem: if black holes can consume physical things that have high entropy, and reduce them to a state of low physical complexity, then they are capable of reducing entropy in a closed system, and our understanding thermodynamics is fundamentally wrong. If they are capable of storing that entropy in an infintesmally small area, then our understanding of quantum mechanics is fundamentally wrong. If it's possible to retrieve information from a black hole, then our understanding of relativity is fundamentally wrong. So either some fundamental principle in physics is wrong, or someone will eventually come up with some very clever solution that reconciles these competing principles.
smokes blunt what if our universe is a black hole, maaaaan
I hope something is wrong, that's more fun.
Since I found someone willing to explain this in the wild, could you say more about Planck units?
If so
Am I understanding the implication correctly that, as far as our ability to measure things is concerned, the universe is organized into something analogous to voxels (in the true sense) and frames? How does movement work, is it just the rate at which quanta blip from one unit of Planck space to the next? If laterally adjacent spaces have the same mass, does that mean if they move laterally at the same speed, at each interval one space remains the same while one loses mass and another gains it? i.e. if you have 01100 and move it one to the right, you have 00110, with the middle one not changing.
It's been years since I studied it so I may need to brush up my knowledge to explain it properly.
One thing to note is that there are different interpretations of QM, so one might agree with the interpretation of flipping bits, while another might argue that the object is moving through infinitely-divisible space, on a smaller scale than it is possible to observe, and the bits are just the limits of what is measurable. For practical purposes, either works and it's more of a philosophical question of whether we can extend scientific principles to things and scales where it's impossible to test or observe.
I definitely recall something about using two-dimensional pixels rather than three-dimensional voxels in this context, even though it seems extremely counter-intuitive. It has something to do with surface areas but I definitely can't explain it on my lunch break lol.
counterpoint Elon Musk is infinitely dense
i gotta get a degree or something cuz this shit still makes no fuckin sense to me
I have a physics bachelor's and it's helpful when this stuff comes up, but I gotta tell you, there is not a lot of money in understanding black holes
That actually leads to the concept of plank stars, where once the mass reaches the planck length it rebounds
Interesting, I wasn't familiar with that term bc it was coined shortly after I studied this stuff but it seems to be referring to similar stuff to I described (the ideas behind it are older than the term itself).
I actually think all of that makes sense to me. Incredibly fascinating stuff, this has made black holes seem slightly less alien. And it's not like humanity is at all new to the idea of fundamental principles we thought we figured out actually being wrong.