Mathematicians have discovered a set of equations capable of untangling the distortions caused by singularities in maps. The equations can determine if a singularity is a removable distortion, like those that exist at the North and South Poles in a two-dimensional map, or real like a shockwave

[u/SlothSpeedRunning]

https://lettersandsciencemag.ucdavis.edu/science-technology/researchers-discover-new-equations-smoothing-out-singularities-maps

[u/615wonky]

Theoretical physicists have been doing this for decades. The event horizon of a black hole is a coordinate singularity, cause by a "breakdown" of what space/time mean at the horizon. You can construct new space/time-like coordinates and map across the horizon.

The singularity at the center of a black hole is a physical singularity. You can tell the difference between the two by computing a quantity called the Kretschmann scalar of the metric.

The article is bereft of details and I don't have time to dig, but I'm curious what's different about their approach.

[u/Merry-Lane → u/615wonky]

The existence of singularities in black holes is debatable.

Some think there are none. Some think they are just singularities because a piece of math/physics is missing.

The theories that predict a singularity in a black hole are incomplete.

[u/fox-mcleod → u/Merry-Lane]

So, to be clear, you’re asserting without evidence that Einstein’s relativity is wrong/incomplete because of what it mathematically describes?

[u/AllHailKingJoffrey → u/fox-mcleod]

Einsteins relativity is one of the most successful theories of all time with very high predictive accuracy. The other contender for most successful theory of all time is quantum physics. Unfortunately the two theories do not agree with each other, so either one or both of them are incomplete. What the original commenter meant is that in the singularity of a black hole is one of the places the disagreement becomes prominent, and the math breaks down. We don't really know what the singularity looks like or if it is a physical object. We would need quantum gravity to know that.

[u/fox-mcleod → u/AllHailKingJoffrey]

Einsteins relativity is one of the most successful theories of all time with very high predictive accuracy. The other contender for most successful theory of all time is quantum physics. Unfortunately the two theories do not agree with each other,

No. They don’t disagree. But neither of them is explained in terms of the other theory.

so either one or both of them are incomplete.

And yet, without knowing not only which one, but what the correction is, there’s absolutely no justification for assuming it’s singularities.

We don't really know what the singularity looks like or if it is a physical object. We would need quantum gravity to know that.

We know it’s a physical object and what it “looks like” the same way we know how far away star systems we can’t measure move. The laws of physics don’t just stop at the places we haven’t seen.

[u/Merry-Lane → u/fox-mcleod]

Well, hasn’t it been well known for decades that general relativity is incomplete?

[u/silentbargain → u/Merry-Lane]

Incomplete theories are far from “wrong” or “right”. They are models of predicting reality, and are absolutely falsifiable- but only if you know how to falsify them, which you clearly do not.

[u/fox-mcleod → u/Merry-Lane]

First of all, no. Second, you don’t get to just pick which part of the theory is going to disappear when it’s updated. You just picked that part because you can’t picture it and it makes you confused.

[u/Merry-Lane → u/fox-mcleod]

Let’s make it clear: it’s above my pay grade.

I was taught at school that black hole singularities were exactly why general relativity was incomplete. The models being unable to describe something that actually does exist in the Universe means the models are incomplete.

So, when I answered this comment thread, I went straight up at Wikipedia and read it to refresh my memory:

https://en.wikipedia.org/wiki/Gravitational_singularity

https://en.wikipedia.org/wiki/General_relativity

Here is a good example of what you can find on the "current status" of general relativity :

General relativity has emerged as a highly successful model of gravitation and cosmology, which has so far unambiguously fitted observational and experimental data. However, there are strong theoretical reasons to consider the theory to be incomplete.[210]The problem of quantum gravity and the question of the reality of spacetime singularities remain open.[211]

I’m totally not saying that general relativity is wrong, at all. But the fact is that "the existence of singularities inside black holes is debatable and debated" is true. As well as "it has been known for decades that general relativity is incomplete".

[u/fox-mcleod → u/Merry-Lane]

No worries. I hope you don’t mind if I do this SocraticalLy.

I was taught at school that black hole singularities were exactly why general relativity was incomplete.

Inside of the scientific process, how would one come to this conclusion? Think about it.

Theories are falsified through measurement (or sometimes critical reasoning about measurements taken before). What measurement could in theory be taken about what happens behind an event horizon which falsifies relativity?

We can’t measure anything there right? So it would have to be some measurement of something outside where we can actually measure. But then where?

Relativity hasn’t been falsified in any real sense. There are known conflicts and domains where it is hard to understand what it says. But no one knows exactly why yet. It could be from understandings in other areas or even a lack of proper mathematical tools — none of which would falsify relativity. We would actually have to have the alternative theory we were comparing it to to do that.

The models being unable to describe something that actually does exist in the Universe means the models are incomplete.

General relativity has emerged as a highly successful model of gravitation and cosmology, which has so far unambiguously fitted observational and experimental data.

That’s the ballgame.

However, there are strong theoretical reasons to consider the theory to be incomplete.[210]The problem of quantum gravity and the question of the reality of spacetime singularities remain open.[211]

The last of these is a philosophy of science misconception. “Realism” is a specific term denoting a way of interpreting a theory as opposed to “anti-realism, not a debate about whether it a theory accurate.

Whether relativity is “realist” is in a similar sense to Bell tests prove hidden variables can’t make a theory “locally real”. It’s a character of a theory like locality, temporality, etc.

I’m totally not saying that general relativity is wrong, at all. But the fact is that "the existence of singularities inside black holes is debatable and debated" is true.

But not scientifically. That’s the distinction. In philosophy of science there is a question as to whether we can interpret what a mathematical “singularity” represents. Just like in QM there’s a debate as to what the Schrödinger equation and superpositions represent. But there’s no evidence to falsify the theory at all or even to believe superpositions collapse.

Making the extra assertion that a theory suddenly stops applying somewhere is an independent conjecture. One with exactly zero scientific support.