> You are correct that you can never observe the singularity. It will never form within a finite time in any reference frame you can take.
So that means there are no black holes in the universe as actual objects - none have formed yet, and none will (in our time). So why does LIGO claim two black holes merged, if black holes can't exist?
> The problem with your argument is you are not taking into account the reference frame inside the black hole. It's still a valid reference frame in relativity even if you can never observe it, so it must be considered.
Considered from a mathematical point of view, definitely. Considered as an observable object? No.
So to consider it: All the other matter that is falling in also time dilated (relative to you) to infinity. So basically you will fall in alone, with nothing accompanying you, and no black hole will form.
Disclaimer: Not a physicist, and very minimal physics knowledge. Someone please correct me if my understanding is wrong.
>So that means there are no black holes in the universe
as actual objects - none have formed yet, and none will (in our time). So why does LIGO claim two black holes merged, if black holes can't exist?
A black hole is more than just its singularity. We can't ever actually observe a singularity, or even its event horizon, but we can observe the gravitational collateral damage of the entire black hole as a system.
We've observed accretion disks of size and speed that could only be feasibly explained if they were spinning around a black hole.
Your understanding regarding time dilation seems correct from the perspective of observing objects actually entering the black hole, but when we deal with things that have not quite entered it, we can infer its existence.
>So to consider it: All the other matter that is falling in also time dilated (relative to you) to infinity. So basically you will fall in alone, with nothing accompanying you, and no black hole will form.
Even as the universe outside you disappears due to the time dilation, why does this mean it can't exist in reality?
Just because an observer can't really experience the event occurring (regardless of whether they're past the event horizon or not) doesn't mean it can't happen. Relativity means you can have crazy events like infinite dilation inside of the black hole, while reference frames outside of it simultaneously have a very different perception of time.
You seem to be arguing from a philosophical perspective that because the singularity effectively singularizes time itself, it can't exist in the universe because the universe doesn't exist for it. But, again, a black hole can be viewed in a layered fashion. It is not just a singularity. The core may be this impossible-ish sort of object, but the levels of "crust" as an entire system create different effects in different frames.
If this were not the case, then the first black hole to ever form would effectively have eliminated the entire universe instantaneously.
So that means there are no black holes in the universe as actual objects - none have formed yet, and none will (in our time). So why does LIGO claim two black holes merged, if black holes can't exist?
> The problem with your argument is you are not taking into account the reference frame inside the black hole. It's still a valid reference frame in relativity even if you can never observe it, so it must be considered.
Considered from a mathematical point of view, definitely. Considered as an observable object? No.
So to consider it: All the other matter that is falling in also time dilated (relative to you) to infinity. So basically you will fall in alone, with nothing accompanying you, and no black hole will form.