An alternative criticism to the other comment. I actually don't really know what your sentences are trying to say. When you say, 'Black holes don't exist (time dilation prevents them from forming in a finite time)'. Do you mean that you think a singularity would form asymptotically slowly from an outside frame of reference as gravitational time dilation increased? That's the most generous construction I can give your statement and it's still ridiculous because the event horizon would exist anyway so the effect will be the same.
I think the majority of people try to be generous and give the benefit of the doubt, but I'm a physics grad and even after a lot of thought I'm not sure what you're saying. It's hard to give informed criticism in that case but easy to downvote and move on.
> Do you mean that you think a singularity would form asymptotically slowly from an outside frame of reference as gravitational time dilation increased?
Yes.
> it's still ridiculous because the event horizon would exist anyway so the effect will be the same.
How would exist? It would only form after infinite time - time dilates as a function of how close it is to a black hole (i.e. you don't have to already be a black hole to dilate time), reaching infinity as it forms the event horizon.
> I think the majority of people try to be generous and give the benefit of the doubt, but I'm a physics grad and even after a lot of thought I'm not sure what you're saying. It's hard to give informed criticism in that case but easy to downvote and move on.
Thanks for the reply. If I gain nothing else except an understanding of how a black hole can ever form the downvotes would be well worth it. As best as I can understand it can't form, yet everyone just seems to implicitly believe it can.
The rest I just kind of threw out there to see what criticism I would get (none as of this writing, just some insults), but the black hole one really bothers me because that one is grounded in ordinary, orthodox, descriptions of black holes.
Every description describes them as matter caught falling in infinitely slowly, yet simultaneously say matter actually falls in and somehow forms a black hole. It's a contradiction - I can't be the only person in the entire world to see that.
Oh, I see now. Yeah, you're right. From our outside frames of references we'll never see anything cross the event horizon, instead matter approaches the event horizon asymptotically slowly. In our exterior frame of reference/coordinate system you'll not see one form and because they'll never form from the outside we'll never see a black hole because there aren't any.
So as far as that goes you're right. What this doesn't mean is that black holes don't exist in any reference frame. The simple test is to jump into the black hole. Time dilation won't affect you, you're in a free fall after all, following your geodesic. You'll pass a well defined event horizon and pass into what is undeniably a black hole.
I think the majority of people try to be generous and give the benefit of the doubt, but I'm a physics grad and even after a lot of thought I'm not sure what you're saying. It's hard to give informed criticism in that case but easy to downvote and move on.