# Can singularities be ever formed from an outsiders perspective? [duplicate]

As far as I know, as an object gets closer to an event horizon, gravitation time dilation makes it move slower from an outside perspective, so that it looks like it take an infinite amount of time for the object to reach the event horizon. It seems like a similar process should slow the formation of the black hole itself: As the star collapses, its gravitational time dilation makes itself collapse more slowly.

This makes me wonder: from a perspective of an outside observer, can a singularity ever form?

E.g. someone on earth observers a massive star collapse, forming a black hole. From his perspective, the mass gets closer and closer, but does it ever form a singularity before the black hole evaporates?

Furthermore, if from the perspective of a mass collapsing into a black hole, its time slows down and the outside universe "speeds up", could this mean that the black hole evaporates before me, the mass, can become singularity?

UPDATE: Let me show you my reasoning and correct me when I'm wrong (I assume I will be at some point): From a far away observer the black hole forms. Over a very long period it evaporates. In the end, it evaporates down to nothing. According to this link, the black hole cease to exist, the potential singularity is no more.

Now, from a perspective of a massive star: I begin to collapse. All the mass gravitates towards my center. Meanwhile, due to gravitational time dilation from GR, my time ticks slower relative to the rest of the universe. My size crosses the Schwarzschild radius, an Event Horizon is now present. However, now I start to lose mass due to Hawking Radiation. From an outsiders point of view, this is very slow, but from my point of view this is getting faster and faster. Could the singularity form before Black Hole's mass is evaporated?

• I realize similar questions has been asked before, but they never asked about the perspective of an outside observer, or they were never fully answered about that regard. Commented Apr 28, 2021 at 9:51
• NOTE: I especially care about the singularity itself, not about an event horizon. Commented Apr 28, 2021 at 9:52
• This has definitely been asked before, especially from the perspective of outside observers. See physics.stackexchange.com/q/480971 physics.stackexchange.com/q/168095 physics.stackexchange.com/q/5031 Commented Apr 28, 2021 at 9:59
• @Eletie I've read those two questions, all the answers and more questions here and in other sources. Most of the question and answer gravitates (sorry for the unintentional pun) around misunderstanding of time relativity, formation of singularities without EH etc. To me, none of the answers have fully answered my question. Commented Apr 28, 2021 at 11:53
• Yes, even for evaporating black holes the conclusion would be the same. If you study the Penrose diagrams for collapse + evaporation you can see this too. Commented Apr 28, 2021 at 13:25