It's definitely possible to cross an event horizon.
What SillyCow is saying is that a local observer free-falling into a blackhole won't be able to notice themselves crossing any particular horizon at all. An apparent horizon (indicated as a region of blackness) always remains ahead of them.

I guess I'm trying to get his to stop splitting hairs. There is an inside to the horizon. Forget reference frames and relative to the observer. If you are falling towards the black hole, at some point you will cross the horizon. The question is, what is inside the horizon? The word "inside" is explicit. Clearly, we are talking about an observer viewing from the outside. If I am looking at the black hole through a telescope, what is on the other side of the horizon? There IS a "other side of the horizon".

This splitting hairs just dances around the question.

I guess I'm trying to get his to stop splitting hairs. There is an inside to the horizon. Forget reference frames and relative to the observer.

When speaking about relativistic effects, you can never forgot reference frames. This is not "splitting hairs", it's fundamental to the physics involved.

It's definitely possible to cross an event horizon.What SillyCow is saying is that a local observer free-falling into a blackhole won't be able to notice themselves crossing any particular horizon at all. An apparent horizon (indicated as a region of blackness) always remains ahead of them.

I guess I'm trying to get his to stop splitting hairs. There is an inside to the horizon. Forget reference frames and relative to the observer. If you are falling towards the black hole, at some point you will cross the horizon. The question is, what is inside the horizon? The word "inside" is explicit. Clearly, we are talking about an observer viewing from the outside. If I am looking at the black hole through a telescope, what is on the other side of the horizon? There IS a "other side of the horizon".This splitting hairs just dances around the question.

I didn't see it as splitting hairs to avoid the question; it was an attempt to improve the question.
i.e. Different observers see the horizon at different places, so their view of what counts as "inside" is different, so the question isn't rigorous enough.

Also, it actually does partially answer it. If A thinks that B&C have crossed the horizon, but B thinks that only C has crossed the horizon... Then we know something about the inside. B's description is a description of a view from inside the horizon!

Earth right now could be about to cross the horizon of an ubermassive intergalactic black hole, and we wouldn't notice anything, because theres nothing really special about it.
Usually, the horizon is located at a distance where the gravitational rate of change would spaghettify you, but, a big enough black hole can have the horizon far out in a fairly smooth/safe region of spacetime.

That's according to the theory anyway. Other competing theories have matter crossing the horizon destroyed in a "firewall", but a near identical clone of it "falling into" the hole (or actually becoming a holographic imprint on the surface, which acts like it's falling in, unaware of the dimensional collapse...)

https://www.dropbox.com/s/7wx793jtk4miwyt/warpnav.pdf?dl=0 Still working it out. I think if negative distances are possible, this makes sense.

[edit] Since the forces that hold atoms from collapsing on each other are broken, and the natural course of gravity is followed, do they give negative distance?

Oh god, I know this guy. You're Pincho Paxton, aren't you? I can tell by the way you type.

A long time ago he made a similar thread on TGC where he made outrageous claims and generally just talked gibberish. He was eventually banned.

https://forum.thegamecreators.com/thread/198460

He posted the same claims on science forums and was banned for doing so too:

http://www.sciforums.com/threads/the-pincho-paxton-universe-generator.106794/

https://www.avforums.com/threads/the-pincho-paxton-thread.1199866/

He even created his own forum where he alone posts things.

http://greatestminds.freeforums.net/board/16/general-science

I'm not even going to engage you, Pincho. Last time you made my brain hurt and gave me the urge to strangle myself. It's not worth my time.

...snip...

Never heard of him before, but judging from those link, I'd say you're correct. The "negative radius" and "negative distance" are a dead give away. Pincho seems to have a fondness for negative stuff. In one of the linked threads he mentioned "negative mass"! HUH?

If you don't believe what I say, prove my math wrong. Wait until I solve the Taylor series for gravitational motion along a straight path. Blackhole singularities have 0 volume, or undefined volume, so isn't it possible they have negative radius? That's what the plot would indicate, although it might change after I solve it fully. Right now it' definitely wrong because it doesn't fall towards the gravity source.

If you don't believe what I say, prove my math wrong. Wait until I solve the Taylor series for gravitational motion along a straight path. Blackhole singularities have 0 volume, or undefined volume, so isn't it possible they have negative radius? That's what the plot would indicate, although it might change after I solve it fully. Right now it' definitely wrong because it doesn't fall towards the gravity source.

You don't have any math to prove wrong. Explain "negative radius". If a radius goes past zero, it would be positive, would it not? What is "negative direction"? If I am at the point of origin and I go backwards, am I moving in a negative direction? What happens if I turn around?

Circumference, call it displacement if that fits better. Negative radius is then a negative displacement in space measuring from the extremity closest in time.

Switch B and A and you get a positive number.

Which makes more sense to you:

A - B or B - A?