A very very very large black hole (1e999 solar masses - larger than the mass of the universe) would theoretically be large enough that crossing the event horizon would be unnoticeable. The singularity would be several thousand ly away from the EH, so there would be no sheer stresses or tidal forces to speak of.

And yet -- No, you could not dip a cable down across the EH and get any signal. Space and Time coordinates reverse on the other side of the EH, so cable or no cable, a signal can only travel "up the cable" by going backwards in time. Even if the signal could do that, your future self wouldn't be there to receive it, so you can't get any information that way.

You could, however, live a very nice life just inside the EH, on a nice little planet orbiting a sun like star in a quaint dwarf Galaxy spiraling into the singularity over the course of a billion years or so....

idk why, but it bothers me that you stopped spelling out black hole and event horizon, than switching to BE/EH

Spacetime is warped inside the event horizon so that all vectors point to the center. Any signal attempting to leave would ultimately travel the wrong direction, even if by wire.

Additionally, time dilation would redshift any signal into complete obscurity even if it could leave the event horizon.

Near a stellar black hole, gravitational sheering would sever any cable.

Near a supermassive black hole, things get... weird. From a distance the event horizon seems like a pretty solid line, but the closer you get the harder it is to see exactly where it is as spacetime starts to stretch around you. You might even end up inside the event horizon without even realizing it.

Because gravity becomes so strong at the event horizon no material could survive the stresses to do what you are saying. It's literally impossible.

This thread makes me recommend watching PBS Space Time on Youtube episodes on Black Holes: https://youtube.com/playlist?list=PLsPUh22kYmNBl4h0i4mI5zDflExXJMo_x&feature=shares

especially the one on Events in Black Holes: https://youtube.com/watch?v=vNaEBbFbvcY&feature=shares

then What Happens at the Event Horizon?: https://youtube.com/watch?v=mht-1c4wc0Q&feature=shares

and then the Escape the Kugelblitz Challenge: https://youtube.com/watch?v=v3hd3AI2CAA&feature=shares

>Edit...I was under the impression that it was thought at least POSSIBLE to survive INside the event horizon of a large enough BH, hence my question above

You are correct, under certain conditions. You've gotten a lot of categorical answers essentially saying that you'll spaghettify once you hit the event horizon. This is not the case for sufficiently large black holes (say, galactic core black holes). Once you're talking millions of solar masses, you could pass through the event horizon comfortably (and maybe even without knowing it).

The total gravitational forces at the event horizon are indeed enormous, but that doesn't necessarily matter too much for something that's already free-falling into the black hole. What spaghettifies you isn't the total gravitational force, it's the gravitational gradient, i.e., the difference in gravitational force across a given distance. As you get closer and closer to the center of the black hole, the gradient steadily increases, to the point that the force at one end of a macro-sized object (say, an astronaut) is dramatically stronger than the force at the other end. It's that gradient in the gravitational force that squishes things, but where that happens relative to the event horizon is entirely a factor of the black hole's mass. For supermassive black holes, that point lies comfortably within the event horizon. For solar-mass black holes, it can actually begin outside the event horizon.

Now, to get back to your question: if it's possible that something can pass through the event horizon without being instantly crushed, why can't we tie/bolt/weld a camera to something sturdy outside the event horizon and make observations that way? We could chain it to a big rock some arbitrary distance away, but that's not going to do us any good. Remember: once something crosses the event horizon, there's no speed it can travel to get back out, and no energy you can expend to push/pull it out. (And any photons traveling up the wires from the camera likewise don't move fast enough to escape.) So in very short order, either your chain will break or the whole structure will be yanked right into the event horizon.

Your question got me thinking: nothing can escape from inside the event horizon, but what if we suddenly deform the event horizon so that something slightly inside is no longer inside it? If you have a second black hole moving at relativistic speed tangent to the event horizon (or two black holes orbiting each other very rapidly) could the event horizon be deformed so that a signaling device that was slightly inside the EH send out a pulse of very redshifted light?

At the atomic level things are held together with the electromagnetic force. This force is mediated with photons. The gravity at the event horizon is so strong that photons cannot move away from the singularity. This means that it is not possible to pull anything out because those bonds cannot exist without photons bouncing between them.

This would be absolutely impossible. Like, completely.

Correct me if I'm wrong, but the statement "gravity is so strong that nothing can escape" encapsulates a lot more physical ramifications than just a really strong "pull force" coming from the center of the black hole. Defeating gravitational stress in itself is mostly meaningless, because there are other mechanisms keeping you inside a black hole.

Spacetime becomes curved to the point where there is no path out of the black hole. You could be alive and your spacecraft be perfectly functional, any direction you choose will only take you around the inside of the event horizon, even if you could go faster than the speed of light.

Also remember, from a relativity standpoint, objects at the event horizon have stopped in time. I'm not sure this is perfectly correct, but from the perspective of an outside observer, your "pendulum tether" would only ever asymptotically approach the event horizon - there would never be an "upswing" with which you could pull anything out. So yes, if you could pull a wire out, you could have the information at the end of it, but you can't pull it out, so no universal secrets for you.

Now, the craziest part is that those last two paragraphs are two different ways of saying the same thing. Even weirder, we also already know of a mechanism by which energy can escape a black hole: quantum tunneling (see: Hawking Radiation). We just need to invent a method of information transfer via quantum tunneling, and then we could have someone transmit the information back out to us from just "inside" the event horizon. There are other problems with this, like: when would you expect to receive a return signal from an observer that has crossed the event horizon?

Current BH research suggests that you can recover all of the information about what has fallen into a black hole by looking at the "soft hair," which are the spacetime traces of the objects that have stopped in time at the event horizon - you don't even need any fancy camera on a wire.

Listen I'm hearing Interstellar... Cameras, Event Horizons, Black Holes... It's nutzo. Why not talk about white holes, yeah, suns. The surface of a sun is LESS dramatic than a Black Hole, lots of gravity, lots more energy, and you are just gonna stick a camera in and pull it out, because the Event Horizion is ............

Anyway, all I'm saying is it IS easier to dip a camera into a sun, THAN a Black Hole.

You, or the cable, or camera could cross the event horizon, but could never escape it. Just as we all inevitably move forward in time, you would inevitably move towards the singularity.

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I think the part that is confusing you OP, is that there are many reasons why this is impossible First reason - Requires infinite energy- since there's mass beyond the event horizon, you have to pull it back against the pull of the black hole, hence infinitely hard by definition of event horizon

Inside black hole you cant send a signal - again, requires FTL travel and also black hole geometry is not like on earth. In fact, the points are discontinuous, so past the event horizon, everything points towards the center.

No, once you are inside the event horizon any "direction" of force only brings you closer to the singularity. The winch would eventually break.

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Light is nearly pure energy with no mass.

Your theoretical cable has near zero energy and is almost entirely mass.

Black holes (collections of mass) pull on mass much more than energy.

Your cable would be pulled apart - ie spaghettified - long, long before it reached an event horizon, given an event horizon is the point where even a massless particle like light can’t escape.

Your premise is garbage.

You can’t get anywhere near an event horizon and survive because of the crushing gravity and high energy particles that orbit Black Holes.

You also cannot put something on a line and pull it back from the Event Horizon because Gravity is too strong, which is why there’s an Event Horizon in the first place; that is the point from which nothing macroscopic can return.

If you tried this the line would just get sucked into the Black Hole and whatever it’s attached to would get ripped from its foundations and also sucked into the Black Hole.

Escape velocity being irrelevant? At what point does the sheer energy needed to “winch” said camera out of the black hole’s event horizon become irrelevant? The amount of energy needed to complete said task would probably amount to more energy than humans are capable of producing on a global scale.

I get the thought “why hasn’t anyone else thought of this?” But that thought is almost always coincided with complete lack of education on the subject matter.

Even if you could move another super massive black hole next to another super massive black hole close enough to distort the gravity well of the event horizon, to drop a tethered camera into the event horizon, you would have distorted where in space the event horizon actually is, and would need to go deeper. If you could properly suspend a ship(with out it tearing itself apart in such an extreme environment) between 2 black holes, and carefully navigate both their orbits, (as they too are moving objects)hang a long enough tether that is lets say more indestructible than the fictional adimantium, with a camera on end, and casually dipped it in for a look see beyond the event horizon. #1 it would start off so incredibly bright it would blind a camera, let alone a human eyeball. You gotta think it is absorbing so much material and splitting and fusing atoms together not to mention not letting light( photons which have zero mass) escape its gravity well to a point it creates an event horizon in the first place. All those photons are just as trapped as physical material that does have mass. It would be brighter than taking a human eyeball into the core of the sun where fusion acts. Billions of years of photons cascading inside never to leave would be the most brightest thing beyond your imagination. #2 Lets say we made our camera indestructible. After you proceeded down past the outer layer, i would imagine it to be like any star, the mass of material begins to coalesce into liquids and then solids and fusion continues on the inner layers until you reach the core, at which point the stupendously bright light and speed of which material almost nearly falls at 0.95% the speed of light and is evacuated again at 100% speed of light, the gear shifts in material exchange would boggle ones mind to the point that one couldn’t fathom the idea. But basically to peer through the event horizon of a black hole would be like looking at any other star. Granted that star is a million times the mass of our solar sun or more, but yeah. It would just be another star.

And that my friends is how you write a kurzgesagt video

Apologies, care to specify, stanx?

Firstly, we have to imagine the physical forces at work in a BH somehow don't disallow this operation from coming even close to it's desired objectives (This camera, its tether, and everything else is somehow immune to the erasure it would surely suffer anywhere close to the vicinity of a BH).

Now that we have evaded that seemingly absolute objectively guaranteed outcome, we can view the event horizon and beyond it on our cameras feed. What exactly would you be expecting to see? It would almost assuredly not be something valuable to us as visual data. It would not be representative of anything. Light and matter within a singularity... Our minds cannot compute, and there likely isn't anything to compute.

I think the mystery of it all lets us run wild where we normally find rigid knowledge reminding us of how things ARE and MUST be. But despite its complexity and some unknowns, the likelihood of an EH being the gateway to something interesting like an inverted reflective Universe or something, it is almost nil. The theory of Wormholes to me is much more interesting and plausible. And if they do exist, despite our personal inability to probably ever utilize them or exploit them, the actual physics at play may represent something that is actually something right out of science-fiction. They do probably end up somewhere. That is cray-cray!

Btw no worries on your original misconception. It is always good to wonder and ask questions. Make everyone else think, because we are getting way to used to not doing so in todays world.