My question is what would it look like to get sucked in? If you are safe say 9 feet away, and your arm span is 6 feet, you could conceivably stick you hand into the event horizon and you body core should still be ok. Spaghettification. Got it. But describe what that would actually look like in the real world. Would, for example, your hand just disappear into thin air?
I ask because black hole event horizons are usually depicted as whirlpool-type things. But that’s really a 2D-ish representation of a 3D event. So instead of swirling around a drain would your arm, and I guess your body following it (as in a woodchipper), just vanish before your friends eyes?
Your hand wouldn’t just disappear, it would get pulled towards essentially a point. It would either pull you into it as well, or your hand would be pulled off your arm.
Compressing your hand will break its molecules apart, and make it heat up when it gets close enough to the black hole, so I think you probably would get an accretion disk, but it might be microscopic. It would just look like a bright star. Maybe really really bright.
In thinking about a BH the size of a proton, wouldn’t the gravitational falloff be so short, it’d pull off or suck up only a tiny part of you as you moved through/toward it? Then, once you felt pain, you’d writhe away from it, as whatever matter it did manage to suck off you brightly twirled into nothing in the blink of an eye.
The event horizon being so tiny, you couldn’t see anything non-radiating around the vicinity since visible light’s wavelength is far bigger than a single proton.
Seems to me that the relevant question would be the mechanical strength of flesh, and at what distance from the singularity the gravitational effects would exceed that strength.
In other words, if the gravity from the black hole is only strong enough to actually rip flesh out of you at 1" away, that’s the maximum sized hole it could make in you, because it would just rip that right straight off, and then keep on going.
So if somehow you knew where this black hole was, and you stuck your fingers out toward it, it would probably rip the first foot of your arm off, and leave the rest of you where it is.
The two-dimensional whirlpool-thing you often see depicted is actually an accurate depiction: That’s not actually the black hole itself, but the accretion disk around the black hole. Because the bits of infalling matter interact with each other, they’ll tend to end up in decaying orbits around the black hole, all orbiting in the same direction in mostly the same plane. In the process of their interactions, they heat up and glow, and that’s why we can see them. In such pictures, the hole itself is a tiny black speck in the middle.
Are black holes electrically neutral? That is, would any static charge of our bodies attract it or repel it if it were positively or negatively charged, respectively?
I don’t know what kind of gravity 650 million tons has, but I know the electromagnetic force is relatively much, much stronger than gravity.
Black holes can have an electrical charge, and could in principle have an extremely large electrical charge. In practice, however, if they do they’ll tend to become neutralized, just like anything else with a charge, and real black holes are expected to have a net charge of only a single-digit multiple of the electron charge. Even with the relative strengths of gravity and electromagnetism, that’s not nearly enough to be significant.
Incidentally, it’s also possible for black holes to have a magnetic charge, but don’t ask how a black hole in this Universe would ever acquire one.
So capture a proton-diameter black hole, train a charged particle source at it for a few months, and then steer it around with a really big electromagnetic manipulator and a very powerful space tugboat.
Our Universe is not believed to contain any magnetic monopoles (north without a south, or vice-versa). If it does, though, we can predict very straightforwardly how strong they should be. And it happens that it’s also really easy to build detectors for them. Stanford University therefore had a long-running experiment looking for them. To date, that experiment, and similar experiments run by other institutions, have had exactly one success: On February 14, 1982, one of the detectors recorded something that looked exactly like a magnetic monopole ought to look. It’s still not known just what happened there: It might have been a genuine monopole, or it might have been some sort of glitch in the equipment which coincidentally just happened to look exactly like a monopole, or it might have been a hoax.
As my old advisor used to say, “We know that magnetic monopoles exist. But the number of them might be very small, such as zero”.
The back of my envelope indicates that a 652 million ton black hole would radiate like a black body at a temperature of 188 billion Kelvins, pumping out 837 million watts or so of Hawking radiation, mostly as X-rays and gamma rays.
I’m thinking you’d be fried to a crisp well before you approached within 9 feet.
One somewhat plausible but not currently favored cosmological theory is that there is enough mass in the universe to eventually stop the expansion, reverse it, and collapse back in one big crunch.
If this is true, then to an outside observer the entire universe is a black hole with a radius somewhat larger than the current size of the universe.
The last thing I read said that a monopole would catalyze proton decay, which would release ridiculous amounts of energy whilst vaporizing matter. Or something like that. It sounded pretty terrifying. Is this the current theory?
Yes, but 652 million tons is a whole lot of energy compared to 800 million watts. There’s a whole lot of watts in a ton of mass. It’d take millions of years to dissipate.