In the movie Interstellar, the characters land a shuttlecraft on a watery sattelite of the Giant Black Hole (Gigantor) which is so deep in the black hole's gravity well that time moves substantially more slowly and a few hours become years to the man waiting for them to return.
I realize I do not actually have any valid intuition about this situation but it doesn't strike me as possible.
Am I correct that a craft capable of descending into such a gravity well, stopping to drop off taikonauts and then returning would be capable of instead making a trip in some other direction (not into a black hole's gravity well) at a speed sufficient to cause the equivalent time dialation?
And I don't think we're supposed to think their craft is capable of doing that.
When traveling very fast or being in a strong gravitational field time will pass differently for you relative to an observer at rest or in weaker gravity.
This has been experimentally verified with atomic clocks on high speed jets or by placing one at sea level and one high up on a building/mountain and seeing how they become desynchronized.
The curve gives something like 50% time flow rate at 90% the speed of light. For a few hours to equal 20 years to another guy, they would've had to be right up on that black hole's shit.
They're in a large gravity well, sure, but when they're near the planet, the planet's gravity dominates (that whole [math] F_G \propto 1 / R^2 [/math] thing) and cancels the black hole's gravity. Getting off that planet wouldn't be any harder than getting off any other planet of similar size. I would agree that they're kinda fuzzy on the positioning of the ship and lander relative to the black hole and the planet, but that would be pretty hard to explain in a movie even if the entire audience worked at NASA.
Yea they're probably wrong on allot of specifics but you gotta give them props for trying to present relativistic concepts in the movie.
Most space movies have people zipping around FTL and communicating with people 1,000's oglf light years away instantaneously with no relativistic consequences at all. They just act like it doesn't exist.
Ok, it's no harder to get off the planet near a black hole than anywhere else, but there is definitely a difference in times passage between the ship and the lander implying I think ( ianap ) the lander would have to accelerate against the gravity well to get from the planet to the ship where time was passing more quickly and would have had to do the same in reverse to even travel from the ship to the surface of the planet without crashing through it and ending up in the black hole.
...no. You're lacking an intuition of how inertial frames of reference work.
Why does the Earth not crash into the sun? Gravity is a purely attractive force. Obviously, inertia keeps us in "perpetual free-fall" into the sun: we keep falling towards the sun and missing it. Now think about this new planet that has been recently found, which has a very large orbit. Due to Kepler's Third Law of Planetary Motion, we know that the farther a planet is from whatever it orbits, the slower it has to move (and indeed, the slower it will move).
The ship was not orbiting the water-world planet (as I understood it), but rather much farther outside the gravity well of the black hole. However it still had to keep moving to prevent itself from falling straight towards the black hole, but it was not moving anywhere near as fast as the water-world planet. And as the lander approached the planet (assuming they plotted their trajectory properly) they used the gravitational force of the black hole to speed themselves up towards the planet (at which point they are also orbiting the black hole much faster than the ship). They also make a big deal about how they made their approach very quickly and they only landed successfully because Matthew McConnaughey is a pro-ass pilot.
Now that you see that approaching the planet was rather easy besides the landing part, determining how much energy/fuel it took to return to the ship from the planet is arbitrary. In any circumstance, the lander that they use in that movie is a fucking monster of a ship that doesn't make any physical sense how it is able to undergo the stress it goes and also have enough fuel to make all the landings and take-offs that it does, so I'll agree with you there. It is, however, a movie.
Something worth bringing up, I think in the film that the main ship wasn't orbiting the planet, rather it was orbiting the black hole at a further distance. I've heard people ask how there could be such a difference in time from the main ship orbiting the planet and the lander on the planet to which I"d say there wouldn't be.
>at a speed sufficient to cause the equivalent time dialation?
Gravity IS time dilation, and acceleration has the same mechanistic potential under general relativity to distort time as constant uniform tidal forces do.
So yes, provided constant acceleration on the part of the transport vehicle. Gravity wells are "fun" like that.
You say fall towards the black hole to accelerate to the planet. This seems like it would work. But you've then lost potential energy by falling. To get off the planet and back to the ship you've got to regain that.
Also found this: http://www.sjsu.edu/faculty/watkins/orbital.htm
It seems that for our solar system V(in units of earth's velocity) = 1 / R^(1/2)..
If the center of the moon is 384400 km away and we're 6371 km from the center of the earth and the moon orbits the earth at 1.022 km/s then for the mass of the moon to orbit the earth compressed into a golf ball sized black hole just above it's event horizon at around 8.87 cm(https://en.wikipedia.org/wiki/Schwarzschild_radius) gives about ( 384400 + 6371)^(1/2) / .000887^(1/2) = 21000 km/s. (only 14275 c)
Also that is basketball sized and there is probably much more to consider. If the above held, then couldn't you escape a black hole by speeding up a bit?
I would expect escaping a black hole to require an orbital velocity > speed of light.
Everything inside the black hole was bullshit other than that it wasn't totally unreasonable and I give them props for at least trying to present relativity, most sci fi pretends it doesn't exist.
the whole movie makes no sense anyway fromt he point they introduce the robot, that thing was an order of magnitude more advanced that any other technology they use
what i wanted to ask is: how come the water planet seems to have similar gravity to earth?
That robot was literally Siri-level AI, just because it sounds like Jarvis doesn't mean it has a comparable intelligence. Everything before that black hole shenanigan was portrayed well, despite what the bleeding heart "1 hour 20 years topkek!" autist wants to believe
The gravity around the black hole is pretty strong, but not enough to cause such a time dilatation, as the others said.
BUT, there's others things that we take to account for, such as the frame-dragging inside the ergosphere of the black hole.
To keep it simple, the BH is so massive and spin so fast that it warps space around it, making the objects inside the ergosphere, even those who aren't technically moving, going really fast compared to the rest of the universe.
I don't really know if that's enough to explain such a great dilation, but at least that still better than the
>muh gravity not strunk enouss
we see everywhere here.
Hope that helped, even if that's not enough
I think the autists wanted it to be a relativity documentary.
Movie was fine aside from 5d love and little girls bedrooms being inside black holes, oh and the fact he crossed the event horizon and came back in one piece. He should have died.
> oh and the fact he crossed the event horizon and came back in one piece. He should have died.
That's a misconception. The larger a black hole is the more gentle it is (literally). Supermassive black holes like the one in Andromeda galaxy have the density of water and their event horizon can be entered without being ripped to shreds by tidal forces.
Everyone liked Inception time bullshit so he just decided to do it again. He doesn't give a shit if it's scientifically accurate, he just pandered to the right crowd to make some money. Don't waste your breath on this garbage.
He didn't just turn around and leave, he was thrown back next to Jupiter through a wormhole.
If we view it as simply a point in spacetime to which all world lines converge, sure. But basically we don't know how things happen, or don't, past that point.
Unless the black hole is an artificial construct by fifth-dimensional beings, or at least by humans in the future who can influence spacetime in these ways - which is the contention of the movie.
Interstellar was not scientifically accurate in most ways. A planet orbiting close enough to a black hole to have 100 foot tidal waves all the time would be volcanic and unstable, as the tidal forces would constantly be squeezing and churning the planet
>Time does not exist. If it did, there's be no relativity at all.
>little girls bedrooms being inside black holes
The movie`s black hole was made by the bulk beings to make a normal human pass the singularity`s information to muph.
>so why didn`t the aliens pass the information themselvs?
They couldn`t comunicate because they where to advanced for normal humans to understand what they where trying to say.