Surely Kip Thorne himself has to realize that he's grasping at straws. A lot of the things he mentions are of the type "in this precise, extremely rare situation it is possible, if we ignore all the other side effects". For example, I'm sure his calculations will be correct regarding the planet orbiting a black hole close enough for relativistic effects. What it also means is that the planet would pass through the extremely hot accretion disk twice every orbit, killing everything and evaporating all the water. And considering the speed that a stable orbit would require, that would be a very common occurrence.
The point is: don't claim that you're scientifically accurate. Usually, a good sci-fi movie will set up rules for itself, and follow those rules appropriately. If you make your ruleset "real world physics", you have to be extremely accurate if you still want to make it believable. The rules set up expectations, and breaking your own rules is an instant turn-off for science fiction fans.
The movie shows other cases where it doesn't follow its own rules: they have spaceplanes that can get to orbit from a planet with 1.8 times earth gravity, but not from earth without huge boosters?
For the record: I like Interstellar a lot. It was a great film, and I'll definitely be buying it when it comes out on DVD. I just have my gripes with the lofty claims of accuracy that Hollywood films so love to make.
I liked Intersteller a lot as well, but its plot was horribly contrived in places and the science isn't as good as it was purported to be - even moreso if you include the behaviour of the scientists involved :). The science was certainly better than most other serious sci-fi films though. The real problem with the film is the needlessly long hour of character establishment.
(SPOILER) Rather interestingly, I've seen very little discussion about the christ story in the film - the 33-year-old man, who is also the 'father', who is also the 'ghost'; who disappears presumed dead, only to return; who has the only information that can save humanity (the 'quantum data') and also sacrificed himself to save humanity; and who was helped along by 12 others - one being the questionable [Dr] Man[n] who is weak of spirit. There's a few more other parallels, but the gist is there.
My wife, ordinarily interested in more economic, financial, and fashion-related literature, has been gorging on tesseracts since the movie. She'll adore this. Thank you for the brownie points.
I couldn't agree more. I don't understand why Kip Thorne is so desperate to declare that the movie doesn't violate known physics, when it clearly does, just not in the areas he's most concerned with. Planetary dynamics, propulsion systems... but as long as there aren't Na'vi or dragons on the planets, I suppose they consider it realistic enough. On second thought, Na'vi or dragons might be more realistic than some of what's shown.
FTL travel is "possible" too, if quantum gravity provides some loophole for violating GR on scales where GR is currently assumed. It seems like there's a reasonable basis for excluding it from the plot without declaring it impossible: if Earth technology was that advanced, they wouldn't need to travel to Gargantua's system.
I think Nolan's insistence on the extreme time dilation for the first planet in the plot is a mistake, because if they thought about what time dilation would mean for the readings sent back, they never would have investigated that risky planet first.
What's great about Interstellar, though, is that it gets viewers talking and thinking about physics. On that point, it's far better than Gravity.
>I don't understand why Kip Thorne is so desperate to declare that the movie doesn't violate known physics
I do. At least I think I do. Kip Thorne has published a book named "The Science of Interstellar".
I am sure that book is quite scientific and reasonable. However, the most hyped up attribute of art-science relationship in Interstellar is its "real" physics. If Kip Thorne declares that movie does violate known physics in a direct and unambiguous manner the hype instantly decreases. Lots of sci-fi got science very wrong and Interstellar is considered different in that regard by general public. Less hype -> less sales.
Though, this "interstellar science is real" meme may be a trojan horse and it is ripped apart in the book. I know nothing of that as I haven't read the book.
I am not sure if Interstellar is net benefit to the rational and scientific worldview of an average viewer or not. In the end, magic tesseract creatures and love of the protagonists saves the day, not scientific method.
"In the end, magic tesseract creatures and love of the protagonists saves the day, not scientific method."
It's worse than this! Maybe I'm overthinking this, but I got a strong anti-scientific, anti-rational vibe from the movie.
Consider this: the movie's two top scientists are scheming liars. The professor who ran the whole show lied to everybody because he's smarter than all the dummies on his team. And the guy from the second planet is the most brilliant scientist among the astronauts, and turns out to be an egocentric asshole who develops a sinister plan that endangers the whole mission for his personal gain. Lesson learned: never trust a scientist, they're up to no good!
Second: Rational decision making is for the birds. Our hero decides on an order in which to visit the planets based on the available evidence. Meanwhile, the girl who's allegedly a scientist but who uses "love" as her compass had intuitively favored the "right" planet all along. In fact, things don't start going right until people start doing crazy things based on fuzzy hunches. Lesson learned: Love is a better basis for decisions than evidence and reason.
I get the impression this attitude is "trending" in the US, and it worries me. There's a worrisome anti-science sentiment afoot, apparent in denial of evolution and global warming, opposition to vaccination, a hysteric fear of various foods and distrust of "conventional" medicine.
I didn't get an anti-science vibe. If anything the scene at the school was a pretty transparent poke at the folks today who seek to take accurate science out of school curricula.
The main professor lied to everyone in order to create the will to work on "Plan B", the frozen embryos. He thought folks would never work on that if they all thought they were doomed.
The evil scientist turned bad because of the extreme isolation and thought that he would never see anyone again. It's a variation of the "space madness" trope from 100 science fiction plots--tired, but not anti-science, in my opinion.
I totally agree with you but I feel that our discussion is missing a crucial detail here. A bit of philosophical and cultural theory.
Did you notice how lots of people after the movie were like "Wow, I've got an epiphany, I've understood something." Did that something was about physics? No. It was about philosophy.
And damn, Interstellar philosophy is awful. Postmodernism at its worst.
Happy to share why.
Postmodernism is deeply suspicious of academia and academics. Who were the negative characters? Dr. Mann("the best of us") and Prof. Brand. "Do not go gentle in the dying light" A poem written for the poet's father losing his vision. Who was his father? Literature professor.
Postmodernism rejects reason as a epistemological foundation and states that rationalism is just another narrative. Who was right about the planet? Amelia Brand was. What did she say? "Maybe we've spent too long trying to figure all this out with theory. Love is the one thing that transcends time and space".
Postmodernism is dismissive of science. Did Romilly's data that he collected during the years of scientific pursuit help anyone from the crew or humanity at large? No. Scientific method of trial and error was useless, but "magical tesseract pixies" powered by love saved the humanity and the protagonist.
Millions and millions of movie viewers "understood" that science and reason is not as important as love and magic. My hypothesis is when people were watching this movie they had a bit of postmodern values imprinted in their minds. That was their epiphany.
Christopher Nolan made an dystopian world he pictured a little closer. That is if you agree that modernism or super-modernism philosophy is more conductive to development of humanity than a postmodernism one...
But you know what really gets to me?
Nolan knew all of that. His Memento movie is an example of postmodernist film in the Wikipedia! He was perfectly aware what he was doing.
This citation must be included in the discussion.
--
On a deeper level, Jessica Chastain may have said it best when telling Entertainment Weekly that “Interstellar” is a love letter from Nolan to his daughter, Flora. The film’s production title was “Flora’s Letter.” Underneath it all, that's what "Interstellar" really is — a father-daughter story reflected in the relationship between Cooper and his daughter, Murph (MacKenzie Foy), the two lead characters at the center of the film.
--
A love letter. Now the movie makes perfect sense as an educational content for a child. Question the authority. Promote love. Instill hope and faith.
But at what price for humanity at large? For me, a price that was too high. That's why I consider Interstellar to be harmful, irrational postmodernist trojan horse that supposedly promotes science but actually does the opposite.
Thank you, Christopher Nolan for making humanity a little bit less rational, thank you so much.
The messages from the first planet seemed like one area where the movie got the physics wrong. The characters said that they were getting just the "ok" message over and over again. But because of the time dilation, the frequency of the "ok" message would have dramatically decreased. I wonder if they could have received it at all.
The point of the time dilation is 'plot'. It's to age the daughter to a point where she's now a prominent scientist and can interpret the main character's weird sendings, while not being dismissed as a weird kid.
In terms of the literal events of the film, it's the last planet they should have visited, given the urgency they have to find a place for the people back home - a few months round trip to come back and check it is only a few months back home, but a couple of hours at the known 'time dilation' is decades back home. Doesn't make internal sense... except for 'plot'.
I understand that time dilation was necessary for the plot. They should have found another way to age the crew, though, that didn't violate common sense.
The crew knew about the time dilation before deciding to try that first planet. They should have realized the data they were getting was only about an hour old. Didn't they say something about not getting any communication from the scientist, just automated transmission of probe data? Only an hour's worth of data and no communication from the scientist should have easily put that planet in the last resort category.
I think Thorne is approaching this from a different perspective than you are.
Thorne is aiming this at people who've never even heard of time dilation. He's aiming this at people who, when they hear about the time dilation on Miller's planet due to its presence in a gravitational field, will say that this is all just made up for the plot, having no idea that this has been known since Einstein's general theory was published nearly 100 years ago in 1915.
I also think that the writing of the movie consisted of the following process:
- Nolan proposes something completely outlandish.
- Thorne explains why it won't work.
- Nolan says it's "non-negotiable" for plot purposes.
- Thorne insists it's not possible.
- Nolan says to make it possible.
- Thorne either figures out a set of exotic circumstances in which it's possible (e.g., a time dilation factor of 1 hour = 7 years), or continues to insist that it's just too far fetched (astronauts traveling faster than light -- something that Nolan originally had told Thorne was non-negotiable but eventually agreed to scrap).
Overall, I think this quote from Thorne really sums up the goal behind the movie's science:
> To a great extent, my motivation here was to try to use the movie as a lure to get people who might otherwise not have much interest in science curious about it, by exposing them to strange, exotic phenomena like wormholes. The film is the bait, and the book is the hook I want to use to draw them in even further, to get them to dig in and learn something new. If they are young, maybe they will consider careers in science rather than in finance or law. If they are older, I still think it’s tremendously important that larger fractions of our citizenry possess enough understanding of science to appreciate its powers and its limitations.
It reminds me of something Feynman said before he delivered his famous lectures at Caltech. The students there at the time were getting bored with the curriculum, and Feynman had observed that it's because none of the new and exciting ideas of modern physics were being presented to them. So he designed his lectures to cover relativity and quantum mechanics, even if it meant leaving out a lot of details to fit it into an undergraduate level. I feel like Thorne and Nolan wanted to present a few of the more exciting ideas of modern physics to viewers who otherwise might think they're made up, and when they insist the science is realistic, that's the perspective they're coming from.
I am actually just happy that they are making movies involving space exploration. We really need to bring back space exploration into the minds of the public so we can get support for awesome missions in the future.
The movie shows other cases where it doesn't follow its own rules: they have spaceplanes that can get to orbit from a planet with 1.8 times earth gravity, but not from earth without huge boosters?
That's a possibility, but the special fuel they have would have to have been extremely expensive then. That would have been a fine explanation, and if they had mentioned it in the movie that would be one less point I could make.
But here's another one: They set up this nice system with pings to know what planets might be suitable, but they can't detect when a ping is being repeated instead of actually sent by a person? They couldn't put a timestamp in it, or some minor variation? They couldn't figure out that it's impossible to receive a ping every hour if the relativistic effects mean an hour takes 7 years?
There are other issues like this, I'm sure I could come up with a load more if I had the time :)
What I didn't understand about these pings is wouldn't their wavelength be massively lengthened by the time dilation? How did they even receive Miller's signal if it was redshifted ~60000 times?
That is an excellent point, I didn't even consider that. It's possible they were listening on the correct frequency to receive it, since they knew the redshift was going to happen, but that just leaves more questions as to why they didn't then realize that it definitely couldn't repeat.
But they could. That is exactly why they did know about nice atmosphere and water on the planet, but didn't know about the waves since the first wave that killed first astronaut happened during the landing. They also left one of the team member to do gravitation research and planned to spend as little time as possible on the planet.
Yes, they knew about the relativistic effects. And they could obviously send some data. But somehow they can't figure out that they've been getting a repeat of the same ping for the last 10 years? And even if they couldn't figure that out, how could the person on the planet possibly send a ping every year, if she only spent an hour and half on it according to her frame of reference?
They expected a ping every year, if it ever stopped pinging they would write off that planet. It was up to the scientists to keep the ping going, if they considered the planet still a suitable candidate for humanity. The signal they received from the time dilation planet was supposedly "looped around the black hole" and repeated yearly.
If I remember correctly, one of the characters hand-waved it as (paraphrasing) "multiple echoes of the same signal". Meaning there were no meaningful timestamps
Ping issues were especially bugging me. Take those pings from the relativistic planet. First it is believed that the person has been sending data for many years, yet only after landing do they recall relativistic effects, and that in fact that person has spend only a couple of hours at the surface.
The biggest issue I see is the fact that gravitational time dilation is considerable on the surface of the Miller's planet, but not so much in the relatively close proximity of the planet, where the mothership is. I just don't get that part.
The explanation Kip Thorne offers in his book is that the lander ends up slingshotting around two things, like black holes and neutron stars, that happen to be in the right places to drop the lander into the gravity well and then accelerate it back into a stable orbit close to the planet. Of course, that kind of maneuver twice, on both the descent into Gargantua's gravity well and the return trip, is totally implausible... the idea that there are so many high gravitation objects orbiting Gargantua near the planet's orbit that you can pull it off on no particular schedule... but it might not be physically impossible.
Wouldn't that be yet another reason to avoid that planet like the plague? Even if they set up a colony there, at any time the planet could run into an orbiting black hole or neutron star, or get slingshotted by one of them into an unfavorable orbit or into Gargantua itself.
I figured the mothership was still orbiting the black hole, in a much wider orbit. They could rendezvous by matching orbits using pretty standard manoeuvres, it would just take more time than if it was moving in a similar orbit as the planet itself.
I believe it is possible to set the rules at the real physics level, take 2001: A Space Odyssey as an example. But not if you are forced by Hollywood producers to put all the little pieces that follow inner feelings of the masses. This is what I believe happened to Matrix movies, progressively keeping worse and worse grip on their own rules.
Absolutely, it is possible to claim accuracy, but then you have the hard task of making that actually true. 2001 was better because of that accuracy, but for many movies it's not a good way of doing it. Interstellar could have worked with complete scientific accuracy, or they could simply not have claimed that it was scientific. Either would have been fine.
I agree on the Matrix movies, but they had much more of a free pass already, because the core concepts are so flexible.
To be fair, though, 2001: A Space Odyssey didn't explore nearly as many exotic phenomena as Interstellar did. It was a lot easier for that movie to remain mostly accurate.
Admittedly it's been some time since I watched the full movie, but I don't recall anything in it, other than the highly abstract ending, that would be considered exotic by today's standards. Maybe they were exotic at the time, but they were still quite well understood at the time of the film's production, whereas the interactions near the singularity of a black hole, say, are very much not understood even at the present day.
Did you have some specific examples in mind? I still feel as though 2001, excluding its ending, stayed much further away from speculative topics of theoretical physics than did Interstellar (which in fact has explicit references, in its dialogue, to "the bulk" -- a term from brane cosmology; see http://en.wikipedia.org/wiki/Brane_cosmology).
Well, the ending was a big part of what I was referring to. Plus a monolith appears on ancient Earth overnight without disturbing sleeping hominid animals, and somehow teaches them how to use tools. And another monolith that is buried in the moon for millions of years sends a targeted, powerful radio beam at Jupiter.
Maybe 2001 just did a better job than Interstellar of drawing lines for the audience between "known science" and "alien technology so advanced it looks like magic." So that 2001 still has a great reputation for scientific accuracy despite the fact it contains elements at least as fantastic as Interstellar does.
> Maybe 2001 just did a better job than Interstellar of drawing lines for the audience between "known science" and "alien technology so advanced it looks like magic."
That is true, but it is not enough. A lot of Interstellar criticism comes from the fact that events described as scientifically feasible were in fact not. I will not describe what particular problems can be found in Interstellar because other posts in this thread already touched virtually every possible issue.
"in this precise, extremely rare situation it is possible, if we ignore all the other side effects"
Isn't that storytelling? The impossibly ridiculous plot works only when all the pieces fall exactly as the author wants. Depending on your point of view, all the circumstances that brought intelligent beings into existence on our planet are themselves an extremely rare situation.
Accuracy aside, from a scientific point of view Interstellar was one of the most interesting movies in a long time, and it really made me think about Physics a lot again.
It's really cool to see how much you can actually learn about the universe of Interstellar by making use of some Physics knowledge and the information given to you in the movie.
An example: The first planet they visit orbits Gargantua (the supermassive black hole mentioned in the movie - https://en.wikipedia.org/wiki/Supermassive_black_hole) at a distance very close to its Schwarzschild radius (or event horizon). In the movie, they say that the time dilation there is such that one hour passed at the surface of the planet corresponds to 7 years (!) on Earth. Interestingly, with that information alone we are already able to calculate how close the planet is to the Schwarzschild radius of the black hole by using a really simple formula: https://en.wikipedia.org/wiki/Schwarzschild_radius (here we have to assume that the black hole is not rotating very fast).
Making some assumptions about the mass of the black hole then allows us to see how large the actual Schwarzschild radius is in fact, and if the time dilation shown in the movie is possible (it is). Similarly, if we use the information they give us about the gravity constant on the planet (about 1.3 times Earth gravity if I remember correctly) as well as an estimate of the height of the tidal waves they find there (maybe 200 meters?), we could even estimate the rotation period of the planet.
There are many more examples of clues like this in the movie, which offer great 'Fermi problems' (https://en.wikipedia.org/wiki/Fermi_problem) and allow us to learn many things about the universe presented to us in Interstellar.
Of course I also have to mention the absolutely stunning rendering of the black hole, which incorporated the gravitational lensing effects (https://en.wikipedia.org/wiki/Gravitational_lens) that make the accretion disk of the black hole appear like a halo surrounding it. Also, the rendering of the wormhole as a four-dimensional "hole" embedded in three-dimensional space was absolutely gorgeous.
I also love the movie, but there one thing with the time dilation I suspect does not add up. If the first planet is so deep into Gargantua's gravity well that it has such time dilation, would the energy required to get a spaceship out of the gravity well not be ridiculously huge? Given that they had limited energy, did it make sense to visit that planet first?
The thing about their energy budget was not well done. Why did they need rockets back on earth when they can mount the gravity well of a black hole and multiple planets afterwards? About your point with the order of visits though: I could see them using Gargantua for a slinghot maneuver after the first planet, which should work given the right constellation. It wasn't shown this way though.
Even with a ship capable of overcoming the gravity wells present in the movie, it would likely still make sense to launch from Earth with boosters/staging to increase the amount of fuel/energy available to the ship for the rest of the journey.
Yes, that's a valid argument I think. On the other hand, I'd imagine if our technological level is such that we have SSTO ships (with SSTO even for more massive gravity wells than Earth's), we'd probably not use rockets but have another SSTO tanker fueling up the ship in orbit. You could maybe argue that ressource constraints in their dire situation have forged a situation where they put everything they had into those ships and the rockets were just what they had still lying around from an older age, so they made use of it. It certainly was another artistic choice in order to give it a more familiar feel and I can respect that.
A rocket-scientist (ok, aerospace engineer by training) friend was recently surprised that he hadn't realized this:
"If the radius of our planet were larger, there could be a point at which an Earth escaping rocket could not be built. Let us assume that building a rocket at 96% propellant (4% rocket), currently the limit for just the Shuttle External Tank, is the practical limit for launch vehicle engineering. Let us also choose hydrogen-oxygen, the most energetic chemical propellant known and currently capable of use in a human rated rocket engine. By plugging these numbers into the rocket equation, we can transform the calculated escape velocity into its equivalent planetary radius. That radius would be about 9680 kilometers (Earth is 6670 km). If our planet was 50% larger in diameter, we would not be able to venture into space, at least using rockets for transport."[1]
Yeah this is indeed true, but sadly most movie plots treat distances badly for practicality reasons. The fact that they were able to leave the gravitational field of the planet they visited just using their "space shuttle" was also highly unrealistic, since that planet had about the same mass as Earth, whose gravity well they had to leave using a conventional rocket earlier in the movie. So this part definitely does not add up.
The time dilation was really quite fascinating. However, I assume that the entire planet would not behave as if it had the same time dilation all the time?
Considering the massive dilation (1 hour -> 7 years, a factor of 1 : 61320), wouldn't even relatively small distances on the planet surface create different dilation effects depending on an objects/individuals distance to the black hole?
I'm just wondering if there would not only be noticable effects from a distance (orbit -> planet), but also within visible distance on the surface itself.
If the dilation could act on scales such as the 200 meter wave, I'm having trouble imagining how it would look / behave, if for example the top of the wave was moving "slower" compared to the bottom of the wave.
Fascinating question, I'll have to look into this! I was considering writing a blog post about the movie physics already since there are so many fascinating things to be discovered, but I'll maybe check out Kip Thorne's book about the movie first ;)
The wormhole was perfect, except the travel bit bugged me. They use the 2d analog with paper. The second you pass through the hole in one location you emerge from the hole in the other location. In the third dimension, as they touch the sphere near Saturn they would be leaving the surface of the sphere on the other side. From their point of view they should be about to hit the 'ball' then all of a suddenly then are travelling away from the surface of another ball. Instead they had this tunnel thingy.
> However, in 1962 John A. Wheeler and Robert W. Fuller published a paper showing that this type of wormhole is unstable if it connects two parts of the same universe, and that it will pinch off too quickly for light (or any particle moving slower than light) that falls in from one exterior region to make it to the other exterior region.
Yea I was thinking about that, say a straw. A cylinder to us in the 3d world but in the 2d world one would just see themselves stuck in a circle for awhile. So to up a dimension a 4d whole in a 3d world would I guess appear to us to be a stuck in a sphere? Maybe that is what the movie tried to show, but it still looked like they were travelling in a tube.
It's a supermassive black hole, spinning at close to the maximum permitted (apparently there's a maximum, beyond which photons at either the photon sphere or an event horizon get dragged faster than the speed of light, and Gargantua's spin is ridiculously close to the maximum for the math on the orbit and time dilation to work out, but it does)
If you can find a copy of Thorne's book (it's already leaked to the web) and skim the appropriate sections, it'll clear up some things.
A relativistically spinning supermassive black hole might not be very unrealistic indeed, since it will have ingested the angular momentum of a whole galaxy during its growth and concentrated it in a very small region of space.
> I found that Chris’s huge slowing of time requires Gargantua to spin almost as fast as the maximum: less than the maximum by about one part in 100 trillion. In most of my science interpretations of Interstellar, I assume this spin.
> In 1975, I discovered a mechanism by which Nature protects black holes from spinning faster than the maximum: When it gets close to the maximum spin, a black hole has difficulty capturing objects that orbit in the same direction as the hole rotates and that therefore, when captured, increase the hole’s spin. But the hole easily captures things that orbit opposite to its spin and that, when captured, slow the hole’s spin. Therefore, the spin is easily slowed, when it gets close to the maximum.
> Ultimately, when the hole’s spin reaches 0.998 of the maximum, an equilibrium is reached, with spin-down by the captured photons precisely counteracting spin-up by the accreting gas. This equilibrium appears to be somewhat robust.
In essence, the necessary spin (for an object to stably orbit at a distance for the time dilation needed for the plot), while possible, is not sustainable, based on what we know about physics. But it's allowable as real physics, because there could be some exotic physics involved in keeping Gargantua spinning that fast, possibly intervention by the civilization that created the tesseract.
An aside, but I'm curious. I see this mentioned a lot more often lately, and I know Randall Monroe talks about them a lot in his 'What if?' series, so I'm not sure if it's because of that popularising the term, or if it's just the Baader-Meinhof phenomenon on my part. A Google Trends search suggests increased interest, but it could just be coincidental.
Fermi problems are discussed a lot in Physics, and as a working physicist you always need to be able to quickly estimate the order of magnitude of something when developing ideas for experiments, since calculating everything in detail is usually too time-consuming. So I'd say that this is not a hype but rather a pretty useful skill for any scientist.
Wait what? What about sending "quantum data" back from the black hole? The point is that no information can leave.
Also, from what I learned in high school physics, the body of a human would completely fall apart if it's falling to the black hole, because of the difference in gravity between proximal and distal parts.
These are just the 2 things I noticed and I'm far from a physicist. Basically, it got a couple of things right and a bunch of things wrong. There was a clear preference of emotion over science. It just seemed like "The Core" Version 2.0, but here love and reading books conquers all and is beyond the forces of nature.
I liked Europa Report a lot more even though they didn't invest nearly as much into special effects.
That's an interesting point! The fact that our current theories suggest that no information can ever leave a black hole entails a paradox which is known as the "Black hole information paradox" (https://en.wikipedia.org/wiki/Black_hole_information_paradox). In the movie they resolve this by resorting to gravitational waves, which can "permeate" through space and time by a mechanism not explained in the film. In real physics, there is actually an ongoing debate in the community about whether information can escape from black holes or not, which resulted in a famous bet between Stephen Hawking and Kip Thorne on one side and John Preskill on the other. The fact that Thorne suggests that information can be sent out from a black hole might therefore be a small stab at John Preskill ;)
Concerning the second point, there is actually a pretty fascinating explanation: For a small black hole, the "tidal force" when entering the black hole (i.e. the force difference between your feet and your head) would be so enormous that you'd probably get ripped apart (so-called "Spaghettification" - https://en.wikipedia.org/wiki/Spaghettification). However, the Schwarzschild radius (or event horizon) increases linearly with the mass of a black hole, whereas the gravitational force declines with the square of the radius. Hence, for a supermassive black hole with 10 million solar masses, the tidal force is not bigger than the one you experience here on Earth (https://en.wikipedia.org/wiki/Supermassive_black_hole), and you would probably not even notice when you cross the event horizon. Fascinating stuff.
They glossed over the tidal force in the movie and I assumed it was a deus ex of sorts (in fact, I assumed the whole final act of the movie was more concerned with resolution of the story than with proper Physics). Thank you for this explanation, this is fascinating stuff.
It's still a gloss over, but one of the characters does mention it early on, which I took as indication that it was going to end up being important.
I remember having a similar thought process to all of the above, but they even explicitly call it out as "gentle" with maybe a single really simple sentence on why it was. I don't remember if they made the direct connection to it being supermassive (like they did with its rotation), but it was in the same bit of dialog.
Maybe black holes are nature's true-random-number-generator (via hawking radiation). Energy comes in, energy eventually comes out, but there's no relation as far as wavelength, direction etc.
No idea, I'm an EE not an astronomer, just guessing out of my back end.
I don't know why you're being downvoted, so I'm going to give you a proper reply instead.
Actually, the 2 things you noticed are not that hard to resolve:
- The quantum data was most likely never going to get out of the black hole. They executed the plan on the off chance that TARS was able to figure out how to do it if he had the quantum data. It's not impossible that there is a way to do it, we just don't know it yet.
- Your concern about spaghettification is valid, but the risk of that happening also decreases with the size and mass of the black hole. A stellar mass black hole would rip you apart instantly, but around a supermassive black hole the gravity gradient is a lot gentler. It wouldn't be comfortable per sé, but definitely survivable. You would get ripped apart inside the event horizon, but you could cross it pretty safely.
There is actually a much bigger problem than the spaghettification: every black hole has a shell of light orbiting it at the event horizon. It's light that came in tangentially, and doesn't have enough speed to escape, but is fast enough to keep orbiting. In a black hole of considerable age (like the one in Interstellar), that shell would be very very energetic. I don't know if the ships they were in would be able to survive a blast of radiation that intense, let alone the human and robot inside.
I don't think it's fair to say that they went for emotion over science. They tried to do both, and wanted at least an inclination of accuracy from the start. That's laudable in itself, in a time where most wouldn't bother with that.
Wouldn't spaghettification happen anyway, but at a later point?
Maybe everything after he fell in was a dream of his? This would actually make it much more interesting for me although many people probably wouldn't like this sort of ending.
It would happen, but for a black hole massive enough, that point would be well inside the event horizon. We don't know how deep they actually went into the black hole, or even whether or not the 4D structure was inside the black hole or somewhere else entirely. Everything inside the event horizon is essentially unknown to us, both as scientists and as movie-goers, but the trip up to that point is survivable.
I'm not going to comment on the "cosmic censorship" hypothesis of black holes since that's actually an incredibly difficult topic, but regarding the tidal forces that would rip you apart, there are certainly large enough black holes that would allow you to comfortably enter the event horizon without being ripped apart. But just to give you a taste of how counter-intuitive this subject can be, consider that despite the fact that light cannot escape a black hole it is conjectured (by Hawking no less) that black holes can emit radiation! (The mystifying mechanism of this involves, very roughly, quantum fluctuations at the event horizon spontaneously giving rise to particle/anti-particle pairs, with one particle of negative mass falling into the horizon and the other of positive mass going out.)
The event horizon is only the "point of no return" insofar as it's the imaginary boundary inside of which even the forward light cones are oriented towards the center of the sphere (so that light cannot escape no matter what direction it's emitted in). It's not the point at which the tidal forces are so strong that matter is ripped apart (or even just your macroscopic body).
Gargantua is a spinning "Kerr" blackhole in the movie. The nearly maximally spinning blackhole is central to the movie plot as it is the reason Miller's planet can be in the orbit it is claimed to be, tidally locked to the spin direction of the blackhole. And the "accretion disc" is not really accreting into the blackhole but is just in orbit around the blackhole, cooling off. The accretion discs and the polar ejections we know from astronomy are energetic medusas that'll fry anything that so much as glances in its direction.
I haven't checked the numbers in any way, but is it safe to assume that the black hole is not rotating "very fast"? In the news covering the render software and papers that will be/have been published, it was mentioned that they were surprised to see the effect the rotation of the black hole has on the accretion disk -- that it bends and twists space and light, so insted of a flat, Saturn-ring-lik disk, you end up with the thing you see in screen.
Calculations about time dilation become enormously more complicated in a system where the black hole is spinning, because you get effects like frame dragging that influence the orbits and time. For the purposes of the parent poster, a ball-park number of distance is enough, they don't need the whole shebang.
> For the purposes of the parent poster, a ball-park number of distance is enough
Citation needed.
It's been said repeatedly that considering the strong rotation of the black hole is critical for the situation in the movie to be possible. "It's hard" is not an excuse to ignore a strong effect.
ThePhysicist talks about using the bits of information provided in the movie to learn about the basics of some of the physics behind it. That's why he points to the formula for calculating a Scharzschild radius and not the complicated solutions of Einstein's field equation for Kerr (rotating) black holes. As a learning experience, you don't want to dive into the hardest stuff right away. As a you learn, you'll also figure out what was a ball-park number and what wasn't.
Also, the effect is strong, but in all of the formulas you're already guessing factors such as mass of the black hole, which have a far bigger influence on the end result.
It sounds like he's just discussing certain aspects of the film, while ignoring much more glaring issues. It's not ice clouds that are the issue, it's the entire story.
[Spoiler alert] Here's the whole plot of the movie, does any aspect of it make sense?
Earth is dusty so the simplest solution is to transport all of humanity through a wormhole to another planet. The main characters go through a wormhole and walk around on a planet where 1 hour = 7 years of Earth. Later, to help the mission succeed, the main character detaches from their main spaceship into a blackhole and he ends up in a multi-dimensional space where he sends Morse code messages to his daughter in the past by moving her books and watch. How does he do that? Because love. And gravity. She understands the message which contains gravity data from the blackhole that lets them get everyone off earth. The main character then pops out of the blackhole thing near Saturn and is re-united with his daughter just before she dies.
>he ends up in a multi-dimensional space where he sends Morse code messages to his daughter in the past by moving her books and watch. How does he do that?
Because the multi-dimensional space was set up by higher-dimensional creatures, who also created the wormhole, specifically so he could accomplish all this (right down to preventing him from going on the earlier missions by causing his craft to crash with a gravitational anomaly at the beginning of the film).
That seems like a rather roundabout way to save the human race, no? A love-powered hyper-dimensional gateway used to transmit Morse code sounds like something straight out of h2g2.
(spoilers, obviously) It's a predestination paradox -- so, as with all predestination paradoxes in fiction, the story is a little too in love with the use of it -- but the movie sets the ground rule that the only way to communicate backwards is to manipulate gravity, therefore that's how they're going to have to accomplish it.
As for the love-powered part, everyone's a little too hung up on that set of dialog. There's nothing in the plot that relies on it. Sufficiently advanced magic gravity technology is more than enough. Is any advancement of the plot motivated by more than the fact that he wants to see his daughter again? Sure, if they had listened to Brand's feelings they wouldn't have ended up with crazy guy and would have ended up on a (seemingly) habitable planet, but the human race also would have died on earth and lived on entirely from the test tube embryos.
The whole tesseract section doesn't entirely fit with the tone of the rest of the movie but it's not powered by love.
I liked the film, and it bothers me a bit that they can launch from a planet with stronger gravity using tiny rockets, or that we would consider a planet orbiting the event horizon of a huge black hole as good candidate for our new home.
But my biggest gripe is with the premisse of the film. We have a catastrophic ecological disaster, which is unconvincingly explained in a single sentence by Michael Caine, and our solution is to take the entire species on an intergalactic travel through a worm hole. Instead of, you know, digging a big hole right here and creating an artificial biosphere underground. Or maybe check out Mars or Europa, which are right around the corner.
Or the idea of abandoning Earth because it's too hostile to grow crops with some dust storms, yet the idea of colonising a distant, extremely harsh-for-human-life planet is a more realistic idea. Surely building massive "vertical farms" or other artificial environments here on Earth would be more cost effective and realistic.
Overall I think we may be thinking too deeply about the plot ;-)
Why was the Ranger launched from Earth on a giant rocket, but was single stage to orbit on all the other Earth-like worlds?
The only thing I've been able to think of was that they used some kind of exotic propulsion, like antimatter, therefore there was no sense wasting such a precious commodity to leave Earth if you had a rocket available.
There is the one-off about this being the last of its kind space vehicle, and the booster pack in orbit had been there for quite some time. You can somewhat fanwank that into meaning they had to use older, simpler technology to get the capsule itself into orbit, but then could take advantage of the pre-Blight technology already in orbit for the rest of the movie. That's about the same as your explanation, though.
Pretty weak, so it would be nice if they had at least given us a throwaway sentence or two to wave it away like they did with spaghettification, as the rocket orbital mechanics, at least, were distracting. I imagine the real reason was Nolan wanted to invoke a parallel to the Apollo missions in the liftoff from earth, but didn't want to waste time with the very hard problem of getting off other worlds once you get there.
One thing I cannot understand is... Sure, this movie was very "accurate", all these explanations can make sense, the calculations fit but.. why is nobody talking about the major obviously impossible/inconsistent problems in the plot?
INTERSTELLAR SPOILER BELOW
For example, how did he survive inside a black hole, how did he pass through the Schwarzschild radius with his simple spaceship, why was there no time dilation as he approached the black hole, why did his spaceship break down inside the black hole but he was able to eject with his simple spacesuit and survive, how did he realistically survive out in cold space (at the end, yes okay I know this is technically possible but still..)?
When I watched this movie, I saw a lot of problems that made me think "has a physicist ACTUALLY worked on this and said 'yes, this is accurate'?". And those certainly weren't the minor details like the time dilation on the planet, the structure of the black hole and the icy clouds on that one other planet.
Disclaimer: I enjoyed Interstellar a lot, it was a pretty good movie, although I felt that at times the director was pretty much screaming in my face: "SEE? WE ARE SO REALISTIC! LOOK THERE IS NO SOUND IN SPACE, AREN'T WE REALISTIC?" (sorry for caps lock but it's to provide emphasis)
The science was basically non-existing: controlling a distant device with gravitational waves? Which can only be controlled whenever it is in a specific room? Which stores the information transmitted and repeats it endlessly (otherwise, how is the daughter able to gather all information transmitted)? How long does he spend inside the black hole transmitting what must be like lots of information in morse code, by slowly pulling gravitational waves? Looks to me like several hours / days? What is the time dilation of getting into a black hole if getting into a planet gives you a 1 hour to 7 years ratio? Getting inside / outside a black hole, unharmed? What part of this is current physics domain?
More strange facts: the device in the black hole was supposedly man-made ("we are they"), by the men of the future. But the men of the future can only exist if this particular crisis is overcome. And this crisis can only be overcome if this device is in the black-hole. Granted that the man of the future controls the five dimensions, and thus time, but we currently do not, so we can not in any way survive this crisis. Which means the men of the future will never be, so they can not build the device to survive the crisis.
Just the very simple facts are maybe according to the current scientific knowledge (time dilation, gravity effects, I can even accept a worm-hole), but most of the movie is just an exercise on futility with a very high dose of emotions. Boring, slow and not enjoyable at all. The fact that they are pretending that this is a science-based movie makes it insulting. If you want to do a Hobbit, do it and I'll have a good time, but do not pretend it is based on any established science.
Gravity was a completely different sort of movie, so the comparison makes little sense. Gravity was about the here and now, things we understand and can convey rather easily. This movie explores some of the most strange edges of our current understanding in order to tell a story.
Also, did you miss all of the criticism of the physics in Gravity?
Yeah, Gravity was better, but it did not explore relativity. Its just plain hard to explain relativity, more so to make an actual movie out of it that will appeal to the general public.
possible for supermassive black holes up to a certain distance from the singularity. To my knowledge there's still the possibility of ring shaped singularities that could be passed through and we don't really know yet what would happen there. Unified quantum gravity theory needed first, so remains in the artistic freedom of the director.
* how did he pass through the Schwarzschild radius with his simple spaceship
Again the only question is whether the tidal forces would be too strong and a supermassive black hole does not have extremely strong forces at its event horizon.
* why was there no time dilation as he approached the black hole
I think there was. After returning from the closely orbiting planet they had a few decades such that he now was a bit younger than his daughter, after coming out of the black hole another 50-60 years have passed for the outside world. Granted though, as far as I understand GRT, actually entering a black hole takes literally forever from the point of view of the outside world (i.e. time breaks down completely), but again, we don't know what would happen with quantum gravity, so maybe the infinity would cancel out somehow if our theories were better.
* why did his spaceship break down inside the black hole but he was able to eject with his simple spacesuit and survive
Tidal forces act the stronger the more vertical distance from the gravitational center an object has in itself (i.e. the height of the object from the singularity's point of view). A spaceship is much larger than a human, so it will break down earlier.
* how did he realistically survive out in cold space (at the end, yes okay I know this is technically possible but still..)
You do have a few minutes in space - the coldness isn't actually a problem since nothing can transport heat in a vacuum. It's rather the pressure difference that will give you trouble, but there are some measures such as emptying your lungs that will give you more time.
It's not a science movie. It's fiction. Science is a passenger, not the vehicle. You want science - go watch a Neil DeGrasse Tyson or Carl Sagan (and don't get too wound up about how they gloss things over - the kind of science they're doing is too complicated for an hour long show).
The science used in sci-fi movies is not about the science - it's about the myth of science; the things we wish science could do or lead us to do. But more than that, it's about telling a story. We are not relating facts here, we're off into Joseph Campbell territory.
Even the most scientifically accurate movie is going to do some jazz hands once in a while just to keep things interesting/heroic/funny/whatever because: failure is not an option - the movie has to make money.
This. I could summarize the movie as follows: Science? Check. A guy that wasn't given fair chance, now saves the world? Check. Little girl experiences "ghosts", nobody believes, turns out true? Check. Two main characters fall in love? Check. And so on.
It is all a matter of pleasing the viewer by giving him exactly what he wants. Science is just sexy right now, and that's actually good.
All that I could swallow, if only. If only it made any attempt to even fake it well. If only it didn't ignore plot holes the size of a truck. If I could only figure out what the plot was, or who the characters were (from moment to moment), or what they meant by the words that came out of their mouths. If only it was a real movie, and not just a bunch of images on a screen to give teenagers the impression they're watching a movie.
All of the problems you mention are problems created by the writer, director, producers, etc., and have nothing to do with bad science. They can, and frequently do, show up in every genre of film. One of my favorite films is Big Trouble in Little China (as an example) and I'm sure there are all kinds of issues about the film itself, but I still love the film. Ditto Blade Runner, Brazil, Contact, etc.
Its an interesting question: who failed this movie? The director is easy to blame - why are characters changing without motivation? Who is connected to whom, emotionally? What is that grandfather doing there anyhow? How can a father care deeply about his daughter, but ignore his son (and grandson)? If there're reasons, let us know!
As for science: its more than technical details. Its why they are so dumb.
Why can a 12-year-old out-guess the plans made by the scientists? (We're in a terrible hurry; lets set down on a time-dilated planet for a few hours and let the masses on Earth rot for a decade or two).
Once decided, why park your interstellar ship outside the time-dilation zone, so you can take your shuttle to the surface? Makes no difference to Earth - they wait either way. But the ship burns half their fuel, just station-keeping for 20 years. If it had been time-dilated too, that wouldn't have happened! Not even to mention the poor sap on the ship, stuck waiting for half his life.
Oh I can go on (have, for hours, to my family's dismay)
In hard science fiction, "science" is physics. Maybe chemistry, maybe. But biology is all squishy and such and doesn't carry the mathematical gravitas needed to be taken seriously.
The thing is, you don't really have to explain that, exactly because we don't know what the "rules" of time-travel are, IF it were even possible. We talk about "grandfather paradoxes" and "ontological paradox" in sci-fi, and speculate about what would happen in "real life" if some of these things happened, but the paradox might be completely irrelevant for all we know.
Anyway, for my money, this issue falls well into the "willful suspension of disbelief" category - and didn't affect my appreciation of the movie at all.
I mean, yeah, it was billed as a "scientifically accurate' movie, but it's still science fiction at the end of the day, with the emphasis on "fiction".
It's by far my favorite way to explain time travel system like the one we see in Interstellar, and it's rooted in real science rather than Paradox Philosophy.
One resolution I've seen mentioned is that if Brand succeeded with Plan B then maybe "they" are the ancestors of the Edmunds-planet. That would resolve the paradox at least.
The point is: don't claim that you're scientifically accurate. Usually, a good sci-fi movie will set up rules for itself, and follow those rules appropriately. If you make your ruleset "real world physics", you have to be extremely accurate if you still want to make it believable. The rules set up expectations, and breaking your own rules is an instant turn-off for science fiction fans.
The movie shows other cases where it doesn't follow its own rules: they have spaceplanes that can get to orbit from a planet with 1.8 times earth gravity, but not from earth without huge boosters?
For the record: I like Interstellar a lot. It was a great film, and I'll definitely be buying it when it comes out on DVD. I just have my gripes with the lofty claims of accuracy that Hollywood films so love to make.