On the Science of Interstellar | Hacker News Reader

On the Science of Interstellar

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56 pointsibrahimcesar30 comments

I had no idea Kip Thorne was a producer for this. For non-physicists, Thorne is one of the authors of _the_ general relativity book for graduates, _Gravitation_ [1]. It's this huge telephone book sized tome that was published in 1973, and while it has fallen behind the times with respect to experimental data included in it, it is still unparallelled in scope and depth today in covering Einstein's theory.

I certainly enjoyed the movie, and I really loved the visualizations of a wormhole and of the large spinning black hole, things you usually have to imagine as a physicist without ever seeing with your eyes.

[1] http://www.amazon.com/Gravitation-Physics-Series-Charles-Mis...

pretty cool to see some of the math of this spelled out. I appreciate the effort the author has put into this.

unfortunately, my issues with Interstellar have very little to do with whether or not the black hole was portrayed realistically.

edit: why was I downvoted? for saying I didn't like the movie? come on guys.

Care to share your criticism of the movie? I really enjoyed it compared to the usual superhero sequel

sure. I didn't elaborate in my first post because its slightly off topic considering the article posted is about the science of the movie rather than the writing of the story.

that's where my problem is. I think its a kind of poorly written story. hollow characters, implausible social explanations, and a bit too much deus ex machina. I understand that the deus ex machina elements of the story are at least partially explained by the conclusion, but they are also largely unexplained and creates a premise that we are forced to accept on faith. that harms my suspension of disbelief.

Overall I'd say it was worth seeing, especially on big screen, the effects were great and the exploration of relativistic time dilation was generally really cool in a mass market movie, but there were a number of absurdities.

SPOILERS:

1. Thousand foot high waves don't move across 2ft deep water without breaking. Also, lame camera tricks prevent the astronauts from simply scanning 360d and realizing there's a huge wave bearing down on them. Also, there was no reason whatsoever for Doyle to die on the water planet.

2. Too emo. Too much bawling and crying, too much emotional decision making, the actors weren't convincing as trained scientists or disciplined test pilots. The audience actually burst out laughing when Mann and Cooper got into the fight on the ice planet, and when Cooper just let Mann bash his helmet in a couple times instead of pulling away like normal person would. See 2001: A Space Odyssey and The Right Stuff for how such people should be portrayed. Artistic integrity sacrificed for artful, faux emotional appeal, SOP for Hollywood these days.

3. When Mann crashed the shuttle into the mothership, then Cooper and Brand saved the mothership, one second it was over a planet, and not the first planet they visited that was really close to the black hole but the next one out. The next instant they were in danger of falling into the black hole. Months or years worth of distance traversed in seconds.

4. Cooper saved Brand by dropping both TARS and himself into the black hole, giving Brand on the mothership enough velocity/lack of mass/whatever to escape the black hole. The time dilation effects of him dropping into the black hole should have meant he and Brand diverged greatly in age, yet the end of the movie showed him taking off to go find her, same age.

5. The premise of the movie is that future, advanced, five-dimensional humanity was using its power over gravity, time, and higher dimensions to help humanity of the past survive the dying and 'Marsification' of the earth. But the paradox was never resolved - if humanity of the past couldn't survive on its own, how did it ever become humanity of the future? I suppose they did that on purpose to let the audience have fun debating it afterwards.

There were a few others I can't remember atm, but you get the gist. Some of these, like #3, I suppose have to be done to cram the whole story into a 2hr45m movie (another cool thing about it - nice and long), but others were just annoyingly pointless.

But again, overall it was good, worth watching, and having Kip Thorne co-produce helped a lot. Just don't expect perfection, even with his name in the credits.

1. It was a largely uniformly flat planet. It was only 2ft deep due to the tidal wave borrowing water ahead of it. See videos of Tsunamis doing the same thing

4. I thought this one was explained by the baseball scene at the end as the ball falls upwards when it crosses some sort of mid point.

5. You are thinking of time linearly moving forward, cause and effect. I think the library scene and their explanations of the 5th dimension aimed to explain that time is another dimension that can be altered. "Whatever can happen will happen".

The ball scene at the end happened because the ball hit the 'escape velocity' of the spherical habitat, which allowed it to break the gravitation pull of centrifugal force and get caught by the other side. I don't see how this references the fact that being sent near and even into the black hole didn't cause some massive time differences between the two scientists as it did earlier in the film.

my understanding was the station at the end had true localised gravitation, thanks to the 'quantum data' TARS collected, rather than psuedo gravity induced by centrifugal force

with the baseball the ball left the gravitation of the field's surface and entered the gravity on the other side of the column station's interior surface that held the house

Interesting, it certainly gives an explanation to the not very clear "Why do we need this equation to get people off the planet" question, but then why build the ship as a cylinder (which by design takes advantage of centrifugal force) if they're going to use localized gravity to keep things on the ground? I assumed they had taken advantage of gravity manipulation to save on immense fuel costs of getting the giant payload out of Earth's gravity well, and used centrifugal force while en route.

though unable to answer explicitly a hypothetical of a hypothetical of a fiction.. it is a fun, and arguably healthy'productive exercise to dream on it..

from the perspective of the film makers it seemed like a shout out to the colony art nasa published a while back(i), similar to the shout out to event horizon: 'your explanation opened my mind, bending space time like a piece of paper and passing through it like a pencil.. i'll take it to the next level, what is a hole in three dimensions? open the paper and look at the hole as a circle forming a sphere' fun stuff

if we want to examine the practicality of a cylindrical colony i think we could come up with something.. maybe as a safety measure from space debris? maybe as an engineering consideration: it was easier to build an accommodatingly sized colony like this? easier to maintain a controlled climate? maybe as a lighting'photosynthesis consideration? perhaps it's a 'so preoccupied with whether they could' punchline? perhaps the other side of the column is also utilised space: imagine almost doubling the surface area of the planet by colonising both the surface and the interior of the planet with an inverted zenith; and the film only showed us inside the column, again, as a wink at the audience

(i) http://settlement.arc.nasa.gov/70sArt/art.html

if it had artificial "true" gravity then why was it shaped like a cylinder? typically the cylinder shape is used to take advantage of rotation for centrifugal force "fake" gravity.

i tried to address this concern in the reply above, but i wanted to mention i like your use of ""s, i felt dirty, and considered and reconsidered multiple times the verbage, saying 'psuedo gravity'

i like the idea of gravity perhaps being an effect of inertia due to centrifugal forces, caused by the spinning and orbiting and expanding and mass of objects in space, stead it being it's own agnostic 'force'

in which case setting centrifugal force and gravity as separates would be incorrect, and the ""s wholly necessary

Excellent write up. You did a cleaner job of stating the critiques than I did. http://www.reddit.com/r/movies/comments/2lnleu/discuss_the_b...

#3: I remember it being mentioned that both those planets were orbiting the black hole, Mann was probably on the opposite side of the black hole that Miller was on. Only Edmunds was further. They went to Mann via the farside to avoid the black hole (as they did with Miller), but perhaps the explosion and spin pushed it to the side of the planet that was closer to the black hole.

My understanding is that the water planet was closest to the black hole, as it was the only one they had to be super careful with re time dilation. Eg, every hour on the planet is 7 years on Earth, and some amount longer even just back on the orbiting mothership - Romily aged 23 yrs while he waited up there. That wasn't a problem with Mann's planet, further away from the black hole.

I wrote up some thoughts right after seeing it Friday. I mixed up Mann and Edmund, but otherwise I think I summarized the problems well. http://www.reddit.com/r/movies/comments/2lnleu/discuss_the_b...

stunning, intense

impactical for pith due recursion,

any endorsement requires a full dialogue of caveats only able to discuss after you have seen it

Visual and practical effects were nicely done. Really liked the depiction of the Saturn colony at the end. It's a proposed style from the 60's that has never gotten a proper cinematic representation.

The bad parts of the movie were mainly editing, non rational emotionalism (main characters making obviously bad choices for shallow emotional reasons), and a giant paradox.

With editing, the drone scene was interesting but did nothing to advance the story. School scene was ok but too long.

The entire "power of love" scene was just dumb. People in that situation would not act like that.

The biggest problem was the paradox. Earth is becoming uninhabitable. Future humans must influence the past to save humanity. But there are no future humans in the first place since the Earth is dying. This is the biggest plot hole in the movie and it's the size of a black hole. Even slightly changing the story so that humans do survive, then are reaching back to make the survival process easier would be fine. Kind of a Redemption of Christopher Columbus type of story.

I loved how these brilliant astronauts can't see how loving deceased people could possibly have social utility or could otherwise be explained without resorting to "love is supernatural magic." That is a particularly strong example of how bad the screenwriting is in this film.

If you're on the fence of reading it, I'd say read it. He really put it nicely in laymen terms.

Ok, this is very well written article explaning some problematic parts that people don't understand. But there is one more paradoxal point I didn't get it why and how the writers could not figure it out that, if a nation can't survive in itself and needs help from aliens (later cooper finds out that these aliens are actually us, who are already in 5 dimensional universe) to solve the equation for their existence and if people would die without help of outside, how could their descendens survive and then live in 5 dimensional world to save their ancestors?! This is pure paradox and not possible. And it's very well known that one can be in the future but can't go or change things in the past, even in 5 dimensional universe.

This is a well-worn trope used in many science fiction works dealing with time travel: http://en.wikipedia.org/wiki/Bootstrap_paradox

That is known as the bootstrap paradox (http://en.wikipedia.org/wiki/Bootstrap_paradox). You could argue that the entire point of the movie is to highlight this specific paradox that can result from time travel. As with most time travel paradoxes, and pretty much anything related to time travel, it's not known exactly how things would work out in the real world.

Perhaps in some parallel universe the humans survived and figured out a way to travel between the different universes, and decide to cross over to help this universe survive.

Murph figured the physics out by herself. Her father knew plan A was a pipe dream, and he did abandon her.

She couldn't bear hating her father. The movie is her elaborate fantasy about her father telling her the answer. So elaborate, she hallucinated him on her deathbed. Her father never came back through the wormhole.

Eureka! Thank you!

Fascinating read. I'm generally not too concerned with science being 100% accurate in my sci-fi movies, but to find that it is all grounded in real science - even the far out, funky, stuff of the last act - is pretty cool.

I personally loved the movie, and the cinematography brought me back to the same feeling I had as a kid watching 2001 for the first time. I grew up completely enamored in space and all of the things in it, and some of the shots produced a very visceral reaction. Almost enough to make me regret that I didn't follow the oh so ubiquitous dream of trying to become an astronaut.

How does one explain the frozen clouds? Are those actually possible? How do they remain afloat if they're more dense than the atmosphere?

Apparently the clouds are not all that plausible, but they were left in because they were so visually impressive.

http://news.sciencemag.org/people-events/2014/11/physicist-w...

i'd love a binary where i can have complete control of the camera in these visualizations

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