Hacker News Reader

> Then they land a ship on a planet with a gravity well so intense that it causes big relative time differences

Pedantically, no, they don’t.

They land on a planet deep enough in a black hole’s gravity well to cause significant relative time differences.

(Obviously, this doesn’t change the issue of delta-V to get back to the mother ship, though the difference is relevant to your “the gravity alone should have killed them” comment, since that would only occur of there was a hard surface not in free fall with respect to the gravity well for them to be crushed into.)

> Then they blast off with the same ship and no big clunky chemical rocket stages. Why didn't this ship just blast off of Earth as is?

Maybe because the super drive it uses would have adverse environmental impacts used in Earth’s atmosphere, and Earth has enough of that to deal with, but they cut the exposition-that-doesn’t move-the-plot-forward about that because they were making a movie, not a technical report on the mission’s decisionmaking.

In free fall, in a strong gravity field, you would be torn apart. Just as comets nearing A gas giant, except many times more forcefully.

One end of you is attracted more than the other. In a strong enough field, you would become a string of disjointed atoms, right?

The gravity alone would, actually, have killed them.

The sci-fi author David Weber said something in an interview I read ages ago that stuck with me. It was something to the effect of: "don't spend paragraphs describing how a light switch works in the future." There's a place for true hard sci-fi, but it is niche. The bulk of sci-fi is quite justifiably going to be more or less accurate in places in relation to how well it services the overall combined goals fo the film.

It also somewhat bugs me that pretty invariably the folks that crap all over these movies are huge Trek or Babylon 5 fans, shows that have endless literal magic in them, and they're just fine with it. It's hard not to see this as another form of nerd sniping (note: not directed at you personally, just talking about a dynamic I've seen with many friends).

I'll agree about pretentiousness, but I do think Intersteller should be given credit for working to get more right than the vast majority of flims, but more importantly for doing an original concept where in many ways, GR itself is a main character. That was a bold bet in a world where we have 9 Fast and Furious movies.

So where would one find this true hard sci-fi?

Seveneves by Neal Stephenson is a good starting point. Written by an author that knows how to write pop-thrillers with a very keen attention to the details in his books. It deals with the aftermath of the moon spontaneously breaking apart. No explanation is ever given to the reason. The first line of the book is:

> The moon blew up without warning and for no apparent reason.

If you're looking for something even harder there's one author to stands out. Greg Egan. Most of his books are created by modifying some part of relativity and seeing what kind of world would be the logical conclusion from that modification. From the blurb for his book "Orthogonal".

> In Yalda’s universe, light has no universal speed and its creation generates energy.

> On Yalda’s world, plants make food by emitting their own light into the dark night sky.

Every one of his books are this weird, and he has books worth of education material and graphics to help explain the mechanics of each universe he creates. He has also done some novel discoveries when it comes to superpermutations.

If you don't want to go quite that deep into it all, you could take a look at "The Martian". The movie is a fine piece of work, but the book is really amazing. It goes into a lot more details. Andy Weir, the author, even made sure the phases of Earth and Mars matched up so closely that you can figure out when the book is happening by inferring the travel times and communication delays.

Generally, you won't find much of this genre. Writing space opera (Star Trek, Star Wars, etc.) doesn't require too much. You have to have good characters exploring an interesting scenario, and then write it competently. Proper hard Sci-Fi on the other hand is incredibly difficult. It requires intimate knowledge of things like orbital physics and being able to infer what is and isn't possible within the next ~20 years. This is where most hard Sci-Fi is set because it grounds it the most. An analogous issue is that hard Sci-Fi often "expires". Stories written 30 years ago suddenly start sounding silly because technology developed in a new and at-the-time unexpected direction.

Great recommendations here. One pet peeve I have is that the term science fiction is used a lot in these types of discussions when the more accurate term in my opinion would be speculative fiction, sometimes with some real world science bits thrown in for either convenience or broader appeal.

Particularly in regards to Greg Egan since his books are really out there. I personally recommend Permutation City and Diaspora which I found both amazing (although most of his books are also very good). Seveneves is still on my to-read list, from a lot of reviews I got the impression that the first part of the book is very good while the second part goes a bit downhill. I'll still probably read it someday.

Another recommendation that's a bit more mainstream is the Expanse series which seems to really try to portray some of the real effects of space flight and gravity effects while, again, also throwing some more "out-there and not so realistic" stuff into the mix.

I think the reason people can be happy with something like Trek but nitpick on more realistic attempts is that you hit a sort of uncanny valley. I know space flight in Trek or Babylon 5 is utterly made up, so you accept it and what stands out is the things you are shown that work within that made up framework. But if you show me space flight that’s close to being right then the ways it isn’t are what will stand out.

Yeah, I've thought the same thing and generally agree, but it still bugs me, because more often then not, it's not "uncanny valley" that's driving the distinction in category in my opinion but rather "mass popularity vs nerd cult." The reason I put Bab 5 in there and not Star Wars is exactly because it did work hard to get a lot more of the science stuff closer to right, but equally as flawed as anything in gravity or interstellar. The portrayal of B5's O'Neill cylinder is highly flawed but escapes this same sort of criticism.

I didn’t ever really bother about how well the station actually worked in B5, it and the larger human ships rotated because the humans didn’t have artificial gravity, and that was enough. It fitted in the world they had built. Similarly I never minded that the design of DS9 is non sensical in real terms, it fits with the other things we see in trek so it feels okay.

In contrast I bounced off Gravity because it was trying so hard to be accurate but had characters doing fairly long range orbital maneuvers by eye, and those two things didn’t feel like they fit.

Why do you say it was trying harder to be accurate?

Something like B5 isn’t centrally concerned with things like orbital mechanics, they aren’t the focus of its plots and the way ships behave is more a way to contrast the differing levels of tech. Gravity has a plot centered round how things orbit so when the plot cheats on that it’s jarring.

Likewise when B5 had an episode centered round a character who had been Jack the Ripper, but got the area of London where the murderer had been active completely wrong that felt jarring because the nature of that character felt so central to that episode.

I would humbly submit that Gravity was also not centrally concerned with the parts of orbital mechanics that would make it an utterly boring movie. I continue to fail to see the big distinction here, and why only one of these is described as "cheating."

> It also somewhat bugs me that pretty invariably the folks that crap all over these movies are huge Trek or Babylon 5 fans, shows that have endless literal magic in them, and they're just fine with it.

Interstellar was heavily hyped as being "realistic".

Actual physicist here, too.

Yes, the movie isn't perfect scientifically, but a) it's extremely entertaining, b) gets people interested and listening to me talking about GR and c) saying Gravity is a better movie (in ref. to science) is imo ridiculous (imo Gravity is a pretentious "sciency" piece of drama set in space, but w/e).

Just respectfully disagreeing here. :)

My interpretation, Murph solved the gravity equation all by herself. Plan A was a success. She never really got over her father leaving her.

Probably he couldn't take it and just left. Maybe, they flew into the black hole and died. But she's a genius and needed closure. On her deathbed she had a fantasy or hallucinations about what could have happened. In any case, her super logical mind came up with a story that let her come to grips with the loss of her father. It's a bit grim, but gives enough room (for me) for lots of silliness. that's not what happened. they all died. But maybe, that could have happened. And that's enough for her to find some peace.

Much better explaination than that nonsense about off-screen wizards casting bootstrap spells onto the hexcubes.

Time dilation during their trip to the first planet was because of its proximity to the black hole, not the planets own gravity well.

Thank you. I've been ranting about the "let's use a big rocket to provide visual impact but then forget about it when it's inconvenient to the plot" thing since the movie came out. Interstellar is the type of movie that gets worse the more you think about it.

You taking it a wee bit too hard.

> fact that people think it's realistic is just a kick in the pants

The story is science...fiction. not a documentary on space travel. The realistic bit is obviously hyperbole, no one thinks you can take off a planet that easily. But it was good to move the plot forward. The part people like about that it felt like science anyone who has read popular mechanics (and heard about Hawking- 'S work and something about general relativity & time dilation) can nod their head during scenes that have payoffs that are "intellectually" satisfying.

Now now. Satisfying in that with space travel there are no free lunches and the universe in general is a pretty grim and hostile place.

And the black hole visuals were cool AF. That's a good movie.

You are projecting your beliefs. The popular science crowd thought it was incredibly realistic [1-3]. As you say, the movie is ingratiating to the people who have heard something about time dilation. But even the movie itself gets it horribly wrong. I remember there is a scene of a crew in the orbit of the planet growing old while those on the surface don't because "it is near a black hole" which is true, but the distance between the surface of the planet and the orbit to cause such massive time dilation would imply the humans should liquefy in their suits. Overall, I found Interstellar to go out of the way to use science to explain events in the movie and then asked the viewers to ignore applying the same principles to other parts. I have no problem with science fiction, but if you try to explain the fiction, you have to keep the universe consistent.

[1] - https://www.cbsnews.com/news/interstellar-science-explained-...

[2] - https://www.smithsonianmag.com/smithsonian-institution/why-i...

[3] - https://blogs.scientificamerican.com/observations/parsing-th...

Incredibly realistic....for a film.

An actual incredibly realistic film would be very very boring. Now let's follow Bob as he runs vibration testing on a small sensor in the rocket for the 12th time.

And now the crew spend 12 years travelling through space with nothing happening.

Maybe we can show some people debugging the AI code for the robot

Nolan's typical output is films that are a little smart, but seem to believe themselves to be very smart, while delivering a few really cool scenes, moments, or visuals, but not much else. Interstellar's firmly in that category.

> The crew being sent to save the Earth blasts off in a big ol' chemical rocket with stages. Yeah, fine. I guess rocket tech hasn't advanced all that much in this future. Then they land a ship on a planet in a gravity well so intense that it causes big relative time differences (Note: the gravity alone should have killed them). Then they blast off with the same ship and no big clunky chemical rocket stages. Why didn't this ship just blast off of Earth as is? The energy to get off Earth is nothing compared to getting out of a gravity well that deep! I guess Nolan thought an oldschool staged rocket looked cool.

For some reason I thought they mention it in the movie, but perhaps not and I simply read it elsewhere: fuel. The chemical rocket allowed them to take a large(r) payload into Earth's orbit and dock with the primary ship all while conserving the fuel that the landers had up there. Resources that were not easy to come by.

> The new age emotions resolution was just a big ol' F U to the crowd. Lazy, sloppy writing.

The writing did vary wildly between overly vague and overly explaining things, but I blame the trailers for people thinking this was what the movie was about. The only person making this argument turned out to be wrong (everyone left on earth would have died if they listened to her at the time) and she was making it out of desperation, not from logic.

The resolution was sufficiently advanced technology (no different than transporters or Ringworld construction). Love only transcended time and space in the sense that love is what drove the characters to do what they did.

I doubt there is much advancement in a time where the moon landing is considered fake as stated in the school scene in the movie. And maybe the ship could blast of earth without the rockets but why wasting fuel at that time in the mission? They can't refuel later on so every unnecessary fuel consumption is bad.

That part of the movie, about the moon landing history being purposely witheld from kids, just devastated me.