The fatal flaw in The Martian's ending
HTML-код
- Опубликовано: 9 май 2023
- Physics has a word or two to say about The Martian’s so-called scientific accuracy.
Ridley Scott’s critically acclaimed science-fiction film, The Martian (2015), based on the book of the same title by Andy Weir, has been lauded as a masterpiece of scientifically accurate science fiction film making. From start to finish there are very few mistakes and some are issues that have come to light from research published after its release. However, physics is the bearer of bad news for the ending which undermines that near-perfect record of accuracy…
This is a guest video from Thomas Rintoul, a master's student in astrophysics at the University of St Andrews. Support him in his sci comm growth and check out his socials:
RUclips: / thomasrintoul
Twitch: / thomastrosci
Twitter: / thomas_rintoul
Instagram: / thomas.rintoul
--------- II ---------
You can support this channel by becoming a patron at / simonoxfphys
--------- II ---------
More about me www.simonoxfphys.com/
My second channel - / simonclarkerrata
Twitter - / simonoxfphys
Insta - / simonoxfphys
Twitch - / drsimonclark
--------- II ---------
Music by Epidemic Sound: epidemicsound.com
Some stock footage courtesy of Getty.
Edited by Luke Negus.
In this guest video, an astrophysics researcher reviews the accuracy of the ending of The Martian with Matt Damon, talking about thrust vectoring, the calculated acceleration gain from venting your spacesuit, and the likely outcome of the film's depiction.
Huge thanks to my supporters on Patreon: Quinn Sinclair, Ebraheem Farag, Ivari Tölp, Fipeczek, Mark Moore, Philipp Legner, Zoey O'Neill, Veronica Castello-Vooght, Heijde, Paul H and Linda L, Marcus Bosshard, Liat Khitman, Dan Sherman, Matthew Powell, Adrian Sand, Stormchaser007 , Daniël Sneep, Dan Nelson, The Cairene on Caffeine, Cody VanZandt, Igor Francetic, bitreign33 , Rafaela Corrêa Pereira, Thusto , Andy Hartley, Lachlan Woods, Andrea De Mezzo.
Frida Sørensen, Ned Funnell, Corné Vriends, Tom Bailey, Aleksa Stankovic, Indira Pranabudi, Chaotic Brain Person, Simon H., Julian Mendiola, Woufff, Ben Cooper, Mark Injerd, dryfrog, Justin Warren, Angela Flierman, Alipasha Sadri, Calum Storey, Mattophobia, Riz, The Confusled, Conor Safbom, Simon Stelling, Gabriele Siino, Ieuan Williams, Tom Malcolm, Leonard Neamtu, Brady Johnston, Rapssack, Kevin O'Connor, Timo Kerremans, Thomas Rintoul, Lars Hubacher, Ashley Wilkins, Samuel Baumgartner, ST0RMW1NG 1, Morten Engsvang, Cio Cio San, Farsight101, Haris Karimjee, K.L, fourthdwarf, Sam Ryan, Felix Freiberger, Chris Field, Yohan Cernik, ChemMentat, Kolbrandr, , Shane O'Brien, Alex, Fujia Li, Jesper Koed, Jonathan Craske, Albrecht Striffler, Jack Troup, Sven Ebel, Sean Richards, Kedar , Alastair Fortune, Mat Allen, Colin J. Brown, Mach_D, Keegan Amrine, Dan Hanvey, Simon Donkers, Kodzo , James Bridges, Liam , Wendover Productions, Kendra Johnson. 
Наука
The reason we say it's the most scientificly accurate space movie isn't because it's incredibly accurate, just that most other movies are incredibly inaccurate
But also that almost every good film has to break the rules of reality or they'd be pretty boring. The Martian would have been terrible if he suffered muscular atrophy and then just died, alone.
@SaintPhoeniix I agree, but I feel like the ending was unnecessary, they couldn't just made an excuse that the ascent vehicle actually DID have enough fuel, but then it wasn't aligned properly or whatever and it damages a module of the interplanetary orbiter for some drama
It is also based on a fantastic and very accurate book
@@SaintPhoenixx That’s not true, it would just appeal to a narrower audience. But an audience would definitely exist for a completely accurate film. And he wouldn’t have needed to die for it to be realistic. We’ve done rescue missions before (albeit not on humans).
Mushrooms 🤙
What always bugged me about the movie ending is Commander Lewis disregarding that Beck is the EVA specialist with MONTHS of training in this type of rescue. She's just like "I'm not risking another crewman's life" as if that is all it takes to successfully use an MMU pack in an intricate maneuver.
That really annoyed me as well!
"How hard could it be?" Famous last words as she drifts off into space.
Ha, in the book, he doesn't poke a hole in his suit, and beck does the rescuing.
The movie just wanted a more dramatic ending, and I liked it, so I don't care, lol.
Amen, brother!
@@MagicCardboardBox Plus they wanted to drift off MCU Iron Man success with that reference.
Let's all thank Thomas for being kind enough to devote time to help Simon in this time.
Ok....I was wondering who this is lol
That's lovely! And yes, thanks Thomas! Thanks for filling in and pedant vids are a guilty pleasure 😊 thank you for a great video! Makes me wonder whether he could have used a push off with his legs to add more velocity?
I'm pretty sure you messed up the numbers at 7:45. Because 0.15m/s2 is quite a significant acceleration. That's about lunar gravity and it is plenty to travel a few hundred meters in just a couple seconds. sqrt(312*2/0.15) gives me about 64.5 seconds to cross the distance and he'd hit the hermes at a rather painful 10 meters per second. Equivalent to a 5 meter fall on earth. He'd actually have to flip his thrust around halfway to avoid breaking bones on impact. Even if you take the 11m/s relative velocity into account, that would only add about a minute of burn time to cancel out. Which would make it quite useful for this scenario.
If I do the math on the thrust from a 1cm2 hole with a 4.3psi pressure differential, I find about 3 newtons of force. Assuming Mark + spacesuit weighs about 150kg that gives an acceleration of 0.02m/s2. About an order of magnitude less than your numbers. Using this thrust it would take Mark about 3 minutes to cross the distance and he'd manage a delta-V of about 3.6m/s over that time. Not as dramatic as shown in the movie, but still quite significant and potentially useful in the rescue scenario. If Mark starts thrusting about 10 minutes before the intercept, he'd have cancelled out all relative velocity by the time the Hermes and he have their rendezvous.
Yeah that's what I was thinking, just from ear the math felt like it didn't match, an hour for cancelling out the velocity and close a 300m gap was an absurd number considering any even vaguely significant amount of constant acceleration.
I'd also say that, while the movie's "flying like iron man" is ridiculous (because yes, spinning in place like a moron) he could have just put his hand between his legs, effectively sitting on it, like our Scotsman recommends, or hugged it/pointed outwards so the hole pointed at his stomach, and directed himself backwards onto the ship.
It could probably work, though it'd be a lot more stupid than just... jumping? A good push against the capsule would probably propel him fast enough to cross 300m in a few minutes too with a loss less stupidity to it, it's not as if he'd fall back..? And it would have still made a good scene with the commander having to "catch him" as he flew past without any control.
edit: a typo
I suppose you also have the acceleration from gravity to take into account, not sure what this would be
@@alfredholmes9899 The acceleration due to gravity is irrelevant since the Hermes and Mark are both affected equally by it. They are getting pulled towards Mars at the same rate so it all cancels out. It's the same reason that astronauts doing spacewalks at the ISS don't fall away from the station.
@@alfredholmes9899 As Harmenkoster said, they're all in orbit and as such that doesn't really come into the equation, this is all about relative velocity, you can imagine the two bodies as having a trajectory relative to each other that they're following (a curved one, but you can abstract it to a straight line since over such a small distance it's barely relevant) whilst suspended in space, to move from one to the other you simply need to hit the point in the other object's trajectory where it will be by the time you get to it.
@@IKetoth Maybe I don't understand the situation fully, I was assuming Matt Damon basically went vertically upwards and so wasn't actually in orbit (or was in one very close to a straight line). Even if he was in orbit though you'd have to do some work against gravity. If they're both in orbit at height h and h + 312 then assuming you can do .15 ms^-2 of acceleration and Matt Damon has a mass of one kilogram, he'd have to do .15 * 312 J of work against gravity (ignoring the need to speed up etc). So if he is able to do this then the height that this occurs at is such that .15 * 312 = GM(1 / h - 1 / (h + 312)), and so h ~ 150 000 km, which is a bit high
The unforgivable sin the pickup scene in the Martian film commits isn't really the scientific inaccuracies... It is making characters who have previously been extremely competent into undisciplined idiots.
The real joy, at least for me, is that the Marian is a story of people being smart. Typical drama is someone creating a problem by doing something dumb, and the heros overcoming it despite doing a lot of dumb things. The filmmakers did so well, but apparently just couldn't resist reverting to that form for the ending :(
PS: Blowing the hatch on the Hermes was a wee bit dumb (though at least there was an explanation)... But it was narratively cool. It was an obvious callback to Watney's idea of venting his suit. But having to blow it (as opposed to just opening it) is a callback to the tensions between the crew and the bigwigs at mission control.
Yeah, the narrative explanation was that there were *hardware* interlocks that would prevent having both sides of the airlock open at the same time, meaning non-destructively opening the outer door while having the inner door open simply wasn’t an option they had in the time scale available to them.
@@Vessekx I forget about that. Yes, that does actually make sense.
BTW: I remember Weir saying that the only really egregious "doesn't make sense" thing in the story (from his POV) is the storm at the beginning... Mars atmosphere is too thin to cause damage like that. Since the book was pretty much written online with a ton of nerds picking it apart every time he posted the draft of a new section, it was pretty thoroughly vetted ;)
@@qed100 I honestly don't remember if that is in the book... I doubt it.
I liked the film quite a bit, but the typical 'Hollywood action sequence' part at the end felt like it was part of a totally different (and not so good) film to me.
@@travcollier it was not. Watney brings cutting his glove as an option, but they decide the lack of control makes it too risky.
@@qed100
I absolutely agree! That EVA without a safety line was totally against "common sense" and NASA protocols. It was just a piece of typical Hollywood crap. What is sad is that very few other people seem to have caught that.
Isn't the atmosphere on Mars so thin that the foundational idea of a storm strong enough to blow a comms array into him with enough force to throw him, doesn't work?
That is true - Andy Weir has admitted that was a mistake he made when writing the book. But that doesn't make much of a video!
@@ThomasRintoul he knew it was wrong when he wrote it, but he needed it to make the intro gripping and interesting
Yes, the atmosphere on Mars is just about 1 percent of the Earth's atmosphere, so the wind should have been about 100 times faster than the same win on Earth that would lift the same object... That is how I understand, maybe I am wrong about how fast it should be, but it is a fact that the atmosphere is so thin that it was wrong from a scientific aspect.
Not only this, but the Martian thin atmosphere renders a storm that causes the emergency evacuation that happens in both the film and book pretty much impossible. But as they rightly point out: "Where is the fun in it?"
I was coming to say this too. I think this is far more unscientifically accurate. But I must admit, it does set up a good movie. I can forgive them as they do have a space pirate! I was also wondering what happened to Simon's accent for a minute - thanks for the great guest video.
I've only seen the movie once. From what I remember or misremember the fatal flaw isn't at the end, it's at the beginning. Unless I missed the part where they made the Martian atmosphere denser, a Martian windstorm could only barely flutter a flag much less shake a spacecraft. Ingenuity would have been flung far and wide if that were the case.
The author of the book also realised he made that mistake with the initial sandstorm about halfway through the book. He elected not to do a full rewrite though and decided to keep it. In the second half of the book, a whole subplot revolves around Watney getting caught in a martian sandstorm that is so hard to see, he only detects it based on his solar production loss.
This bugged me when I was like 16 and saw Red Planet in theaters and after everything I'd heard about The Martian I was _shocked_ that it made the same mistake...
@@llYossarian Yeah, even extraordinarily smart people will get things wrong.
It was needed to create an emergency. Hard to think of another emergency that could strand an astronaut although I’m sure NASA pays a couple doomsday thinkers to do just that.
@@chrissmith7669 Yes. It was exciting. Sometimes a little knowledge ruins things. I suppose if I hadn't heard that the book was "scientific" and that the movie was based on the book I would have ignored it.
Shouldn't it say it takes him over a minute to reach? He js accelerating at 0.15 m/s2 so the distance of 312 m is covered after 64.5s and his final speed is about 10 m/s.
Yup, he forgot that t is squared in the equation x = 1/2 * a * t^2, so he got 4160s instead of 64
Rookie mistake, but that happens to the best.
@@booketoiles1600 Thanks, I was super confused about where the 1/2 came from. That makes a lot of sense that he just forgot to square it. But tbh. If you just look at the numbers it was quite obvious, that's why I was super surprised.
When you say, the explosion wouldn’t work because there is nothing for it to push against , is that strictly true? The air in the ship gets pushed in one direction and the air pushes the ship in the opposite direction. Newton 3 . No?
That's literally how it works. The air doesn't have to "push" against anything. It's that it's moving in a retrograde vector to the craft. It's the same as gas recoil from a firearm I would have thought
@@arnesaknussemm2427 the point is those two forces balance out
7:51 if the acceleration is 0.15m/s/s then you have a mistake.
assuming initial speed is 0 then x=(at^2)/2
[you can view it as calculating the area under the graph of the speed, the area being a right angle triangle with the base of t and the height a*t] so
312=(0.15*t^2)/2
4160=t^2 and here is the mistake forgetting to take the square root
so t=64.5 seconds (rounded up).
checking: start speed 0, end speed 64.5*0.15=9.675m/s
since it is a linear increase in speed we can take the average 4.8375m/s over 64.5sec we get 314 meters!
Yeah, I mean even eye-balling it this is wrong.
After 7 seconds, he’d be at 1m/s, and from then on It’s at most 312 seconds to cover 312m, which is, last time I checked, about 5 minutes, not over an hour.
It really doesn’t make a lot of sense.
Also, why would the hermes be “long gone?” Their relative speeds are matched, and assuming they are on an orbit that doesn’t decay immediately, they can just hang around, and then fly away once they have time again.
Is the issue that the speed is mismatched, too?
You'd be at 0.6 m/s, not 1.
@@alyeanna ah, sorry, my mistake. Feel free to change it to 7 seconds then, and my comment stands
Something is off in the numbers Simon is showing, but he isn't wrong about about the forces from gases escaping from a small hole is just not enough. Imagine this, your lunges can blow air about half as hard (2.3 psi) as what's being calculated in this scenario. So two people huffing and puffing on you is about the equivalent force you would expect coming from Watney's glove. Did anyone take into account the mass of Mark Watney and his space suit?
@@Fs3i Yes, the video forgot that time is squared in the equation for velocity and forgot to take the square root to get actual time. The math would come out to 64 seconds, but it would even be less than that since he is trying to reach Commander Lewis who is tethered and much closer.
The explosion is needed to solve the issues of off axis thrust and variable thrust that would occur as the inner door opens. Additionally, a sliding door (Star Trek Style or Star Wars Style) would likely jam under the pressure difference as it is being pushed sideways. Also, if I were to design an airlock door that I did not want opened while the lock was under vacuum, I would make sure it was going to have to swing inward, to prevent someone from opening it and evacuating the ship, or try to have it seize up if it was to slide open under that much force difference. While an explosive is not the best solution on a ship for a variety of reasons, it simplifies the math for the writer and solves the problem of the airlock being designed to prevent them from having both doors open.
Door would fling open very quickly so the amount of off axis thrust on a ship of that weight would probably be less of a concern than the broken hatch flying off and impacting critical parts of the ship, which always seem to be the only parts of SciFi space ships that get hit with debris.
Its been a while since I've done some proper physics (about 6 years), so thought I'd give a the calculation of how long it would take Mark to travel to the Hermes a try, and I think I'm missing something. Using v = u + at, and assuming u=0, and v also being equal to v/t, we can rewrite this as a = s/t^2. Filling in the numbers we know, s=312 meters, and a= 0.15 m/s^2, we get that t would be around 45 seconds. Factoring in an initial relative velocity u = 11 m/s (I'm assuming relative to the Hermes?), we get 0.15t^2+11t-312=0. With quadratic equations we get a solution for t= 21.85 seconds. What am I missing here?
EDIT: it should say "and v also equal to s/t"
you are right but your formula is wrong.
s=(at^2)/2 you can view it as calculating the area under the graph of the speed, the area being a triangle with the base being t and the height a*t. so
312=(0.15*t^2)/2
4160=t^2 so here they made of the mistake of forgetting to take the square root
so t=64.5 seconds (rounded up).
checking our math start speed 0 end speed 64.5*0.15=9.675m/s
since it is a linear increase in speed we can take the average 4.8375m/s over 64.5sec we get 314 meters!
@@elraviv 64 secs is not an hour declared in video. right? and seems acceptable to not miss your mars-earth taxi
As a professional Ecomomist, let me just say how thrilling it is to see eleven people in this comment thread take us all the way through the laborious calculations here, and end up with eleven completely different answers. I'm told Economics isn't a science because shit like this happens to us when we talk on camera, but .... :P
youre assuming the 11m/s is in the right direction. If this were the case, watney wouldn't need to accelerate at all because they'd already be on a collision course
@@elraviv I come up with the same number. I think he got the conversion from secs wrong.
Possibly a bigger issue (for the movie, at least) is Mark's ship is portrayed as just going up. The mothership would just whizz right past him in like an eyeblink! But then, I can't understand why that SPACE HOTEL couldn't have as much Delta-V as they needed. Like, literally throw out some of the furniture! That would have let them go deeper - possibly into high atmo - giving Mark a lot more flexibility in case things didn't go exactly to plan.
To get into escape velocity rockets move close to directly up or they'll end up experiencing "rapid unscheduled disassembly"
They start going straight and then slowly move sideways, and to escape they would be going up for much further as well.
@@grapetoad6595 Yeah, there are different ways to get that sideways velocity for sure. Depends on a lot of factors, but given the wispyness of Mars' atmo, I would think you'd be going sideways pretty early on. Again, this could just be an artifact of how the launch was shot in the movie and I'm likely overthinking.
But I need the spa on my return journey from Mars!!
you can bun stright up to skip planet's orbit and go straight into escape trajectory, most rockets go into orbit arount the planet first to have more time for low thrust but efficient engines, as MAV had high thrust engines it could just go up
@@grapetoad6595 _"To get into escape velocity rockets move close to directly up or they'll end up experiencing "rapid unscheduled disassembly""_
...in Earth's atmosphere. The single biggest reason for the initial vertical launch is to get out of the thick part of Earth's atmosphere as quickly as possible while going still so slow that you don't experience "rapid unplanned disassembly". On a body without any atmosphere, there is _zero_ reason to not start almost horizontally almost immediately (just a little upwards to clear the ground). The situation on Mars is much closer to the latter than the former.
I think the reason it was considered accurate is because the book was accurate, the movie took a lot of creative freedom and changed some of the less dramatic moments and sacrifices the accuracy in it.
Great video Tom. Really interesting. Hope Simon will be back to us soon.
2 biggest things I noticed: The wind on Mars couldn't knock over the MAV, and in the movie they have the hab canvas flapping in the storm. There's too much pressure difference, no flapping.
I enjoyed this very much, thank you! Also, loved the reference to Simon as "the Weather Man", haha!
Yeah, that was so funny.
"And now, here's Simon with the weather."
If he was accelerating at 0.15m/s^2, he would clear 300m in just slightly over a minute as he would be covering distance d = 0.075t^2 where t is time and d is set equal to 300m
He could have probably pushed off the rocket before thruster ran out.
What bugged me the most was how a piece of plastic and duct tape was able to hold in the pressure of the habitat that was large enough to cause explosive decompression.
In the book he uses resin specifically designed to seal the seams of the hab
Then said plastic flops back and forth as if the side with the most pressure keeps changing...
my main gripe was the whole atmosphere thing too. but for different reasons... the dust storms such a thin atmosphere creates are strong enough to lift dust and fines from the martian surface but not strong enough to flail a human being around. the wind speeds would have to be like 600 kmph + to have that effect.
Also:
can't make compost from poop alone and not in that timeframe, you need microorganisms
Mars soil he used has perchlorates that would kill plants
ionizing radiation would've killed him
communication Earth-Mars takes several minutes, depending on orbits
making water in his habitat would've cooked him alive since the reaction he used (or would use in real life) is highly exothermic and the chemicals would kill him, nevermind the explosion
there are a lot more smaller mistakes concerning technology and physics
Absolutely in love with this scottish science rant, 10/10.
Hi Thomas, thanks for this video. I hope Simon is doin well.
One point: anyone worked with gas under pressure knows that gloves must be used to hold the container. If not, you can easily get frostbite, as the container going to atmospheric pressure gets really cold. I did not watch the movie, but he must be screaming from the pain of his freezing hand - the same hand that controls the thrust vector.
I can't believe I never thought of this. You're tight!
I remember when I watched The Martian in the theater for the first time when Mark suggested poking a hole in his glove I was thinking "Won't he just spin around in a circle?" and then when he did and he was "flying around like Iron Man" was like "Yeah, no way this would ever work, but, hey, it's a movie, they get pretty much everything else dead on (which is really good for sci-fi) and its cool visually so what the hell, I'll give it to them."
Great video! I'm not sure it that's the intended effect, but it makes me want to re-read the book. I remember being dissapointed with the movie ending because I thought it deviated from the book too much and seemed kind of overcomplicated, now I know it wasn't just due to "they've changed it and now it sucks" effect.
Yeah, the "pickup" is pretty much entirely different between the book and the film, and by far the worst part of an otherwise pretty great film IMO.
It is really jarring how the portrayal of the characters as competent and sensible just got thrown out the window for what someone obviously thought was "more exciting drama" 🙄
@@travcollier Pretty sure the ending in the movie was a throwaway joke in thr book.
I wish you had done a clearer job of explaining exactly how the ending went in the book once the Iron Man scenario was rejected. Basically, they did a bunch of math and calculated exactly how to close the distance and match the speed, then they went and did it and Mark was pretty much exactly where they calculated that he would be and Beck (not mission commander Lewis) gets there easily without having to disconnect the tether.
He apparently missed things in the book. Because in the book, they use the attitude thrusters to make the rendezvous from the initial 68km to a few hundered meters. But they are moving WAY too fast for intercept. After Watney wakes up, he proposes the Iron Man plan, which Cmdr Lewis rejects. But that is what gave her the idea of venting the ship to slow down for intercept. They mention in the book that they can't open one door while the other door is also open. They have only 39 minutes from when the found out they were too far away and had to use the attitude thrusters, so now they have even less time.
Yes, Johanssen did override the programming to do the Rich Purnell maneuver, but they don't say, in the book or in the movie, how long that took. So a bomb to blow the outer door is not that far fetched, since it was faster than trying to over ride a safety system again, likely requiring multiple systems to be overridden, like the telemetry and comms systems were to keep NASA from overridding the Rich Purnell maneuver. They didn't need that strong a bomb, as once the door failed in one part, all the air rushing out would finish the deal.
As you said, Beck went to get Mark, with Vogel back stopping him on the tether. Beck didn't get off the tether and Mark stayed in the MAV until hooked up to Beck. Of course the movies have to spice things up, even though I think the book version would have worked in the movie, but probably only for sci-fi nerds and they wanted to get the general audience in as well.
I wonder if he would have had as big objections, if for the final flying bit in the movie, if his hand was down in-between his legs, so that it would be closer to center mass.
@steveaustin2686 The problem for the airlock isn't a hacking issue (though maybe in the movie it is worded such that it sounds like it is). In the book the airlock doors are PHYSICALLY incapable of opening if the other door on the airlock is already open.
Maybe he didn't cover it because it wasn't relevant. Or maybe to encourage you to pick up the book and read it for yourself. :)
damn simon clark changed his facial structure and the color of his facial hair by sheer will
and most importantly the way he talks
Although I don't remember how it was depicted in the movie, it is likely that the door opens inwards and could therefore be VERY difficult to open, thus the need for the explosives?
yeah like airplane doors
I kept wondering how the atmosphere was thin enough to not matter at the end of the movie, but thick enough to generate a horrific storm at the start of the movie.
That point at least is pretty reasonable. Mars does have a thin atmosphere, and it also has incredible dust/sandstorms that have covered huge swathes of the planet. The difference between real Martian storms and the one in the film is that on Mars, the particles are very fine. Still dangerous, still enormous amounts of material being moved around and gathering in drifts, eroding rocks etc, but it wouldn't be like a sandblaster, maybe more like emptying a giant vacuum cleaner into the air. Impaired visibility, darkened sky, it would get everywhere, potentially interfere with electronics, stick to surfaces (static) and generally just be really awful to deal with.
@@purklefluff
The storm at the beginning is not at all realistic. There just isn't enough mass to tip the MAV or tear off the antenna that impales Watney, regardless of the wind speed. However, the unrealism of the storm scene was a necessary sacrifice to set the plot in motion.
It wasn’t able to generate a storm like they show at the beginning of the book. The author knew this and he took it as his one non-scientific conceit because he wanted a man - vs nature story and it was the best way he could come up with to get Watney into the situation to make the rest of the story possible.
Hello Tom, I was in a bit of a fugue going from one video to another in my subscriptions feed and for a moment thought "huh, that's funny: Scott Manley has taken over Simon Clark's channel." LOL.
Thank you for doing this.
Simon announced a guest hosting on his channel in his last video
@@embreis2257 I remembered that and for a few seconds thought Simon's first guest host was Scott.
What if Mark has the ability to control his farting, and therefore the pressure release from his suit, like Leonard Rossiter in the film ‘Le Petomane’?
Would've solved all the problems. It'd be more scientifically accurate _and_ make a much more exciting climax.
In the book he fries his comm gear by accident and loses contact with Earth before he travels to the launch site. On the way he makes the joke about being the first space pirate because no one gave him permission to use the ascent vehicle.
In the movie they make the same joke but they never lose radio contact, so it doesn't make sense that he doesn't have permission.
So from a movie perspective, I really do get why they wanted Watney to do the flying. If it wasn't for that, the entire rescue sequence would be 100% secondary characters doing things to save the main character who sits around waiting. He did the manual prep work on the rocket, but past that, he wouldn't *do* anything. It's not just a more dramatic ending for him to go iron man, it's almost demanded by the nature of a good story. The thing I would have changed would have been to have Beck try to reach him, run out of tether, and then Watney uses the iron man strategy to close the remaining few meters.
I respectfully disagree. While Mark Watney is the main character, the crew of the Hermes are all important characters in their own rights. The book ending of having them combine their skills and work together to rescue Mark is exactly right thematically. Having Lewis suit up and rescue Mark was a mistake in the film because it made her look as if she didn't trust her team. It made her look like a control-freak who elbows her people asside and tries to do everything herself than a commander who knows and trusts her people. It was a real shame because up to that point they'd established her as a good commander.
A C02 Fire extinguisher would have done the job perfectly....
Overall, if they really wanted to bring this Iron man idea onto the screen without making it look too dumb it would have been easy to fix it.
First, say that the explosion actually changed the ship velocity so that now it's getting closer to Mark's pod, but this velocity is still not enough just for a tiny correction needed, so this should accounts for the fact that the acceleration from the thrust is too little to reach them.
Second, make Mark put his arm between his legs, riding it in a very awkward position, or even behind his back, in a way he can actually be able to control better the center of mass.
I came to the comments to say that putting his arm between his legs would have been sufficient to create a jet directly below his center of mass.
That wasn't the spacesuit that's was shown, it was the Mars pressure suit.
One underappreciated thing the movie does well is placing their microphones off-axis so we don't hear the insides of the speaker's mouth. Voice vector control?
What pained my eye more was the Johanssen weightless scene inside the Hermes, when she glides (on rails... literally...) along the corridor and transitioned down into the rotating section and got "sucked" in. Ouch.
Excellent video, and ace to meet you! Question - would the glove hole trust vectoring be more practical if he'd pinned his hand at his groin with his other arm? It would still have been bad and ineffective, but would that alone allow a better position for the thrust?
I think so, or just point the palm away from his center of mass. Combine that with jumping off from the rocket and, hey... not too bad imo.
The Martian is actually the last second(s) hallucination of the brain of a dying Hugh Mann in the movie Interstellar. :-) He read the book as a kid and then his dying brain superimposed an inaccurate ending.
Seeing as the same actor is also starring in Oppenheimer, it's safe to say the nuke in that film will be the result of an airlock mishap.
The other major error is at the beginning and Watney fully admitted it. Due to the thin atmosphere dust storm winds are not nearly as powerful. In fact, a sufficiently long stay, should expect and be prepared for dust storms.
But without it, the story wouldn't happen.
He didn't have to make it to the Hermes. He just had to make it to Commander Lewis on the tether, who was much closer.
It's always nice to see you, Thomas! Have you read Three Bodies Problem trilogy? Do you thinks it's also scientifically accurate?
Haven't read the book but at least its premise, the dark forest theorem isn't scientifically accurate. It's a popular theorem proposed by many science tubers to answer the fermi paradox but it itself has many fatal flaws. It's the idea that the rules of Earth's nature apply on a cosmic scale: level 2 species as predators regarding level 1 species and their habitable planets as prey. This however is a very hollywood-inspired theorem.
To point out just some the major flaws:
1. We expect there are civilisations that are so advanced they regard less advances civilisations merely as insects, hence crushing them under their feet if they happen to live on some resources they need. The flaw here is that many people expect exponential technological innovation to progress endlessly which is untrue. We currently live in a state of hyperexponential growth, where one invention leads to multiple others. But no hyperexponential growth can go on for long. There are many fields where we're already scratching the borders of what's physically possible. Unless there are whole new physical worlds currently hidden from our view, we should expect to some day experience a slower growth in developing new stuff. Most progress in human history strongly correlates with number of humans living on earth. When we grew tenfold, so did our creative output. But we've already outgrown what earth is able to support and will need to turn into a decline some day. Given that, we might already be 30 % as developed as we'll ever be. I don't expect there to be a potential for another million times the current progress, at least not without giving up our organic brains. If that's true, the insect analogy stated before will never be a thing, unless they are actual insects.
2. We greatly underestimate time and space. The prey one species is aiming for will have become its predator upon arrival. Let's say there is an alien civilisation in our cosmic proximity at 100 ly distance. The most probable point in time they first detect us is when we start using radio waves. Let's say they start their large invasion ships shortly after detecting us, they will still need hundreds of thousand of years of interstellar travel to ever reach us. In all that time we will further develop, and dramatically outperform whatever super old knives they will bring to the gun fight. If they are into our resources, those will long have been used up by ourselves, rendering any plans of mining our planet useless in the first place.
3. They are scientists. You can't have interstellar space ships if you don't have science, collaboration and probably society. Don't expect level 2 species to be some xenomorph blobs with no sense of empathy. Life is rare in the universe, if it even exists outside our solar system. The most precious thing a species can look for is not another habitat or whatever. If they are level 2, they have already figured out how to survive using whatever resources they have or got into asteroid mining. No, if anything, they will visit an inhabited planed to study its life forms. To learn from their biology, culture, science, maths, cosmology, technology, maybe even music and entertainment. You wouldn't destroy that, what for - water? Gold? Those exists on many planets. Life itself is a 1 in 10000000whatvermanyzeros find and that's the coolest thing anyone or anything can look for in this universe, a distinctively developed alien species and what it has to say about the universe.
There's many other reasons that may come to mind, but I'll stop it here. The dark forest theorem is a nice little thought experiment but it doesn't add up to those indisputable facts. Other than that premise this reply is focusing on, I suppose there are many cool ideas in the aforementioned book that may be scientifically accurate. Just keep in mind that no science fiction book could ever be scientifically accurate without being boring as hell. Almost every scifi franchise adapted some kind of teleportation (wormholes, time travel, warp speed, slip stream, hyper space) to make any of its story work at all whereas there is no scientific evidence that anything like that could ever exist. We are most likely destined to be alone forever so we may as well let everyone know we are here to talk. Just in case.
As a fanatic of "hard" (realistic) SciFi myself, I'd prefer it being more accurate, and also showing more of the crew doing things in space. But it helped nail the ending of the movie. And the distance gap wasn't 300m, because they had 250m+ of tether. So he only needed to make the closest approach (at the right time) to be 50m less.. but would be easy to lose the audience.. but say either he took a heavy object from the capsule, and threw it AWAY from Boss-Chick, or she untethered and risked relying on her jetpack.. I think it worked out ok.. as for Three Body Problem.. lol? I found it quite readable, but ALL of the "science" in it is ridiculous. Twilight is more Scientifically Accurate..
bro.. let my guy have his "iron man" moment in peace 😂 (good vid tho)
Yeah this, event accurate shows like the expanse leave room for drama and spectacle.
I'm gonna have to disagree with your points here. I believe, given the scenario of Mark's ship and the main ship being ~ 300m apart, rescue is not only feasible but actually quite easy to do. Here's my reasoning:
With just the acceleration of 0.15m/s2, he could travel 367m in 70s. This is assuming point mass. As you mentioned, the problem of thrust vectoring comes into play. However, and here's my main point, *if he was to assume a 'superman' pose with this hand curled backwards*, the centre of mass would be (almost) directly behind forward thrust at all times. Slight adjustments in his arm orientation would let him steer directly toward the main ship.
To slow down, limit gas outflow by squeezing the hand and slowly do a 180 degrees turn. This, again, doesnt have to be that accurate as the following step takes care of inaccuracies. Once roughly turned 180 degrees, assume superman pose in the opposite direction and decelerate w.r.t main ship. Orient hand such that deceleration takes place as linearly as possible.
Rinse and repeat the closer you get to the ship.
Although the movie tries to go about it the wrong way using an iron-man technique, if you forgive minor technicalities like this and think about it more holistically, there's absolutely nothing impossible about it.
Also, with more favourable bernoulli terms and a larger glove hole, you could very easily achieve a larger acceleration and, given you can control the outflow by squeezing the palm, do the aforementioned manoeuvres much more quickly; all within a couple of minutes.
and do you think he has enough air in his suit/tank for this journey of 70s or so? if you poke a hole in your spacesuit can you really prevent air escaping just by pressing down on it?
I clicked on this video first thing in the morning and was super confused until he said I’m not Simon 😂
The most ludicrous thing in 'The Martian' is that Sean Bean doesn't die.
He does sort of die, in that he gets fired from his career and retires to play golf.
That's because he never went outside. Sean Bean only dies outdoors. (Joking, but he is never outside until the credits roll.)
My biggest issue with scientific accuracy in movies was in the movie Gravity where ..... wait for it ..... they got how gravity works wrong (Clooney magically falling away from Bullock while they were both in the same orbit).
Another disappointing space movie.
The real issue with the book, IMHO was at the beginning. As you mentioned during the video, the atmosphere on Mars is so thin that it's almost non-existent. This means that there would be NO WAY that the ship would blow over during the sandstorm. The solar panels that Mark had to clear off after every storm? Yeah...those things would never survive if the wind was strong enough to topple the ship. The antenna would also not have had enough velocity to puncture his suit or him.
Still and all, it was a great book and a good movie.
yeah i remember after the movie came out that people said the storm at the beginning that kicks off the plot wouldntve been an issue because of the lack of atmosphere
I totally appreciate and am impressed by your nerdiness with explaining what really should have happened, but having read an extremely large amount of Science Fiction over my lifetime (I'm 65) I have to say as Deus Ex Machinas go this one isn't to bad.
This was a great Video. And yes Simon is the tallest man on Earth. Or maybe that's due to me being a Hobbit
Maybe you need to eat more breakfasts.
He could have just jumped. Possibly achieving 4 m/s velocity and still have air to breathe. I prefer implausible over impossible.
Enjoyed this video thank you 😊
A similar thing I've pondered - what about a fire extinguisher as a makeshift thruster? Would that give a usable amount of thrust and be controllable? I've seen this in not one but three movies - Titan AE, Wall-E, and Gravity, and maybe there are more I don't know of.
Yes, a Co2 extinguisher would function in a similar way to an RCS thruster albeit with a lot less control since the valve is meant to open with little action.
About why they had to use a bomb in the book, yes they hacked the Hermes before but it took johanssen a week. she even specifically mentions how Hermes has four redundant computers all checking each other, and how she needed to reprogram them one at a time. there was no way to hack into the hermes and open that door in time, they all knew it. hence, bomb.
that or maybe Hermes has mechanical interlocks between the airlock doors, so unless they were to start digging into the walls they would never manage it.
I would have thought the fatal flaw in the movie would have been the fact the storm at the beginning of the movie dont actually happen on Mars.
Liked and Subscribed, this was entertaining as hell... Watney doin' the ass vectoring was pretty funny, lol.
I found myself shaking my head in disbelief at that part of the movie. Intuitively it just didn’t seem like it would work. Thanks for putting some numbers to it and confirming my suspicions.
You could argue the opening the door would create a thrust off the centre of mass rotating the space craft rather than slowing it down. Using a bomb lets them create a hole in the centre of the door presumably along the direct centre of mass of the craft.
The fire extinguisher stunt in Gravity had the same force vectoring issue, but they made up for it with the cool move of using the extinguisher itself as propelant mass at the end.
What about the "Fatal Flaw" in the opening. The ship could have never blown over in a Martian dust storm!
You've missed the most important part:
Even if Watney reaches the ship at the right place and the right time, the ship is already moving way over Mars's escape velocity but Watney is only at the apoapsis of a suborbital flight. Watney would just see the ship zipping in front of him many km/s faster than himself (or end up in pink mist and pulverize a part of the ship).
The entire point of him making the MAV lighter was so that it could reach escape velocity though.
Nice one - pedants rule. Love to see you do "Gravity". So many issues that it distracted from the enjoyment of the magnificent visuals of the film.
I thought the premise of enough wind pressure to tilt the launcher when matt was left behind was dumb too ?
With the scene right before Matt Damon blasted off into space, he could not possibly be responding to a live count-down because of his communication distance.
Wouldn't an explosion increase the exit velocity, thus increased thrust? Seems like the way we use most rockets rather than just bleeding off the fuel mix
only if the explosion increased the pressure inside the room significantly by producing a lot of gas
cool vid but jesus turn down the gain on your microphone
it's horrible
Getting both doors open wouldn’t be a matter of hacking some code. Air pressure will make it physically impossible to open a door before you’ve equalized the pressure on both sides. (And any engineer who designed an airlock that could open its doors with unequal pressure on each side should be fired immediately.)
Great job Simon, this bugged the shit out of me as well.
Is the ending scientifically accurate? Was anything scientifically accurate? Very little, if you look at it seriously. It's a movie!
Great video pointing out something interesting from a highly scientific movie. Thanks
Well, realistically this plot had zero chance to happen, it is McGyver pushed to absolute limit.
The thin foilcoverup of the massive massive hole in the base was hilariously wrong too. As was the storms windpressures. But these were essential for the plot.
Maybe a stupid question, since I haven't seen the movie or read the book, but rather than using the space suit hole trick, couldn't he just have jumped? How much speed would you get from that?
Not a stupid question. I wondered this myself. Looking into acceleration and force of a vertical jump, you'd be lucky to achieve 2.5m/s2, not nearly the ~10m/s2 needed. And those are numbers from athletes on Earth, not someone in a spacesuit in zero G, so you would never get close to even that number.
Thanks for the breakdown!
It might have been an option (haven't calculated it) to take a pressure bottle with him, one of those that he used to clean the solar panels with and tie it to a rod to use as a chariot, pointing the stick to where he wants to go. No idea whether the weight of the bottle would completely counter the benefit.
The McGuyver Martian survives alien environment with garbage bags and duct tape.
This is the sort of error I usually forgive because there is so little practical difference between holding his hand outstretched, flying like superman and holding it over his head, flying backwards feet first compared to so much visual difference between the two that its worth it cinematically speaking.
Thank you for your work and great analysis but I'm confuse. Is the Martian an entertaining motion picture or a documentary ?
You ignored the whole issue of deltaV. I can't remember the numbers but assuming that the air escaped the Hermes at the speed of sound at sea level (which is a good approximation at first but it gets slower as the pressure drops) I worked out that you'd need to vent something like 10% of the Hermes' mass to get the change in velocity that they claimed.
Thank you, Thomas, for this wonderful video. I've been making thrust vectoring jokes ever since this movie came out.
Thanks for running the movie for me!
You mean beyond the idea that Mars could ever gather up enough wind to topple a ship?
I was hoping that you'd show/explain the math on if venting (explosively or not) atmosphere from Hermes would provide enough thrush to slow down such a massive vehicle, too!
I hereby demand a director's cut version of The Martian with the 1-hour long thrust vectoring footage uncut!
My favorite part was Mark dismantling the escape ship to get rid of any extra weight. When someone question replacing heavy roof with parachute, aerodynamics and pilot protection was considered. Mars has very thin atmosphere and escape ship would accelerate to no atmosphere in seconds. Besides, Mark was likely to pass out from 12 plus G's... and he did. No sure how accurate, but whole sequence was worth watching more than once.
For what it's worth, I'm a silly artist and hobbyist game dev that mainly gets science knowledge from RUclips, and I would've pointed out those problems too. When you mentioned the hole being cut initially, I immediately guessed that the lack of propulsion would be a problem.
The most comical part is Watney when he's grappling the line and being reeled in just, um, stops venting magically...
Thpmas, accessible and entertaining (and informative) it was. And I'm going to be even more 'critical' of science-fiction type movies in the future (or at least have a good laugh at them). Thoroughly enjoyed the passionate Scotsman, thanks mate.
I learned a lot - awesome and thanks.
There's also the slight issue of freezing to death. If you expand that much oxygen that quickly from the high pressure tank, there's a good chance that the the heating system (if there is any at all) wouldn't be able to keep up.
One inaccuracy in the movie that gets me is, after the air lock ruptures and there is a gaping hole in the habitat, Watney seals it with plastic sheet, duct tape and sealant. The sheet ‘bellows’ in and out. Given the higher air pressure inside the habitat than outside, surely the plastic sheet should basically become concave (from the inside perspective) and fairly rigid.
Also, whilst the repair may have sealed the air lock, there is absolutely no heat insulation provided by the plastic sheet. Given the temperature on Mars can drop to as low as 150 C, the temperature in the habitat would drop drastically - as demonstrated by the flash freezing of the potato plants when the rupture occurs. Despite this Watney is shown walking round with just a towel around his waist after the air lock is breached and sealed up.
Another thing I thought of with O2: there is a valve between the bottle and suit, which I doubt would be able to open wide enough to account for loss thru the hole.
8:11, why would the Hermes be long gone? I can't remember that scene specifically but were they going to accelerate and not wait for the other crew to try and return?
Don't forget the winds on Mars couldn't possible lift Matt Damon up and throw him across the landscape. Atmospheric density isn't there to accomplish that..
Thrust vector could be fixed by pointing away from your center of mass (looking like Iron Man when he's firing his palm blasters. Also you made a big error confusing velocity and acceleration at 7:45. With 0.15 m/s^2 it would only take about 65 seconds to reach the Hermes and a little bit more to cancel out the 10 m/s velocity difference, instead of an hour like you stated.
We're just going to have to sacrifice a few astronauts to see who's right.
I disliked the ironman sequence because mark watney suggested doing it in the book and got a resounding “no go”… Imo it felt more balanced that his heroics and clever thinking was at an end when he reached the ascend module, after which it was others turn to shine (I know he did the refit, but that was totally under guidance).
In the book, Mark never gets to be iron man. He’s just saved while still sitting in the ship
Thank you for pointing out that Andy W. did not have it in the book, it was a cinematic bias.
Who gave you your physics degree?
In what world does it take an object accelerating at 0.15m/s^2 "over an hour" to travel less than 400m?
Could he have achieved the necessary velocity with a jump powered by his legs? Then just used the air to course correct? Would this be feasible?
Nice video! I will give your channel a shot :)