The Rocket Science of 'The Expanse'

The Expanse is a TV show based upon a series of books by James S. A. Corey. It's won a great deal of praise for its 'gritty realism', portraying life in the solar system 300 years from now. I got a lot of questions about how realistic the spacecraft were in the show, whether physics allowed for engines with the performance demonstrated by the spacecraft, so let's do the math.
TV Show Website
www.syfy.com/th...
Many of the numbers required to compute performance were taken from this short story.
www.syfy.com/th...
And finally, check out the Atomic Rockets website for a deep dive into the analysis of Sci-Fi technology
www.projectrho....

[@4tech69]

I stumbled on Expanse a couple months ago. Binged every episode.

[@ig2d]

i stumbled across it recently as well - binged the first series but thd hot really bored of it really quick. i don't think i even made it to thd end of the first episode of season 2

[@ELCADAROSA]

Just watched all three seasons. Can’t wait until the fourth season comes out. A fifth season supposedly has been approved, so ... time will tell.

[@CouchCit]

I binged the entire series this past week, and honestly I think the show is super overrated. It was good, but also frustrating to watch.

[@zakabog]

@@CouchCit What was frustrating to watch with the show? I enjoy the books a lot more, but the show was good I just wish they continued the story and didn't cancel it.

[@anekdoche7055]

same but im a bit late

[@reddeadrazor8257]

"Accelerating @ 7G's for a period of 37 hours..." Scott Manley: "Fly safe!"

[@timothymclean]

"The rocket science of a Syfy show? Oh, this is gonna be good." "The science in this show is actually relatively good, aside from one plot-mandated miracle technology. And even that is kinda close to some vaguely-plausible technology currently in the very early prototype stages (aside from heat issues)." "...Well, I'll be darned."

[@migkillerphantom]

It's based on a book series that is semi-hard. So it's diamond when compared to syfy's usual crap

[@TheRezro]

It has some hilarious screw ups, but that semi-hard stule is so rare it is still quite decent.

[@hellothere_1257]

I love this show. It's not 100% perfect when it comes to scientific accuracy, but you actually need to search for mistakes and don't have them punched in your face every other minute if you played KSP. All the manoeuvrers are actually done correctly in a way that is both sensible and respects the laws of momentum. The story is not too shabby either and once you get to episode 4 you get treated with the most realistically accurate space battle I have ever seen in visual science fiction, period. Definetly give this show a try.

[@suicidal_camo_eisberg765]

REMEMBER THE DONNAGER!

[@saintmayhem9873]

REMEMBER THE CANT

[@Zanzubaa]

I do love the Expanse. It is realistic 'enough' ya know. With the ships doing things like turning retrograde to de-accelerate. Really nice touches like 'belters' having their own unique sounding accents. It kind of reminds me of Babylon 5 crossed with Galactica.

[@TheRezro]

It has some hilarious screw ups but overall it is nicely done neo space opera.

[@webby2275]

I was just happy to see reaction control thrusters on the ships to help orient them, not to mention the kind of details that the ships have in general. It's really awesome.

[@takokick]

continuing with the theme of the video; It's really cool how they do all those maneuvers, but alas the speeds in which they happen on screen would surely squash the crew, I think. I don't recall that the forces present when rotating the ships would ever have been addressed.

[@Zanzubaa]

Well they met me half-way at least, that is all I ask. The real laws of physics can be so tedious, it is like they do not care about making a good sci-fi story at all, how rude! =p

[@maroon5man]

but have you even read the book if you like the show than you have to read it theres 6 books so you can know kinda what they might put on the show although they've left out and changed so much in the show

[@MyUnclejay]

Ironically, I work on the vfx for the series...the name of my studio? Rocket Science Visual Effects....

[@sid2112]

Dude, thank you for helping to make a decent show. First good show I've seen in years. Seriously, thank you. Keep up the good work.

[@GyroCoder]

Nice work! It kicks ass.

[@klacklery]

It's absolutely incredible

[@williamwalker57]

No way!!! This is my favorite show at the moment!! Thanks!!

[@TheOneTrueDragonKing]

Then you're aware that the show's "science" is a lie? That none of the stuff your VFX portrays is actually based on real-world science? Because according to real-world scientists, the science of the Expanse... isn't science at all.

[@ineinerbank]

from what i got from the books, 1/3 g is the preferred cruising accel in the expanse, as it is comfortable to martians and earthers, and belters are often very used to it (seeing ceres in the books provides spin gravity of a third g on its outer levels). also it is mentioned, i think, that during long haul missions they alternate between acceleration and coasting at zero g and using mag boots.

[@Kanglar]

How to stay sober: Drink every time Scott blinks.

[@pocok5000]

I think he is reading. I checked a paper on this, they estimated the average blinking rate to be around 17/min, but it goes down to 4.5/min while reading.

[@BrucknerMotet]

Dávid Kertész Good point. The presentation is too rapid and cogent to be extemporaneous. so it's either completely memorized or prompter-assisted. Nonetheless, the presentation is engaging enough (e.g., use of hands, varied tonalities, consistent behaviors, etc.).

[@argiebarge7955]

" extemporaneous." id rather be drunk

[@ghostdog2041]

Not only that, but he’s an angry looking guy.

[@TanteEmmaaa]

i want to know what the black spots on his finger are.

[@CptFantabulous]

I recall reading in the back of the first or second Novel that the writers(since it is actually two people under a pen name) talked about how the drives actually work. Rather they said that it didn't matter how they actually work since that doesn't add anything to the story. Which is kind of true since the only time they talk about them in the books in any detail is when something has gone wrong with them. I recall in one book they mention the ship dumping its core to avoid melting down.

[@Allcozeltser]

If I remember correctly, books stated that Epstain drive was an improvement on a "Fusion torch" drive.

[@MachineMan-mj4gj]

Epstein himself was a fusion drive engineer who tinkered with drives "at home." It's entirely possible he discovered a series of improvements to heat and thrust management over fuel consumption to make a miracle super-drive. After all, penicillin was discovered by accident, who's to say an Epstein drive wouldn't be?

[@lukas.prochazka]

@@MachineMan-mj4gj And he didn't kill himself

[@MachineMan-mj4gj]

@@lukas.prochazka Well, this Epstein did at least.

[@seanabsher5577]

@@MachineMan-mj4gj on accident.

[@5Andysalive]

@@MachineMan-mj4gj penicillin was discovered by mold, which happens a lot in nature. You won't find a new engine just lying in the forrest one day. Or if, you'd rather be very suspicious. However, before he did all this, he managed The Beatles. And that's more important than some rocket stuff.

[@TiagoNugentComposer]

In season 4 they show the inside of the fusion reactor. It is an inertial confinement reactor.

[@Mr.Nichan]

*inertial

[@lambree4947]

the expanse is a very good show, excited for next season

[@Red-ur5xj]

WEDNESDAY ITS BACK :D

[@ThreesixnineGF]

REALLY??? *writes down on calendar

[@orosee]

Season 1 really surprised me, I went out and got myself all of the books from Audible right away. The I realized that Season 1 was only half of Book 1, so there's quite a bit to come if the series isn't cancelled prematurely (I hope not!). Only now finished Book 2 (I only really have 2 days every 3 months to read/listen at length) and that ended with a cliffhanger that connects with Book 1, I absolutely need to make more time.

[@TheArklyte]

which will do justice to power armor too, judging by the trailer.

[@jonnyblaze2006]

power armor? cant help but go Fallout there

[@mikvance]

Atomic Rockets is an incredible site I've used for years now. Crummy navigation and odd organization buy really thoughtful explanations of technology advantages, limits and alternatives.

[@69Kazeshini]

i do enjoy reading and looking at the explanation for things on that site

[@Aleksandar6ix]

Fiction or not, The Expanse gives us the right blend of sci-fi and realism to actually believe this could be a future of space travel that we may one day expect! I love this show for that, and know very well no show will ever be truly realistic - because then we'd have nothing.

[@ExtremeCostumes]

Helium 3 is unbelievably abundant, just not on the Earth. Since they have explored the solar system, clearly they have access.

[@fathampton]

ExtremeCostumes and they specifically talk about new sources being found in the belt and (I think) Jovian moons.

[@Mortlupo]

Xenon (Xe) is the prefered fuel for Ion type drives.

[@livefire666]

The moon is covered in it!

[@Weaseldog2001]

Xenon is not a fuel. It's an inert gas. Xenon is a propellant in an ion drive. And in the show, the drives are nuclear.

[@Hyperious_in_the_air]

[spoilers] Jules-Pierre Mao's protomolacule research lab was moved to a retired He3 refinery on Io, so it's safe to say that it's a pretty big industry.

[@CockatooDude]

Yes! Scott watches The Expanse! It really is the best sci fi show to come out in a decade.

[@CuttlefishEmpire]

CockatooDude impressive. Does Star Wars count as science fiction?

[@martyhammer481]

big no

[@martyhammer481]

Simple Jack and a Horse Word!

[@rejest05]

Uhm... Galactica.

[@Keithustus]

Battlestar Galactica, then District 9, then Rogue One, then The 100, then The Expanse. There is no other sci-fi during this period.

[@JoshKaufmanstuff]

This video sent me on a learning spree to understand all of the relevant terms discussed here. I'd know nothing about science without science fiction and awesome communicators like @Scott Manley !

[@N1lav]

I thank Scott Manley for introducing me to the show. The 4th season was already out when I watched this video and now I am totally hooked on the show. I am currently waiting for my friend who lives in UK to get me the books. I have never read any novel but I am gonna give this one a try.

[@illustriouschin]

I loved most of the books in the series and was very glad to discover the creators of the show making an effort to do justice to the source material.

[@danielsancarter]

is it one continuous g? I always figured it was maybe like a quarter g. since belters and Martians have no problem with it, and if it was one g it'd just be constant gravity torture

[@scottmanley]

+Daniel Carter more massive ships, mean less acceleration.

[@danielsancarter]

Scott Manley Yeah. I made this comment when I started the video because I noticed that when you first described the thrusters you said they were able to produce a continuous one g for days at a time. And Ceres only has like .3 m/s2, and while I assume they enhance the gravity (probably spin gravity[cause thrust gravity would be absolutely and totally impractical on a planetary scale]) a ship like the cant probably isn't constantly pulling more than maybe a quarter g. And while I do agree that whatever they're using is fantastical I just don't see any of them pulling one full constant g. Especially given their size. But yeah. Stick one on the iss and you'll pull seven gs without a problem

[@delayed_control]

Probably Martian ships use quarter g instead.

[@kesrevill]

Daniel Carter the books specify pellets, magnetic containment, and fusion as being the main propulsion and power source of most ships, also when they're moving at a relaxed pace they "burn" at roughly half-G, but in extrenuating circumstances, ie; combat, the ships in the Expanse will sometimes run a sustained 7-9G of acceleration, not including evasive maneuvers. keep in mind most of the ships featured are gunships or Corvettes, as Mr. Manley said, bigger ships accelerate slower.

[@danielsancarter]

Keisuke Revill that's what I figured based on what I'd seen on the show. What with the way they're secured during the battle sequences and the fact that everyone wasn't dying during average acceleration. I just knew they weren't pulling a constant one g which is what I mainly noticed in the beginning of the video.

[@nanmonstaway3599]

On prime now, syfy was dumb enough to cancel it and Amazon bought it right up

[@alistairthomson8710]

Picture yourself as an 1835 engineer trying to explain how someone in the year 2017 would 'drive' from New York to LA in under two days. You'd be talking big steam engines, most efficient routes to minimise rail gradients, most efficient coal and best refuelng and watering schedules. AND being so far off the actuality ...

[@scottmanley]

+Alistair Thomson however in 1824 Sadi Carnot had already determined theoretical limits on how efficient an engine can be en.m.wikipedia.org/wiki/Carnot_cycle so a scientist of the era could imagine the engines of today, they could even do the math on modern engines. There are fundamental limits we know off that can't be exceeded.

[@frankmueller2781]

@@scottmanley Point of order: There is no such thing as settled science. The above comment is true, but only so far as we *NOW KNOW.*

[@cadkls]

@@frankmueller2781 No lol that's not how the real world works. Physics, as we know it today, is incredibly accurate. If it wasn't, our technology wouldn't work because we would be missing some vital component, some crucial piece of information. It simply doesn't happen. I suspect the reason most currently experimental technologies today are indeed missing a piece of information crucial to the efficient functioning of such a device. Fusion power being a prime example. What we know now, we know. Physics won't outright change, all we will do is add to it. The mathematical framework of relativity didn't change classical mechanics, it just added to it, side classical mechanics doesn't work at very high speeds or in large gravity wells. Quantum mechanics didn't alter what we know about physics, classical mechanics remained the same, thermodynamics remained the same, the behaviour of light remained the same mathematically. We just added more to it. Our understanding of thermodynamics hasn't changed despite the new fields of physics joining the club in relativity and quantum mechanics. Thermo has remained unchanged. I'm all for optimism, but I'm also a realist. We are approaching our limit in understanding physics, and I sincerely hope that isn't the case and we do discover some completely new avenue that revolutionizes our technology. But I also very much doubt it.

[@frankmueller2781]

@@cadkls you are mistaking consensus for "settled". We do know a lot about physics, but there are some major holes, and filling in those holes may radically change what we now think that we "know." We can calculate gravity, determine gravity, predict gravity. We know a great deal about except for one critical part: How? There have been dozens of theories over the centuries, but nothing to indicate that we are any closer to that answer. (Hence why some still refer to the *'Theory* of Gravity'. The Church and science was once in consensus with the "fact" that we lived in a Geocentric universe. Galileo was obviously a kook. When we start to become too sure of ourselves is when we usually end up falling on our ass.

[@Raz.C]

@@frankmueller2781 In all fairness, Frank, cadkls and Scott are correct. While it's within the realm of mathematically demonstrable reality that what you suggest might be correct, it's such a vanishingly small possibility that we'd sooner see sheep take over the world in a bloody uprising, where they shear humans to make clothes for themselves and then agonise about whether it's morally right to eat us, or not. As unlikely as that sounds, it's also mathematically within the realm of possibilities, but realistically, it's never gonna happen. I'm a chemist, so I don't have any specialisation in physics (even though I did a number of physics subjects as electives) but even so, chemists have to delve quite deeply into the realms of particle physics, nuclear physics and thermodynamics (conversely, you NEVER see a physicist having to study macromolecules or organic and analytical chemistry to further their understandings...). Thus I'm of the opinion that chemists (the competent ones, at least) have a very good understanding of the broad strokes of how our universe (and our system [that's an entropy joke, by the way]) works. So I can tell you- without being invested in this as a physicist, that cadkls was spot-on in his description. If you still doubt his overview, I think the only way you'll know why we hold this position is to go to a good university and spend four odd years finding out for yourself. You also might look into a subject called The Philosophy of Science, offered by some universities, which explains the how scientific revolutions (as per your Gallileo example) work. The TLDR version of that is: We're nowhere near a scientific revolution of the sort and anyone who tells you otherwise is only saying so because they don't understand how science, or scientific revolutions happen.

[@StoneLegion]

Oh nice. This the only place I get educated these days :)

[@michaelselinger9490]

VSauce?

[@BasicEndjo]

too few uploads on vsauce

[@jefdamen2977]

It's good tho

[@Hiramas]

Check out Tom Scott, too.

[@uhli1896]

if you're interested in physics and not tooo afraid of a bit of theory and maths check out pbs spacetime, just started watching them recently and it's (one of) the best physics channels on yt imo

[@LazerFocus3113]

Oh, man... I heard about The Expanse, put it on my list and forgot about it for a month. Finally took time to watch it and watched the entire first season in one sitting. Surprisingly good sci-fi show.

[@Kaodusanya]

i think your intro is actually what keeps me coming back its so catchy. Different from any other youtube channel.

[@AbbreviatedReviews]

This background music is very tense, which is weird because nothing tense is happening.

[@P4INKiller]

A bald man with a Scottish accent is speaking directly at us about imaginary spaceships without blinking. I'm shitting my pants.

[@mynaimrie]

@@P4INKiller I was gonna say something like "he's holding his shit back or something " But yours is more creative, yeah.

[@gustavogargioni7197]

Once again, 11min of science&egineering with Mr. Manley. Thank you Scott.

[@unbannablebob395]

I was feeling sort of smart today, so I watched this to fix it.

[@wraith0078]

Okay. Beware of the Atomic Rockets website. It's a rabbit hole. There goes my workday, LOL.

[@shawnwhippie6430]

I love these books. I also loved the fist season of the show. 10/10 would watch again.

[@SMhydra]

Shawn Whippie 2nd season is almost upon us

[@Red-ur5xj]

Wednesday feb 1st

[@suicidal_camo_eisberg765]

You know whether it will be just on Syfy then or on Netlix too?

[@Red-ur5xj]

Scifi

[@kcircuit8684]

It is on amazon video

[@jcdrake01]

I'm reading Ciobla Burn right now and really enjoying the series. It is a lot like WJ Williams Praxis, but not so much hard military stuff. I actually find a lot of parallels between The Expanse and the Mass Effect universe, not in technology, but the type of place they live in and the sort of stories they are telling. That being said, as the series goes on it definitely gets into some stuff that is way more fiction than science, to the point where it might as well be magic.

[@reginaldinoenchillada3513]

1:30 "Its a gizmo that allows for storytelling. " liked. Subscribed.

[@KillahMate]

Appreciate the shoutout to Atomic Rockets, really a site any subscriber to this channel should be reading.

[@lesdewitt6430]

These physics I first remember from reading Iain M. Banks sci-fi book “The Algebraist” back in 2004. It goes further than the expanse by having the crews filling their lungs with breathable liquid to stop lungs being crushed, and because it is inter system the effect goes on for months.

[@georgegrogee5991]

Breathable liquid was in James Cameron's 1990ish film the Abyss for diving at ridiculously depths. Iain Banks wasn't innovating as per usual

[@addison1024]

8th book of the Expanse does the same, actually (though you probably made this comment before it was released). I wonder if it was a reference or coincidence

[@EveyJamo]

Hypestein drive engaged! Scott, you've managed to make season 2 week even better!

[@CultofThings]

Live long and prosper

[@aepceo1]

I'd like to point out that in the TV series, they said that fusion torches were ancient technology essentially. It was invented a good long while before the drives they were using at the "modern" time in the books. So when you start talking about torch drives at around 10:30, you're missing the fact that they didn't use that technology anymore.

[@Steampunk_Ocelot]

I'm missing the show so I'm back trawling for this type of vid before I listen to the books on audible again . I love these types of videos where it gets into the gritty bits of the expanse world building

[@Rdasboss]

Scott if i ever write a sci-fi script i'm hiring you. I hope you accept homemade chocolate chip cookies as currency. In my defense they are pretty awesome.

[@darthcole4668]

That sounds like an acceptable form of payment to me.

[@pandur1337]

Best payment ever! 😉

[@knutdergroe9757]

Now if they are chocolate chocolate chips cookies I would be running..... 😎

[@jaeslow6347]

Your a legend and your videos are an example of what KZbin should primarily be made up of.

[@exilestudios9546]

lol you mean you dont like the endless supply of videos of grown men and women playing videogames designed for 5 year olds while screaming? because thats most of youtube right now

[@cheddar2648]

Well who doesn't want a mansion in Beverly Hills paid for by your Minecraft videos?

[@scottmanley]

Screw Beverly Hills, I want my mansion to be in Oakland

[@cheddar2648]

I figured a space yacht or Moon base for the Great Scott Manley.

[@skylarking12]

In The Expanse, it's shown and described that the attitude control thrusters run on steam piped from the engine room. To me this suggests a fusion plant that in turn heats water (derived locally from harvested asteroidal ice) to ultrahot steam to get a blend of relatively high Specific Impulse coupled to high thrust.

[@scottmanley]

Yeah that's what's called 'teakettle mode' it reduces radiation hazards to nearby ships at the expense of low efficiency. To get the performance Epstein demonstrated you can't have much in the way of wasted mass so pure fusion exhaust is the way to go.

[@threebillion6]

I'm more than halfway through book 3 right now. I love it a lot. suggested by a co worker I haven't been able to put it down and I'm glad he's going to write more in the future. I haven't seen the show yet besides episode one which was ok but I'm going to wait until I finish what's written in the series before watching the show. I'm glad you did a video on their engines though. In was always a little curious.

[@Vladimir-hq1ne]

I've lost my consciousness at 7.12G being worn hi-G suit in the anatomic seat liner - at my youngest prolific year of 20. That was the possibility to participate in the test. 2 weeks in recovery. Pal of mine got 8.1 and became a jet test pilot.

[@chrisgaming9567]

Oh, cool, what did it feel like?

[@MisterSquid1]

It feels horrible, it happened to me when i was a kid

[@mihy26]

I was in the front seat of a Steen Skybolt aerobatic plane and I thought it was the G-forces of this very tight loop that was 'sinking' me into my seat (we were pulling almost 5-G ) ; it dawned on me later that I was starting to black-out . . .

[@rickperry2145]

When we watch science fiction shows like this we need to keep in mind that serious scientific breakthroughs and major technological advances will occur over the next century or two that we cannot accurately predict. I love The Expanse and I'm very grateful that someone tried to make something with a great story and at least attempted to use real science.

[@296jacqi]

My favorite space show everrrrrr. I can’t get enough. I rewatch episodes while waiting for new ones. It’s so good.

[@ChristopherDoll]

Love the books, and awesome of you to take this on for your channel. Cheers!!

[@Svitman]

The other series based on same engine principe is Larry Niven/Jerry Pournele series about moties (Mote in gods eye), they use hydrogen as a fuel there, but i dont remember if it was explained to detail because it is few years since i read it.

[@erichimmelblau877]

I can't wait for Expanse season 2 next week!

[@calebolds9609]

I enjoy whenever these kinds of videos preface it with "it is a plot device" because I feel like a lot of science channels forget that while covering sci-fi tech

[@xilaithownage2453]

Scott thanks for this review of "The Expanse" by one of my favourite authors. I have just spent the weekend watching series 1 on Netflix. I would never have known about it without watching you CHEERS!!!

[@Zerepzerreitug]

Atomic Rockets is beyond awesome :D it helped me tons with some research and number-crunching when I did a sci-fi webcomic. 10/10

[@whitslack]

Loved this analysis. One point stuck in my pedantic craw, though: the singular of "nuclei" is "nucleus." You made that verbal mistake a couple times at least.

[@JonIceInternational]

You are amazing at this kind of videos. We all love it. And thanks for pointing me to the direction of this show. I didn't know it and now I'm going to watch it. Thanks !

[@8749236]

I visited the filming location when the cast crew was filming at U of T. (One of the cast crew told me the show is called The Expanse) I was asked to watch the show when it come out, which I regret I forgot about it. =(

[@EtzEchad]

You wouldn't need to use radiators to get rid of the excess heat. You could use a flash-evaporator to cool it. By running liquid hydrogen over the hot spots, it would evaporate and give you more thrust. The ISP from that would be way down compared to electrodynamic thrust, but maybe you could use an electrostatic field to accelerate the hydrogen even more after it is vaporized. What will be possible 200 years from now is beyond what we can imagine now. The problem with "The Expanse" is that most of the technology isn't advanced enough, rather than too advanced. I mean, is it really likely that they will have revolvers and flat-panel displays two centuries from now? This show will look outdated 10 years from now, much less 200.

[@scottmanley]

The problem with this cooling concept is that the thrust from evaporative cooling will have much lower specific impulse, so the spacecraft would not manage to get to 5% of the speed of light.

[@EtzEchad]

Scott Manley Indeed. I realized that when I made my original post. :) What do you think of the idea of accelerating the hydrogen electrodynamicly after using it for cooling?

[@scottmanley]

It's possible, but the net energy density still has to come out at 50terajoules per kg of fuel/coolant. So, too much coolant will drop energy density and make it less efficient than engine in story. The heat is so extreme that the boiloff rate would be too high.

[@EtzEchad]

Scott Manley Well, I pretty much agree with your reasoning. I think that with 200 years of engineering effort that the problems are probably solvable though. We are like engineers in the 18th century saying that 600 mph speeds are impossible because you couldn't make sail cloth strong enough. There are a lot of other issues with The Expanse though, like "Where are the computers?" and, as the XO asked in the first episode, "Why is everything so dark?" I love your videos Scott. We have about a 95% overlap in our interests but you have massively more energy than I do. I don't know how you do it.

[@samk108]

David Messer Do you mean why isn't everything automated? The darkness is a thematic choice. Earth is cast in sterile light, Mars and the Belt are dreary.

[@Mummele]

isn't nucleus singular and nuclei plural? great video in any case!

[@williamlloyd3769]

Small point: James S. A. Corey is joint pen name of authors Daniel Abraham and Ty Franck.

[@livefire666]

As Scott Manley accurately described the difficulty of actually building a fusion rocket powered space craft that can reach a continues acceleration of 7 Gs, in the show all the space ships only do and or maintain 1 G and likely half that most of the time. And that should be entirely possible, especially in the 23 century. Also the reaction of a fusion torch drive takes place outside the ship.

[@UNSCPILOT]

They also did point out that the ship doing 7G killed him, the gravity might have only been part of what got him, even if the ship didn't roast itself with radiation and heat he might be toast from running that high that long

[@impylse]

The Expanse probably the best sci-fi show in recent history, i just wish they didnt stretch out all the science fiction as much as they did from episode 2 to 10. Only the pilot episode was trully engaging. Cant wait for season 2 tho!

[@astrophonix]

"Probably"? LOL. It's easily the best sci-fi series ever!

[@ruparker-jones1891]

I just want a t-shirt with "Thick radiation shielding will convert all those neutrons into YEET!"

[@michaelchaney2336]

I love the expanse and mad props to Scott Manley for doing the science in front of everyone. I had the fun idea of using plasma coils to funnel fusion spent plasma around the reactor to magnetic mirrors to reflect the radiation and absorb it. This would increase the efficiency of the fusactor as named in another of my favorite authors L E Modesitt Jr.

[@scottmanley]

+Michael Chaney yep, that's the idea, the problem that I point out is much of the energy comes off in a form that can't be affected by magnetic mirrors.

[@randomnickify]

I think you have to make independent movie (part of movie) on neutrons and why they are called neutrons. Lots of people in comments seems to be lost too deep in "magical forcefield" area. :D

[@michaelchaney2336]

Scott Manley what about a molten salt reactor as shielding? Neutrons make nuclear reactions run faster and heavier atoms absorb xrays better.

[@scifirealism5943]

@@michaelchaney2336 that'll work.

[@Psycandy]

here's my rule of thumb with my work in film: anybody can freeze-frame the video and even if that person is an expert in the matter, they must be completely convinced that the presentation is plausible (baseline) or groundbreaking (high bar). This applies to physics, computer code, animals, psychology, everything, particularly aspects where the script falls short - like being vague about propulsion. The Expanse was 'realistic' because it is set in the near future, but it forces impossible pressures on physics (and commerce and human nature) just so the pace of the show is maintained. Corey also overlooks the fact that humans, being terrestrial, developed machines which are better suited to hostile environments, and all the efficiencies this technology affords is somehow forgotten as mankind scraps logic in order to have a suppressed faction and, by that measure, conflict. "Let's explore the universe!" "OMG what about war?". The Chinese want to mine the moon, so by Corey's measure, the hordes of Chinese slave laborers should be met with even more US troops armed to the teeth, and the labourers revolt and tadaaa there's your war. Sloppy, lazy writing that somehow confuses scientific achievement with the mentality of the dark ages and ignores, completely, any and all costs. Why send a machine, which is efficient, when you can send a human, at astronomical cost, to fail at the same task? So that war on Earth may be extinguished? Whatever the case, if Corey adjusted the timeline it could be plausible, but then that 'gritty realism' is lost. The series is a bad story, well told, kudos to the production for pulling that off despite the flawed screenplay and sketchy adaptation.

[@Supergecko8]

So cool I love The Expanse

[@MVHiltunen]

This argument of thrust reaction energy being impinged on the ship sounds convincing at face value but is not quite valid. For example: The reactions that take place at the chambers and engine bells of modern rockets - let's take Falcon 9 as an example - release enough energy to melt the structural materials of the whole rocket many times over. For falcon-9 the rocket releases about 4 Terajoules during a 160 second burn. If we assume for simplicity's sake that the bottom of the rocket is made of nothing but titanium, just half a percentage of this is enough to melt and vaporize half a meter of the bottom of the rocket off. Enough to completely erase the engines. Yet this clearly does not happen, and if we assume just one centimeter of titanium is eaten away this way (in reality it's even far less) then Falcon-9 demonstrates the ability to have less than one thousandth of one percent of the launch energy contributing to the meltdown of the engines! In reality the thermodynamics are a bit complicated and one can't just take a lump of energy and dump it somewhere and see if that's enough to melt something. Engine chamber materials can to a large extent stand the temperatures of combustion in the chamber. If that doesn't melt them, then there is no immediate effect that damages them in any way no matter how long the engines fire.

[@89DerChristian]

Thing is though that the energy in a conventional rocket is guided outside the nozzle into the environment. The waste energy Scott is talking about here is generated inside the reactor and cannot be guided (Neutrons) therefore being fully, or to a large part, absorbed by the ship.

[@viermidebutura]

Neutrons and x-ray photons vs infrared to uv photons in a moving column of plasma

[@ayporos]

@@89DerChristian That's where I feel you and Scott fail short as far as 'theorycrafting' goes. Scott's whole argument is based on the idea that the produced neutrons (let's ignore the radiation for now) cannot be guided (which he explains) AND are produced omnidirectionally (which he doesn't address, but just assumes as a given). Now, of course this is just 'science fiction' and theorycrafting, but who's to say that they didn't invent a way to actually control the fusion reaction in such a way that they can direct the produced neutrons from the reaction?.. I know what you're about to say: "Heisenberg's uncertainty principle".. and you'd be right.. if you assumed no headway was made to circumvent or diminish it. But again, that's an assumption. Heisenberg's uncertainty principle doesn't state an upper limit, simply that there 'probably most likely' is a limit beyond which we cannot increase accuracy. Who's to say you'd need to even get close to that limit to be able to guide/point the products of a fusion reaction 'well enough' to provide immense thrust while also not melting your spacecraft? D'yall think Newton or Einstein discovered what they did by saying "that's impossible because of !"? Of course not. :)

[@dsdy1205]

@@ayporos neutrons flying everywhere is not a problem of heisenberg, it's a problem of statistics saying they will be emitted isotropically and the fact that they're neutral and can only be deflected by unachievably strong magnetic fields (the kind you find in pulsars) or bulk interactions with matter (i.e. impinging heat)

[@dsdy1205]

@@ayporos to add on, 5 percent impingement is actually pretty generous on Scott's part considering actual studies done on how we might do this couldn't get much better than 10% for the most radical designs

[@EberKain]

Love your educational videos. Would love to see one on stage decoupling.

[@darthrevenchist89]

They don't go into detail in the books but they do mention in the first chapter of the first book that they found a way to "deal" with the heat issue. They are also always worried about destroying ships and other vehicles with their drive emissions. One ship in particular had drives big enough to destroy an entire ship dry dock if they were activated too close. And this station is huge.

[@chumprock]

I'm going to have to watch this a couple times..

[@twiexcursori]

As always, the impossible is more realistic than the implausible. Still, one appreciates the attempt :p

[@dbmail545]

Studying a sci-fi scenario where fusion propulsion has a high-impulse mode and a low impulse mode. The high impulse mode can give up to 10G acceleration while the low impulse drive is very efficient but maxes out at a fraction of one gravity. Trying to make an interesting story of not having the fuel for a high impulse transit but not having enough resources to keep the crew alive for the low impulse transit.

[@LordCucumber77]

Love The Expanse, can't wait for season 2. 1st of February!

[@danielbeck2739]

I once had a chat with someone about possible fuel sources for a ship. Now this I have to give him credit for this one. He had put a theoretical design out based on extensive research in to the subject surrounding the issue of the neutrons and the unique properties of deuterium and tritium. His idea was to actually add two other molecules to the mixture. The idea was to use them as a sort of filter and catalyst agent to reduce the offset of the potential build up of the neutrons and to recover some H3 to try to reuse. The design of the engine was enormous, hundreds of "Neutron Sinks" as he called them, would retain the charge and the excessive heat. Though I'm not in expert mind you, but in relation to how this system could be used effectively the group I was with looking at this came to the conclusion that this system would have to be applied to much larger ships. Like Tycho Station, or the Donnager being the smallest you could effectively utilize this system with. Or the Canterbury, ships with an impressive mass that would be able to house the sinks and the recycling scrubbers. Now to power this you would need some kind of high yield source of power. Most the material you spend is into the propulsion, this system would need a impressive solid state nuclear reactor or something that can generate tremendous amount of energy to maintain the amount of power required to direct and control the propulsion plant itself. I don't recall what the two other molecules were, this was put out almost a year or so ago. Approximately around the time Expanse had come out and in the first few episodes. This idea was originally brought up to a site I was part of were people had designs for things in games. An example would be like a steam airship in D&D that used little to no magic. There had to have been 50-something designs submitted, but many were concept art design. A hand few had any technical design application was put into them. Another and probably one the best ones I was part of was done in part to a space game. Two women had asked the general population for a design for a ship based on the in game currency and resources available. The group I mentioned before actually met up and started from this request. We had 8, 3 actual designers. Two of them did architectural, one did engineering. A geometry professor from a university, another mathematician, a civilian contractor for the army who did radar work, a chemist who had some knowledge in metallurgy, and then there was me. At the time I was submariner in the navy, my experience in that kind of enclosed environment gave the design vast amounts of redundancies and safety features that the GM of the campaign hadn't even considered. Now we did later on pick up a few others, two of which had extensive knowledge in physics. Their take on the system was more on the questionable side as in they had doubts, but given that this person had gone very deeply into the operation of how to collect the neutron build up and the method as to disperse it safely did have them a bit intrigued. To disperse the build up then sinks would actually vent out into space, now the sinks had a very in depth and extensive cooling system running through out. His theory had put it out that the gases and leftover junk could be super cooled to a gel or a form of liquid. Venting it out to space on the dark side of a planet or some kind of orbital body to allow it to tumble and melt on re-entry made it so that liquid would be vaporized. The charge be nullified as it was basically released in the ionosphere, or out in vacuum away from the ship and crew. Major downside to this system is you would need two more holding containers of some sort for the extra fuel sources. Upside, the question of what to do with the charge had been answered thoroughly and in a safe way for the crew. The site I mentioned is no longer up and has been down for some time unfortunately, but if the "A-Team" as we were dubbed, could see this vid I bet money either one of the two physics majors could identify what the two other molecules were and how they would interact with in this proposed system way better then I could. My knowledge was directed more towards the coolant and the refrigerating system required to super cool the build up and the best way to maintain it.

[@UNSCPILOT]

one thing to keep in mind is with the massive heat output of the engine, even a relatively small amount of excess heat could be used to generate considerable power, with a bank of high output capacitors used to initiate startup when needed, in reality you could either entirely forgo a separate reactor or use a small one to trickle charge the capacitors needed to jump-start the reaction, entirely dependent on the distance you need to cover and the other energy needs of the ship

[@MrC0MPUT3R]

Kevin Macleod should be given google stock for how much his music has improved youtube

[@henrytjernlund]

Being an SF writer, thanks for the Atomic Rockets link.

[@gurururuwarararara8164]

Published anything yet? I’d love to read!

[@mattiasdevlin1363]

Proton and Boron-11 electrostatic fusion would be ideal in this case, all reaction products are helium nuclei and energy. If the exhaust plasma is dense enough it will carry most of the energy with it out of the structure, but I reckon cooling will still be required or the nozzle will melt pretty darn quickly. Don't know if it would be powerful enough to be an analog with the drives depicted in the expanse, but enough to open up our solar system for exploitation and our closer neighboring stars for unmanned exploration in reasonable timescales.

[@ineednochannelyoutube5384]

You need an isp of roughly a million seconds, and a TWR of 10 to be as good as the show.

[@Codebreakerblue]

+Scott Manley I love your MOOSE shirt. lol

[@scottmanley]

I designed it myself: www.cafepress.com/szyzyg

[@thePronto]

Who's here for the premier of Season 4 tonight?

[@thePronto]

Oh, what? They released the entire season in one go! Now I have to implement my best discipline not to binge it in one weekend. Son of a...

[@zwussow]

I'm always reminded of the Kzinti Lesson from the ringworld books. The Expanse rockets would make amazing weapons but they don't use them as such often.

[@PrasadHonavar]

Awesome and thanks. I was looking for an video on Epstien drive.

[@OverlordZephyros]

What would be the most realistic FTL travel? or the most likely? Im trying to create a hard sci fi military story, I got everything as real as possible like ballistics weapons and no ship to ship battles (ground battles only), but the great distances between stars makes for hard storytelling to be believable.

[@Davin2014]

Have the same question.

[@doriphor]

Probably the Alcubierre Drive or the Kugelblitz Engine? I wouldn't know for sure.

[@migkillerphantom]

"What is the most realistic FTL drive" is the exact same question as "what is the most realistic type of magic spell". It's impossible according to everything we know.

[@bobbytables464]

Wormholes or Alcubierre drive. But since FTL is going to be a handwave anyway, you can come up with whatever you want. I always enjoyed the FTL of the 40k universe. Basically, work out what kind of mobility you absolutely need to make the story possible, invent a plausible-sounding technology that provides it, and work out internally consistent rules for this technology. Then treat those limitations as real as you would anything in the real world.

[@thanatifloraa]

The Alcubierre Drive is theoretically possible with current physics models. Though it relies on exotic particles that we havent observed. But that seems like your best bet

[@derekupdegraff9777]

Great video, Scott! There's actually a hint as to the mass ratio of Epstein's ship in the fact that they said "over 7 g" initial acceleration and gave a 37 hour burn time (i.e. an average acceleration of ~11.5 g), which means the mass of the ship can't radically decrease if the average thrust stays constant. At 7.5 g (presumably Epstein wouldn't have said over 7 if it was over 8), the mass ratio is about 2.5 and v_e is about 16,000 km/s.

[@elliotsmith9812]

Bravo Scott. Do you want to take on all the questions regarding the Space X colonial transport? Like how does the in orbit refueling work and how many flights are required? Do they have to land on a pole to produce the return flight fuel? How long does that really take? When they leave Mars, do they have to refuel in Mars orbit before they head for home? If you dropped the engines, could it float in the atmosphere of Venus? How hot would it be? If not, how big a balloon would it take?

[@jhill4874]

Scott, my head hurts! I left physics classes in college, many, many moons ago. 😁

[@jekanyika]

Have you read any of Alistair Reynolds books?

[@hellothere_1257]

I did read one of them. The science was rather solid but I didn't really like the story and characters all that much.

[@ronin47-ThorstenFrank]

I very much like them! Would like to know if Scott knows them too.

[@illustriouschin]

What is your favorite Alistair Reynolds book?

[@mekawasp]

I read all of them, but I have to agree with Hellothere_1. I didn't enjoy the stories that much, I'm just really into scifi and couldn't help reading them all anyway :p

[@jekanyika]

Pushing Ice is my favourite.

[@Loop-flow]

"Since I'm lazy" he says, then continues to bombard us with cold hard not-lazy science stuff :)

[@skierssuck88]

A lot of your speculation such as power of the exhaust propellant and fuel is answered in the books. I would recommend reading them and doing an updated video of this. The authors got a lot of feedback from many fans who are in the know about this stuff after the first and second book came out and so wrote into the books these ammendments

[@EmilyAndClark]

I'm a software engineer. I remember a professor doing a proof in a datacom course showing that modems could never go over 4800 baud. Can't be done over normal phone lines. A month or so later faster modems came out. Trying to explain the future soley with our engineering is interesting but often flawed. I'm not talking about expecting physics to change but the art of engineering is in the novel application of physics.

[@PaulPaulPaulson]

How do they protect their ships from the NAN-virus? B-)

[@suicidal_camo_eisberg765]

Interstellar quest reference?

[@quintinflower1317]

6:41 it will convert the energy to yeet, eh?

[@wyrmofvt]

Atomic Rockets is the bomb for sci-fi goodness! You get a like for that alone.

[@itbe]

So cool. I've watch you report on space for a couple years. Just started watching The Expanse (finally). I go looking for videos about the show and boom! There's Scott Manley! Nice!

[@supershmooperme]

I'm hoping for it to be the next Babylon 5 In fact, this made me want to watch Babylon 5 again

[@harrykrust7984]

funny , just started watching the series again last night for same reason.

[@ImperativeGames]

You can't have two Babylon 5, but it's very good and almost unique =)

[@jaxativejax662]

I love The Expanse but they sure do play fast and loose with gravity and none of their ships, particularly the military ones where you think that it'd be a "no-brainer", seem to be designed to account for gravity that only exists under certain conditions. Surely every single crew member would have a duty station in a chair and be strapped in at all times particularly during alert situations but instead all you see are hard edges and what would be clear health and safety violations even if the ships had reliable, constant gravity that doesn't need power or active systems. Also. what would be the inertial load on a vessel that's trying to do a 180 turn to decelerate at 1% of light speed, surely that would be a "super science" technology vastly greater than anything else on the show.

[@bosyber]

In the books, on normal ships, as 'crash couches' where they are required to strap in, especially in combat and/or when expecting other maneuvering; the Roci does have those in the show, as does the transport Miller takes in season 1, but in the bigger ships later in the show they tend not to show these, especially for the bridge and such.

[@rubengholstoniii1086]

Fuel Pellets, that is what I was curious about. I love the Expanse, but the science behind what is possible is mindblowing.

[@leatherindian]

Robert Sawyer is a Canadian science fiction author who goes into great detail on any topic he happens to include in his books. He researches extensively and consults leading experts in whatever field he is writing about. Had Sawyer written this series, we would have detailed explanations of how the engines work. 🇨🇦

[@acapulkojik2223]

Finaly I know a TV show where there is no FTL, also I think this is the only future the human species will have.

[@85cadian]

Well, not so long ago humans thought the same about flying.

[@weatheranddarkness]

I guess it depends how much lies in the gap between quantum physics and gravity. String theory still seems to be quite a bodge and dark emery and dark matter are still stuck with those qualifiers for the meantime. What can we expect to uncover about the possible when we close those gaps? Will we open new fundamental questions about the nature of existence? Or will we actually have a complete basis of understanding the physics of everything at that point?

[@novafire1150]

honestly without a ftl drive (or hope for one) why bother with space exploration...

[@acapulkojik2223]

Two words. Anti-Matter.

[@milky_wayan]

by the time we're ready for interstellar travel on biological timescales we'll have surpassed biology anyways. robots and post humans will inherit the galaxy.

[@Halli50]

Ehrm... Reverse engineering a fictional engine?

[@alexlandherr]

Thank you for making this video, i really appreciate the time you took too make this video possible. It taught me something very interesting.

[@howardmiller5381]

I like your M.O.O.S.E. t-shirt. The recent failure of a Soyuz launch led me to think about the concept of life boats in space. The Soyuz currently parked at the ISS has to be used sometime by January, which means that the current lifeboat strategy is to continually replace it. Maybe it's time to start thinking of an RTE (Return To Earth) vehicle that can be docked for long periods of time, needing only minor inspection. Then if a real Get Out Of Dodge moment ever arrives, how to get out of Dodge will be way down on the checklist.

[@Gunjamed]

he3 is on the moon :D so says the internet

[@scottmanley]

+Gunjamed C. Not enough to fuel this kind of thing.

[@EliyanBrize]

Not to mention the moon nazis controlling it.

[@Gunjamed]

indeed hidden on the dark side, I think Scott played iron sky invasion but I'm not 100% on that.

[@UNSCPILOT]

Enough to get us started, if you go to Isaac Authur's SFIA channel he has a recent episode talking about harvesting mass quantities from Neptune and Uranus, like, stupidly large quantities that would make out current energy needs look adorable

[@maroon5man]

Am I the only one who actually read the books? Like the show gets so much wrong it's rediculous

[@samk108]

John Stevens I've read both and love both. The books have their style, but are paced very strangely. The TV show has to be a visual experience, and it has to be in bite sized ~45 minute chunks rather than keeping pace for 400 pages. This results in more character being added (the corporate spy), some being changed (Havelock), and some being added early (Avasarala). If you made a word for word copy of the books, you would attract SOME of the book audience, but everyone else would be off-put by the odd style and the presumption that you understand the world.

[@maroon5man]

I agree with that but I do wonder if they continue the series to book 4 how they are going to make it work since havelock appears in it (there are actually 6 books)

[@samk108]

John Stevens Easy: he decides that being a street cop isn't for him after being impaled, so he finds a cushy position on Titan. After a few years, he and his girlfriend decide to strike out on the frontier and he takes on a security job on the Edward Israel. Different paths to the same place. They made Havelock a more sympathetic character for a reason.

[@adodgygeeza]

The two author's of the original work are producers of the show. On that basis I'd suggest that the adaptation is as faithful as budget, cast and the different parameters of the medium allow.

[@patrikkarlsson9463]

Does it really "get things wrong" or is it merely the adaptation they wanted to go for?

[@fuffoon]

I am a sci-fi addict so why haven't I watched this? It sounds very cool and well done.

[@mikepatton8691]

I'm rewatching Scott's video and saw your comment, just curious if you've watched the show yet?

[@vp21ct]

I shall forgive them the lack of radiators this time. Though, personally, I'd have loved it if they'd have actually included them, making the ships look like those from Children of a Dead Earth. That would have been absolutely awesome.