There's nothing particularly idealized about it in the book -
they probably just slid over the politics involved there.

If there was politics in the book it was completely omitted in the film. In the film the portrayal was that China volunteered their top secret booster for purely humanitarian reasons and it made it seem like the director of the Chinese space agency made the decision while in reality that decision would have been made by the Chinese Central Committee.

Yeah, very different from the book, then.

I'm guessing somebody higher up made Ridley Scott change that part to minimize any potential political ramifications, a la the Red Dawn remake.

I'm pretty sure that was the case especially when you consider how important the Chinese market is now to Hollywood.

I don't think she looks that bad, I just don't think there's anything special about her. Plain is the optimal word.




The Jedi Master

Is the book really that way? i.e. Full of exposition rather than narrative?

I'm a sci-fi writer myself, finishing up my own novel and purposefully washed out a ton of expository prose for narrative devices to make it more accessible--so I'm curious more than anything. I enjoyed the movie. It was fantastic. Perhaps when I'm done I'll read the novel, too.

Most definitely- it was wonderful in that respect. When Watney is describing using the hydrazine propellant from the lander with the O2 generator to make water, I found myself absentmindedly doodling out chemical formulas on the back of a napkin I had handy before I even fully realized I was doing it. Same thing with the power calculations for consumption of all the equipment, and the capacity and efficiencies of the solar cells.

After watching this film it got me thinking about the Hermes and in particular the revolving part of the ship.

Would the people inside actually be walking on the outside wall of the living area (number 1) because of the rotation, or would they have to walk on the walls (number 2) as force would be then actually be pushing against their feet?

If they walk on the outside walls (2), as they do in this film, and most if not every other sci-fi film, what force would keep them stuck to the wall?

I understand centrifugal force throws mass outwards, but would this work in space?

Please excuse my painting skills, and image isn't to scale. ;;)

Red lines indicate rotation.



Mick.

An excellent question Mick and that schematic is quite good! It's much better than what I could draw.

I guess we can thank 2001: A Space Odyssey for creating the concept of the rotating station and inspiring other films.

Inertia is inertia, be it on a planet or in space. Yes, they would walk on the outside of the walls as in number one. The rotational velocity might not have been perfect in the movie, nor modeling of them accelerating as they go down the ladder tube (or maybe it was I don't recall as I remember them just floating down it)--but yes. I was particularly enthralled with how they did the shadows. That was an amazing effect.

I remember seeing something like this in the fantastic National Geographic Picture Atlas (novel) from the early 80s called "Our Universe."

I believe this was the picture they used in it...



Notice how everything is on the outside wall.

Cheers guys, yeah I was thinking about these big doughnut shaped space stations and always thought that would work, common sense an all that, but...

It wasn't until The Martian that I stopped and gave it some thought. I am just trying to get my head around how centrifugal force works in zero gravity, would it? Would it have any bearing on this?

I am trying to imagine someone in zero-g floating inside one of these and then it starts to rotate, how would inertia take over to keep them pinned to the outside wall and not the side wall coming round to hit them?

Appreciate your reply's,

Mick.

There is a shot exactly like that at the end of Interstellar.

Mick, they'd have to be spinning pretty fast to stand upon wall 2. I think they'd reach the rotational speed to maintain the necessary centrifugal force for the outside walls long before they reach the speed to press them against wall 2. I'm just speculating though.

BTW, did anyone else find that transition between the zero gravity transit and the long laddered tunnels to be a tad dangerous? If the person misses that ladder in the first 10 feet, they're probably going to pick up speed fairly quickly and fall 20+ feet down the tube and through the exterior wall of the craft. Keep in mind that they are "backing" into the tubes so that they are vertical when they encounter the ladder.

Gravity is meaningless. We as Earthlings have a hard time detaching ourselves from a force we are bound to every day. Gravity is only one of the four universal forces--there are others like the weak, strong and electromagnetic. Gravity does not dictate how inertia works in the universe.

You only need to understand Newtonian physics to visualize it.

Force = mass times acceleration
An object in motion remains in motion unless acted upon by another force.

The spinning station works by accelerating you in a circular motion but constantly away from the central axis. You in effect orbit the station in an inertial way. As long as you do not oppose it, you will remain stuck to that wall. You're still in space. If you oppose the acceleration and remain in the air, you are still weightless--until you allow the structure to accelerate you outwards towards that wall.

It is not true "gravity" but it is an inertial substitute.

Yeah--it was a pretty famous painting/picture back in the mid-70s.

I have two questions concerning the "Hermes" as depicted in the film.


Would it even be possible to construct something like the Hermes with our current day technology?


And if it is possible what would be the approximate price tag for such a ship?

We have to build a new space station in order to contruct the Hermes as the ISS is ill equipped but we could build Hermes with current technology but it will run probably be above a trillion dollars.

ISS listed cost is $150 billion. Hermes would probably cost $500 billion or so. That is if built by NASA. If built by private industry, like SpaceX, maybe $75-$100 billion.

The blue force lines would be in effect when the ship is first accelerating the rotation. Once the ship reaches its rotational rate that force would be gone and they would be subjected to the "outward" force of constant rotation.

#2 could only happen when first spinning it up, if it were set to "ludicrous speed!"... and even then only for maybe a minute... and you wouldn't be walking on either wall but slumped in that corner.

But basically once it was spinning, your own intertia would match, and you'd be doing #1.

Personally I think such a ship would likely cost over a trillion now. But by the time we actually build it, costs will have gone up dramatically, and total cost would likely be above 5 trillion.

Keep in mind we don't really have an appropriate propulsion for this.. At least AFAIK. Some have suggested that a Saturn type booster might do the trick for smaller ships to Mars, but for a giant like this... I don't believe we have anything. such propulsions are being developed.

Cosmic and solar radiation may be a huge stumbling block to such travel. Mars offers little protection. And enroute there is no protection other than what we bring with us.