Katie and I saw WALL-E 1.4 times over the weekend. (We had it from Netflix on Saturday, and then on Sunday we were babysitting a child who wanted to see the first forty minutes of it before bedtime.)It's a really great movie, and well worth seeing even for those without kids. I must admit to one small area where I was unable to suspend my disbelief, however. The premise of the movie is that humans have destroyed earth and have established a colony on a massive spaceship in the outer solar system. The colony thrives for over 700 years in resort-style luxury, but they grow soft and fat because their bones disintegrate in the microgravity of outer space.
Given the technological wonder that is the spacecraft and all the amazing things it is shown to be capable of, why can't the ship be piloted in a large circle? That could provide a downward acceleration of 9.8 meters per second squared and thus mimic gravity of the earth. I just don't get it.
You believe a robot has emotions but can't believe that the physics in this heightened reality might just be a little bit different? That definitely make me "lol". I hate realism rants, it totally misses the point of movies.
ReplyDeleteI do agree, but your so-called "realism rants" are fun! I allow myself such rants when the quibble is clearly outside the premise of the movie. The premise here is that humans destroy the planet, emotional robots are everywhere, etc. I accept all of those, since they are necessary to enjoy the story of the movie. The premise of the movie implies that all action takes place in our solar system, though. Is it unreasonable, then, to expect that the normal laws of physics would apply?
ReplyDeleteI haven't seen this movie yet - it is high on my list, though - but my impression was that the people living in this spaceship were lazy. And how better to be lazy than living in zero-g?
ReplyDeleteAlso, most sf books that don't have "magic gravity" in their ships use large cylindrical vessels so that you can spin them, which is perhaps easier and more energy efficient to do than continually piloting in a circle. Though if they have total technological power, maybe piloting in a circle is easy too.
What marcus said: you don't want to expend fuel going in circles (which you will need to do unless you're in orbit around something). Much better to have a continuous rotation, which should have no energy cost in a frictionless space without other interfering forces.
ReplyDeleteAndrea was bugged by the inconsistency of the fire extinguisher propulsion system.
To follow up on Jan's comment: if you're orbiting something, then you're in free-fall anyway, and therefore "weightless".
ReplyDeleteSpinning cylinders have their disadvantages too, though, because of angular momentum conservation. If your entire ship is a giant gyroscope, it'd be quite difficult to steer. Even if only a fraction of the mass is spinning, changing the ship's direction would really do a number on the low-friction bearings.
(Marcus, do any sf schemes use counter-rotating cylinders so that net angular momentum is zero?)
Yes, I should have added that it seemed that they had unlimited energy. They wasted it in several places with reckless abandon. They hinted at an impressive ability to harness solar power. So piloting in circles should be easy, given how aware they were of the problems of bone density loss.
ReplyDeleteWhat was the inconsistency of the fire extinguisher propulsion system? That seemed feasible to me.
ReplyDeleteI don't get the piloting in a circle bit replicating Earth's gravity. I clearly did not learn enough physics. The decrease of force on bone induces osteoporosis, similar to that seen in astronauts. Calcium/D supplements and strapping people to treadmills (thus forcing them to run due to the physical length of their legs and inducing tensile force on bone), decreases the osteoporotic proclivity. I don't see the need for changing the course of the ship...
ReplyDelete