Planet of the Apes (2001) | ||
[XP] | Starring: | Tim Roth, Helena Bonham Carter, Kris Kristofferson, Mark Wahlberg |
Directed by: | Tim Burton | |
Written by: | William Broyles Jr., Lawrence Konner, Mark D. Rosenthal | |
Sit a few million monkeys down at typewriters; give them enough time (say a few hundred million years); and, supposedly, they will eventually write a physics book. Unfortunately, this seems to be the physics book used as a guide for Planet of the Apes. In the opening scenes we fast-forward a couple of decades and are taken inside a Deep Space Ninestyle station orbiting beneath the rings of Saturn. It's an astonishing place, with people walking around inside the roomy spacestation just like they would on Earth. Yet, the station is not rotating. In fact there's no discernable means of creating the artificial gravity. We're evidently supposed to believe that new principles of physics have been discovered which can produce artificial gravity from wishful thinking. The spacestation, of course, includes a major facility for training apes to fly spacepods. After all, humans are just too valuable to risk on dangerous missions, and apparently no one has heard of robots or remote-controlled vehicles. When a mysterious and threatening electromagnetic storm suddenly appears, one of the little fellows dutifully dons his flightsuit, climbs in the nearest pod, and zips off to investigate. When he disappears into the storm, his human trainer, in monkey-see-monkey-do style, jumps in another pod and follows. He runs into a bright light which transports him to a strange planet several hundred years in the future. We know this because the clock in the pod whirls forward so fast we can hardly read the numbers. We thought we were going to be treated to one of those time-lapsestyle recordings of the hero dying, decaying, and turning to dust before our very eyes. Remarkably, however, our hero's biological clock took the time travellicking and kept on ticking at its normal rate. He ages all of thirty seconds. The pod comes streaking across the sky trailing smoke like a meteor and crash-lands in a swamp. It smashes through numerous trees and catches on fire. Our hero would have been fried were it not for the fact that the pod ends up at the bottom of a pond. Fortunately our hero pops the hatch and emerges unharmed. Keep in mind that the pod is an oversized Easter egg with a clear plastic front and a fin on the backnot exactly the vehicle of choice for blazing, tree-smashing, re-entry fun. It's common in movies for swimmers to have impossibly good underwater vision, but this movie takes it to a new depth. The hero returns to the swamp in the dark of night and dives into the murky waters to recover needed objects from his spacepod. In spite of the conditions he has no problems visually identifying underwater objects from several feet away. Chimps on the planet speak perfect English and are at least two times larger than chimps in the spacestation. These talking chimps can jump about twenty feet (six meters) from a standing position while wearing suits of armor. The strength of the chimps would be proportional to the cross-sectional area of their muscles and increase with the square of the scale-up factor. So doubling a chimp's size would increase his strength by a factor of four. Unfortunately, the chimp's weight would have increased with the cube of the scale-up factor. He would now weigh eight times as much. His strength-to-weight ratio would be half its former value. We never see the spacestation chimps jump anywhere close to twenty feet. Doubling a chimp's size and making him wear armor would make such incredible jumps even less likely (see Scaling Problems). The action on the planet consists of an escape attempt complete with the standard amounts of fighting, near captures, and wandering about in search of the spacestation. It seems that the entire spacestation has somehow come down from the sky and landed on the planet within walking distance of the hero. This is some spacestation! Not only can it produce gravity with unknown principles of physics but it can handle the rigors of re-entry without disintegrating and killing all its inhabitants. At one point we're treated to the ultimate sparking-bullet scene. One of the chimps has been locked behind a bulletproof window and tries to blast his way out with a high-powered space pistol . Earlier this pistol was capable of blowing trees in half, yet it can't even mar the surface of the window when fired repeatedly at the same place. However, its projectiles ricochet all over the space confining the chimp. Each ricochet produces a large flash with accompanying sparks. The sparks from one ricochet have not even subsided before several more ricochets occur. It's a veritable indoor fireworks display. The movie may never be a sci-fi classic like its predecessor but the sparking ricochet scene will definitely be one for the annals of bad movie physics. Like the spacestation, the Easter-egg pods are also remarkable. At one point the hero jumps in a pod, fires up its boosters, and flies off the surface of the planet disappearing into outerspace. NASA used a rocket ninety-five feet four inches (twenty-nine meters) long and ten feet (three meters) in diameter just to launch the first American John Glenn into a relatively low Earth orbit. His capsule was about the same size as the pod although certainly not the same shape. True, the Easter egg could have an extremely advanced nuclear energy source, but it would still have a major problem. Rocket engines work by forcing large quantities of hot gasses at very high velocities out the back. According to Newton's third law, the force of the rocket engine pushing the gasses backwards is part of an action-reaction pair of equal-sized forces which act in opposite directions. The other half of the pair is the force from the hot gasses pushing the rocket forward. This is the force which propels the rocket. The size of the force can be calculated using Newton's second Law:
Where m is the mass of the hot gasses and a the acceleration of the hot gasses. Even with a huge supply of energy, nothing is going to happen to a rocket's motion unless it has a lot of mass to push out the back side. On the Earth's surface, air could provide the mass by being sucked in and propelled out, but this would work only for a few miles of space travel before the atmosphere becomes too thin. Ultimately, to overcome gravity and reach outerspace, a launch vehicle has to contain both a large supply of energy and a large supply of mass. However, it gets even more complicated. Since the mass used for propulsion is not instantly consumed it adds to the mass of the vehicle. This in turn requires even more propulsion mass and energy for a launch. In short, the mass of the fuel supply ends up being many times larger than the payload launched into space. Having a huge supply of mass to push out of thrusters is not a major problem for a vehicle designed only for use in outerspace. It can be propelled with relatively small forces since it does not have to overcome the force of gravity. Such a vehicle could not be launched from the Earth's surface with only its own propulsion system. In the movie, controlling the Easter egg on re-entry was a real problem, at least for humans. The movie's hero crashed every time he tried to land. Our little chimp friend has no such problem. He makes a flawless landing after a fiery re-entry. However, this apparent contradiction can be explained by careful observation of the movie. Evidently, when one is jostled about in a turbulent electromagnetic storm and about to go dangerously out of control it's important to rapidly turn banks of toggle switches on and off. Obviously, apes have a clear advantage over humans in this activity. They have twice as many articulated digits, assuming, of course, they don't wear shoes. |