The Science of Gravity

The first time I watched the film Gravity, I admit I was a bit disappointed - probably because all the hype in the movie critics circle led me to have really astronomical (ahem) expectations for the film. It was the second time I watched without any accompanying expectations that the full impact of Gravity hit me like high speed debris from space. It was one of the most visually arresting movies ever made, and the special effects are near realistic. Go watch Gravity in a good theater with 3D. (I cannot believe I'm saying this, but the 3D actually works in the movie). You'll be dazzled.

The Plot (lots of spoilers):
Rookie astronaut Dr.Ryan Stone (Sandra Bullock) is on a mission to service the Hubble Space Telescope along with her mentor Matt Kowalsky (George Clooney). Meanwhile, a Russian satellite is shot down, creating a cloud of debris that moves at dangerously high velocities. The Space Shuttle is quickly destroyed by the debris, and Dr. Stone has to find a way to return to the planet below. The two protagonists reach the International Space Station, only to find that re-entry is impossible with the Soyuz. The debris which revolves around the earth faster than a speeding bullet returns every 90 minutes to its starting point - an orbital time bomb. Matt dies while in the process of entering the Space Station, leaving Ryan to fend for herself and to find an escape using the Chinese space station Tiangong.

The Good Stuff:
While there are many goof ups in the realism of the movie, it is much more faithful to reality and science than most other sci fi movies. There are a lot of things which the movie got right, and here are a couple of good things I noticed which are based on the truth:

• The Earth. My God, the first shot in which they show the Earth was really beautiful. It was also a nice touch to show things with no particular up and down - it took me a while to realize that we were seeing South America tilted sideways. The first 20 minutes are a single shot, with the camera moving freely and the focus moving back and forth between the characters, the earth and the space shuttle.

• The debris problem is based on a real thing, the cloud moving at high speeds will cause a cascade effect as it destroys more debris which make matters worse. This is called the Kessler's syndrome. Something like this is also the basis for the anime Planetes.

• The stars were accurate! It's not a big thing, but I actually saw real constellations like Scorpio, Orion and Pleaides pass by in the background. (Yes, I'm a big geek I know) Many other movies just make do with a random star background for the night sky (although, the movie fell prey to this during a pivotal scene when Ryan Stone is disconnected from the space shuttle arm and keeps spinning as the camera pans to reveal the center of the Milky Way....and random stars.)
• The space station, shuttle and the Soyuz capsule were captured effectively as well! Check out this video of Sunita William's tour of the ISS in which she shows the Soyuz capsule - the controls and the interiors look recognizably familiar to the ones shown in the movie. There were comments by members from the space program on reddit.com claiming that they got even the right kind of pencils floating around in the ISS! 

There are other good science moments in the movie, both subtle and overt, like:

• Ryan being propelled backward when using the fire extinguisher to put out the flames and hitting herself  
• The flames in damaged electrical parts in the ISS being spherical (just after the "womb" scene when she enters the ISS) as they actually are in space. The station then catches fire, possibly because of those parts. This is an actual concern in the Space Station too.
• The trails from when Tiangong falls to pieces on the Earth's sky hauntingly reminiscent of the Columbia Space Shuttle disaster
• The Soyuz requiring just a single burst to set it in motion and not slowing down after that (since there is no air drag in space and Newton's laws) 
• Matt requiring fuel (which he does not have) to brake his motion when he reaches the space station (Acceleration and deceleration do require bursts)
• Dr. Stone counting the angles so that she can use the fire extinguisher to propel her exactly at the moment she is facing opposite to her target, when she is trying to reach the Chinese space station
• The smoke from electric parts staying stationary and not rising inside the Shenzhou (no gravity), and 
• The overall lack of sound in space.

The Not-so-good Stuff
While its more accurate than many other movies, it does have a bunch of unfortunate goof ups. Since the movie has set itself to a high standard of accuracy, the goof ups are all the more visible when compared to the stuff it got right. That is, if you are making a movie which does not assume a very high standard of realism, like Armageddon or the Avengers, you do not have to worry about getting every detail right, and mistakes which would otherwise have been groan inducing are given a free pass.

Probably the most unforgivable violation of realism also happened during one of the film's pivotal scene. Ryan and Matt are held by tether but Matt asks her to let go for some reason. Matt disconnects and he gently floats away, never to return. That's just wrong! The shot clearly shows that both of them had stopped moving, and Ryan only had to pull the tether a little bit and Matt would move towards her. he wouldn't have drifted away when he disconnected, he would have stayed put. He was such a good character too, watching him die was difficult.

Then there were more goof ups:

• The station hopping thing was very unrealistic. The Hubble, the ISS and Tiangong are in vastly different orbits. Even with the space shuttle it is impossible to travel from Hubble to rendezvous with the ISS. The movie makes an assumption that all the three are in the same orbit, but even then i doubt if Matt's "jet pack" could have let them cross the distance.
• Ryan used a fire extinguisher for propelling herself toward the Chinese station, but if you had done it the way she did, you'd be spinning relentlessly. You'd have to position your burst so that they push you "through" your centre of gravity - that is, the line of action of the force should pass through your CG, which is somewhere in your hip area. The anime Planetes got this right, as it showed people using small thrusters attached to their arms positioned so that they push through your CG.
• Communications would not have gone, the comm satellites occupy a much higher orbit. The debris cloud will expand and enlarge sure, but they will remain largely within orbit. Half of North America sadly would not have lost their Facebook.

There are a lot more things that come into my mind but I'll leave it at that -  a simple Google search will come up with articles by real astronauts discussing the movie. I also think it would be better to keep the criticism to a low sometimes - imagine when an aspiring director comes up with a movie that actually tries to be good and real at least to a certain extent - and people focus on the bad bits, inaccuracies and goof ups and frighten them off every time! That's not going to create any incentive for them to make another good movie!  As the behaviorists would say, there are no positive reinforcements or rewards.

Themes and style:

• The visuals were perhaps the most striking element. The 3D actually works! Oh, already said that. 
• Many people have commented (a friend of mine who watched the movie stoned included) that the scene when she enters into the airlock and curls up into a fetal position invokes the imagery of of the comfort of the womb. There is even a tether she had just used which looks like an umbilical cord! Whether or not this was intentional, it was a great shot -  that was a relief from the relentless action. 
• There were couple of other imagery as well, like when she is inside the Soyuz there is a Russian art piece of Jesus, and when later she enter the Shenzhou, she is greeted by ...the laughing Buddha.  it was a good statement of how in space borders could merge.
• The subtlety of the movie was awesome. Even in the thrill sequences, the movie was good it its subtle details. The most grabbing-the-edge-of-your-seat moment was perhaps the one when she goes for a spacewalk to remove the entangled parachute. Her 90 minute alarm goes off, and she keeps turning to check if the debris had arrived. As we see her trying to get it fixed, we suddenly notice a movement in the background, but its gone. One of the solar panels seem to have moved. Then it happens again, this time more obvious and some other part breaks off, and Ryan does not notice. Slowly, the pieces come and Ryan turns tentatively to meet a horrifying sight - thousands of debris hitting the station to pieces creating one of the best destruction porn I had seen in a movie. 
• The soundtrack was another highlight. Since there are no sounds during the space scenes, the soundtrack had to suggest the sounds like when the debris hits the shuttle and the space station. The music adequately rises and falls - slightly reminiscent of the Hans Zimmer's Joker theme. There's also a particularly striking motif - a rhythmic, pulsating, offbeat and synthesized sound that somehow fits the movie really well. it is particularly obvious during the start and end of this re-entry music theme. The symphonic elements are good too.

The Final Verdict:

The movie is definitely worth your watch, it is probably one of the best experiences I have had in theater. it is also good for the science - there are quite a few goof ups, but you'd have to go all the way to 2001: A Space Odyssey or Contact to find a more accurate movie.

~Cee