Duality and computation in the MCU

I  took my kindergartener to see Avengers: Endgame recently. My son was a little disappointed, complaining that the film had too much talking and not enough fighting. To me, the immense popularity of the Marvel Cinematic Universe series and so-called science fiction/fantasy in general is an indicator of how people think they like science but really want magic. Popular science-fictiony franchises like MCU and Star Wars are couched in scientism but are often at odds with actual science as practiced today. Arthur C Clarke famously stated in his third law that “Any sufficiently advanced technology is indistinguishable from magic.” A sentiment captured in these films.

Science fiction should extrapolate from current scientific knowledge to the possible. Otherwise, it should just be called fiction. There have been a handful of films that try to do this like 2001: A Space Odyssey or more recently Interstellar and The Martian. I think there is a market for these types of films but they are certainly not as popular as the fantasy films. To be fair, neither Marvel nor Star Wars (both now owned by Disney) market themselves as science fiction as I defined it. They are intended to be mythologies a la Joseph Campbell’s Hero’s Journey. However, they do have a scientific aesthetic with worlds dominated by advanced technology.

Although I find the MCU films not overly compelling, they do bring up two interesting propositions. The first is dualism. The superhero character Ant-Man has a suit that allows him to change size and even shrink to sub-atomic scales, called the quantum realm in the films. (I won’t bother to discuss whether energy is conserved in these near instantaneous size changes, an issue that affects the Hulk as well). The film was advised by physicist Spiros Michalakis and is rife with physics terminology and concepts like quantum entanglement. One crucial concept it completely glosses over is how Ant-man maintains his identity as a person, much less his shape, when he is smaller than an atom. Even if one were to argue that one’s consciousness could be transferred to some set of quantum states at the sub-atomic scale, it would be overwhelmed by quantum fluctuations. The only self-consistent premise of Ant-Man is that the essence or soul if you wish of a person is not material. The MCU takes a definite stand for dualism on the mind-body problem, a sentiment with which I presume the public mostly agrees. 

The second is that magic has immense computational power. In the penultimate Avengers movie, the villain Thanos snaps his fingers while in possession of the complete set of infinity stones and eliminates half of all living things. (Setting aside the issue that Thanos clearly does not understand the the concept of exponential growth. If you are concerned about overpopulation, it is pointless to shrink the population and do nothing else because it will just return to its original size in short time.) What I’d like to know is who or what does the computation to carry out the command. There are at least two hard computational problems that must be solved. The first is to identify all lifeforms.  This is clearly no easy task as we to this day have no precise definition of life. Do viruses get culled by the snap? Do the population of silicon-based lifeforms of Star Trek get halved or is it only biochemical life? What algorithm does the snap use to find all the life forms? Living things on earth range in size from single cells (or viruses if you count them) all the way to 35 metre behemoths, which are comprised of over 10^{23} numbers of atoms. How do the stones know what scales they span in the MCU? Do photosynthetic lifeforms get spared since they don’t use many resources? What about fungi? Is the MCU actually a simulated universe where there is a continually updated census of all life? How accurate is the algorithm? Was it perfect? Did it aim for high specificity (i.e. reduce false positives so you only kill lifeforms and not non lifeforms) or high sensitivity (i.e. reduce false negatives and thus don’t miss any lifeforms). I think it probably favours sensitivity over specificity – who cares if a bunch of ammonia molecules accidentally get killed. The find-all-life problem is made much easier by proposition 1 because if all life were material then the only way to detect them would be to look for multiscale correlations between atoms (or find organic molecules if you only care about biochemical life). If each lifeform has a soul then you can simply search for “soulfulness”. The lifeforms were not erased instantly but only after a brief delay. What was happening over this delay. Is magic propagation limited by the speed of light or some other constraint? Or did the computation take time? In Endgame, the Hulk restores all the Thanos erased lifeforms and Tony Stark then snaps away Thanos and all of his allies. Where were the lifeforms after they were erased? In Heaven? In a soul repository somewhere? Is this one of the Nine Realms of the MCU? How do the stones know who is a Thanos ally? The second computation is to then decide which half to extinguish. The movie seems to imply that the choice was random so where did the randomness come from? Do the infinity stones generate random numbers? Do they rely on quantum fluctuations? Finally, in a world with magic, why is there also science? Why does the universe follow the laws of physics sometimes and magic other times. Is magic a finite resource as in Larry Niven’s The Magic Goes Away. So many questions, so few answers.

Science and the vampire/zombie apocalypse

It seems like every time I turn on the TV, which only occurs when I’m in the exercise room, there is a show that involves either zombies or vampires. From my small sampling, it seems that the more recent incarnations try to invoke scientific explanations for these conditions that involve a viral or parasitic etiology. Popular entertainment reflects societal anxieties; disease and pandemics is to the twenty first century what nuclear war was to the late twentieth. Unfortunately, the addition of science to the zombie or vampire mythology makes for a much less compelling story.

A necessary requirement of good fiction is that it be self-consistent. The rules that govern the world the characters inhabit need to apply uniformly. Bram Stoker’s Dracula was a great story because there were simple rules that governed vampires – they die from exposure to sunlight, stakes to the heart, and silver bullets. They are repelled by garlic and Christian symbols. Most importantly, their thirst for blood was a lifestyle choice, like consuming fine wine, rather than a nutritional requirement. Vampires lived in a world of magic and so their world did not need to obey the laws of physics.

Once you try to make vampirism or zombism a disease and scientifically plausible in our world, you run into a host of troubles. Vampires and zombies need to obey the laws of thermodynamics, which means they need energy to function. This implies that the easiest way to kill one of these creatures is to starve them to death. Given how energetically active vampires are and how little caloric content blood has by volume, since it is mostly water, vampires would need to drink a lot of blood to sustain themselves. All you need to do is to quarantine all humans into secure locations for a few days and all vampires should either starve to death or fall into a dormant state. Vampirism is self-limiting because there would not be enough human hosts to sustain a large population. This is why only small animals can subsist entirely on blood (e.g. vampire bats weight about 40 grams and can drink half their weight in blood). Once, you make vampires biological, it makes no sense why they can only drink blood. What exactly is in blood that they can’t get from eating flesh? Even if they don’t have a digestive system that can handle solid food, they could always put meat into a Vitamix and make a smoothie. Zombies eat all parts of humans so they would need to feed less often than vampires and thus be harder to starve. However, zombies are usually non-intelligent and thus easier to avoid and sequester. It seems like any zombie epidemic could be controlled at very early stages. Additionally, why is it that zombies don’t eat each other? Why do they only like to eat humans?  Why aren’t they hanging around farms and eating livestock and poultry?

Vampires and sometimes zombies also have super-strength without having to bulk up. This means that their muscles are much more efficient. How is this possible? Muscles are pretty similar at the cellular level. Chimpanzees are stronger than humans by weight because they have more fast twitch than slow twitch muscles. There is thus always a trade-off between strength and endurance. In a physically plausible world, humans should always find an edge in combating zombies or vampires. The only way to make a vampire or zombie story viable is to endow them with nonphysical properties. My guess is that we have hit peak vampire/zombie; the next wave of horror shows will feature a more plausible threat – evil AI.

Technology and inference

In my previous post, I gave an example of how fake news could lead to a scenario of no update of posterior probabilities. However, this situation could occur just from the knowledge of technology. When I was a child, fantasy and science fiction movies always had a campy feel because the special effects were unrealistic looking. When Godzilla came out of Tokyo Harbour it looked like little models in a bathtub. The Creature from the Black Lagoon looked like a man in a rubber suit. I think the first science fiction movie that looked astonishing real was Stanley Kubrick’s 1968 masterpiece 2001: A Space Odyssey, which adhered to physics like no others before and only a handful since. The simulation of weightlessness in space was marvelous and to me the ultimate attention to detail was the scene in the rotating space station where a mild curvature in the floor could be perceived. The next groundbreaking moment was the 1993 film Jurassic Park, which truly brought dinosaurs to life. The first scene of a giant sauropod eating from a tree top was astonishing. The distinction between fantasy and reality was forever gone.

The effect of this essentially perfect rendering of anything into a realistic image is that we now have a plausible reason to reject any evidence. Photographic evidence can be completely discounted because the technology exists to create completely fabricated versions. This is equally true of audio tapes and anything your read on the Internet. In Bayesian terms, we now have an internal model or likelihood function that any data could be false. The more cynical you are the closer this constant is to one. Once the likelihood becomes insensitive to data then we are in the same situation as before. Technology alone, in the absence of fake news, could lead to a world where no one ever changes their mind. The irony could be that this will force people to evaluate truth the way they did before such technology existed, which is that you believe people (or machines) that you trust through building relationships over long periods of time.

Fun with zero gravity

Here is the video of the band OK Go filmed on a plane doing parabolic arcs. OK Go is famous for having the most creative videos, which combine Rube Goldberg contraptions with extreme synchronized choreography. The video of Upside Down and Inside Out is a single shot. Each zero gravity arc is about 30 seconds long. The intervening hyper gravity arcs are compressed in the video although it is very hard to detect in the first viewing.