The difference between humans and computers is just two letters
The movie Blade Runner 2049 is - by far - my absolute favourite sci-fi movie of all time, and this is largely due to the amazing talent of its director Denis Villeneuve (who first studied science before turning towards filmmaking).
The movie is not just visually breathtaking (shout-out to its production designer Dennis Gassner) but also a philosophical treasure trove, impossible to fully comprehend in a single viewing.
I've probably watched it countless times by now and still discover new subtle details, but here I only want to focus on one very short dialogue between the android officer "K" and his virtual companion "Joi".
In this scene, both K and Joi skim through a vast DNA database to locate the missing child of a replicant while the following conversation unfolds:
Joi: Mere data make a man. A and C and T and G. The alphabet of you. All from four symbols. I'm only two, 1 and 0.
K: Half as much but twice as elegant, sweetheart.
The four letters Joi was referring to (A-C-T-G) represent the four nucleotide bases that make up our human DNA. Ordinary computers, on the other hand, use only a two-letter alphabet, 1 and 0 (aka binary). However, do these two additional letters truly mark the fundamental difference between humans and computers?
Like most questions, the answer really depends on your perspective or, as computer scientists would frame it, the level of abstraction.
From an information theory perspective, both humans and computers are primarily information storage systems operating via discrete states, which are represented by symbols (aka "the alphabet of you"). Both humans and computers store information in sequences of these symbols, and both can theoretically encode "any" information, provided that the sequence is long enough.
So, if computers can encode the same information as biological systems using only half the alphabet, is K right in concluding that binary systems are twice as elegant as four-letter biological systems?
Well, yes and no. When looking at the human system as a whole, this wouldn't be a fair comparison because, at higher levels of abstraction, biological systems operate very differently from silicon-based ones.
DNA is not executed in the same way as computer code. Instead, it interacts in a multi-layered biochemical system, which is far too complex to do it justice here. Also, in biological evolution, error tolerance is vital for survival, which is why biological systems come with built-in redundancy and repair mechanisms.
Computers, on the other hand, require exact precision to remain reliable (although error-correcting codes do exist). However, in the realm of electronics, binary is more stable simply because it is more tolerant of noise. Despite requiring longer sequences, it can actually achieve the same level of complexity as four-letter systems, or any number of letters that make up a system (which is amazing).
So in the end, we could rightfully say that a two-letter system is more elegant, not because it requires fewer sequences, but because it requires fewer letters to begin with. In fact, a binary system provides the most minimal sufficient structure to encode any digital information. So yes, K was actually right (in a way).
I hope you enjoyed this brief journey into the science behind the Blade Runner universe. See you in the next post!