Is the quantum computing in ‘Devs’ really possible?

A history of determinism

The hypothesis that we can predict the future through information is actually not as modern as it might sound. For millennia, philosophers have been speculating about the universal relationship between cause and effect, and which (if either) exists at the service of the other. Does cause always precede effect? Or does the ‘potentiality’ of any substance already exist in its ‘actuality’, as Aristotle would have it? And, if so, is this knowledge accessible? The show itself references the rich history of the problem it taps into in episode 7, when physicist Stewart quotes French scholar Pierre-Simon Laplace. The quote is lengthy, and unattributed.

We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at any given moment knew all of the forces that animate nature and the mutual positions of the beings that compose it, if this intellect were vast enough to submit the data to analysis, could condense into a single formula the movement of the greatest bodies of the universe and that of the lightest atom; for such an intellect nothing could be uncertain and the future, just like the past, would be present before its eyes.

Though this sounds like the cutting edge of scientific thought, only rendered possible through the development of quantum mechanics throughout the 20^th century, Laplace wrote the idea down in 1814.

The omniscient intelligence that Laplace imagines, which has come to be called ‘Laplace’s demon’, was probably conceptualised in his age of Enlightenment not as a demon, but as God. Religion has posited since time immemorial that our future is known and determined by a higher being. Whether the knowledge is held by God, an advanced civilisation as per the holographic principle, or by a machine as in Devs, humanity have always wanted to know whether we truly have free will. If Laplace or Forest are correct, and all of the information about our past and future is already stored in the quantum energy of the universe, then we do not. And the future can be known.

Is Forest’s machine possible?

There are two predominant theories in quantum physics that assume the complete determinism of the universe and they’re both mentioned in the show: The De Broglie-Bohm or ‘pilot wave’ theory, and the Many Worlds Interpretation. The logic of the first theory is used in the parable of the pen: there is one set course for history, and it can be ascertained through quantum information. The Many Worlds theory, however, states that every time a ‘decision’ is made at a particle level, time branches into separate realities whereby every possibility is realised, creating possibly infinite different universes. You might recognise this theory from such classics as Spiderman: Into the Spider-Verse.

Whilst Forest’s team initially works under the premise that the pilot wave theory is correct, it turns out that the equation for Many Worlds holds the key to making the quantum computer run. If either turns out to be true in reality, however, Dev’s proposition that we could peer into our future potentially still holds.

These two theories of determinism are by no means fringe in the scientific community. They have a pretty hefty backing by a large number of modern physicists, and they’re gaining clout over time as scientists increasingly reject the Copenhagen interpretation.

However, just because the quantum theory bears up, doesn’t mean that Forest’s machine is possible.

As computer scientist Dr. Scott Aaronson points out in an interview about the show, a computer or algorithm of any kind, quantum or no, can only output information equivalent to the data it receives. In order for it to make calculations regarding everything that ever will be, it has to know the current and past situation of everything that ever was.

‘I doubt that reconstructing the remote past is really a ‘computational problem’ at all, in the sense that even the most powerful science-fiction supercomputer still couldn’t give you reliable answers if it lacked the appropriate input data,’ Aaronson says, adding ‘As far as we know today, the best that any computer (classical or quantum) could possibly do, even in principle, with any data we could possibly collect, is to forecast a range of possible futures, and a range of possible pasts.’

‘The data that it would need to declare one of them the ‘real’ future or the ‘real’ past simply wouldn’t be accessible to humankind, but rather would be lost in microscopic puffs of air, radiation flying away from the earth into space, etc.’

In other words, in order to predict the trajectory of a pen exactly, you’re going to need to know quite literally everything about the circumstances that made it roll in the way it did. The microscopic fluctuations of the dust motes around it, which in turn are affected by the weather in the local area, which in turn in affected by the position of the moon and on it goes. It’s an impossible amount of data.

So, in order to build a quantum computer like the one in Devs, Google or IBM would have to not only harness quantum energy but come up with a completely new and unprecedented system of information gathering that exceeds anything we have now by a silly order of magnitude.  It’s probably (and thankfully) not likely that any Musk type tech billionaires are going to be elevated to complete clairvoyance anytime soon.

What, then, can we expect from the first quantum computers inevitably heading our way?

A more likely quantum future

Well, the main selling point of quantum computing as we understand it is its ability to dwarf our current processing capabilities. Imagine the most powerful computer you could possibly build, then build a trillion identical copies each operating in parallel dimensions. This is the promise of quantum computers: they utilise principles of probability to perform an incomprehensible amount of equations simultaneously.

The most immediate implications this would have for society are in the fields of medicine, trading, and AI. The basic principle of AI is that the more feedback you give a computer program, the more accurate it becomes. With quantum computing, the ‘trial and error’ learning curve needed to push AIs into the Westworld model of sentience and comprehension will be significantly reduced. Quantum algorithms will be able to speed up language processing capabilities, enabling AI to understand human communication more robustly.

When you think about it, pretty much all areas of technological development – disease research, weather prediction, even election polling – are based on algorithms and data. A quantum computer could deal with all of this information in a fraction of a second and use it to make predictions just as fast. Whilst we may not be able to feed such a device atomic information on the entire history of the universe, we can input the history of the US stock market, results of drug trials, or current renewable energy modelling.

We would be able to use this information to determine an ideal ‘model’ for society – using student data and learning statistics to produce personalised curriculum, predicting job market growth and demand for skilled and knowledgeable workers with precision, and accurately predicting social indicators like income inequality to advise legislators.

Google has already made some headway in this with their 53-qubit quantum prototype (for reference, when a character asks Forest how many qubits his computer can process, he responds ‘a number that seems meaningless to put into words’, so Google has a way to go yet). Researchers performed a trial early in 2019, where they reportedly asked their computer to solve a calculation proving the randomness of numbers produced by a random number generator that would have taken the world’s fastest traditional computer, Summit, around 10,000 years to process. The quantum computer came up with an accurate proof in 3 minutes and 20 seconds.

Essentially, the result of quantum computers will be knowledge on an unprecedented scale. The most exciting applications of quantum computing are almost certainly things which we cannot yet conceive. Whilst it’s not possible now to create Forest’s vision of a complete all-knowing machine, knowledge and technological production tends to trend upwards exponentially. Unlocking the quantum realm will, in turn, give us far more questions to answer, and produce more keys to doors that we didn’t know existed. Maybe, behind one of these doors, it will be possible to predict the future.

For now, all we can do hope is that whomever finally commercialises the power of the quantum computer will do so at the service of humanity, not their bottom line.