Quantum computers, will they lead to skynet?
Could you compute 189274234 x 88982370 in your head? Never mind, you would struggle even given a pen and paper, that’s why we have computers/calculators to do such computations, an average calculator could do it faster than the time one would take to write all the numbers down on a piece of paper. If the devices can compute faster than our minds, can they also think faster than us? Any westworld fans reading this must be reminded of rehoboam. But why is such a thing just scifi and not a reality yet, is it just out of goodwill we don’t want to create such a thing, I doubt so, I personally would bet that if it were possible we would have seen its existence by now. Fortunately its not within the realms of our capabilities to construct such a device. As Roger penrose argued in his famous writeup on the working of minds in the book “The conquerors new mind”, there is something non-deterministic about the nature of reality itself and some part of our thinking itself is non-algorithmic.
Some part of the thinking process being non-algorithmic is a rather disappointing surmise for the AI enthusiasts and some of them would want to strongly disagree on this point since it fundamentally says you could do whatever you want but will never be able to give true intelligence to a machine via the means of algorithms. I would rather stray away from this debate, in fact the statement I want to make here is that there is hope for what the AI enthusiasts want to achieve but its hidden away from the scope of traditional computers.
There is little to debate about the non-deterministic nature of reality itself. This has been established by the widespread adoption of quantum theory by the scientific community, and the theory itself being backed by extraordinary experimental evidence. I would like to clarify that quantum theory in itself is not non-deterministic, it’s a perfectly deterministic theory like any other physical theory governed by equations which determine the state of any system given its initial conditions and the conditions under which it evolves. The infamous weirdness of the theory comes in where it imposes that the state of a system as represented in its equations is given as a superposition of all possible distinct states it can physically be in. Let me break that down for you,
Say you tossed a coin up and want to know whether you get a heads or tails when you catch it back. From common knowledge we know that there is 50% chance of either getting a heads or tails but its only one of them and not both. Say you tossed the coin and caught it back in your hand, but have not opened your fist to check its an heads or tails, the laws of quantum mechanics say that the coin is in a state of superposition of heads or tails, Although it sounds absurd but its not really so if we understand what the superposition means, it means that if we used the equations of quantum mechanics by giving it the initial state of the coin and how the coins state is getting affected, the equations will give us a superposition state at each time which indicates the probability of each distinct outcome(i.e. heads or tails) that the coin could physically be in. This is very much in line with our understanding of the coin toss problem. However the key to grasp here is quantum mechanics equations never predict what the actual outcome is, only give a superposition state which is a sum of all possibilities multiplied with their probabilities. This is the source of the famous schrodinger’s cat problem. Quantum mechanical equations will say that at any point of time there is a probability that the cat is dead or alive, and this superposition of possibilities is maintained till someone actually checks on the cat.
As soon as there is a measurement of the outcome the superposition of the possibilities breaks down and nature assigns a singular outcome to the thing we are trying to measure be it a cat or coin or an electron. The weird and not quite understood part of quantum mechanics is this where the superposition breaks, since each possibility has an assigned probability in the superposition, how is nature deciding which possibility to pick, is someone playing dice to decide on it. This was the question that even puzzled the pioneers and founding fathers of quantum mechanics but we really don’t have an answer to it.
As quantum theory predicts that unless there is a measurement process or someone checking on it all systems are in a state of superposition of existing in different possibilities, could we harness this property to enhance traditional computers in some way?
David Deutsch in his famous lectures on quantum computing, puts forward the approach using the idea of multiple universes, think of the superposition imposed by quantum mechanics as that the system is existing in each possible state in one universe, Anything the system experiencing in one universe will not only impact it in that universe but also in every other universe. This is not a scifi idea but just an intuitive way to look at the workings of quantum mechanics.
One does not need to be a physicist or a computer scientist to know that doing things in parallel will lead to faster results. Often the issues with doing things in parallel is that we could well divide an action in parts and decide to do each of them in parallel, but results from each individual of them will be required in other parts and those parts cannot be done without doing the parts whose results are required, effectively making the parallelizing mundane
The idea put forward by David Deutsch in his lectures is to achieve this parallelism in the quantum realm. by having the parallel processing happen in multiple universes and since happenings in each universe effect the others simultaneously, all actions can be executed simultaneously and the impact of results from one individual part of action on others is taken care by the interference amongst the multiple universes or entanglement of quantum states as its popularly called amongst in the quantum community. By accessing the abilities of the quantum realm we can greatly reduce the number of different steps needed to happen to execute an action.
From the google experiment we know of one computation which takes 10000 years can be done in the quantum realm in few seconds, and this speed up is a result of being able to harness the superposition in quantum systems for parallel processing and exponentially reducing the number of iterations in the computation.
However not every action or a computation problem can be reduced in a way where it can be fed into the multiple universes of the quantum realm to harness its parallel processing power. For the multiplication problem as I asked at the beginning, a traditional computer is the best we can do for it, there is no speed up for such things in the quantum realm.
However what really makes quantum computing interesting is that if we could eventually find a way to run an AI learning algorithm in the quantum realm, say for example a deep learning neural network on a quantum computer, the things the AI would take 100’s of years to learn about, it can process and learn all of it in seconds and keep on learning and evolving more at a much faster rate, will this eventually give it an ability to consciously think? That is if we think conscious thinking ability is an advanced natural algorithm that has evolved over millions of years of evolution, there is no reason to not believe that if a computer fed with a self learning and improving algorithm will develop a consciousness, and a quantum computer is what would make something like this practical.
But if aspects of our intelligence are hidden in the non-deterministic and non-algorithmic parts of nature, I believe these to be arising out of the process where the superposition as imposed by quantum mechanism breaks, since we have no approach to know what possibility the superposition breaks and settles to. If a device could be built of which this process is an inherent feature, would it start to evolve eventually and grow a mind? Is that how we will truly bring an Android into existence?
The answers to these very fundamental and existential questions are at stake on the evolution of the quantum computing. We are not just looking at a faster computer, we are looking at something much more capable, a truly intelligent computer, remember skynet?
