Predicting the Future: A Thought Experiment

Is it theoretically possible to build a machine powerful enough to predict the future? And how precisely can we do it? Let’s discuss.

Origin of Discussion

It was a few months back when I was having a discussion with my friends at University at 3 AM at night. We frequently indulge in these kinds of discussions on varying topics and it’s usually fun because of a strong disagreement on the opposite side. Getting to the point I proposed that:

Theoretically, we can build a machine, powerful enough such that if we input the complete details of the world at a time, information of each and every particle in it, where it is and what it’s attributes are like velocity and acceleration with precision, we can predict how the world will look in the very next instance.

Now my friend disagreed. He said that the world is filled with so much randomness/noise that it is impossible to predict the state of the world the next instance no matter how powerful the machine is.

I reminded him that the machine we are building can take this into account because truly there is no randomness possible in the world. Now some of you might disagree with me here. I am no physicist myself. But here is my line of thought for you, “how can you inject randomness in the universe?”. I did some digging around and results were very interesting.

Disclaimer: This isn’t a completely scientific thought experiment or study, however I have tried to take in account most of the available scientific information or facts as possible.

our theoretical machine

Is randomness deterministic?

The question now narrows down to this: “Does randomness emerges from our lack of knowledge or behavior of the universe is truly random?”

If the answer is later, i.e. the universe is actually random then even theoretically we can not build the machine because we will never know how a particle will behave the very next instance no matter how much information we have about the particle and the surround it interacts with. But as I come to know about it, we are far from the answer and the debate is still on.

Is noise or randomness truly random or it’s just that we can’t comprehend it as of now?

Our current understanding of Quantum Mechanics

In order for our machine to work, we will need to input the information of every particle: atomic or subatomic. To deal with these particles we need Quantum Mechanics. But the problem is according to our current understanding of QM theory, “even knowing perfectly the state of a system at a given time, we cannot predict the state of the system at a future time.”

But why you may ask? Here is an informational excerpt from Wikipedia:

Because As per its mathematical formulation, quantum mechanics is non-deterministic, meaning that it generally does not predict the outcome of any measurement with certainty. Instead, it indicates what the probabilities of the outcomes are, with the indeterminism of observable quantities constrained by the uncertainty principle. The question arises whether there might be some deeper reality hidden beneath quantum mechanics, to be described by a more fundamental theory that can always predict the outcome of each measurement with certainty: if the exact properties of every subatomic particle were known the entire system could be modeled exactly using deterministic physics similar to classical physics.

In simple terms, we have two fractions of Physicists:

1. The first fraction believes that quantum mechanics is an incomplete description of nature. There are so-called “hidden” variables that QM theory doesn't take into account and it depends on the level of the physical description of the model under study. Here is an example to understand it: “if a gas is described in terms of temperature, pressure, and volume, then the velocities of the individual atoms in the gas would be hidden variables”. It is because we are observing the model on a more abstract level and missing the underlying variable like velocity which is responsible for how the gas acts. When we don’t realize we are missing this hidden variable, the flow or the action of gas appears to us as “random”.
2. The other fraction believes that there is no deeper deterministic reality in quantum mechanics. There is no hidden variable that we are not taking into account.

God does not play dice

This is a famous quote from Albert Einstein who spent many years of his life looking for a fundamental deterministic theory called — the hidden-variables theory. A theory that takes into account all the hidden variables and hence can predict everything with precision eliminating probability or randomness as we know it.

But we later learned about Bell’s theorem, which implies that local hidden variables don't exist and hence that there is no more fundamental theory that “explains away” the non-determinism of QM. However, it does not rule out the existence of non-local hidden variable theories — the most famous of which is Bohm’s interpretation.

So after this brief study, I decided I will go with the former fraction and believe that we can understand as well as predict the so-called “randomness”, we just need a better perspective for observation and access to the non-local hidden variables that can account for the randomness.

Now that our theoretical machine has the following inputs:

1. The current state of the universe, with precision. I am saying precision because as we discussed that once we have access to the non-local hidden variables, we can with precision know the current attributes like position or velocity or mass of a subatomic or atomic particle.
2. All the rules which govern the material interaction.
3. The time we want to know the state of the world from now.

Voila! we have an output. The future state of the universe developed from a purely mathematical model. But is it actually possible? I think it is. Well theoretically only for now. Building such a powerful machine that can do that level of calculations is another problem. Along with it, we will have to wait until the next breakthrough occurs and someone sheds some light on those hidden variables and that theory, maybe, will help us understand the world from a new perspective or dimension.

Remember these are just my thoughts and not a scientific study so there is a chance that some errors or wrong attributions may have crept in. Let me know if you find any. This is my twitter. You are also invited to join my newsletter here.

What are your thoughts on it?