Maxwell’s Material Mind…

One of the great unanswered questions in science is the basis of consciousness, but what about thinking generally? What is the nature of thought and intelligence? There is a long tradition that tells us that thinking is something apart from materialism, that it’s a process or activity that can be best described as an intrusion of the spiritual world into the physical realm. Even if low-level perception and cognition is mechanical, the highest levels of human insight surely lie beyond mere brain wiring to something transcendent.

Interestingly, science can address this question, and the answer is: no. In fact we can show that minds have measurable attributes, and thus must be material. The argument is relatively simple, but it proceeds from the assumption that the laws of thermodynamics are true.

Specifically, the second law of thermodynamics states in part that the total entropy of any isolated thermodynamic system tends to increase over time. It has been well established in the physical, chemical and biological sciences that this law is not only true, but represents a bedrock principle. If it can be shown to be false, then virtually anything we have come to understand about the universe can be shown to be false as well. As Sir Arthur Stanley Eddington said in part in 1927:

[…] if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.

A restatement of the second law is that a system at thermal equilibrium can do no work. If we have a vessel with a hot gas on one side and a cold gas on the other we can place a fan between them and as the gasses mix – the hot rushing into the cold – the fan will spin, doing work. However, if we have a vessel which has a gas at a uniform temperature, the fan will not spin.

We know from statistical mechanics, however, that not all the molecules in the gas are moving at the same rate. Some are moving fast and some are moving slow. Suppose we could use this difference to generate work – that would be a way around the second law. Therefore, if we assume that the second law is true – as we do – then the ways to get around it must be invalid.

Brownian motion is a kind of thermal random motion easily observable under the microscope. Surely we could place our fan into a gas and it would spin with similar thermal motion. It would, but in both directions equally thus doing no work. Suppose, however, that we add a ratchet to the fan so that it will only spin in one direction. Then it would do work, would it not?

Actually, no. As the legendary physicist Richard Feynman demonstrated, the problem is that the ratchet will be of the exact same scale as the fan and will be subject the same random forces. Thus it will operate randomly in the same manner as the fan and there will be no net work. This is good, since violations of the second law show that everything we know is wrong, all things being equal we’d rather that it be right.

But what if the ratchet was under intelligent control? Normally a ratchet requires more force to move one direction than the other. This was the condition that Feynman assumed in his calculations which led him to conclude that the second law could not be violated by a simple mechanical system. But let’s imagine that the ratchet is instead a freely moving axis with a lock. The lock as two positions: open and closed. In the closed position the fan is locked, while in the open position the fan moves without friction. The closed and open positions have neutral entropy – that is whatever change in entropy is the result of going from open to closed is undone by going from closed to open.

Now we have a situation, originally envisioned by James Clerk Maxwell in 1867, in which intelligence could be used to violate the second law of thermodynamics. Someone with the knowledge of the location and momentum of molecules in the gas could decide when to open and close the lock attached to the fan. This “demon” – as Maxwell imagined it – could perform work using just the ambient temperature of the gas. The entropy of the lock itself would average out and the result would be work – the rotation of the fan – despite the uniform and random distribution of gas trajectories. Thus thermal energy plus intelligence equals real work.

Let’s assume, for as we did at the start, that the second law of thermodynamics is sacrosanct. What has to give in this thought experiment? In order for the smart fan not to violate the second law, intelligence itself has to increase entropy. At the most fundamental level, the thinking – the observation and computation – that’s required for the smart ratchet has to equal or exceed the entropy that is diminished by the turning of the fan. Since thinking must affect entropy, this means that thought is material.

This is a huge result. There are many who believe that thinking, understanding and belief itself reside totally outside the physical realm. If that were true, however, it’s not an exaggeration to say that everything we know and can validate scientifically would be false. So if we know anything, we know that thinking, knowledge, and belief are things that have a material basis. Knowing something must have a physical analog that forces it to waste as much entropy as it could possibly generate. This derives simply and logically from the second law of thermodynamics, like night follows day.

- jack*

Comments

[markp]

Great post! I think that maybe your conclusion is off however, because it relies on the assumption that the second law is sacrosanct.

I think it is reasonable to say that immaterial intelligence operating on the material world would give the appearance of violating the second law. The problem is that this kind of intelligence would be (by definition) *outside* of the isolated thermodynamic system required, so it wouldn't actually be violating anything, and the second law could remain intact.

More generally I think it is fascinating to contemplate since it means that if there is *any* kind of realm beyond the material (spirit, mind, god, etc) able to influence the material (body, small objects, weather, etc) then it should also be observable as an apparent violation of the 2nd law.

Unfortunately I can think of no situation in which such effects would be large enough to be measured...

[jack*]

Good points, markp. You could certainly preserve the second law by expanding the thermodynamic system to include the spirit realm, but I don't think most spiritualists would be comfortable with the consequences of that.

First it would mean that the spirit realm has a physics, with a statistical mechanics compatible with the material realm. It's people uncomfortable with the notion that minds can be built of complex interacting parts that retreat to the spirit realm in the first place.

Secondly if the total system still obeys the second law, that means that entropy in the spirit realm is also non-decreasing. I don't think most spiritualists would agree with the idea that heaven is running down.

Of course most religious people will simply declare that God can violate the second law at will. It's only those with a position somewhere in the middle that will find these conclusions troubling.