The challenge of free will and reality beyond the purely physical

Emergence. This word is used to explain complex phenomena where the behaviour of the full system can not be explained by the behaviour of the parts. Recently, emergence has been helping to explain consciousness and free will.

Reductionism is the classic focus of science. If you explain the behaviour of the parts of the system then you have explained the entire system. The smaller you go, the more fundamental the science you are learning. As science has pushed the boundaries smaller and smaller, we have followed a strange path of simplification. For years, a limited number of atoms arranged neatly in the periodic table was explained in terms of only three “fundamental” particles - the electron, proton, and neutron. Only now are we realising it's a bit more complex. Our worldview has been altered by the discovery of a slew of new “fundamental” particles in high energy particles accelerators. Three "fundamental" particles were joined by 6 quarks (up, down, top, bottom, strange, charm), four force particles (gluon, photon, Z-boson, W-boson), 6 leptons (electron, muon, tau and their corresponding neutrinos), the Higgs boson and whatever we need to explain gravity: the long sought-after “theory of everything!”

But, if we know the “fundamental” laws of the parts of everything, do we really understand everything?

Let’s take an apparently simple situation - foam. Foam is a collection of gas bubbles with liquid between them. At the most fundamental level, every molecule in the foam is in a fluid state - free to move and without a fixed position. However, if you ask whether or not the entire foam acts as solid (holds its shape) or a liquid (takes the shape of its container) - the answer is both - depending on the external conditions. Ultimately, you can not answer the question "is the foam a solid or liquid?" ONLY from information about the state of its smallest pieces. You need information about a larger scale of the foam. This is the heart of emergence and requires science that goes beyond reductionism. It is also the source of Nobel Physicist Phil Anderson’s relatively famous article - More is Different. In physics, we find the product of putting lots of stuff together is not always more of the same stuff but can actually result in very different kinds of physics.

What does this have to do with consciousness? We can pretty much agree that neurons are not conscious - at least the molecules in them are not - but we usually agree that people are. This is basically the same problem as foam being solid when its parts are not! With foam, we have some idea where the solid properties come from - the bubbles get in each other’s way. But there are still major details to work out - which is why I have a job! With consciousness, we are probably even further from understanding the rules at the scale of the brain that makes consciousness possible - but we know it is likely to be an emergent property.

Now, the interesting thing is that emergent properties generally do not depend on the specific matter making up the system. Instead, emergent properties depend on other aspects of the relationships between the parts. So, foam, sand, slurries, pastes and so on all have similar emergent properties - even though the smallest parts are fundamentally different. Foam is made of all fluid elements, sand is solid elements, slurries are both solid and fluid at the fundamental limit. This suggests that consciousness is definitely NOT limited to neurons. It is not the neurons that make us aware of ourselves, but something else about the way they connect and interact. Supposing we had another system with similar connections and interactions, even if made of very different stuff - then it too could be aware of itself. The obvious object to think about are computers that we build. Interestingly, the way they are connected is extremely different from the way our brain is connected - so it will take something very different to make a conscious computer!

What about free will? The ability to make a choice? Free will has additional challenges. A key feature of emergent properties is that they represent new laws that describe physics at a different “scale” but they always arise in a way that the other “fundamental” laws of physics at the smaller scales are not violated. If I return to the example of the foam, for it to hold its shape and act like a solid never requires any individual molecule in the gas bubbles or liquid walls to be anything other than a gas or liquid particle. The shape of the entire foam can be maintained while all the molecules in it are free to move. Likewise, for a system to be “conscious” in the sense that the system is “aware of itself” as an individual, does not require any particular behavior of the individual parts - they can still do their thing.

Free will is more difficult to understand in terms of emergence. At its core, free will is about the ability of a well-defined collection of particles to impact their future state in a way that represents a “true choice” between two outcomes - and not the result of any “decision process” that is the result of the “laws of physics”. Here is the problem - all descriptions of physical reality - whether reductionist and focusing on the smallest objects or emergent and focusing on the behavior of the system - by definition are descriptions that include the set of rules by which different states of the system are connected. In some cases the rules are probabilistic, but there is a still a rule that says a system in state A can change to a system in state B, C, D, etc. and what conditions lead to any particular change, and in cases where the rules are probabilistic, the probability of that change. One can certainly imagine that this set of rules for a person could be very different than the fundamental laws describing the particles making up the system - and designed in such a way that the fundamental laws are never violated by the changes at the system level.

Free will in its strictest form involves a fundamentally different way of viewing how the system changes. It is conceptually the fact that some entities, when evaluating certain actions, have the ability to make an independent decision as to which state to select next that makes free will different. The entity may still have a restricted set of choices - I can not arbitrarily choose to turn lead into gold or to fly - but within that set of choices, there are no set rules governing the choice. It is this absence of any rules that makes free will fundamentally non-physical. The one rule that seems to apply is the condition that the choices do not cause the parts that make up myself or the environment to violate the rules of physics. It is this absence of a “connecting” rule that makes free will fundamentally different from emergent properties.

Now, I fully recognise that central to my definition of free will is the “non-rule” feature - and one can imagine different definitions of free will. But, from a fundamental perspective of “being responsible for my choice” - I do not see how one can make a definition of free will that preserves any sense of responsibility on my part AND has a set of rules that makes it a property of the physical world. For me, it is this challenge of free will that strongly supports the conclusion that if free will is a part of reality, reality extends beyond the purely physical.

生活:生活的概率——有什么机会啊f life occurring on this planet? The standard argument is the chance of life is incredibly rare. Why? Evolution is based on random processes - molecules have to come together just right to form DNA, which has to be just right to form proteins, which has to be lucky and have membranes form around them, etc. At each stage, the probability is very low, and put all these events together - it should never really happen! There is one fundamental problem with this argument - the Earth is not a system at equilibrium and this is not really the right point of view to ask the question. What is the right point of view?

To get to the right point of view, one can first look at the behaviour of fluid molecules in a thin layer of oil in a frying pan. As the oil just sits there in the frying pan, the molecules execute random motion. One never expects the oil to form coherent “convection” rolls. This is a consistent flow of some oil up and then down in a circular fashion that when viewed from above forms a regular pattern - often of stripes or hexagons. The odds to form such regular patterns from random motion are clearly essentially zero.

But, HEAT the pan UNIFORMLY from below, and things change. At a critical temperature difference, the oil is going to form convection rolls in an organized pattern with PROBABILITY ONE! This happens because the relevant laws of physics are not the ones describing the individual oil molecules, but the laws of physics describing the system as a whole - EMERGENT BEHAVIOUR.

生活这是什么意思?好吧,我一锅油s simple enough that we know both the laws for the individual molecules and the laws for the system as a whole - so we can predict the range of heating from below that produces convection rolls. For the Earth, things are sufficiently complicated we barely understand the laws for the parts - nevermind the entire system! But, experiments clearly demonstrate that whatever the laws, the parameters are in the range that gives life - and intelligent life at that! Therefore, there is a range of parameters in which it is very reasonable to declare the probability of getting life to be ONE. So, the real questions are - how wide is that parameter range? And how common in the universe is that parameter range?

We are constantly discovering more and more planets in a similar set of conditions to Earth - therefore, we realise that the probability of life elsewhere is most likely very high. But, there is one other feature of our analogy to oil. We know that, in systems that undergo a change from one state to another (no convection to convection, no life to life), there is a well defined time period for the change to occur - it is not instantaneous. So, just like we know one set of conditions for life to occur - we know the rough time it takes to reach intelligent life. This strongly suggests that other life has not visited Earth yet - so we are all evolving at roughly the same rate!