At Scientific American John Horgan interviews physicist George F. R. Ellis. The interview touches on topics in science, philosophy, and religion that may be of interest to readers of this blog. What follows are sections of most interest to me.
Horgan: Lawrence Krauss, in A Universe from Nothing, claims that physics has basically solved the mystery of why there is something rather than nothing. Do you agree?
Ellis: Certainly not. He is presenting untested speculative theories of how things came into existence out of a pre-existing complex of entities, including variational principles, quantum field theory, specific symmetry groups, a bubbling vacuum, all the components of the standard model of particle physics, and so on. He does not explain in what way these entities could have pre-existed the coming into being of the universe, why they should have existed at all, or why they should have had the form they did. And he gives no experimental or observational process whereby we could test these vivid speculations of the supposed universe-generation mechanism. How indeed can you test what existed before the universe existed? You can’t.
Thus what he is presenting is not tested science. It’s a philosophical speculation, which he apparently believes is so compelling he does not have to give any specification of evidence that would confirm it is true. Well, you can’t get any evidence about what existed before space and time came into being. Above all he believes that these mathematically based speculations solve thousand year old philosophical conundrums, without seriously engaging those philosophical issues. The belief that all of reality can be fully comprehended in terms of physics and the equations of physics is a fantasy. As pointed out so well by Eddington in his Gifford lectures, they are partial and incomplete representations of physical, biological, psychological, and social reality.
And above all Krauss does not address why the laws of physics exist, why they have the form they have, or in what kind of manifestation they existed before the universe existed (which he must believe if he believes they brought the universe into existence). Who or what dreamt up symmetry principles, Lagrangians, specific symmetry groups, gauge theories, and so on? He does not begin to answer these questions.
It’s very ironic when he says philosophy is bunk and then himself engages in this kind of attempt at philosophy. It seems that science education should include some basic modules on Plato, Aristotle, Kant, Hume, and the other great philosophers, as well as writings of more recent philosophers such as Tim Maudlin and David Albert.
Horgan: Physicist Sean Carroll has argued that falsifiability is overrated as a criterion for judging whether theories should be taken seriously. Do you agree?
Ellis: This is a major step backwards to before the evidence-based scientific revolution initiated by Galileo and Newton. The basic idea is that our speculative theories, extrapolating into the unknown and into untestable areas from well-tested areas of physics, are so good they have to be true. History proves that is the path to delusion: just because you have a good theory does not prove it is true. The other defence is that there is no other game in town. But there may not be any such game.
Scientists should strongly resist such an attack on the very foundations of its own success. Luckily it is a very small subset of scientists who are making this proposal.
Horgan: Krauss, Stephen Hawking and Neil deGrasse Tyson have been bashing philosophy as a waste of time. Do you agree?
Ellis: If they really believe this they should stop indulging in low-grade philosophy in their own writings. You cannot do physics or cosmology without an assumed philosophical basis. You can choose not to think about that basis: it will still be there as an unexamined foundation of what you do. The fact you are unwilling to examine the philosophical foundations of what you do does not mean those foundations are not there; it just means they are unexamined.
Actually philosophical speculations have led to a great deal of good science. Einstein’s musings on Mach’s principle played a key role in developing general relativity. Einstein’s debate with Bohr and the EPR paper have led to a great of deal of good physics testing the foundations of quantum physics. My own examination of the Copernican principle in cosmology has led to exploration of some great observational tests of spatial homogeneity that have turned an untested philosophical assumption into a testable – and indeed tested – scientific hypothesis. That’s good science.
Horgan: You are a Christian, more specifically a Quaker. Does your faith have any effect on your scientific views, or vice versa?
Ellis: It may affect to some degree the topics I choose to tackle, but it cannot affect the science itself, which has its own logic that must be followed wherever it leads without fear or favour, within the domain of application of the relevant theories.
My philosophical and religious views must of course take present-day science seriously, but in doing so (a) I distinguish very clearly between what is tested or testable science and what is not, (b) I make strenuous efforts to consider what aspects of reality can be comprehended by a strict scientific approach, and what lie outside the limits of mathematically based efforts to encapsulate aspects of the nature of what exists.
Many key aspects of life (such as ethics: what is good and what is bad, and aesthetics: what is beautiful and what is ugly) lie outside the domain of scientific inquiry (science can tell you what kind of circumstances will lead to the extinction of polar bears, or indeed of humanity; it has nothing whatever to say about whether this would be good or bad, that is not a scientific question).
Attempts to explain values in terms of neuroscience or evolutionary theory in fact have nothing whatever to say about what is good or bad. That is a philosophical or religious question (scientists trying to explain ethics from these kinds of approaches always surreptitiously introduce some unexamined concept of what is a good life by the back door). And they cannot for example tell you, from a scientific basis, what should be done about Israel or Syria today. That effort would be a category mistake.
Horgan: In some of your writings, you warn against excessive determinism in physics, and science. Could you summarize your concerns?
Many scientists are strong reductionists who believe that physics alone determines outcomes in the real world, This is demonstrably untrue – for example the computer on which I am writing this could not possibly have come into being through the agency of physics alone.
The issue is that these scientists are focusing on some strands in the web of causation that actually exist, and ignoring others that are demonstrably there – such as ideas in our minds, or algorithms embodied in computer programs. These demonstrably act in a top-down way to cause physical effects in the real world. All these processes and actual outcomes are contextually dependent, and this allows the effectiveness of processes such as adaptive selection that are the key to the emergence of genuine complexity.
Horgan: Einstein, in the following quote, seemed to doubt free will: “If the moon, in the act of completing its eternal way around the Earth, were gifted with self-consciousness, it would feel thoroughly convinced that it was traveling its way of its own accord…. So would a Being, endowed with higher insight and more perfect intelligence, watching man and his doings, smile about man’s illusion that he was acting according to his own free will.” Do you believe in free will?
Ellis: Yes. Einstein is perpetuating the belief that all causation is bottom up. This simply is not the case, as I can demonstrate with many examples from sociology, neuroscience, physiology, epigenetics, engineering, and physics. Furthermore if Einstein did not have free will in some meaningful sense, then he could not have been responsible for the theory of relativity – it would have been a product of lower level processes but not of an intelligent mind choosing between possible options.
I find it very hard to believe this to be the case – indeed it does not seem to make any sense. Physicists should pay attention to Aristotle’s four forms of causation – if they have the free will to decide what they are doing. If they don’t, then why waste time talking to them? They are then not responsible for what they say.