Meeting Sir Roger Penrose in Brussels at the Vrije Universiteit Brussel (2009)
What is reality? That is the root question Roger Penrose ponders over in his book The Road to Reality from 2004. Can Penrose’s mathematical view of reality shed a new light on the discussion about science and religion?
The road to reality
Sir Roger Penrose (°1931) is a British mathematician and physicist who is mainly known for his pioneering work in the field of cosmology and the theory of relativity, collaborating with Stephen Hawking. [1] In The Road to Reality, over 1,100 pages long, Penrose comprehensively covers a broad range of subjects from contemporary physics, from the standard model of particle physics, the general theory of relativity, quantum mechanics and the big bang theory to his own approach, twistor theory, to arrive eventually at the question ‘What is reality?’.
The leitmotif
The leitmotif in Penrose’s view is his realization that everything in physical reality seems to correspond to very strict mathematical principles, with a precision that surpasses any imagination. [2] The most spectacular example Penrose gives us is PSR B1913+16, two very compact neutron stars in orbit around one another. Extremely accurate measurements of their gradually contracting orbit (through the emission of gravitational waves) has led to a correspondence between observation and the predicted value from the general theory of relativity to an astounding precision of 14 decimals. [3]
A deep mystery
Why there is such an unimaginably precise correspondence between physical reality and very sophisticated mathematical models is a deep mystery for Penrose for which he doesn’t have an answer. But the idea that mathematics would be a kind of mental net we cast over reality to order our experiences seems extremely unlikely to Penrose in the light of these discoveries. [4] Identifying physical reality with an abstract, platonic reality of mathematical forms is a bridge too far for Penrose. But “the more deeply we probe Nature’s secrets, the more profoundly we are driven into Plato’s world of mathematical ideals”. [5]
And God?
What do all these reflections from The Road to Reality have to do with the subject ‘science and religion’? At first sight: nothing. Save for one single exception Penrose never refers to God in this bulky work. [6] But precisely this fact sheds a surprising light on this theme. The mere fact that one of the most renowned scientists of our time has succeeded in writing a work of this size about the current view of realitywithout spending as little as one sentence of attention to this theme says quite a deal. You will have a hard time trying to find reflections about God, science and religion in the numerous books, articles and interviews of Roger Penrose. Even when asked about them explicitly, his answers remain very parsimonious. During an interview in 2005 he was asked whether his scientific work had had any influence on his belief in God, to which Penrose replied:
“God is a somewhat ill-defined concept and I very definitely do not believe in the traditional idea of God as shared by most people […] Science may have its limits, but if you want to know what is true in the world, you must rely on a scientific method. You can also go searching for truth in old books. Perhaps those old books have something important to say, but their writers did not necessarily have the knowledge offered by current science.” [7]
Science and ‘ultimate reality’
Roger Penrose is open to mystery, but in another way than one is possibly used to in religious circles. In Penrose’s work you will look in vain for philosophical or theological discussions about ‘ultimate reality’. No carefully wrought analyses of arguments and counterarguments of philosophers and theologians about what they might have to think of his view. Penrose nowhere explicitly denies the existence of God. But it’s simply not a question he is concerned about, the existence of God is not required in his worldview. When asked about it, he might perhaps answer, like in former times Pierre-Simon de Laplace, that he doesn’t need the hypothesis ‘God’. [8]
Continental drift
No matter how much some philosophers and theologians may agitate about a view like that from Penrose, the crucial difference is that Penrose himself does not delve into questions like these at all. Instead of collisions of worldviews (e.g. between naturalistic and theistic approaches to reality) we observe a “continental drift”. The world of modern science and that of traditional philosophy and theology (this last one very often still in an Aristotelian frame of reference) are slowly but certainly drifting apart. Religiously inspired explanations of reality are not refuted, but vanish slowly into the shadows. The question is not so much whether or not God exists. God may very well exist, if you would like. But rather: does the universe need God? That turns out to be less and less the case. [9]
Notes
This blog post was originally posted on July 25, 2015 at:
[1] See e.g. Stephen Hawking & Roger Penrose, The Nature of Space and Time, Princeton, Princeton University Press, 1996.
[2] For instance, the experimentally measured value of the magnetic moment of an electron corresponds with the theoretically predicted value to a precision of 11 decimals. Richard Feyman compared this to measuring the distance of New York to Los Angeles to the accuracy of the thickness of a human hair (in QED. The Strange Theory of Light and Matter, Princeton, Princeton University Press, 1985 (repr. 2006), p. 7).
[3] To give an idea what that means: 1 to 1014, that is ten million times more accurate than the precision of Newton’s theory of gravity in the description of the movements of the celestial bodies in our solar system (“only” 1 to 107). For this discovery, Joe Taylor and Russell Hulse received the Nobel Prize for physics in 1993.
[4] Roger Penrose, The Road to Reality. A Complete Guide to the Laws of the Universe, London, Jonathan Cape, 2004, p. 1027.
[5] Roger Penrose, ibid., p. 1028-1029.
[6] Roger Penrose, ibid., p. 754, where he uses the expression ‘act of God’ in a rather rethorical question about the precise initial conditions at the beginning of our universe, at the moment of the big bang.
[7] Bram Delen & Wim Gemoets, Penrose: schaken, computers en wc-papier, inVeto, year 31, number 13, 14 Februari 2005, p. 7 (in Dutch, my translation).
[8] Cfr. the famous statement of Laplace, when Napoleon asked him why his book about celestial mechanics contained no mention of the name of God: “Sire, I had no need of that hypothesis.”
[9] Originally published in Dutch in Geloof & Wetenschap, May 2015, http://www.geloofenwetenschap.nl/index.php/opinie/item/603-roger-penrose-wiskunde-werkelijkheid-en-god.html
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