Preview: "Top-Down Cosmology and Model-Dependent Realism. A Philosophical Study of the Cosmology of Stephen Hawking and Thomas Hertog"

Doctor in philosophy and moral sciences (VUB).

Title of my dissertation: Top-Down Cosmology and Model-Dependent Realism. A Philosophical Study of the Cosmology of Stephen Hawking and Thomas Hertog, Uitgeverij VUBPRESS Brussels University Press, 2021.

dr.. Alexander François van Biezen

Supervisor: prof. dr. Gustaaf C. Cornelis.

Popular-scientific abstract

Within the domain of history and philosophy of cosmology, I investigated the cosmological work of Stephen Hawking — the famous British scientist in a wheelchair — and Thomas Hertog — his Flemish disciple — between 2006 and 2018. In 2006, Hawking and Hertog put forward a new framework called top-down cosmology. This approach starts from the present (“at the top”), with the properties of the universe as we can observe it today, and works its way back to the past (“down to the bottom”). This framework views the origin of the universe as all possible histories layered on top of each other. The universe did not have a single, unique beginning. Instead, it began in about every possible way.

What makes top-down cosmology stand out, compared to many other competing approaches, is Hawking’s attempt to scaffold his cosmological work by means of his philosophy of model-dependent realism. Scientific realism holds that our best scientific theories are approximately true and that the unobservable objects they refer to really exist. Hawking claims it is meaningless to ask whether a theory is real, only whether it agrees with observation. When two competing, even mutually incompatible, theories agree with observation, it is impossible to say one is more real than the other. From a philosophical point of view, model-dependent realism is seriously flawed, because it is insufficiently worked out with regard to modern model theory and self-refuting as a philosophical claim (as Hawking dismissed philosophy altogether). However, from a cosmological point of view, it gave Hawking and Hertog a practically unconstrained liberty to play with concepts and tools of different branches of physics needed to construct their cosmological models.

            To find out whether model-dependent realism is just a brazen and failed attempt at philosophising or a brilliant strategic move with solving a fundamental cosmological problem in mind, I examined the relationship between top-down cosmology and model-dependent realism from different angles. I have come to the conclusion that, when viewed from a broader perspective, Hawking’s and Hertog’s approach in cosmology is indicative for a gradually changing attitude within the scientific community of fundamental physics and cosmology about what counts as “the scientific method”. Traditionally, a theory was regarded as scientific when it made predictions which could be falsified through experiment or observation. However, recent decades gave rise to physical theories like string theory whose predictions lie way beyond the reach of what is currently technically possible. Top-down cosmology fits in with this growing trend of a more lenient view towards falsifiability of a theory and a stronger focus on the conceptual characteristics of a theory (like simplicity, elegance, range, internal and external consistency) to evaluate its viability.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Science and Religion: Coming Out of the Trenches

For many people today, saying that science and religion are in conflict is knocking on an open door. However true this may be, simply stating a problem doesn't solve it. It doesn't suffice to mark this conclusion – science and religion are in conflict – as a mere end point in some logical chain of reasoning and then just leave it at that. What is far more intriguing and fascinating is the question: where do we go from here? How can we move beyond the conflict?

Not a fruitful starting point

           Simply stating that science and religion are in conflict is not a very fruitful starting point for a dialogue on the relationship between science and religion. Far more interesting is the concrete observation that some specific religious beliefs can be in conflict with some specific scientific beliefs and the ensuing question what to do if a concrete, specific conflict arises.

Science and religion as two different language games

            Science and religion each have their own specific discourse and operate within their own domain. Only science is entitled to cognitive claims about physical reality. As far as science is concerned, religion is purely epiphenomenal. Science gives us knowledge about physical reality, science and the growth of knowledge consist of finding good explanations (David Deutsch).[1]

           Religion - at least as seen from this individual, cognitive perspective (because religion is far more than that) - pertains to personal perception and an emotional attitude towards reality, it doesn’t add any knowledge about reality. Referring to a famous concept of the philosopher Ludwig Wittgenstein, we could say that science and religion are two different language games which only show some resemblances at the surface. Science and religion are not on the same level, because they are fundamentally different. Conflicts between science and religion are prone to occur only when one tries to put science and religion at the same level as alternative explanations of reality. Whenever a religion claims to be a separate, alternative source of knowledge about the world in its own right, it runs the risk of coming into conflict with science.

A meaningless trench war

            However, I do fill very ill at ease with those who merely content themselves with defiantly pronouncing the bankruptcy of religion as a legitimate explanation of reality, only to throw the baby out with the bath water. I dislike the fervour with which some seem to like to indulge themselves in a meaningless trench war between science and religion, as if ‘science’ and ‘religion’ would be two monolithic blocks, facing each other in an apocalyptic battle – which they are not.

        As a philosopher and a theologian, I am far more interested in examining how religions evolve and transform under the external influence of major scientific developments. Throughout history, we have witnessed that religions react and adapt to their environment, even if only partially and with a certain time lag. This becomes even clearer when we focus on religion as it is experienced as a lived religion by its members in contrast with religion as an official doctrine. Whenever there is a major shift in society which deeply influences its overall worldview – the emergence of the modern natural sciences, the eventual break-through of the Enlightenment, just to name a few - members of religious groups do not remain “untouched” by these changes and will somehow adapt in the way they experience and live their religion.

          Undoubtedly, the profound discoveries in twentieth- and twenty-first-century science and the ensuing changes in the overall scientific worldview will have a significant influence on the way traditional religions will cope with their own traditions of religious explanations of reality dating back to a pre-scientific era. However, as numerous times in the past, rather than simply succumbing to the dominant scientific worldview of the twenty-first century, it may be expected that religions will – each in their own way – try to “survive” so to speak and come to grips with diminishing the cognitive dissonance between their inherited explanatory tradition and the newly emerging secular worldview.

Scientific knowledge and what it means to us as a human being

            Knowledge about the universe is one thing, trying to come to grips with how to respond to this new knowledge as a human being, trying to figure out what this new knowledge means for us as human beings, is quite another. For us, as human beings, objective knowledge about the universe is not something insular, something disconnected from the rest of what makes up our Lebenswelt. It is an integral part of our human world where you also have art, poetry, music, philosophy, and, yes, theology: activities which all say and contribute something about what it means to be human. 

The Snowflake Generation

        Today’s society witnesses a growing, worrisome tendency of polarisation, of groups of people turning in on themselves in the absolute conviction that they are right. The unwillingness to accept that there are groups of people with whom you disagree at a fundamental level because, for instance, you do not share their faith, is growing by the day. Instead of welcoming and celebrating this kaleidoscopic difference, as a basis for living together, we see an ever-increasing sensitivity for being “offended” by other views of the world, forms of life, ways of living. Even when they are only apparent in absolutely trivial, purely cultural details as styles of clothing or ways of greeting. A sensitivity which is sometimes coined as “the Snowflake Generation”.

Out of the trenches

            If you want to find out about the fabric of reality, if your aim is to arrive at objective knowledge and good explanations about the universe, then you will have to rely on science and scientific methods. But how you respond to this scientific knowledge as a human being is something else. Just like this response can be a piece of art, or a poem, or a philosophical or theological reflection, it can also constitute a feeling of religious belonging. There is no reason whatsoever for science and religion to dig in their heels in the trenches. Religions can keep on cherishing their age-old traditions, their elaborate rituals, their meticulously transmitted sacred texts, drawing from their deeply symbolic and historic value, as a response to our need to feel at home in our world, as a precious cultural heritage and a source of personal spirituality and identity. But when it comes to factual truth claims about the world, it is to science they should turn.       

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[1] Deutsch, D., The Beginning of Infinity. Explanations that Transform The World, London, Penguin Books Ltd., Kindle Edition, 2011, p. 120.

Science and religion: where the shoe pinches

"How would the universe look like according to you if it was not created by God?” We address this question to a religious theist. His surprising reply leads to a very interesting train of thought.

A universe without God

According to its own colophon, ForumC is a Dutch Christian forum for religion, science and society, aiming at "connecting the Christian faith with the big questions that arise within science and society". One of its initiatives is the Dutch website Geloof en wetenschap (= ‘Religion and science’) [1], offering news, opinions, background information and personal stories about the relation between science and religion.

Some time ago, in a discussion following my opinion piece A Case for Naturalism on this Dutch internet forum [2], I raised the question: “How would the universe look like according to you if it was not created by God but originated in a completely natural way?” [3] The reply I received was very instructive as to the point I want to raise:

“Huh? Why do you think this question is actually answerable at all for a theist? If the universe would not have been created by God, then it wouldn’t exist. This question sounds like: “You are now listening to a splendid performance of Schubert. Now, just imagine that the singer you hear singing does not exist: in which way would this song you now hear be ‘different’? Such a question is grammatically correct, but utterly absurd.” [4]

Conflict between worldviews

Why is this reply so instructive? Because it is indicative for a crucial and irreconcilable divide in the ‘science and religion’ debate. What is a bona fide scientific hypothesis from the perspective of the atheist naturalist,  is brushed aside by the religious theist as an illegitimate, ill-defined question – grammatically correct, but utterly senseless. This divide in perspective makes clear that what is at stake here is not a clash between science and religion, but between two mutually exclusive worldviews: philosophical naturalism and theism.

Philosophical naturalism

The philosophical naturalist does not a priori rule out the possibility of a supernatural Creator. When the philosophical naturalist rejects the hypothesis of a supernatural Creator as an explanation of reality in favour of a naturalist explanation, then this is solely because he or she a posteriori came to the conclusion that there is a complete lack of evidence for this hypothesis. From a scientific point of view, the naturalist argues, we cannot conclusively prove or disprove that the universe was created by an all powerful, supernatural god. But instead of simply complying with an agnostic conclusion (“We really don’t know”), the naturalist goes one step further and says: since we have no evidence whatsoever to believe that the universe was created by an all powerful, supernatural god, there is no reason to start advocating such a train of thought, not in the least because we now have much better naturalistic alternatives. On the other hand, the religious theist is not even willing to consider this train of thought, not because after careful consideration it has been found to carry not enough weight as a scientific hypothesis, but because the question itself does not make any sense whatsoever.

Beyond the stalemate

This seems to be an unbridgeable gap. However, there is a very interesting exception to the theist position outlined above: Guy Consolmagno (°1952), Jesuit, astronomer, former professor at MIT and Harvard, and since September 2015 the director of the Vatican Observatory. In his book God’s Mechanics, he seems to have no problem in recognising the validity and self-consistency of non-theistic and atheistic explanations of the universe. [5] According to Consolmagno, what distinguishes them from a theistic stance towards the universe is the addition of God as Creator as an axiom (which is, by definition, independent of other axioms). In other words, Guy Consolmagno sees no problem in “putting the rabbit in the hat”. On the contrary, he explicitly shows where and how he does it:

“Only when you assume a designer God in the first place does the evidence of design “proving” His existence leap out at you. Yes, the order in the universe can be seen as consistent with the assumption of an “intelligent designer”; it’s a fine consistency argument. But it proves nothing—atheists can also come up with their own self-consistent explanations with no place for a designer [...] in any event, choosing to believe or not believe in the God axiom comes first, before you even start to do the science.” [6]

An intriguing question

A very interesting train of thought that leads to an intriguing question: does Consolmagno’s approach - adding God as Creator explicitly as a separate axiom, not related to any observable feature of the universe - allow for treating theism and philosophical naturalism as two equivalent, self-consistent views of reality? Or is this a bridge too far?

Notes

This blog post was originally published on April 14, 2016 at:

https://blog.associatie.kuleuven.be/alexandervanbiezen/science-and-religion-where-the-shoe-pinches/

[1] This Dutch internet forum www.geloofenwetenschap.nl on science and religion was made possible by a subsidy of the Templeton World Charity Foundation for the project ‘Strengthening the Science-Religion Dialogue in the Netherlands’. Nevertheless, ForumC states explicitly that the published opinions are the sole responsibility of the authors and that these opinions do not necessarily reflect the views of the Templeton World Charity Foundation nor those of ForumC. 

[2] Dutch title: Een pleidooi voor naturalisme (24 August 2015),http://www.geloofenwetenschap.nl/index.php/component/k2/item/627 , originally published in English as a blog post A Case for Naturalism,https://blog.associatie.kuleuven.be/alexandervanbiezen/a-case-for-naturalism/

[3] See: Comment (9853) by Alexander van Biezen on 2 September 2015, 18h21 (original text in Dutch): “Hoe zou volgens jou het heelal er uitzien als dit niet door God was geschapen maar op een volledig natuurlijke manier was ontstaan?”

http://www.geloofenwetenschap.nl/index.php/component/k2/item/627#!/ccomment-comment=9853

[4] My translation of comment (9881) on 3 September 2015, 08h47 (original text in Dutch): 

“Huh? Waarom denk je dat die vraag überhaupt beantwoordbaar is voor een theïst? Als het heelal niet door God was geschapen, dan was het er niet. Deze vraag klinkt als: “Je zit nu te luisteren naar een prachtige uitvoering van Schubert. Stel je nu eens voor dat de zanger die je nu hoort zingen er niet was: op welke manier zou dit lied dat je nu hoort dan ‘anders’ zijn?”. Zo’n vraag is grammaticaal correct, maar volstrekt absurd.”

http://www.geloofenwetenschap.nl/index.php/component/k2/item/627#!/ccomment-comment=9881

[5] See Consolmagno, G., God’s Mechanics. How Scientists and Engineers Make Sense of Religion, San Francisco, Wiley, Kindle Edition, 2008, p.13.

[6] Ibid., p.13-14. You can compare this with the role of axioms in geometry. When you choose to replace in geometry the so-called parallel postulate – Euclid’s fifth axiom – by another axiom, you will get non-Euclidean geometries which are internally just as consistent as Euclidean geometry.

Roger Penrose's Eternal Universe: the Escherian Stairwell

Could there be anything before the Big Bang? Does this question even make sense? The legendary British scientist Roger Penrose thinks it does. He has come to believe that the universe is eternal, and that our universe is just one aeon in an endless cycle, like an Escherian stairwell. An extraordinary view, more akin to the Hindu Rigveda philosophy of a universe eternally in flux.

The Standard Big Bang Model

Current-day standard cosmology has it that our universe began about 13.72 billion years ago with the Big Bang. Although the Big Bang theory gives an exceedingly accurate description up to the very early moments of our universe, the actual Big Bang itself (at time t₀) does not form a part of it. Extrapolations up to the Big Bang itself result in a singularity, which basically means that our scientific theories themselves break down and are no longer valid at that point. The Big Bang is considered as a singular boundary of information. Asking what might come “before” the Big Bang is a meaningless question, like asking what lies south of the South Pole.

Before the Big Bang?

But that doesn’t prevent scientists to keep on trying to wrap their heads around this “impenetrable barrier”. In 2010, the eminent British scientist Roger Penrose together with Vahe Gurzadyan claimed to have found evidence in the cosmic microwave background in the form of concentric circles that could possibly point to an era before the Big Bang. These circles are supposed to be a kind of gravitational ripples, resulting from colliding black holes in the “previous” universe, hereby providing us a window “beyond” the Big Bang. [1] It is comparable to ripples in a pond after you have thrown a heavy stone in it. Long after the stone has disappeared below the surface, you will still have a dissipating web of peaks and troughs, giving a clue as to what has happened.

Penrose has come to believe that there is an era before the Big Bang and, what is more, this era somehow gives rise to an extremely low degree of entropy, as a result of which entropy can steadily increase after the Big Bang. In his book Cycles of Time, Penrose extrapolates this idea even further: our universe is just one of many in an endless cycle, where each Big Bang initiates a new universe following the one before, each time resetting the entropy to an extremely low value. [2]  His cosmology reveals an eternal universe, reminiscent of an Escherian stairwell, endlessly going up and down at the same time.

At the very beginning: no mass, no metric, no time

Basically, Penrose’s reasoning boils down to the idea that as we rewind the movie of our universe and come very, very close to the Big Bang, the temperature and energies get so high as to render the rest mass of particles negligible and eventually to make it disappear altogether. But as this happens, we enter into a very strange phase of the universe. In Cycles of Time, Penrose goes to great lengths to explain that it is rest mass which determines the metric of the universe and which determines the rate of clocks. However, for massless particles, like photons, whizzing at the speed of light, there is no such thing as time. There is no “tick of the clock”, so to speak. It is very difficult to imagine, but for a massless particle, there is no difference between the instantaneous “now” and eternity.

When we enter this phase of the universe where there is no longer any rest mass, the metric of General Relativity no longer applies. The geometry of the universe becomes radically different. Instead of the metric of General Relativity, we have to use another kind of geometry, a so-called conformal geometry without a metric, i.e. without any distance.

The end of eternity

Next, Penrose envisages the very far future of our universe, long after the last star has gone out, and all the matter in the universe has eventually been swallowed by black holes. When the overall background temperature of the ever-expanding universe finally drops below the surface temperature of black holes, they will – very slowly – start evaporating due to Hawking radiation. As a result, still according to Penrose, all particles with rest mass will eventually decay into massless radiation. Once again, conformal geometry without distance, without the passage of time, will reign supreme.

From aeon to aeon

With a very ingenious mathematical construction using conformal geometry, Penrose maps the “end of time” (the era when there are only massless particles of radiation) to the big bang of a new era (with also nothing but massless particles). The vanishing of matter and time (and distance) results in a smooth conformal boundary of space-time from which a future universe will emerge. Our universe is but an aeon in an infinite sequence of aeons.

Very interestingly, the origin of Penrose’s extraordinary cosmological view has a curious personal twist. Gustaaf C. Cornelis, a Belgian philosopher of science specialised in the field of cosmology, recounts the story of Penrose giving an interview for the Dutch journal NRC-Handelsblad in 2011:

“In this [interview], he reiterated that in 2005 the thought of residing in a universe with only gravity waves and light particles remaining was depressing to such an extent that he was looking for a new interpretation framework.” [3]

Highly controversial

Let it be very clear: Penrose’s model is highly controversial and goes straight against the inflationary model which has gained wide acceptance over the years, and not without good reason for that matter: the inflationary model provides by far the best explanation of everything we can observe in the universe.

Roger Penrose himself is very aware of the fact that his model is not without serious difficulties. To name just one, his model presupposes that all matter in the universe (i.e. all particles with rest mass) will decay into massless radiation. It is still very far from clear that this will actually happen. [4]

But whether Penrose’s model is “true” or not, that doesn’t matter. Science is about building and searching for models, and weighing one model against the other against observational data, and not about deciding whether a model is “true” or “real”.

Theological curiosities

Although Penrose himself is an atheist [5], he is aware of the fact that his theory of an infinite cycle of aeons “is a bit more like Hindu philosophy” than the standard Big Bang theory, as he himself puts it. [6] Be that as it may, for him this is nothing more than a theological coincidence, a pleasing curiosity. [7]

Although this theological coincidence doesn’t play any role whatsoever in Penrose’s research, it can be easily imagined that an eternal cosmology in whatever form could be troublesome for some theologians. For instance, for the American Christian philosopher and theologian William Lane Craig, well-known from his public debates with renowned cosmologists like Sean Carroll, the idea that the standard Big Bang theory seems to favour an absolute beginning of the universe (which it doesn’t) plays a crucial role in his apologetics. Whatever the outcome might be, at the very least it shows that current-day cosmology for some theologians is found to resonate with the Christian account of creation.

Creatio continua?

Other theologians however will be quick to point out that even an eternal universe is not incompatible with the idea of a Creator. Even if there is no creation out of nothing, God can still be invoked as the ‘Ground of Being’, as the one who ‘sustains the world’, seeing the concept of creation as ‘allowing the universe to exist’ (cfr. the theological notion of creatio continua, continuous creation). The Dutch theologian and philosopher of religion Taede Smedes ingeniously tried to solve this conundrum by stating that the Big Bang theory neither confirms nor denies the idea of acreation from nothing, because scientific theories are theologically ambiguous. [8] We can easily extrapolate this statement to eternal cosmologies as well.

Metaphysical superfluity

However, stating that scientific theories are theologically ambiguous is very short of admitting that scientific theories are simply not in need of superfluous metaphysical or theological add-ons. The universe does not need anything to sustain it. ‘Being compatible’ with science is not enough to warrant the addition of supplements to scientific theories which do not have any explanatory value and are not needed to account for scientific evidence.

Relic of the past

Whether Penrose’s theory of eternal cycles of time is flawed or not, that is not the point. Currently there are at least a dozen competing models of eternal cosmologies, each of which runs into heavy criticism. And whatever model will turn out to gain acceptance over others will be decided upon by scientific criteria, not by religious ones. It is not up to religions to make claims about how the universe works.

What matters is that Penrose’s model is a completely self-contained scientific theory which accounts for the entire universe without having to rely on anything outside it. Insisting that having a completely self-contained scientific model which accounts for the observational data is not enough is a relic of an outdated view of the world, linked to an obsolete way of thinking, predating the era of science.

Notes

This blog post was originally published on January 14, 2016, at:

http://blog.associatie.kuleuven.be/alexandervanbiezen/roger-penroses-eternal-universe-the-escherian-stairwell/

[1] See Gurzadyan, V.G. and Penrose, R., Concentric circles in WMAP data may provide evidence of violent pre-Big-Bang activity, (November 2010) in

http://arxiv.org/ftp/arxiv/papers/1011/1011.3706.pdf (accessed January 11, 2016).

[2] Penrose, R., Cycles of Time. An Extraordinary New View of the Universe, London, Random House, 2010.

[3] Cornelis, G. C., Het geheim van de kosmologie ontrafeld. Ten dienste van een waarheid, Brussel, ASP editions, 2012, p. 320 (and footnote 1222, p. 409), my translation. A highly recommendable work on the scientific developments leading up to current-day cosmology, in Dutch (title: The Secret of Cosmology Unraveled. In Service of a Truth).

[4] To this day, it is not certain that electrons will ever decay, and recent research revealed that the minimum life span of electrons is at least 5 quintillion times the age of the current universe (6.6 x 10²⁸ years). See: Agostini, M. et al., Test of Electric Charge Conservation with Borexino, Phys. Rev. Lett. 115, 231802 – 3 December 2015,

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.115.231802 (accessed January 11, 2016).

[5] See the interview with Roger Penrose, Big Bang follows Big Bang follows Big Bang, BBC News, 25 September 2010, 

http://news.bbc.co.uk/today/hi/today/newsid_9032000/9032626.stm (accessed January 11, 2016).

[6] Brean, J., Sir Roger Penrose: Scientific Heretic, (7 October 2008),

http://www.uncommondescent.com/science/sir-roger-penrose-scientific-heretic/(accessed January 11, 2016).

[7] Ibid.

[8] See Smedes, T.A., God en de menselijke maat. Gods handelen en het natuurwetenschappelijk wereldbeeld, Zoetermeer, Uitgeverij Meinema, 2006, p. 111, in Dutch (title: God and the Human Dimension. God’s Acting and the Scientific Worldview)

Roger Penrose: Mathematics, Reality and God

                               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:

http://blog.associatie.kuleuven.be/alexandervanbiezen/roger-penrose-mathematics-reality-and-god/

[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

Philosophy and the Bearers of the Torch

In July 2015 Stephen Hawking, one of the most brilliant physicists of our time, spent some time at the University of Leuven in Belgium with the Belgian physicist Thomas Hertog, with whom he closely works together on cosmology. Kathleen Cools, a well-known Belgian journalist, followed Hawking during his visit and had a two hour interview with him.

Stephen Hawking: “Philosophy is dead.”

At their very first meeting, Hawking was curious to know whether Kathleen Cools, the journalist who was going to interview him, had a science background. When she told him she had studied philosophy, almost apologetically adding “That’s not a real science, I guess”, he promptly replied: “I said: philosophy is dead. [pause] Maybe not quite dead.” [1] Later on, during the interview, Cools came back to him about his earlier statement “Philosophy is dead” and asked him: “Can we ever do without philosophy, because it helps people to ask the very old and important question of Socrates ‘How should we live? What is the good life?’”. Hawking gave her the following answer:

“Philosophers used to give the answer. But philosophers have not kept up with modern science. It is scientists who now add to the advancement of human understanding.” [2]

This is reminiscent of The Grand Design (2010), in which Hawking (together with Leonard Mlodinow), never afraid to rock the boat, wrote:

“Philosophy has not kept up with modern developments in science, particularly physics. Scientists have become the bearers of the torch of discovery in our quest for knowledge.” [3]

Although Hawking is known for his witty humor, he seems to be dead serious on this subject and, as the Belgian documentary clearly shows, he still firmly adheres to this view.

Fluttering the philosophical dovecotes

Needless to say, this bold statement made quite a stir and fluttered a lot of philosophical and theological dovecotes, some of which at best reproached Hawking of making self-refuting philosophical assertions, at worst scorned him as downright philosophically and theologically illiterate.

Be that as it may, many scientists simply do not see any reason anymore to be interested in most of the debates that are nowadays classified under the label ‘philosophy’. To paraphrase an Arab proverb: the dogs bark, but the caravan of science moves on.

This evolution didn’t leave the philosophical community unstirred. There is an increasing support among scientifically oriented philosophers (and, who knows, possibly even some scientifically oriented theologians?) for the idea that the days of metaphysics as a quest for a priori truths about reality are definitely over and that the only viable source of objective knowledge about reality is science (which boils down to a posteriori empirical evidence combined with mathematics). A view which I deeply support.

Fundamental physics rules

One of the figureheads of this turn to science in philosophy is James Ladyman, both a physicist and a philosopher of science. [4]

Ladyman advocates a radically naturalized metaphysics centered around empirical verifiability in which fundamental physics takes the driver’s seat. Fundamental physics is like the rules of chess: it puts a constraint on the kind of games you can play. Just one example of what this entails, given by the cosmologist Sean Carroll: the idea that some form of consciousness could persist after we die and our bodies decay into their constituent atoms is completely incompatible with the currently known laws of fundamental physics.

“If you claim that some form of soul persists beyond death, what particles is that soul made of? What forces are holding it together? How does it interact with ordinary matter? Everything we know about quantum field theory (QFT) says that there aren’t any sensible answers to these questions.” [5]

A very strange universe

Why do brilliant people like Stephen Hawking and James Ladyman so steadfastly adhere to their scientific perspective on reality? Apart from many other possible reasons, they are both motivated by the profound realization that science, especially fundamental physics, has revealed a very strange universe, very far removed from our everyday, evolutionary-based intuitions. As Hawking puts it:

“Common sense is based upon everyday experience, not upon the universe as it is revealed through the marvels of technologies such as those that allow us to gaze deep into the atom or back to the early universe.” [6]

As a result, both Hawking and Ladyman have become deeply skeptical with regard to the possible role of common sense intuitions about the nature of the universe in the process of scientific discovery.

No need for the supernatural

A second trait which both Hawking and Ladyman share in common is the underlying naturalist idea that there is only one natural reality and that the quest for an explanation of the universe doesn’t require any reference to a transcendent reality “outside” the universe itself.

This idea seems to upset quite a lot of people. Why would that be? Somehow, the idea has taken hold that in order for some religious worldviews to be true, you need to have a kind of supernatural realm next to the whole of natural reality. Accepting any form of ontological naturalism would then be incompatible with these particular religious worldviews.

The more interesting question, though, is: do religions necessarily presuppose a transcendent reality? How would religions look like without the supernatural?

Notes

This blog post was originally published on November 8, 2015, at:

http://blog.associatie.kuleuven.be/alexandervanbiezen/philosophy-and-the-bearers-of-the-torch/

[1] See part 1 of the interview, 04’50’’ ff. You can watch this interview (in English) as part of a two-episode documentary on Stephen Hawking’s visit to Belgium (partly in English, partly in Dutch):

Part 1:

https://www.youtube.com/watch?v=Esg2rxG_Rmo 

Part 2:

https://www.youtube.com/watch?v=-YaTBBx4deI 

[2] See part 2 of the interview (link in note 1), 07’55’’ ff.

[3] Hawking, S. & Mlodinow, L, The Grand Design, London, Bantam Books, 2010 (repr. 2011), p. 13.

[4] For a concise introduction, see van Biezen, A., A Case for Naturalism, (July 2015), in The Torch of Discovery.

[5] Carroll, S., Physics and the Immortality of the Soul, in Scientific American, May 23, 2011, http://blogs.scientificamerican.com/guest-blog/physics-and-the-immortality-of-the-soul/ (accessed November 7, 2015).

[6] Hawking, The Grand Design, p. 15.