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When science and philosophy collide in a ‘fine-tuned’ universe

When renowned scientists now talk seriously about millions of multiverses, the old question “are we alone?” gets a whole new meaning. Our ever-expanding universe is incomprehensibly large – and its rate…

‘To be, or not to be – and not to exist at all. Ever.’ Eddi van W./Flickr, CC BY-SA

When renowned scientists now talk seriously about millions of multiverses, the old question “are we alone?” gets a whole new meaning.

Our ever-expanding universe is incomprehensibly large – and its rate of growth is apparently accelerating – but if so it’s actually in a very delicate balance.

It’s then incredible that the universe exists at all. Let us explain.

In a 2004 review in Science of Searle’s Mind a Brief Introduction, neuroscientist Christof Koch wrote:

Whether we scientists are inspired, bored, or infuriated by philosophy, all our theorising and experimentation depends on particular philosophical background assumptions. This hidden influence is an acute embarrassment to many researchers, and it is therefore not often acknowledged. Such fundamental notions as reality, space, time and causality – notions found at the core of the scientific enterprise – all rely on particular metaphysical assumptions about the world.

This may seem self-evident, and was regarded as important by Einstein, Bohr and the founders of quantum theory a century ago, but it runs against the grain of the views of working scientists in the post-war period.

Karl Popper. Wikimedia Commons

Indeed, 21st-century mathematicians and scientists seem to have little need of philosophy.

The glory days of Karl Popper, who argued that falsifiability was a hallmark of good science, and Thomas Kuhn, who noted the phenomenon of paradigm shifts, are long gone — in science, if not in the humanities.

For many years, scientific philosophy as practised by scientists has languished, punctuated only by lapses such as the Sokal hoax, when NYU physicist Alan Sokal wrote a tongue-in-cheek article with a lot of scientific nonsense that was accepted by a leading journal in the postmodern science studies field (and launched a cottage industry of similar hoaxes).

But maybe the tide is finally turning. Perhaps modern science really needs philosophy after all.

Cosmic coincidences

The main drivers here are some truly perplexing developments in physics and cosmology. In recent years physicists and cosmologists have uncovered numerous eye-popping “cosmic coincidences,” remarkable instances of apparent “fine-tuning” of the universe.

Here are just three out of many that could be listed:

  1. Carbon resonance and the strong force. Although the abundance of hydrogen, helium and lithium are well-explained by known physical principles, the formation of heavier elements, beginning with carbon, very sensitively depends on the balance of the strong and weak forces. If the strong force were slightly stronger or slightly weaker (by just 1% in either direction), there would be no carbon or any heavier elements anywhere in the universe, and thus no carbon-based life forms like us to ask why.

  2. mag3737/Flickr, CC BY-NC-SA
    The proton-to-electron mass ratio. A neutron’s mass is slightly more than the combined mass of a proton, an electron and a neutrino. If the neutron were very slightly less massive, then it could not decay without energy input. If its mass were lower by 1%, then isolated protons would decay instead of neutrons, and very few atoms heavier than lithium could form.

  3. The cosmological constant. Perhaps the most startling instance of fine-tuning is the cosmological constant paradox. This derives from the fact that when one calculates, based on known principles of quantum mechanics, the “vacuum energy density” of the universe, focusing on the electromagnetic force, one obtains the incredible result that empty space “weighs” 1,093g per cubic centimetre (cc). The actual average mass density of the universe, 10-28g per cc, differs by 120 orders of magnitude from theory.

Physicists, who have fretted over the cosmological constant paradox for years, have noted that calculations such as the above involve only the electromagnetic force, and so perhaps when the contributions of the other known forces are included, all terms will cancel out to exactly zero, as a consequence of some unknown fundamental principle of physics.

But these hopes were shattered with the 1998 discovery that the expansion of the universe is accelerating, which implied that the cosmological constant must be slightly positive.

It was a Nobel prize-winning discovery too.

This meant that physicists were left to explain the startling fact that the positive and negative contributions to the cosmological constant cancel to 120-digit accuracy, yet fail to cancel beginning at the 121st digit.

Curiously, this observation is in accord with a prediction made by Nobel laureate and physicist Steven Weinberg in 1987, who argued from basic principles that the cosmological constant must be zero to within one part in roughly 10120 (and yet be nonzero), or else the universe either would have dispersed too fast for stars and galaxies to have formed, or else would have recollapsed upon itself long ago.

The Anthropic Principle

In short, numerous features of our universe seem fantastically fine-tuned for the existence of intelligent life. While some physicists still hold out for a “natural” explanation, many others are now coming to grips with the notion that our universe is profoundly unnatural, with no good explanation other than the Anthropic Principle — the universe is in this exceedingly improbable state, because if it weren’t, we wouldn’t be here to discuss the fact.

Xanetia/Flickr, CC BY

They further note that the prevailing “eternal inflation” big bang scenario suggests that our universe is just one pocket in a continuously bifurcating multiverse.

Inflation cosmology, by the way, got a significant experimental boost with the March 17, 2014 announcement that astronomers had discovered gravitational waves, signatures of the big bang inflation, in data collected from telescopes based at the South Pole.

In a similar vein, string theory, the current best candidate for a “theory of everything,” predicts an enormous ensemble, numbering 10 to the power 500 by one accounting, of parallel universes. Thus in such a large or even infinite ensemble, we should not be surprised to find ourselves in an exceedingly fine-tuned universe.

But to many scientists, such reasoning is anathema to traditional empirical science. Lee Smolin wrote in his 2006 book The Trouble with Physics:

We physicists need to confront the crisis facing us. A scientific theory [the multiverse/ Anthropic Principle/ string theory paradigm] that makes no predictions and therefore is not subject to experiment can never fail, but such a theory can never succeed either, as long as science stands for knowledge gained from rational argument borne out by evidence.

And even the proponents of such views have some explaining to do. For example, if there are truly infinitely many pocket universes like ours, as physicists argue is the case, how can one possibly define a “probability measure” on such an ensemble? In other words, what does it mean to talk of the “probability” of our universe existing in its observed state?

But others see no alternative to some form of the multiverse and the Anthropic Principle. Physicist Max Tegmark, in his recent book Our Mathematical Universe, argues that not only is the multiverse real, but in fact that the multiverse is mathematics — all mathematical laws and structures actually exist, and are the ultimate stuff of the universe.

Eddi van W./Flickr, CC BY-NC-ND

Modern science needs philosophy

With this backdrop, a growing number of scientists are calling for head-to-head interactions with philosophers. In a recent New Scientist article, cosmologist Joseph Silk reviews these and other issues now faced by the field, and then notes that such problems, probing the meaning of our very existence, are closely akin to those that have been debated by philosophers through the ages.

Thus perhaps a new dialogue between science and philosophy can bring some badly needed insights into physics and other leading-edge fields such as neurobiology. (Indeed, there is a burgeoning sub discipline of neurophilosophy.)

As Silk explains,

Drawing the line between philosophy and physics has never been easy. Perhaps it is time to stop trying. The interface is ripe for exploration.

This article first appeared on Math Drudge.

Join the conversation

23 Comments sorted by

  1. Joseph Bernard


    Science needs Philosophy to dislodge the grip of religious dogma and help steer us closer to what is, what if and what could be.

    1. Joseph Bernard


      In reply to Joseph Bernard

      nb you may like the following 5 part videos on the subject by

      "Philosopher and physicist Paul Davies gives a fascinating and thought-provoking talk on the possibility of an ultimate explanation for our universe. Dismissing the multiverse and God, he outlines an idea for finding an explanation for the universe and physical laws within the universe itself."

    2. Tim Dean

      Philosopher at UNSW Australia

      In reply to Joseph Bernard

      Perhaps philosophy might perform that role, but I take the point of this article to be that science specifically needs philosophy to the extent that science depends on assumptions about the way the world is that are derived from philosophy (i.e. non-empirical investigation).

    3. Henry Verberne

      Once in the fossil fuel industry but now free to speak up

      In reply to Joseph Bernard

      I have not seen the video but some weeks ago I saw an article in the Euresis journal (see my post on this topic quoting from the article). I have a link to a PDF that is well worth reading. I have no idea if it is arrant nonsense but Paul Davies is a respected theoretical physicist.

    4. Joseph Bernard


      In reply to Tim Dean

      Yes, I look forward to the day when philosophy is an integral part of scientific thinking. The sooner this happens to the sooner we are able to doors to new possibilities which seem to be currently limited to a “flatlander” view of the world (uni/multiverse). The more we look the more we find in this seemly infinite universe and I believe that we are limited by what we are prepared to accept. The goog news is that which we are willing accept is ever changing as we climb the rungs of consciousness…

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  2. JB Rawson


    Great stuff: thanks very much for this mind-expanding effort. I'd love to know more about the Anthropic Principle - I'll go off and read more, but hope to see more here on The Conversation too.

  3. Bruce Caithness


    David Deutsch in "The Beginning of Infinity" passionately positions Karl Popper as not only still relevant but vital. I do wonder how often Popper's multiple philosophical themes are explored in his original writings rather than filtered through Kuhn's and Lakatos's misreadings.

    1. Ian Fraser

      Independent researcher

      In reply to Bruce Caithness

      Not reading Popper in the original is missing the opportunity to read an uncommonly clear articulation of philosophical problems and proposed arguments in response.

      And I was so pleased to find that even Popper found Kant difficult.

  4. Alexander Naraniecki


    "David Deutsch, the inventor of quantum computation has called for a return to Popper, however to his cognitional theory rather than his more famous falsificationist methodology. Deutsch has recently argued that in the area of Artificial Intelligence, computational models based upon inductivist theories of intelligence or ‘input-output’ models will never lead to anything remotely like the creation of intelligence no matter how much data is inputted and processed. Deutsch argued that scientists working…

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  5. Patrick Maher

    Retired Doctor of Psychology and Academic

    Mind you. I think everyone has missed the most irrefutable of scientific facts - the centre of the multiverses is in Canberra right now. Or is he in the West - campaigning?

  6. John Campbell


    We need to be very careful we don't fall for the little likelihood trap, down that way leads to amazement, religion and metaphysical nonsense. I can cut an orange in half, not only do I realize that I'm the only person that ever existed to have seen the inside of that orange, but of all the millions and millions of oranges that have ever existed what is the probability of my looking at this precise one. Clearly something very close to zero. So then I can speculate at how remarkable an event it is…

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    1. Paul Miller

      logged in via LinkedIn

      In reply to John Campbell

      "we could have an infinite number of universes where the only difference could be the length of the string I was holding in my hand"

      I would imagine such a scenario would not arise as the circumstances that led to you holding a 6" piece of string as opposed to a 100 metre length of string would have involved other differences arising.

      "As There are an infinite number of possible lengths .."

      Whilst it may be conceded that there are an infinite number of possible lengths the application of varying lengths to 'string' would most certainly be very finite.

      "One common misconception among some people seems to be if you had an infinite number of universes all things would be possible and happen"

      I'm not sure you've made it clear why this is a misconception.

      OTOH I love the simplicity of your orange cutting analogy and will henceforth consider using it instead of my '100 coin tosses' example I've been using.

  7. Joe Gartner

    Eating Cake

    In an infinite multiverse it would be far more startling if there wasn't a universe capable of supporting intelligent life... not that there would be any observers to feel miffed about it.

    1. Chris Steketee

      logged in via LinkedIn

      In reply to Colin Kline

      Actually, I regret to say much of this is nonsense, eg #4: it shows a woeful lack of understanding of physics when he thinks the argument depends on the particular units of measurements in which the physical constants are expressed.

    2. Colin KLINE

      logged in via email

      In reply to Chris Steketee

      Chris Steketee seems to be muddled.

      STENGER actually says that "the constants" arbitrarily vary depending on the units used, AND THAT is why claiming that a particular number, with a particular unit, is meaningless for using as a confirmation of "fine tuning" !

    3. Chris Steketee

      logged in via LinkedIn

      In reply to Colin KLINE

      I'm not commenting on the Stenger book, which I have not read, only the link that you posted. At that link, he is using the fact that the numerical value depends on the units used as an argument against fine-tuning, which it patently is not. This is like saying that the speed of light is not constant because it can be written as 300,000 km/sec or 186,000 miles/sec.

  8. Yoron Hamber


    Sweet stuff Jonathan and David. Natural science as it once was called, the study of nature. You could possibly relate it to a question of what makes 'dimensions' too :) In our natural world we find dimensions, every object we hold prove them to exist. And so we construct a universe building on this idea.

    Then comes Einstein with his ideas of a SpaceTime, where nothing is as it seems, both time and distance becoming observer dependent, still real, but just real for you, measuring. Puts every observer once more into a universe's heliocentric focus.

    Then comes QM, going inwards, scaling down, searching for 'bits', or no 'bits' at all? Whatever makes a universe exist.

    What if a dimension just comes from the way it connects? A local definition of properties, spreading as rings on the water, to us becoming a 'inside'?

  9. Henry Verberne

    Once in the fossil fuel industry but now free to speak up

    Physicist Professor Paul Davies (author of "The Mind of God" and other books) has argued that "somehow the universe has engineered not just its own awareness but its won comprehension".

    In relation to the multiverse he asks: "Just as one can mischievously ask who made God, or who designed the designer, so can equally well ask why the multiverse exists and who or what designed it." .."the popular multiverse models merely shift the problem elsewhere- up a level from universe to multiverse."


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  10. Doug Hutcheson


    The circumstances of our universe accidentally produced us. We are not the reason for the creation of this universe. Intelligence in our universe appears in at least us, but we do not know how many other types of intelligence it may hold and we cannot conceive of what these intelligences may be like. Equally, we cannot imagine what, if any, intelligences might have evolved if our universe was different, or in any parallel universes.
    To think there may be an overarching reason for our existence, other than as a result of pure chance (luck?), smacks of hubris.

  11. Danya Rose

    logged in via email

    The fundamental problem with the anthropic principle is that faced by the puddle amazed that the hole in which it lies exactly fits is shape.

    It should not surprise us at all that we live in a universe seemingly fine-tuned for our existence; we could exist in no other!

    As it stands, our current state of knowledge is not sufficient to answer the questions that the anthropic principle requires we must in order to give it any credence. To wit: what ranges of these parameters are actually *possible…

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  12. Steve Ruis


    Surely the authors jest. Philosophy hasn't answered a question definitively in 4000 years of human history and to claim "In short, numerous features of our universe seem fantastically fine-tuned for the existence of intelligent life." is incredible. That certain elementary particle parameters need to be the way they are for life to exist (at least as we know it) I will buy, but to distinguish intelligent life from non-intelligent life from subatomic particle physics beggars the imagination. And the authors do not address the simple: if those parameters did not support life as we know it, we wouldn't be here to notice that. Now, if the parameters of subatomic particles did not support life, that would be interesting!

    1. Arnd Liebenberg

      self-employed carpenter and joiner; exploring the possibilities of post-capitalist society

      In reply to Steve Ruis

      " Philosophy hasn't answered a question definitively in 4000 years of human history"

      That is true enough, but Philosophy can, ideally, prompt us to ask the right questions and discard the wrong ones. Besides, I tendentially side with Karl Marx's dictum that 'all philosophy hitherto has got it wrong. Philosophy has tried to explain the world. However, the idea is not to explain it, the idea is to change it!'

      He also realised that 'everything that is solid, melts into air'.

      I'm not just trying…

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