Further and deeper exploration of paradoxes and challenges of intuition and logic can be found in my recently published book, Probability, Choice and Reason.

It shouldn’t be possible for us to exist. But we do. That’s counterintuitive. Take, for example the ‘Cosmological Constant.’ What it represents is a sort of unobserved ‘energy’ in the vacuum of space which possesses density and pressure, which prevents a static universe from collapsing in upon itself. We know how much unobserved energy there is because we know how it affects the Universe’s expansion. But how much should there be? The easiest way to picture this is to visualise ‘empty space’ as containing ‘virtual’ particles that continually form and then disappear. This ‘empty space’, it turns out, ‘weighs’ 10 to the power of 93 grams per cubic centimetre. Yet the actual figure differs from that predicted by a factor of 10 to the power of 120. The ‘vacuum energy density’ as predicted is simply 10120 times too big. That’s a 1 with 120 zeros after it. So there is something cancelling out all this energy, to make it 10 to the power of 120 smaller in practice than it should be in theory. In other words, the various components of vacuum energy are arranged so that they essentially cancel out.

Now this is very fortuitous. If the cancellation figure was one power of ten different, 10 to the power of 119, then galaxies could not form, as matter would not be able to condense, so no stars, no planets, no life. So we are faced with the 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. In fact, 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 collapsed upon itself long ago. How likely is this by chance? Essentially, it is the equivalent of tossing a coin and needing to get heads 400 times in a row and achieving it.

Now, that’s just one constant that needs to be just right for galaxies and stars and planets and life to exist. There are quite a few, independent of this, which have to be equally just right, most notably the strength of gravity and of the strong nuclear force relative to electromagnetism and the observed strength of the weak nuclear force. Others include the difference between the masses of the two lightest quarks and the mass of the electron relative to the quark masses, the value of the global cosmic energy density in the very early universe, and the relative amplitude of density fluctuations in the early universe. If any of these constants had been slightly different, stars and galaxies could not have formed.

There is also the symmetry/asymmetry paradox. When symmetry is required of the Universe, for example in a perfect balance of positive and negative charge, conservation of electric charge is critically ensured. If there were an equal number of protons and antiprotons, of matter and antimatter, produced by the Big Bang, they would have annihilated each other, leaving a Universe empty of its atomic building blocks. Fortuitously for the existence of a live Universe, protons actually outnumbered antiprotons by a factor of just one in one billion. If the perfect symmetry of the charge and almost vanishingly tiny asymmetry of matter and antimatter were reversed, if protons and antiprotons had not differed in number by that one part in a billion, there would be no galaxies, no stars, no planets, no life, no consciousness, no question for us to consider.

In summary, then, if the conditions in the Big Bang which started our Universe had been even a tiniest of a tiniest of a tiny bit different, with regard to a number of independent physical constants, our galaxies, stars and planets would not have been able to exist, let alone lead to the existence of living, thinking, feeling things. So why are they so right?

Let us first tackle those who say that if they hadn’t been right we would not have been able to even ask the question. This sounds a clever point but in fact it is not. For example it would be absolutely bewildering how I could have survived a fall out of an aeroplane from 39,000 feet onto tarmac without a parachute, but it would still be a question very much in need of an answer. To say that I couldn’t have posed the question if I hadn’t survived the fall is no answer at all.

Others propose the argument that since there must be some initial conditions, these conditions which gave rise to the Universe and life within it possible were just as likely to prevail as any others, so there is no puzzle to be explained.

But this is like saying that there are two people, Jack and Jill, who are arguing over whether Jill can control whether a fair coin lands heads or tails. Jack challenges Jill to toss the coin 400 times. He says he will be convinced of Jill’s amazing skill if she can toss heads followed by tails 200 times in a row, and she proceeds to do so. Jack could now argue that a head was equally likely as a tail on every single toss of the coin, so this sequence of heads and tails was, in retrospect, just as likely as any other outcome. But clearly that would be a very poor explanation of the pattern that just occurred. That particular pattern was clearly not produced by coincidence. Yet it’s the same argument as saying that it is just as likely that the initial conditions were just right to produce the Universe and life to exist as that any of the other pattern of billions of initial conditions that would not have done so. There may be a reason for the pattern that was produced, but it needs a more profound explanation than proposing that it was just coincidence.

A second example. There is one lottery draw, devised by an alien civilisation. The lottery balls, numbered from 1 to 59, are to be drawn, and the only way that we will escape destruction, we are told, is if the first 59 balls out of the drum emerge as 1 to 59 in sequence. The numbers duly come out in that exact sequence. Now that outcome is no less likely than any other particular sequence, so if it came out that way a sceptic could claim that we were just lucky. That would clearly be nonsensical. A much more reasonable and sensible conclusion, of course, is that the aliens had rigged the draw to allow us to survive!

So the fact that the initial conditions are so fine-tuned deserves an explanation, and a very good one at that. It cannot be simply dismissed as a coincidence or a non-question.

An explanation that has been proposed that does deserve serious scrutiny is that there have been many Big Bangs, with many different initial conditions. Assuming that there were billions upon billions of these, eventually one will produce initial conditions that are right for the Universe to at least have a shot at existing.

In this apparently theory, we are essentially proposing a process statistically along the lines of aliens drawing lottery balls over and over again, countless times, until the numbers come out in the sequence 1 to 59.

On this basis, a viable Universe could arise out of re-generating the initial conditions at the Big Bang until one of the lottery numbers eventually comes up. Is this a simpler explanation of why our Universe and life exists than an explanation based on a primal cause, and in any case does simplicity matter as a criterion of truth? This is the first question and it is usually accepted in the realm of scientific enquiry. A simpler explanation of known facts is usually accepted as superior to a more complex one.

Of course, the simplest state of affairs would be a situation in which nothing had ever existed. This would also be the least arbitrary, and certainly the easiest to understand. Indeed, if nothing had ever existed, there would have been nothing to be explained. Most critically, it would solve the mystery of how things could exist without their existence having some cause. In particular, while it is not possible to propose a causal explanation of why the whole Universe or Universes exists, if nothing had ever existed, that state of affairs would not have needed to be caused. This is not helpful to us, though, as we know that in fact at least one Universe does exist.

Take the opposite extreme, where every possible Universe exists, underpinned by every possible set of initial conditions. In such a state of affairs, most of these might be subject to different fundamental laws, governed by different equations, composed of different elemental matter. There is no reason in principle, on this version of reality, to believe that each different type of Universe should not exist over and over again, up to an infinite number of times, so even our own type of Universe could exist billions of billions of times, or more, so that in the limit everything that could happen has happened and will happen, over and over again. This may be a true depiction of reality, but it or anything anywhere remotely near it, seems a very unconvincing one. In any case, our sole source of understanding about the make-up of a Universe is a study of our own Universe. On what basis, therefore, can we scientifically propose that the other speculative Universes are governed by totally different equations and fundamental physical laws? They may be, but that is a heroic assumption.

Perhaps the laws are the same, but the constants that determines the relative masses of the elementary particles, the relative strength of the physical forces, and many other fundamentals, differ but not the laws themselves. If so, what is the law governing how these constants vary from Universe to universe, and where do these fundamental laws come from? From nothing? It has been argued that absolutely no evidence exists that any other Universe exists but our own, and that the reason that these unseen Universes is proposed is simply to explain the otherwise baffling problem of explaining how our Universe and life within it can exist. That may well be so, but we can park that for now as it is still at least possible that they do exist.

So let’s step away from requiring any evidence, and move on to at least admitting the possibility that there are a lot of universes, but not every conceivable universe. One version of this is that the other Universes have the same fundamental laws, subject to the same fundamental equations, and composed of the same elemental matter as ours, but differ in the initial conditions and the constants. But this leaves us with the question as to why there should be only just so many universes, and no more. A hundred, a thousand, a hundred thousand, whatever number we choose requires an explanation of why just that number. This is again very puzzling. If we didn’t know better, our best ‘a priori’ guess is that there would be no universes, no life. We happen to know that’s wrong, so that leaves our Universe; or else a limitless number of universes where anything that could happen has or will, over and over again; or else a limited number of universes, which begs the question, why just that number?

Is it because certain special features have to obtain in the initial conditions before a Universe can be born, and that these are limited in number. Let us assume this is so. This only begs the question of why these limited features cannot occur more than a limited number of times. If they could, there is no reason to believe the number of universes containing these special features would be less than limitless in number. So, on this view, our Universe exists because it contains the special features which allow a Universe to exist. But if so, we are back with the problem arising in the conception of all possible worlds, but in this case it is only our own type of Universe (i.e. obeying the equations and laws that underpin this Universe) that could exist limitless times. Again, this may be a true depiction of reality, but it seems a very unconvincing one.

The alternative is to adopt an assumption that there is some limiting parameter to the whole process of creating Universes, along some version of string theory which claims that there are a limit of 10 to the power of 500 solutions (admittedly a dizzyingly big number) to the equations that make up the so-called ‘landscape’ of reality. That sort of limiting assumption, however realistic or unrealistic it might be, would seem to offer at least a lifeline to allow us to cling onto some semblance of common sense.

Before summarising where we have got to, a quick aside on the ‘Great Filter’ idea, relating to the question of how life of any form could arise out of inanimate matter, and ultimately to human consciousness. Observable civilisations don’t seem to happen much from what we know now, and possibly only once. Indeed, even in a universe that manages to exist, the mind-numbingly small improbability of getting from inanimate matter to conscious humans seems to require a series of steps of apparently astonishing improbability. The Filter refers to the causal path from simple inanimate matter to a visible civilisation. The underpinning logic is that almost everything that starts along this path is blocked along the way, which might be by means of one extremely hard step, or many very, very hard steps. Indeed, it’s commonly supposed that it has only once ever happened here on earth. Just exactly once, traceable so far to LUCA (our Last Universal Common Ancestor). If so, it may be why the universe out there seems for the most part to be quite dead. The biggest filter, so the argument goes, is that the origin of life from inanimate matter is itself very, very, very hard. It’s a sort of Resurrection but an order of magnitude harder because the ‘dead stuff’ had never been alive, and nor had anything else! And that’s just the first giant leap along the way. This is a big problem of its own but that’s for another day, so let’s leave that aside and go back a step, to the origin of the universe. Before we do so, let us as I suggested before our short detour, summarise very quickly.

Here goes. If we didn’t know better, our best guess, the simplest description of all possible realities, is that nothing exists. But we do know better, because we are alive and conscious, and considering the question. But our Universe is far, far, far too fine-tuned, by a factor of billions of billions, to exist by chance if it is the only Universe. So there must be more, if our Universe is caused by the roll of the die, a lot more. But how many more? If there is some mechanism for generating experimental universe upon universe, why should there be a limit to this process, and if there is not, that means that there will be limitless universes, including limitless identical universes, in which in principle everything possible has happened, and will happen, over and over again.

Even if we accept there is some limiter, we have to ask what causes this limiter to exist, and even if we don’t accept there is a limiter, we still need to ask what governs the equations representing the initial conditions to be as they are, to create one Universe or many. What puts life into the equations and makes a universe or universes at all? And why should the mechanism generating life into these equations have infused them with the physical laws that allow the production of any universe at all?

Some have speculated that we can create a universe or universes out of nothing, that a particle and an anti-particle, for example could in theory spontaneously be generated out of what is described as a ‘quantum vacuum’. According to this theoretical conjecture, the Universe ‘tunnelled’ into existence out of nothing.

This would be a helpful handle for proposing some rational explanation of the origin of the Universe and of space-time if a ‘quantum vacuum’ was in fact nothingness. But that’s the problem with this theoretical foray into the quantum world. In fact, a quantum vacuum is not empty or nothing in any real sense at all. It has a complex mathematical structure, it is saturated with energy fields and virtual-particle activity. In other words, it is a thing with structure and things happening in it. As such, the equations that would form the quantum basis for generating particles, anti-particles, fluctuations, a Universe, actually exist, possess structure. They are not nothingness, not a void.

To be more specific, according to relativistic quantum field theories, particles can be understood as specific arrangements of quantum fields. So one particular arrangement could correspond to there being 28 particles, another 240, another to no particles at all, and another to an infinite number. The arrangement which corresponds to no particles is known as a ‘vacuum’ state. But these relativistic quantum field theoretical vacuum states are indeed particular arrangement of elementary physical stuff, no less than so than our planet or solar system. The only case in which there would be no physical stuff would be if the quantum fields ceased to exist. But that’s the thing. They do exist. There is no something from nothing. And this something, and the equations which infuse it, has somehow had the shape and form to give rise to protons, neutrons, planets, galaxies and us.

So the question is what gives life to this structure, because without that structure, no amount of ‘quantum fiddling’ can create anything. No amount of something can be produced out of nothing. Yes, even empty space is something with structure and potential. More basically, how and why should such a thing as a ‘quantum vacuum’ even have existed, begun to exist, let alone be infused with the potential to create a Universe and conscious life out of non-conscious somethingness?

It is certainly a puzzle, and arguably one without an intuitive solution.

Exercise

If the conditions in the Big Bang which started our Universe had been even a tiniest of a tiniest of a tiny bit different, with regard to a number of independent physical constants, the galaxies, stars and planets would not have been able to exist. But if we didn’t exist, we couldn’t have asked the question as to why they were so right. In any case, since there must be some initial conditions, the conditions which gave rise to the Universe and life, however fortuitous, were just as likely to prevail as any others. So there is, for both reasons, no puzzle to be explained. Is this a convincing rebuttal of the ‘Fined Tuned’ universe problem. Why? Why not?

Derek Parfit, ‘Why anything? Why this? Part 1. London Review of Books, 20, 2, 22 January 1998, pp. 24-27.

https://www.lrb.co.uk/v20/n02/derek-parfit/why-anything-why-this

Derek Parfit, ‘Why anything? Why this? Part 2. London Review of Books, 20, 3, 5 February 1998, pp. 22-25.

https://www.lrb.co.uk/v20/n03/derek-parfit/why-anything-why-this

John Piippo, Giving Up on Derek Parfit, July 22, 2012

http://www.johnpiippo.com/2012/07/giving-up-on-derek-parfit.html

A universe made for me? Physics, fine-tuning and life https://cosmosmagazine.com/physics/a-universe-made-for-me-physics-fine-tuning-and-life

John Horgan, ‘Science will never explain why there’s something rather than nothing’, Scientific American, April 23, 2012.

https://blogs.scientificamerican.com/cross-check/science-will-never-explain-why-theres-something-rather-than-nothing/

David Bailey, What is the cosmological constant paradox, and what is its significance? 1 January 2017. http://www.sciencemeetsreligion.org/physics/cosmo-constant.php

Fine Tuning of the Universe

http://reasonandscience.heavenforum.org/t1277-fine-tuning-of-the-universe

The Great Filter – are we almost past it? http://mason.gmu.edu/~rhanson/greatfilter.html

Dragon Debris?

Fine Tuning in Cosmology. Chapter 2. In: Bostrom, N. Anthropic Bias: Observation Selection Effects in Science and Philosophy. 2002. http://www.anthropic-principle.com/?q=book/chapter_2#2a

Last Common Universal Ancestor (LUCA)

https://en.wikipedia.org/wiki/Last_universal_common_ancestor

David Albert, ‘On the Origin of Everything’, Sunday Book Review, The New York Times, March 23, 2012.