Learned jaws were on the ground yet again when it was realized that if that value was just one decimal place shorter – that is, the actual positive energy was 10119 times less than the total (or 118 zeroes after the decimal point and before the 1) – then the universe as we know it simply couldn’t exist. It would expand too quickly for galaxies, stars or planets to form. Referring to this as the ‘biggest fix in the universe’, Davies points out that this tiny difference – a point between the 119th and 120th decimal place – is the thinness of the knife edge on which all life is balanced.14 In answer to the dilemma posed by this ‘staggeringly precise’ balancing of the vacuum energy, Leonard Susskind writes: ‘This seems like an absurd accident and we have no idea why it should happen. There is no fine-tuning quite like this in the rest of physics.’15
However, while acknowledging that there is no viable alternative to an ‘anthropic explanation’,16 Susskind does not imply the existence of a ‘grand designer’. For him this phenomenon can only be explained by whatever is behind the anthropic effect as a whole, which to the conventional scientist means the illusion of design. For Susskind, however, as for many scientists, there is only one solution to the conundrum: the marvellous and all-encompassing notion of ‘multiverse’.
INSIDE THE MULTIVERSE
According to the fans of this fashionable hypothesis, there are millions or billions, perhaps an infinite number, of universes, co-existing invisibly alongside our own, each governed by its own laws of physics. We just happen to live in one that happens to be biofriendly. It may appear to have been custom-made for us, but as this universe is, by definition, one that will sustain our sort of life and the only one we can perceive, this is the only one we know about.
The multiverse is a concept that turns the virtually impossible into the almost inevitable. To use the lottery analogy again, if your ticket automatically entered you into several million draws simultaneously, it would hardly be surprising if your numbers came up somewhere. The same logic dictates that by positing millions upon millions of universes, the odds that at least one would boast the right conditions for life are drastically shortened.
The multiverse theory is the only alternative to design that remains within the bounds of scientific credibility and allows the anthropic conundrum to be debated without professional anxiety. Bernard Carr explains that physicists regard the multiverse hypothesis as the ‘legitimization’17 of the anthropic principle.
However, unfortunately for its many scientific fans, there are major problems with the multiverse. First, and surely the most damning, is that it is purely a theory with not a shred of solid data to back it up. There are three basic, competing models of the genesis of multiple universes that may keep physicists agog with debate and busy formulating mathematical models of how they might work, but this seems a hollow exercise as none of the models have the remotest hope of ever being proved. In fact, it is impossible to gather evidence because interaction between universes is by definition also impossible.
On the other hand, multiverse theory can be used to predict certain features of this universe. But as American theoretical physicist Lee Smolin, founder of the Perimeter Institute for Theoretical Physics in Ontario, Canada, notes:
Within the standard model of elementary-particle physics, there are constants that simply don’t have the values we would expect them to have if they were chosen by random distribution among a population of possibly true universes … In fact, I know of no successful predictions that have been made by reasoning from a multiverse with a random distribution of laws.18
The theory also violates another highly-prized scientific principle, Occam’s razor, expressed by the great twentieth-century physicist Sir James Jeans as, ‘We must not assume the existence of any entity until we are compelled to do so’,19 or, in other words, the simplest explanation is usually the best. As Paul Davies wryly comments: ‘To invoke an infinity of other universes to explain one is surely carrying excess baggage to cosmic extremes.’20
The complete absence of evidence does not justify the extraordinary confidence with which the multiverse is promoted as a solution to the anthropic conundrum. In a 2008 radio discussion, British theoretical physicist Fay Dowker stated that ‘the existence of the multiverse, if we can establish it, would eliminate the question of why the laws of nature are the way we see them’.21 If we can establish it …
In the introduction to Universe or Multiverse? (2007), Carr acknowledges that the multiverse hypothesis:
… is highly speculative and, from both a cosmological and a particle physics perspective, the reality of a multiverse is currently untestable. Indeed, it may always remain so, in the sense that astronomers may never be able to observe the other universes with telescopes and particle physicists may never be able to observe the extra dimensions with their accelerators.22
He goes on:
For these reasons, some physicists do not regard these ideas as coming under the purview of science at all. Since our confidence in them is based on faith and aesthetic considerations (for example mathematical beauty) rather than experimental data, they regard them as having more in common with religion than science.23
In recent years the multiverse theory has become inextricably bound up with two others: string theory and the related M-theory. These are now locked in a symbiotic – indeed circular – relationship. To put it baldly, one is taken as proof of the other. Unfortunately, however, both the string and M-theories suffer from the same problems as the multiverse. And a growing chorus of physicists are volubly expressing doubts about their validity and whether, despite all the time, effort and often almost hysterical enthusiasm devoted to them, they are nothing more than a complete dead end. One of the most withering attacks on string theory came in 2006 from Lee Smolin in his book The Trouble with Physics.
String theory – often called ‘superstring theory’ in a rather pitiable attempt to make it sound sexier – posits that instead of being single points, subatomic particles are all manifestations of a single type of vibrating one-dimensional string-like entity that expand and contract as they gain or lose energy. As they are beyond tiny, one-trillionth of a trillionth the size of an atom, obviously no one has ever seen one. They only definitely exist within the realm of mathematical formulae.
String theory was formulated in the mid-1980s and was quickly recognized as the best hope for the physicists’ dream of a theory that would unify relativity and quantum theories, the grand unified theory or theory of everything. However, it rapidly moved in the opposite direction. As it failed to explain certain things, variations were suggested to account for them, and so every attempt to fix the initial problem ended with another variant of the basic theory – adding new excrescences to the equations. As the number of variations multiplied exponentially, creating new sub-theories, each with its own problems, attempts to fix those led to more variations. And so on.
Physicists belonging to the old guard reacted with alarm. Richard Feynman declared: ‘I don’t like that for anything that disagrees with an experiment, they cook up an explanation – a fix-up to say, “Well, it still might be true.”’24
The numbers involved are literally beyond imagining. Based on the currently-understood value of certain cosmological parameters, when all the different variables are taken into account, there are around 10500 possible versions of string theory. That’s 1 followed by 500 zeroes – difficult enough to write down, let alone imagine – about six times the number of atoms calculated to exist in the observable universe. As Smolin points out:
Even if we limit ourselves to theories that agree with observation, there appear to be so many of those that some of them will almost certainly give you the outcome you want. Why not just take this situation as a reductio ad absurdum? That sounds better in Latin, but it’s more honest in English, so let’s say it: if an attempt to construct a unique theory of nature leads instead to 10500 theories, that approach has been reduced to absurdity.25
In 1995 the term ‘M-the
ory’ was coined in an attempt to bring order to the chaos. M-theory simply means the single theory that is assumed to lie behind all the variations of string theory and which, once established, will reconcile them all. Although ‘M’ was chosen randomly – like labelling an unknown quantity ‘X’ – those to whom it is the ultimate answer have happily tied themselves in knots trying to work out what it means, suggesting it might stand for ‘magic’, ‘mystery’ or ‘mother’. Those who are undecided about its value suggest maybe it stands for ‘maybe’. Sceptics prefer ‘myth’. Despite the fact that M-theory is simply shorthand for a desperately needed, but currently nonexistent solution to the complex problems posed by string theory, many physicists now solemnly make statements like ‘according to M-theory …’
In a seminal paper in 2002, Leonard Susskind, the ‘father of string theory’, one of those who originally formulated it in the late 1960s, proposed a unification of the string and multiverse theories that made a virtue of the vagueness of M-theory. He was compelled in that direction by the astonishing precision of the near-cancellation of vacuum energy that we discussed earlier, which he realized could only point to an anthropic explanation. Susskind proposed that every variation of string theory was as correct as any other – each simply defines the laws of physics for a different universe. In what he termed a ‘landscape’ of string theories, he proposed that rather than one theory of everything, there are really lots of ‘everythings’, each with its own theory.
So, although the term ‘M-theory’ was originally invented as an umbrella term for the 10500 competing variations of string theory, its advocates, most prominently Susskind and Stephen Hawking, have turned it into a single theory in its own right. This ‘proves’ that there are 10500 different string theories defining the laws of physics for 10500 different universes, and is therefore taken as proof that the multiverse is real.
This may be an ingenious exercise in explaining one unknown by another, but that’s all it is. As we have seen, the multiverse theory is after all by definition untestable, and M-theory unproven to say the least. As Jim Al-Khalili, theoretical physicist at the University of Surrey, commented:
The connection between this multiverse idea and M-theory is … tentative. Advocates of M-theory … would have us believe that it is done and dusted. But its critics have been sharpening their knives for a few years now, arguing that M-theory is not even a proper scientific theory if it is untestable experimentally. At the moment it is just a compelling and beautiful mathematical construct … 26
The situation thus becomes very much like the argument between those who insist their chosen god is bigger and better than any other, a line that so rouses Richard Dawkins’ ire. To him, this is ludicrous even to begin to debate, as no gods exist. Yet here we have a very similar attitude. The arguments about multiverses and string theory are basically theological debates without a god or gods.
Clearly the multiverse explanation of why we live in a biofriendly universe is (to put it as kindly as we can) at best speculative. As Smolin comments, because the multiverse hypothesis can’t be confirmed by direct observation, it can’t be used as an explanation and conversely, ‘the fact that we are in a biofriendly universe cannot be used as a confirmation of a theory that there is a vast population of universes.’27 The late John Archibald Wheeler, who took on Einstein’s mantle in the 1950s, discovered black holes and is widely regarded as the greatest theoretical physicist of modern times, considered the multiverse as unscientific speculation that carried ‘too much metaphysical baggage’.28
Paul Davies explores an ironic and amusing twist to the multiverse theory, one that takes the story into rather unsettling Matrix-esque territory. This invokes another sci-fi idea that is nevertheless taken seriously by many scientists, that of simulated universes. Building on the ideas of British philosopher Nick Bostrom, Davies explored the implications presented by the simulated universes concept in the ‘design vs. multiverse’ debate.
As Davies pointed out in an article in 2003, since multiverse theories posit an infinite number of universes, anything anyone can think of will inevitably happen in one or more of them. Although only rarely will one universe possess the right conditions for life, there will still be masses of inhabited universes. (After all, what’s a small percentage of infinity?) In some of them, civilizations will have arisen that are so technologically advanced they will have developed their own computer-simulated, Matrix-style universes. For all we know, we might be living in one. (But how would we ever know if there were no red pills?) After all, a civilization that can simulate one universe can simulate many. As Bostrom points out, the ability to run such simulations wouldn’t remain confined to a civilization’s scientists, but would eventually filter down to students, schoolchildren, artists and even hobbyists. Programmers might even create universes where the inhabitants are advanced enough to simulate their own universes. The logical outcome would be that the majority of universes would be artificially designed.29
This provocative scenario does, of course, depend on the multiverse theory being correct in the first place, and Davies is far from convinced of this. The point of his paper is that if one accepts the multiverse, then one also has to accept that the odds are in favour of our universe actually being simulated. So, pushed to its logical conclusion, even the multiverse theory supports the idea of design!
What surprised Davies was the enthusiasm with which proponents of the multiverse such as Lord Rees took to their idea.30 They are much more willing to accept that our universe is designed by a computer programmer than that it was designed by a God or gods – even though the distinction is of course, essentially merely semantic. To humanity the Great Programmer(s) would be divine and omnipotent – so they might as well be gods.
A DESIGN FOR LIFE
Even with such prestigious opponents as Wheeler, most physicists and cosmologists accept the multiverse theory. But are so many of the best modern scientific minds simply clinging to it just because they’re afraid of facing the very unwelcome implications of the anthropic principle?
The evidence underpinning the anthropic principle suggests one of two scenarios: either the cosmos was intelligently designed, specifically to produce intelligent life, or there is something about it that makes it seem like this is the case. The only suggestion that has been made about what that ‘something’ might be is the multiverse. This presents us with a straight choice between one or the other. And if the multiverse is wrong then science itself proves that the universe is designed for life.
This choice is recognized by most leading physicists such as Stephen Hawking, who writes that the anthropic principle ‘suggests either intelligent design or, if there are trillions of universes as M-theory proposes, that luck and probability are enough to make our existence feasible’.31 In his 2010 The Grand Design, co-written with Leonard Mlodinow, he comes down firmly on the side of the multiverse and M-theory, which led to his well-publicized pronouncement that God did not create the universe, while acknowledging that M-theory hasn’t yet been proven. Jim Al-Khalili, however, points out that this is essentially the same logic as those used by religionists. While they use fine-tuning, along with their faith, as evidence for the existence of God, Hawking and his fellow advocates of M-theory seize on it – together with the assumption that there is no God – as evidence for their own hypothesis.32
No less a figure than Steven Weinberg, the eminent American Nobel prizewinning theoretical physicist, when discussing the enigma of the vacuum energy, writes that if further research confirms this seemingly miraculous balancing act ‘it will be reasonable to infer that our own existence plays an important part in explaining why the universe is the way it is’.33 Susskind calls Weinberg’s statement ‘the unthinkable, possibly the most shocking admission that a modern scientist could make: man’s place in the universe may indeed be at the centre’.34 Of course, despite those words, Weinberg, champion of the ‘pointless universe’, will not agree for a moment that man is at the centre
of things. He goes on:
For what it is worth, I hope that this is not the case … I hope that string theory really turns out to have enough predictive power to be able to prescribe values for all the constants of nature …35
But if string theory finally and comprehensively falls, as it shows every sign of doing, then we will be left with Weinberg’s reasonable inference that the presence of intelligent life is fundamental to explaining the universe. This would mean that science itself effectively provides overwhelming evidence for the designer universe, which of course means there must be a Grand Designer.
We are often told that science is an evolving, self-correcting process, in which its laws and theories are never fixed but merely contingent, the best conclusions that can be drawn from the available data. It is also implicitly understood that future discoveries may completely overturn current thinking and lead to a revision of the theories. But when it comes to the anthropic principle this reasoning suddenly falls by the wayside.
The best available data from physics – the hard facts it has amassed, which can then be tested experimentally and empirically – points unequivocally to a universe fine-tuned for intelligent life. However, the majority of scientists argue that one day we will have better data that will show this to be an illusion. But all their supporting ‘evidence’ is theoretical, speculative and untestable. We can imagine what would happen in any other field of human endeavour if someone admitted they had factual evidence pointing in one direction, but then declared they can think of a hypothetical reason why the opposite, which unfortunately is impossible to test, is true.
Why should this be? Why should the normal rules of science change when it comes to the anthropic principle? The justification for making it a special case is that a designed universe violates one of the most fundamental principles on which the scientific worldview and method is based. The scientific revolution, we are told, came about when thinkers realized that physical phenomena could best be explained in terms of mechanical processes and laws that are purely a consequence of the way the universe is – without presupposing the existence of a designing and guiding intelligence.
The Forbidden Universe: The Origins of Science and the Search for the Mind of God Page 22
