Cosmic fine-tuning – Scientific study of the universe in recent decades has revealed an intricate and finely tuned ensemble of factors that make our
existence possible. The seminal text is probably Brandon Carter’s 1974 paper Large Number Coincidences and the Anthropic Principle in Cosmology. These factors,
sometimes (as in the title of Brandon Carter’s paper) question-beggingly called anthropic coincidences, are necessary conditions for life as we know it and as
we can conceive it. (For that reason, some have argued that the proper term ought to be biocentric rather than anthropic.) That they exist is not in question.
It’s their significance that’s debated. There are various lists of these, some fairly long. For the sake of brevity, though, I’ll concentrate on just six of
them as they’re listed in the appropriately titled book Just Six Numbers written by Sir Martin Rees, the Astronomer Royal of England, former Master of Trinity
College, Cambridge, and past President of the Royal Society. “Two of them,” he says, “relate to the basic forces; two fix the size and overall ‘texture’ of our
universe and determine whether it will continue forever; and two more fix the properties of space itself”.
1. The ratio of the electromagnetic force to the force of gravity (N).
This can also be expressed as the electrical force between two protons – you’re not going to have to remember this, but I want you to get the sense of it. This can be expressed as the electrical force between two protons divided by the gravitational force between them. N equals 1,000,000,000,000,000,000,000,000,000,000,000,000. If it were slightly smaller than the value we actually see, Professor Rees says, “only a short-lived miniature universe could exist: no creatures could grow larger than insects, and there would be no time for biological evolution.”
2. The strong nuclear force.
The strong nuclear force accounts for the firmness with which atomic nuclei bind together. It determines how long stars live. It has a value of 0.007 and it “controls the power from the Sun and, more sensitively, how stars transmute hydrogen into all the atoms of the periodic table.” Without the heavier elements – especially carbon – life as we know it would be impossible. But if the value of this constant were .006 or .008, neither they nor we would exist.
3. The amount of matter in the universe – (Ω) (omega).
The cosmic number Ω is a measure of the total amount of material in the known universe, regardless of the form in which it occurs, whether in galaxies and diffuse gas or in so-called “dark matter” and “dark energy.” Ω answers the question of “the relative importance of gravity and expansion energy in the universe” after the big bang. “If this ratio were too high relative to a particular ‘critical’ value,” Professor Rees explains, “the universe would have collapsed long ago; had it been too [low], no galaxies or stars would have formed. The initial expansion speed seems to have been finely tuned.” It’s rather, he says, “like sitting at the bottom of a well and throwing a stone up” with such precision that its rise comes to a stop at precisely the top of the well. “[A]t one second after the Big Bang,” he continues, “Ω cannot have differed from unity by more than one part in a million billion.”
4. Cosmic repulsion (λ) (lambda).
In 1998, cosmologists recognized the importance of cosmic antigravity in controlling the expansion of the universe. In particular they noticed that it becomes increasingly important as the expanding universe becomes more diffuse, darker, and emptier. “Fortunately for us (and very surprisingly to theorists),” says Martin Rees, “λ is very small. Otherwise its effect would have stopped galaxies and stars from forming, and cosmic evolution would have been stifled before it could even begin.”
5. The ratio of the gravitational binding force to rest mass energy (Q).
“The seeds for all cosmic structures – stars, galaxies and clusters of galaxies – were all imprinted in the Big Bang.” Q determines what might be called the “texture” or “fabric” of the universe, and is, thus, fundamentally important. Its value is about 1/100,000. “If Q were even smaller,” writes Professor Rees, “the universe would be inert and structureless; if Q were much larger, it would be a violent place, in which no stars or solar systems could survive, dominated by vast black holes.” “Q,” he continues, was “imprinted in the very early universe,” and “the ‘embryos’ of clusters and superclusters – structures stretching millions of light-years across the sky – can be traced back to a time when the entire universe was of microscopic size.”
6. The sixth of the six numbers – the number of spatial dimensions (D).
This may seem a strange one to most of us, but it’s crucial that there are three spatial dimensions. String theory – controversial, I know – holds that there were originally ten or eleven dimensions at the birth of the universe, but they were “compacted” into a lower number. “Life couldn’t exist,” says Professor Rees, “if D were two or four.”
To continue with this: “[W]hy,” asks the famous British cosmologist Stephen Hawking, “is the universe so close to the dividing line between collapsing again and expanding indefinitely? In order to be as close as we are now, the rate of expansion early on had to be chosen fantastically accurately. If the rate of expansion one second after the big bang had been less by one part in 1010, [that’s one part in ten billion] the universe would have collapsed after a few million years. If it had been greater by one part in 1010, the universe would have been essentially empty after a few million years. In neither case would it have lasted long enough for life to develop.”
“[I]f the electric charge of the electron had been only slightly different, stars … would have been unable to burn hydrogen and helium, or else they would not have exploded…. [I]t seems clear that there are relatively few ranges of values for the numbers [for the constants] that would allow for the development of any form of intelligent life. Most sets of values would give rise to universes that, although they might be very beautiful, would contain no one able to wonder at that beauty.”
I’m now going to mention an incredibly large number. Please recall that 1010 is equivalent to the number 1 followed by ten zeros, which is ten billion. 10123, by contrast, is  followed by 123 zeros. Imagine the number 1010 multiplied by 10123. It’s a pretty big number. Sir Roger Penrose, who served for many years as the Rouse Ball Professor of Mathematics at the Mathematical Institute at the University of Oxford, is my source for that number. “How big,” he asks, “was the original phase-[space] volume … that the Creator had to aim for in order to provide a universe compatible with the second law of thermodynamics and with what we now observe?… The Creator’s aim must have been [precise] … to an accuracy of one part in [1010 multiplied by 10123]. This is an extraordinary figure. One could not possibly write the number down in full, in the ordinary denary notation: it would be '1' followed by 10123 successive ‘0’s! Even if we were to write a ‘0’ on each separate proton and on each separate neutron in the entire universe – and we could throw in all the other particles as well for good measure – we [would] fall … short of writing down the [number] needed. [This is] the precision needed to set the universe on its course.” “I cannot even recall,” Penrose has written elsewhere, “seeing anything else in physics whose accuracy is known to approach, even remotely, a figure like one part in 1010(123).”
But numbers in the same general ballpark abound. If, for example, the strength of gravity had been different “by one part in ten thousand billion, billion, billion,” writes Robin Collins, we would not exist.
If the ratio of electron-to-proton mass were larger than it is, chemical bonding would be insufficient for life chemistry. The allowable variation, some have calculated, is about one in . This [is] an incredibly small number. Says Hugh Ross, a Ph.D. astrophysicist turned evangelist, “One part in 1037 is such an incredibly sensitive balance that it is hard to visualize. The following analogy might help: Cover the entire North American continent in dimes all the way up to the moon, a height of about 239,000 miles. (In comparison, the money to pay for the U.S. federal government debt would cover one square mile less than two feet deep with dimes. [That’s still pretty big.] Next, pile dimes from here to the moon on a billion other continents the same size as North America. Paint one dime red and mix it into the [billions of] piles of dimes. Blindfold a friend and ask him to pick out one dime. The odds that he will pick the red dime are one in 1037.” Thus, even Steven Weinberg, a vocally atheist Nobel laureate cosmologist at Princeton, acknowledges that it “does seem remarkably well adjusted in our favor.”
In fact, “[i]f the cosmological constant were not fine-tuned to within an extremely narrow range – one part in 1053 or even 10120 of its ‘theoretically possible’ range of values – the universe would expand so rapidly that all matter would quickly disperse, and thus galaxies, stars, and even small [aggregations] of matter [would] never form.” According to philosopher Robin Collins, the odds of this occurring by random chance are roughly equivalent to those of hitting a bull’s eye on Earth less than the size of a single atom with a dart casually thrown from space. As physicist Stephen Barr comments, “This is one of the most precise fine-tunings in all of physics.”
As Sir Fred Hoyle, another atheist, rather dejectedly wrote, it’s as if “a superintellect has monkeyed with [the] physics, as well as with [the] chemistry and [the] biology, and … there are no blind forces worth speaking about in nature.”
Now, you know, someone might respond to this and say, and people do say all the time, “Well, OK, so the universe is fine-tuned, big deal.” You know, “OK, we live in a universe that makes it possible for us to live. If it didn’t make it possible for us to live, we wouldn’t be here. End of question. You know, that’s it.”
John Leslie wrote a wonderful little book called Universes. He’s a philosopher who looked at this question. He comes up with a nice analogy. He says, OK, that lack of curiosity seems rather unscientific. Imagine you were in front of a firing squad. You’ve been sentenced to die. There are 12 or 15 sharpshooters standing about 25 feet away. They’re aiming at a target on your chest. The person counts down, pronounces the order to fire, they all fire, and … you’re still there. What do you say? “Well, you know, I’m not curious because, obviously, if they’d killed me, I wouldn’t be here to ask the questions. So, you know, so I’m not going to inquire any more to find out why I’m here.” That’s a certain lack of curiosity there, it seems to me.
What I would argue is that it seems to me, that you can at least make the argument. I’m not going to say it’s a slamdunk, but you can at least make the argument, based on these and many other similar things, that intelligence may have been involved in the universe from the start, that there’s something about this that seems as if a superintellect has monkeyed with the physics.
All right, this is the famous “blue marble” image, one of the great pictures of the Earth taken from space. It puts it in a different perspective for us. There are some books that have come out within recent years, one of them bearing the title Rare Earth (I quite like that) in which they make the point that the Earth is really quite remarkable. When I grew up, the Earth was an undistinguished planet, in an undistinguished solar system, in an undistinguished part of the Milky Way galaxy. Big deal, you know. The Copernican revolution supposedly dethroned the Earth and all that. We now learn there are a lot of things about the Earth, including plate tectonics and so on, that are really quite remarkable, and if you don’t have them, you can’t have life.
Now, again, does this prove design? I’m not arguing that. I’m arguing that this is not quite so easy to brush off as it might seem. I’m interested with these in only getting into the 50/50 point where you’re willing to consider the possibility that maybe the universe is a “put-up job,” as Fred Hoyle also called it.