The Anthropic Coincidences
Is the Universe Fine-Tuned for Life?

Like this page:

Share this page:

The 'anthropic coincidences' is a phrase used to refer to the theory that the Universe is so delicately fine-tuned for life that it must have been designed with that purpose in mind, by an intelligent creator-god. The main argument is that if you fiddle with the universal constants of physics (such as the strengths of the weak and strong nuclear forces) and change their values even by a little bit, then the Universe would be completely unsuitable for life as we know it. Therefore, God created the Universe for life, and in particular, created it for mankind here on Earth. The main arguments against this are that the unimaginably vast Universe is almost everywhere completely unsuitable for life, and even here on planet Earth we can exist only on in a thin crust of a planet that is two-thirds made of water (yet we have no gills). Also, it took nine billion years to make the Earth, and then another four billion before Humankind appeared1. The timetable makes no sense: If the Universe was designed for life, it ought to have simply started with life. When it comes to the sun, which religionists are sure was created to warm us, "of all the energy [it emits], only two photos in a billion are used to warm Earth, the rest radiating uselessly into space"1. The theory that God done it this way on purpose simply doesn't make sense. Evolution does a much better job of explaining why and how life evolved, and is a theory based on evidence, unlike the "God designed life" theory, which is based on pure speculation. Not only that, but it simply reeks of egotistical and prideful wishful-thinking to imagine that the creator of a billion galaxies made all of it with our particular species in mind. If we did change the Universal constants, then, for all we know, even more intelligent life could have evolved in even more different ways. In other words we have no knowledge at all to indicate that the current set-up is optimal for life. For these reasons, the anthropic coincidences argument has been abandoned philosophically and even used to argue against the idea of a God, although in its simpler forms it is still vocalized by many laypeople as being a reason for their belief in God2.

1. Intelligent Design: God Designed the Cosmos For Life

Theologians have long argued that the Universe is "designed for life". In particular, Christians and Muslims and others have argued that it is precisely designed for human life. This idea is one the reasons that many people say they believe in God at all, according to Guy Harrison in "50 Reasons People Give for Believing in a God"2. The various physical factors which influence whether or not there is a perfect little planet Earth to house us include not just astronomical considerations, but ones of fundamental physics too. If many of the Universal constants and laws discovered by physicists is just a little different, it appears that the Universe would never have unfolded in a way friendly to life here on Earth. If you multiply together the known essential factors in an attempt to calculate the chance of such as arrangement arising out of pure luck, the odds against our existence are mind-boggling.

In his 1995 book, The Creator and the Cosmos, physicist Hugh Ross [...] estimated the probability that such a combination be found in the universe as 'much less than one in a million trillion.' He concluded that only 'divine design' could account for human life. However, Ross presented no estimate of the probability for divine design. Perhaps it is even lower!

"God, the Failed Hypothesis: How Science Shows That God Does Not Exist"
Prof. Victor J. Stenger (2007)1

But something is wrong with this argument. Because it appears that the more we perceived the vastness of space, with billions of galaxies each with billions of stars, many of those with planets... and all separated by unimaginably large distance which mankind will never cross, the more it seems that the Universe was not designed for our species. Even just here on Earth, we live in a thin habitable strip on the surface of a planet that is mostly covered in water, our existence teetering inbetween ice ages and global catastrophes brought by asteroids and all sorts else. Compare our existence to the vastness of time and space, and it seems ridiculous, egotistical and prideful to imagine that this is all for us. We are opportunists, living in a tiny niche that by pure chance happens to be have been stable and adequate enough to allow life to develop.

The apparent role of anthrocentrism in the belief that the Universe was designed just for us has led many critics of religion to ridicule and poke fun at those that use this argument.

Given the egocentrism that seems to characterize the human race, convincing people that the universe was designed with them in mind is as easy as convincing a child that candy is good for him.

"Intelligent Design" by Victor J. Stenger

Ocean, n. A body of water occupying about two-thirds of a world made for man - who has no gills.

"The Devil's Dictionary" by Ambrose Bierce (1967)

Bertrand Russell the philosopher hits upon this subject in two separate books. Although the Religion and Science quote is most generic, the first one could easily read "Islam" as "Christianity":

Book CoverIf Christianity is true, mankind are not such pitiful worms as they seem to be; they are of interest to the Creator of the universe, who takes the trouble to be pleased with them when they behave well and displeased when they behave badly. This is a great compliment. [...] It is an even pleasanter compliment if He awards to the good among us everlasting happiness in heaven.

"Why I am not a Christian" by Bertrand Russell (1957)3

Is there not something a trifle absurd in the spectacle of human beings holding a mirror before themselves, and thinking what they behold so excellent as to prove that a Cosmic Purpose must have been aiming at it all along?

"Religion and Science" by Bertrand Russell (1935)4

2. Fiddling with the Universal Constants

The main argument of the anthropic coincidences idea is that if you fiddle with the universal constants of physics (such as the strengths of the weak and strong nuclear forces) and change their values even by a little bit, then the Universe would be completely unsuitable for life as we know it. But if the Universal constants were different, then, for all we know, even more intelligent life could have evolved in even more different ways. In other words we have no knowledge at all to indicate that the current set-up is optimal for life.

Physicist Anthony Aguire has independently examined the universes that result when six cosmological parameters are simultaneously varied by orders of magnitude, and found he could construct cosmologies in which 'stars, planets, and intelligent life can plausibly arise.' Physicist Craig Hogan has done another independent analysis that leads to similar conclusions. And, theoretical physicists at Kyoto University in Japan have shown that heavy elements needed for life will be present in even the earliest stars independent of what the exact parameters for star formation may have been.

"God, the Failed Hypothesis: How Science Shows That God Does Not Exist" by Prof. Victor J. Stenger (2007)1

Carbon is used by life because of its useful properties and abundance. It is abundant because it is produced easily in a variety of circumstances. The same goes for the other CHOMSP elements, which together make up most biochemicals.

In short, no fine-tuning is necessary for the production of carbon, oxygen, and the other basic elements of life. They are in fact the elements that are among the easiest to form by common nuclear reactions. So, too, are the molecular ingredients of life easy to produce. In a remarkably simple experiment in 1952, which took only weeks to assemble, graduate student Stanley Miller, working under the renowned chemist Harold Urey, sent a 60,000-volt electrical spark, simulating lightening, through a flask containing a gas of methane, ammonia, hydrogen, and water vapour. At the time, this was thought to simulate the atmosphere of early Earth. The by-product contained amino acids, the basic chemical sub-unit of proteins, and other raw materials of life.

"God, the Failed Hypothesis: How Science Shows That God Does Not Exist" by Prof. Victor J. Stenger (2007)1

It is worth noting that the Miller-Urey experiment had used wrong starting conditions: their assumptions were misplaced. But the wrong conditions STILL produced organic matter. The reason is that many combinations of factors can produce the types of carbon molecules that we call 'organic', and there is no fine-tuning required for their synthesis.

Many of the quotes and references above are from the renowned late scientist Victor Stenger, who has analysed the anthropic-coincidence arguments in great detail, based on his expert knowledge of the laws of physics. He points out that those who make these arguments are normally poorly educated in what the actual universal constants are:

The current standard model of elementary particles and forces contains about twenty-four parameters that currently are not determined by the theory but must be inferred from experiments. This is not as bad as it might seem, since the model accurately describes thousands of data points. In any case, only four parameters are needed to specify most properties of matter. These are the masses of the electron and the two quarks ('up' and 'down') that constitute protons and neutrons, and a universal strength parameter from which the value a and the other force strengths are obtained. [...]

Many of the examples of fine-tuning found in theological literature suffer from simple misunderstandings of physics. For example, any references to the fine-tuning of constants like the speed of light, c, Planck's constant, h, or Newton's gravitational constant, G, are irrelevant since these are all arbitrary constants whose values simply define the system of units being used. Only 'dimensionless' numbers that do not depend on units, such as the ratio of the strengths of gravity and electromagnetism, are meaningful.

Some of the 'remarkable precision' of physical parameters that people talk about is highly misleading because it depends on the choice of units. For example, theologian John Jefferson Davis asserts, 'If the mass of neutrinos were 5x10-34 instead of 5x10-35 kg, because of their great abundance in the universe, the additional gravitational mass would result in a contracting rather than expanding universe.' This sounds like fine-tuning by one part in 1035. However [...] if the neutrinos were ten times more massive, there would be ten times fewer of them in the cosmos, so the gravitational effect would be unchanged. This fine-tuning example, like so many, collapses on several fronts. Philosopher Robert Klee has provided other examples of how numbers have been manipulated to make it seem that fine-tuning has occurred.

"God, the Failed Hypothesis: How Science Shows That God Does Not Exist" by Prof. Victor J. Stenger (2007)1

3. Pure Chance: The Variety of Life in the Universe and the Chances of Life Appearing

There is a huge range of life on Earth, from specialized multicellular beings that are alien and exotic to familiar 4-legged fuzzy pets, and from plant life to viruses that are not much more than chemical assembly-lines. The ecosystem that we are familiar with is clearly not the only possible design for life. Creatures living on Thermal vents at the bottom of the oceans and aphotic life deep in the oceans may as well be two zones of life on alien planets for all their differences to animal life on the surface. But that diversity exists right here on Earth.

Life in other places in the universe could easily be utterly different to ours. Our life is based on organic biochemistry: this is not known to be the only way that life can exist. Where any pattern can reproduce itself, life could evolve, in any medium. Life could exist inside complex echoes of sound waves, in the patterned reflections of radiation, or could form out of the complicated eddies of gravitational fields or in the movement of liquids. Life could be gaseous, liquid or solid, or in combinations that we find it hard to imagine. We could even find that such life exists on our planet and we simply don't see it. Planets themselves could be conscious. Many of these ideas are being increasingly discussed by scientists5. Lovelock imagined that Earth, as a complex planet, is itself conscious and alive, with the whole atmosphere forming its biochemistry (his idea was named The Gaia Hypothesis)6. The point is that we have no grounds on which to assume that life-as-we-know-it is the only form of life.

If you multiply all the possible forms of life, it is easy to see how this "one in a million trillion" figure is irrelevant. There are uncountable billions of planets, moons, asteroids, comets, suns and other space features in which life might occur. It is reasonable to assume that some times, in some places, that does happen. It is not a ridiculous notion to suggest that every now and then life persists for long enough to produce intelligent beings. That life, in those places, clearly would have evolved to be suited for their environment. Life on Earth proves that evolving systems become specialized for their environments. An ecosystem that develops on a planet with a sulphurous atmosphere will contain species that are able to breathe sulphur - and that life that evolves on a waterworld will have gills that enable it to breathe in water. Like all life here on Earth, they evolve to suit their environments excellently. Those intelligent beings, randomly spawned across the Universe, may well then develop religions and primitive explanations for their own existence. And they may all conclude: The Universe was designed for us! Or at least, they will think like that until the size of the Universe, and the adaptability of life, proves to them that the opposite is true: the Universe was designed for no-one, but, where there is a chance, life can sometimes emerge. The Universe isn't designed for life. It is suited only for lucky opportunists.

If you assume that life only arises on one in a billion planets and calculate, therefore, on how many planets life might have evolved, the number is still massive:

It is really hard to guess as to how many places in the Universe intelligent life has developed. You need to know things like how many habitable planets there are, what the chances are of life developing and what the chances are of life surviving long enough to develop as we have (and beyond). Seven such factors were formulated into a single construct known as the Drake Equation in 1961, by astronomer Francis Drake7. The result of this is as estimate of how many times advanced civilisation has appeared in the Universe. But so many of the necessary values were unknown, that previous generations of scientists have concluded that the error margins are too high to draw any conclusion8. However, advanced new telescopes and the slowly dawning space age have allowed many more accurate measurements to be made and current calculations are that life may have arisen on one hundred billion Earthlike planets throughout the Universe if using some dire statistics on how likely life is to appear on any given planet (one in a billion).

"What are the Chances of There Being Alien Life in the Universe?: 1. Calculations" by Vexen Crabtree (2015)

4. Scientific Support for the Idea that the Laws of Physics Mean Life Must Appear

Many scientists have also embraced a form of argument that life must evolve, which are similar to theist arguments, but stem from a completely atheist and materialistic root9. Paul Davies divides them into three types:

  1. Strong anthropic principle: Some scientists say that "the universe must be such as to admit conscious beings in it at some stage"10. On what grounds can scientists justify such a stance? In the early decades of quantum physics, many strange effects were observed that were poorly understood. Quantum physics is still supremely odd. One of the early strands of thought was made famous through Erwin Schrödinger's thought experiment, now known as Schrödinger's Cat. It appeared that fundamental aspects of reality only resolved themselves into concrete form if observed and until that moment, things remained mere statistical probability and sometimes even particles behave as if they are in two different states at once: Superposition remains a fundamental part of quantum physics. The Universe itself remains unstable, unset, volatile, until such a time as it is observed. And this means that it just wobbles around in all possible configurations until the configuration that spawns valid observers becomes dominant. Then, hey presto, what springs into solid existence is a Universe that will spawn intelligent beings.

  2. Multiple-universes: "According to this point of view, there is an ensemble of universes of which ours is but one member. The universe we perceive is only one of a huge, perhaps infinite, collection of universes. [...] Although the overwhelming majority of these universes are unsuitable for life"11. In an infinite set of universes, each with different laws and properties, then every possible Universe must exist. We are "guaranteed [...] that some universe would arise with the laws that we have discovered. No mechanism and no entity is required to fix the laws of nature to be what they are"12. There is no design-for-life - some versions of the Universe just happen to be able to support life, because all possible configurations of the Universe exist. It seems a safe bet that philosophically minded aliens have a tendency to sit in their Universes and think, "this one was designed for us!". They are clearly wrong.

  3. Oscillating universe theory: "The universe will eventually begin to contract, falling back on itself in a gigantic cataclysm known as the 'big crunch'. Some physicists have speculated that the highly compressed cosmos, rather than imploding to oblivion at a spacetime singularity, will 'bounce' at some enormous density" perhaps resetting universal constants and rules to a random value10. Carl Sagan writes that "scientists wonder about what happens in an oscillating universe at the cusps, at the transition. [...] Some think that the laws of nature are then randomly reshuffled [from] an infinite range of possible natural laws"13. This is like the multiverse theory except that there is only ever one Universe, which has existed in an infinite series of configurations. Some of those instances support life. There is no coincidence that we exist on one that allows life to exist - it was an eventual inevitability. No design was required, just pure randomness.

5. No Universal Creator: Energy From Nothing

The "law of conservation of energy" holds that energy cannot be created nor destroyed, only changed in form. This means that although everything in the Universe may be destroyed, the total energy stays the same. This fundamental law of thermodynamics is one of the most important laws in physics, and is applicable at all scales, from the quantum, to the large scale sciences of engineering and chemistry. It is so important that most physics think that this law can simply never be broken.

Many theists have argued that the scientific laws of thermodynamics, in particular the conservation of energy, imply that there must be a God. If energy cannot be created nor destroyed, they say, then this is proof that the entire spectacle of reality has to be the exercise of a creator God. I.e., a God that creates all of the energy, and then, who creates the laws of thermodynamics. On the face of it, it is certainly one way to explain away the existence of all energy.

But it turns out that the explanation isn't necessary, because the current evidence shows that there is no contradiction to the law of conservation of energy, and it all comes down to gravity14. You expend energy to climb out of an energy well, and, if you add up all the energy of objects and masses and take into account gravity and balance this against the gravitational power of black holes and galaxies, we find that the net value of the energy involved is zero. In other words, if all of the energy in the universe can be accounted for as being matched equally by gravity, it appears that there is actually no created energy.

Astronomers can measure the masses of galaxies, their average separation, and their speeds of recession. Putting these numbers into a formula yields a quantity which some physicists have interpreted as the total energy of the universe. The answer does indeed come out to be zero within the observational accuracy. [...] The cosmos can [come] into existence without requiring any energy input at all.

"God And The New Physics" by Paul Davies (1984)15

Physicist Frank Wilczek, who was one of the first theorists to explore these possibilities, has reminded me that he utilized precisely the same language I have used previously in this chapter, in the 1980 Scientific American article he wrote on the matter-antimatter asymmetry of the universe. After describing how a matter-antimatter asymmetry might plausibly be generated in the early universe based on our new understanding of particle physics, he added a note that this provided one way of thinking about the answer to the question of why there is something rather than nothing: nothing is unstable. [...]

[We see that] the total energy of a closed universe is zero, and if the sum-over-paths formalism of quantum gravity is appropriate, then quantum mechanically such universes could appear spontaneously with impunity, carrying no net energy. I want to emphasize that these universes would be completely self-contained space-times, disconnected from our own. There is a hitch, however. A closed expanding universe filled with matter will in general expand to a maximum size and then recollapse just as quickly, ending up in a space-time singularity where the no-man's land of quantum gravity at present cannot tell us what its ultimate fate will be. The characteristic lifetime of tiny closed universes will therefore be microscopic, perhaps on the order of the Planck time, the characteristic scale over which quantum gravitational processes should operate, about 1044 seconds or so. [...]

The very creative cosmologist I mentioned earlier, Alex Vilenkin, who has since become a friend, had actually just written a paper that described in exactly this fashion how quantum gravity indeed might create an inflating universe directly from nothing.

"A Universe from Nothing" by Lawrence Krauss (2012)16

By Vexen Crabtree 2015 Nov 24
Parent page: Human Religions

Social Media

References: (What's this?)

Book Cover

Book Cover

Book Cover

Book Cover

Book Cover

Book Cover

Bierce, Ambrose. (1842-1914?)
(1967) The Devil's Dictionary. Published in Great Britain by Victor Gollancz. Published by Penguin Books in 1971, and quotes taken from a 2001 Penguin Classics reprint. Penguin Group, London, UK.

Davies, Paul
(1984) God And The New Physics. Penguin 2006 edition. Davies is a Professor in theoretical physics who has published ground-breaking research.

Dawkins, Prof. Richard
(2006) The God Delusion. Hardback. Published by Bantam Press, Transworld Publishers, Uxbridge Road, London, UK.

Harrison, Guy P.
(2008) 50 Reasons People Give for Believing in a God. Published by Prometheus Books, New York, USA.

Kaku, Michio. Professor of theoretical physics.
(2014) The Future of the Mind. subtitled "The Scientific Quest To Understand, Enhance and Empower the Mind". Published by Penguin Books Ltd, London, UK. Quotes taken from Amazon e-book.

Krauss, Lawrence. Lawrence Krauss is Foundation Professor in the School of Earth and Space Exploration and the Physics Department at Arizona State University, as well as Co-Director of the Cosmology Initiative and Inaugural Director of the Origins Project.
(2012) A Universe from Nothing. Amazon digital edition. Published by Free Press, New York, USA.

Peake & Smith
(2009) Climate Change. 2nd edition. Originally published 2003. Published by Oxford University Press, Oxford, UK, in association with The Open University.

Russell, Bertrand. (1872-1970)
(1935) Religion and Science. 1997 edition with introduction by Michael Ruse. Published by Oxford University Press, Oxford, UK.
(1957) Why I am not a Christian. Quotes from Fourth Impression of 1967 edition, 1971, Unwin Books.

Sagan, Carl
(1995) Cosmos. Originally published 1981 by McDonald & Co. This edition published by Abacus.

Stenger, Prof. Victor J.
(2007) God, the Failed Hypothesis: How Science Shows That God Does Not Exist. Published by Prometheus Books. Stenger is a Nobel-prize winning physicist, and a skeptical philosopher whose research is strictly rational and evidence-based.


  1. Stenger (2007) "The Uncongenial Universe" Chapter 5.^^^
  2. Harrison (2008) chapter 47: "The earth is perfectly tuned to support life".^^
  3. Russell (1957) p40.^
  4. Russell (1935) p221.^
  5. Davies (1984) p210. The author commends the speculative book Life Beyond Earth, in which the physicist Gerald Feinberg and the biochemist Robert Shapiro "argue the case for life based on plasmas, electromagnetic field energy, magnetic domains in neutron stars and a variety of other bizarre systems".^
  6. Peake & Smith (2009) p195-196.^
  7. "The Future of the Mind" by Michio Kaku (2014) chapter 14 "The Alien Mind", digital location 4941-5235."^
  8. "The God Delusion" by Prof. Richard Dawkins (2006) p137-8, 69-70.^
  9. Krauss (2012) p125. Discusses Steven Weinberg who gave this serious consideration as a result of philosophizing about the Coincidence Problem in relation to the cosmological constant, before dark energy had been discovered.^
  10. Davies (1984) p171-3.^
  11. Davies (1984) p171-3. Also see Gibson (2009) p51.^
  12. Krauss (2012) p176..^
  13. Sagan (1995) p286-288.^
  14. Krauss (2012) p103, p148.^
  15. Davies (1984) p31.^
  16. Krauss (2012) p159,167,169.^

© 2015 Vexen Crabtree. All rights reserved.