|Robert L. Blum, MD, PhD|
Fine-Tuned Universe, God, and
the Anthropic Principle
I just completed my annual trek through the Sierras.
This year I was out for 12 days, backpacking, most of it above 9,000 feet.
During the day I experience the majesty of 4,000 meter granite peaks
formed from plumes of magma deep within the shifting plates of North America and the Pacific.
At night beneath crystalline skies the Milky Way is strewn across the heavens
Not surprisingly in such environs my thoughts always turn to the big questions of life.
How did we come to exist? Why, in fact, does anything exist? Could the Universe
Although I was hiking solo this year, I was astounded by the number of
(One of astrophotographer Serge Brunier’s stunning photos La Voie Lactee (the Milky Way)
There are perhaps two or three dozen physical constants that characterize
It is widely thought by many physicists that these physical constants
Think of a Universe-creating machine with many knobs
Some of these physical constants appear to be so finely-tuned that
I have heard dozens of lectures by leading cosmologists on this topic. This essay is just
Before I launch into fine-tuning, you need to be aware generally of how the Universe
developed over time from its initial seed in the Big Bang. That story is told in a series of articles
(illustration from Wikipedia article on the Big Bang)
13.7 billion years ago: Big Bang occurs from an initial dot of infinitely hot, infinitely dense matter.
10-35 seconds: Cosmic inflation creates a large smooth patch of space filled with lumpy quark soup.
First microsecond: protons and neutrons form from quarks
First few minutes: (as early as .01 seconds) Helium, lithium, deuterium form from proton and neutrons
380,000 years later: Atoms form from nuclei and electrons. Before this the Universe was
opaque. Since electrons were not bound, all light was immediately scattered – like scuba-diving
300 million years later: the Dark Ages end – gravity has enabled the first stars and galaxies to form.
One Billion years: limit of current astronomical observations (highest redshift objects)
Three billion years: clusters of galaxies form; star formation peaks
Nine billion years: Solar system forms: Earth is 4.5 billion years old
(minor footnote: life begins 3.7 billion years ago)
10 billion years: Dark Energy causes accelerated expansion of Universe
two million years ago: Homo habilis evolved (our distant ancestors - early species of hominoids)
two hundred thousand years ago: Homo sapiens evolved
ten thousand years ago: agriculture and later, the first cities
(Illustration is from The Birth of the Universe: The Kingfisher Young People’s Book of Space, 1998.
As I gathered material for this essay, I was delighted to find an outstanding collection of video interviews by many of the physicists who have created the current view of the origins of the Universe. That website is ClosertoTruth, a magnificent collection of interviews of the top-gun physicists on the planet. Robert Kuhn, who conducts the interviews, has selected the cream of the crop: several Nobel laureates, prominent authors, physicists, cosmologists, philosophers and professors of theology. My thanks to Robert Kuhn for making these clips freely available.
As several of the physicists state, there are several possible explanations for fine-tuning.
(I will revisit these and others at the conclusion, but this will help you get my drift.)
Religious explanation: God created the Universe (by setting the knobs just so).
Random luck: It just turned out the way it did. We won the cosmic jackpot.
Grand Theory: An unknown theory forces things to be the way they are.
Multiverse: There are an infinite number of Universes with different laws.
I’ll come back to these later.
Let’s examine one important class of knobs on the Universe-creation machine.
These knobs are called the coupling constants. These are the constants that determine how strongly a particle feels a particular force.
The most famous of these is the fine structure constant alpha, which determines the strength of the electromagnetic force on an electron. (Here I summarize the Wikipedia article on the Fine-structure constant.)
According to quantum mechanics, negatively charged electrons are confined to their particular orbits around the positively charged nucleus by the exchange of photons only of particular definite energies. These quantized orbitals determine how tightly bound
Now, the question is "why is it 1 / 137?" If it were 4% larger, then stellar fusion would not produce carbon, so carbon-based life would be impossible! If it were > .1, then stellar fusion itself would be impossible, and there would no stars in the Universe! As Nobel laureate Richard Feynman put it in 1985 -
"all good theoretical physicists put this number up on their wall and worry about it. Nobody knows where the number comes from. It's one of the greatest mysteries of physics ... You might say the "hand of God" wrote that number and we don't know how He pushed his pencil."
Or consider this quote from Nobel laureate Max Born that appears in Arthur I. Miller's 2009 book, Deciphering the Cosmic Number:
"If alpha [the fine structure constant] were bigger than it really is, we should not be able to distinguish matter from ether [the vacuum, nothingness], and our task to disentangle the natural laws would be hopelessly difficult. The fact however that alpha has just its value 1/137 is certainly no chance but itself a law of nature. It is clear that the explanation of this number must be the central problem of natural philosophy."
Living organisms are made from about two dozen elements, principally carbon, hydrogen,
More recently, because of discoveries just in the past decade, the cosmological constant,
The ultimate fate of the Universe has long been an open question.
Presumably the Universe is expanding as a result of residual effects of the Big Bang,
The current best theory is Dark Energy! All of space is filled with this type of energy,
The cosmological constant (physicists, forgive this simplification) expresses
The cosmological constant is another of those physical constants whose value
So, we are left with a conundrum: how were these dozens of physical constants so finely tuned?
(Michelangelo’s Creation of Man from the ceiling of the Sistine Chapel in the Vatican.)
All we really know for sure is that we are here, and that if conditions had
The Weak Anthropic Principle is what I just stated: since we exist, we must find ourselves
This seems like an obvious truth or tautology, but it is useful nonetheless. Roger Penrose explains
namely, why are the physical constants of nature precisely set as they are?
The Strong Anthropic Principle adds a MUST to the statement. The Universe MUST
So, what is the state of opinion among scientists, philosophers, and theologians?
(Here, I also add my own intuitions – just one man’s prejudices.)
Some Possible Explanations of a Fine-Tuned Universe
1. The absurd universe
Our universe - and it is the only one in existence - just happens to be the way it is.
2. The unique universe
There is a deep underlying unity in physics which necessitates the universe being the way it is. Some grand theory will explain why the various features of the Universe must have exactly the values that we see. (I really like this. It also provides the motivation for thousands of papers on grand unification, string theory, and quantum loop theory. The idea is that these seemingly arbitrary physical constants MUST have their observed values because of some deep underlying structure of nature. Unfortunately, as Martin Rees, the Astronomer Royal, points out in his video interview on ClosertoTruth, our brains at present are possibly too primitive to perceive that deep structure. That discovery may need to await humanity 2.0 .)
Multiple Universes exist having all possible combinations of characteristics, and we inevitably find ourselves within a Universe that allows us to exist. (When I first heard of the Multiverse theory, championed by Stanford physicist Andre Linde, I was delighted. His theory of chaotic eternal inflation creates multiple universes all the time, not just ours. Some of them contain life like ours and others don't. As several physicists comment on Closertotruth, however, this can be viewed as simply a failure to find the grand theory (possibility two). We don't understand why or how our set of physical constants turned out to be so precisely set, therefore, we resort to this fallback position.
A creator designed the Universe with the purpose of supporting complexity and the emergence of Intelligence. If you're religious, this is for you. God created the Universe as we see it. Note, however, that even if you're not religious, there are versions of creationism that still work. Consider the Biocosm hypothesis of James Gardner. Technological society is developing god-like powers of creation. In the future it may be possible to create black holes and other seemingly miraculous feats of cosmic proportion. It's conceivable that our Big Bang was designed by just such a powerful agent or civilization expressly with the purpose of perpetuating intelligent life.
5. The life principle
There is an underlying principle that constrains the universe to evolve towards life and mind. (This appears to be a subset of the unique universe hypothesis above - fascinating and driving lots of research in origins of life and evolutionary psychology. That intelligence evolved, given living organisms, is easy to explain. It confers a large survival benefit for an individual organism. Whether it also confers longevity on human civilization as a whole is not known. The possiblity of technological annihilation of mankind might explain the Fermi Paradox, the apparent rarity of extraterrestrials. The evolution of consciousness as an accompaniment of intelligence is also unexplained.
Note, however, that accepting Darwinian evolution only helps once you’ve got life. That’s just events on Earth in the past 4 billion years. It says nothing about how we got from a sea of hot quarks 14 billion years ago until the Solar system came into existence 5 billion years ago.
Physicist Lee Smolin also offers just such another possibility:
The theory surmises that a collapsing black hole causes the emergence of a new universe on the "other side", whose fundamental constant parameters may differ slightly from those of the universe where the black hole collapsed. Each universe therefore gives rise to as many new universes as it has black holes. Thus the theory contains the evolutionary ideas of "reproduction" and "mutation" of universes, but has no direct analogue of natural selection. However, given any universe that can produce black holes that successfully spawn new universes, it is possible that some number of those universes will reach heat death with unsuccessful parameters. So, in a sense, fecundity or cosmological natural selection is one where universes could die off before successfully reproducing, just as any biological being can die without having children.
So, according to Lee Smolin, black holes may create new Universes,
Will we ever find out which of these theories, if any, really describes the Universe?
All miracles pale beside the miracle of existence. In the first 10-43 seconds the Universe