Were there no example in the world of contrivance except that of the eye, it would be alone sufficient to support the conclusion which we draw from it, as to the necessity of an intelligent Creator.

–William Paley, Natural Theology

In his classic work, Natural Theology, William Paley surveyed a range of biological systems, highlighting their similarities to human-made designs. Paley noticed that human designs typically consist of various components that interact in a precise way to accomplish a purpose. According to Paley, human designs are contrivances—things produced with skill and cleverness—and they come about via the work of human agents. They come about by the work of intelligent designers. And because biological systems are contrivances, they, too, must come about via the work of a Creator.

For Paley, the pervasiveness of biological contrivances made the case for a Creator compelling. But he was especially struck by the vertebrate eye. For Paley, if the only example of a biological contrivance available to us was the eye, its sophisticated design and elegant complexity alone justify the “necessity of an intelligent creator” to explain its origin.

As a biochemist, I am impressed with the elegant designs of biochemical systems. The sophistication and ingenuity of these designs convinced me as a graduate student that life must stem from the work of a Mind. In my book The Cell’s Design, I follow in Paley’s footsteps by highlighting the eerie similarity between human designs and biochemical systems—a similarity I describe as an intelligent design pattern. Because biochemical systems conform to the intelligent design pattern, they must be the work of a Creator.

As with Paley, I view the pervasiveness of the intelligent design pattern in biochemical systems as critical to making the case for a Creator. Yet, in particular, I am struck by the design of a single biochemical system: namely, the genetic code. On the basis of the structure of the genetic code alone, I think one is justified to conclude that life stems from the work of a Divine Mind. The latest work by a team of German biochemists on the genetic code’s design convinces me all the more that the genetic code is the product of a Creator’s handiwork.¹

To understand the significance of this study and the code’s elegant design, a short primer on molecular biology is in order. (For those who have a background in biology, just skip ahead to The Optimal Genetic Code.)

Proteins

The “workhorse” molecules of life, proteins take part in essentially every cellular and extracellular structure and activity. Proteins are chain-like molecules folded into precise three-dimensional structures. Often, the protein’s three-dimensional architecture determines the way it interacts with other proteins to form a functional complex.

Proteins form when the cellular machinery links together (in a head-to-tail fashion) smaller subunit molecules called amino acids. To a first approximation, the cell employs 20 different amino acids to make proteins. The amino acids that make up proteins possess a variety of chemical and physical properties.

Figure 1: The Amino Acids. Image credit: Shutterstock

Each specific amino acid sequence imparts the protein with a unique chemical and physical profile along the length of its chain. The chemical and physical profile determines how the protein folds and, therefore, its function. Because structure determines the function of a protein, the amino acid sequence is key to dictating the type of work a protein performs for the cell.

DNA

The cell’s machinery uses the information harbored in the DNA molecule to make proteins. Like these biomolecules, DNA consists of chain-like structures known as polynucleotides. Two polynucleotide chains align in an antiparallel fashion to form a DNA molecule. (The two strands are arranged parallel to one another with the starting point of one strand located next to the ending point of the other strand, and vice versa.) The paired polynucleotide chains twist around each other to form the well-known DNA double helix. The cell’s machinery forms polynucleotide chains by linking together four different subunit molecules called nucleotides. The four nucleotides used to build DNA chains are adenosine, guanosine, cytidine, and thymidine, familiarly known as A, G, C, and T, respectively.

Figure 2: The Structure of DNA. Image credit: Shutterstock

As noted, DNA stores the information necessary to make all the proteins used by the cell. The sequence of nucleotides in the DNA strands specifies the sequence of amino acids in protein chains. Scientists refer to the amino-acid-coding nucleotide sequence that is used to construct proteins along the DNA strand as a gene.

The Genetic Code

A one-to-one relationship cannot exist between the 4 different nucleotides of DNA and the 20 different amino acids used to assemble polypeptides. The cell addresses this mismatch by using a code comprised of groupings of three nucleotides to specify the 20 different amino acids.

The cell uses a set of rules to relate these nucleotide triplet sequences to the 20 amino acids making up proteins. Molecular biologists refer to this set of rules as the genetic code. The nucleotide triplets, or “codons” as they are called, represent the fundamental communication units of the genetic code, which is essentially universal among all living organisms.

Sixty-four codons make up the genetic code. Because the code only needs to encode 20 amino acids, some of the codons are redundant. That is, different codons code for the same amino acid. In fact, up to six different codons specify some amino acids. Others are specified by only one codon.

Interestingly, some codons, called stop codons or nonsense codons, code no amino acids. (For example, the codon UGA is a stop codon.) These codons always occur at the end of the gene, informing the cell where the protein chain ends.

Some coding triplets, called start codons, play a dual role in the genetic code. These codons not only encode amino acids, but also “tell” the cell where a protein chain begins. For example, the codon GUG encodes the amino acid valine and also specifies the starting point of the proteins.

Figure 3: The Genetic Code. Image credit: Shutterstock

The Optimal Genetic Code

Based on visual inspection of the genetic code, biochemists had long suspected that the coding assignments weren’t haphazard—a frozen accident. Instead it looked to them like a rationale undergirds the genetic code’s architecture. This intuition was confirmed in the early 1990s. As I describe in The Cell’s Design, at that time, scientists from the University of Bath (UK) and from Princeton University quantified the error-minimization capacity of the genetic code. Their initial work indicated that the naturally occurring genetic code withstands the potentially harmful effects of substitution mutations better than all but 0.02 percent (1 out of 5,000) of randomly generated genetic codes with codon assignments different from the universal genetic code.²

Subsequent analysis performed later that decade incorporated additional factors. For example, some types of substitution mutations (called transitions) occur more frequently in nature than others (called transversions). As a case in point, an A-to-G substitution occurs more frequently than does either an A-to-C or an A-to-T mutation. When researchers included this factor into their analysis, they discovered that the naturally occurring genetic code performed better than one million randomly generated genetic codes. In a separate study, they also found that the genetic code in nature resides near the global optimum for all possible genetic codes with respect to its error-minimization capacity.³

It could be argued that the genetic code’s error-minimization properties are more dramatic than these results indicate. When researchers calculated the error-minimization capacity of one million randomly generated genetic codes, they discovered that the error-minimization values formed a distribution where the naturally occurring genetic code’s capacity occurred outside the distribution. Researchers estimate the existence of 10¹⁸ (a quintillion) possible genetic codes possessing the same type and degree of redundancy as the universal genetic code. Nearly all of these codes fall within the error-minimization distribution. This finding means that of 10¹⁸ possible genetic codes, only a few have an error-minimization capacity that approaches the code found universally in nature.

Frameshift Mutations

Recently, researchers from Germany wondered if this same type of optimization applies to frameshift mutations. Biochemists have discovered that these mutations are much more devastating than substitution mutations. Frameshift mutations result when nucleotides are inserted into or deleted from the DNA sequence of the gene. If the number of inserted/deleted nucleotides is not divisible by three, the added or deleted nucleotides cause a shift in the gene’s reading frame—altering the codon groupings. Frameshift mutations change all the original codons to new codons at the site of the insertion/deletion and onward to the end of the gene.

Figure 4: Types of Mutations. Image credit: Shutterstock

The Genetic Code Is Optimized to Withstand Frameshift Mutations

Like the researchers from the University of Bath, the German team generated 1 million random genetic codes with the same type and degree of redundancy as the genetic code found in nature. They discovered that the code found in nature is better optimized to withstand errors that result from frameshift mutations (involving either the insertion or deletion of 1 or 2 nucleotides) than most of the random genetic codes they tested.

The Genetic Code Is Optimized to Harbor Multiple Overlapping Codes

The optimization doesn’t end there. In addition to the genetic code, genes harbor other overlapping codes that independently direct the binding of histone proteins and transcription factors to DNA and dictate processes like messenger RNA folding and splicing. In 2007, researchers from Israel discovered that the genetic code is also optimized to harbor overlapping codes.⁴

The Genetic Code and the Case for a Creator

In The Cell’s Design, I point out that common experience teaches us that codes come from minds. By analogy, the mere existence of the genetic code suggests that biochemical systems come from a Mind. This conclusion gains considerable support based on the exquisite optimization of the genetic code to withstand errors that arise from both substitution and frameshift mutations, along with its optimal capacity to harbor multiple overlapping codes.

The triple optimization of the genetic code arises from its redundancy and the specific codon assignments. Over 10¹⁸ possible genetic codes exist and any one of them could have been “selected” for the code in nature. Yet, the “chosen” code displays extreme optimization—a hallmark feature of designed systems. As the evidence continues to mount, it becomes more and more evident that the genetic code displays an eerie perfection.⁵

An elegant contrivance such as the genetic code—which resides at the heart of biochemical systems and defines the information content in the cell—is truly one in a million when it comes to reasons to believe.

Resources

• The Cell’s Design: How Chemistry Reveals the Creator’s Artistry by Fazale Rana (book)
• “FYI: I. D. IN DNA Deciphering Design in the Genetic Code” by Fazale Rana (article)
• “The Genetic Code: Simply the Best” by Fazale Rana (article)
• “Mitochondria’s Deviant Genetic Code: Evolution or Creation?” by Fazale Rana (article)
• “Biochemical Synonyms Optimized, Part 1 of 2” by Fazale Rana (article)
• “Biochemical Synonyms Optimized, Part 2 of 2” by Fazale Rana (article)
• “Protein Amino Acids Form a ‘Just Right’ Set of Biological Building Blocks” by Fazale Rana (article)
• “Why These 20 Amino Acids?” by Fazale Rana (article)
• “The Optimal Design of Metabolism” by Fazale Rana (article)
• “Metabolism: A Cascade of Design” by Fazale Rana (article)

Many people who witnessed the great eclipse of 2017 will remember it as a wondrous spectacle. But one amateur astronomer saw the event as an opportunity to reproduce measurements of the celebrated general theory of relativity, which provides the basis for understanding cosmological models of our expanding universe.

In 1915, Albert Einstein first presented his new model for describing gravity to the Prussian Academy of Sciences. Motivated by the notion that the laws of physics should not depend on location in or motion through the universe, Einstein had developed what we now call the general theory of relativity (GR). When first published, GR did not make much of a splash. Even after three or four years, Einstein lived in relative obscurity until a key measurement in 1919 brought him scientific fame.

A solar eclipse that traversed the Atlantic Ocean from South America to Africa propelled Einstein’s theory to prominence. According to GR, the gravitational well of the Sun should deflect light from distant stars by a predictable amount—an amount twice as large as predicted by Newtonian gravity. Like any solar eclipse, weather can unravel the best-laid plans. So astronomer Sir Arthur Eddington planned for two groups to make the critical measurements. Eddington and astronomer Sir Frank Watson Dyson traveled to Sobral, Brazil, while sending fellow astronomers Andrew Claude de la Cherois Crommelin and Charles Davidson to Príncipe Island off the west coast of Africa. Both groups found clear enough skies to observe stars during the eclipse. Eddington used the observations from Príncipe Island to compare star locations during the eclipse and six months earlier (when the same stars are in the sky at night). Eddington published a paper in 1920 declaring that “results of the observations here described appear to point quite definitely to . . . and confirm Einstein’s generalised relativity theory.”¹

This first test of GR brought international recognition to Einstein and started a long chain of experiments that establish GR as arguably the most accurate description of the universe known. However, some people have questioned whether Eddington’s result actually supported GR or whether he may have shown some bias.² History shows that GR is correct and that subsequent reanalysis of Eddington’s data validates his conclusions. Yet, scientists continually seek to improve upon results.

Donald Bruns, an amateur astronomer from San Diego, used a $4,000 telescope and a $5,000 camera to execute a plan he had perfected over two years. He took his setup to Casper, Wyoming, to photograph the 2017 eclipse and measure the deflection of stars as originally done by Eddington. Analyzing the data from his observations, he measured a deflection coefficient of 1.7512 arcsec.³ This value agrees with the predictions of GR within 3%, a marked improvement over previous optical attempts that had only achieved 10% accuracy. According to Physics Today, Brun’s work is “the most accurate and precise ground-based optical version of the Eddington experiment.”

Although Bruns’s research doesn’t fall into the class of “breakthrough,” it does represent scientists’ ongoing pursuit to understand the intimate and minute detailed workings of the cosmos. It also shows that relatively inexpensive projects can contribute significant results. But most importantly, it highlights the incredible curiosity and creativeness that drives humans—bearers of God’s image—to know the truth!

In a New York Times editorial, Paul Davies made this provocative statement:

Clearly, then, both religion and science are founded on faith—namely, on belief in the existence of something outside the universe, like an unexplained God or an unexplained set of physical laws, maybe even a huge ensemble of unseen universes, too. For that reason, both monotheistic religion and orthodox science fail to provide a complete account of physical existence.

Davies basically argues that scientists must largely accept that the laws of physics work without having an adequate understanding of why they work. Nothing about the laws of physics specifies that they must appear the way they do or that they should exhibit the regularity, order, and understandability that they do. As you could imagine, the claim that science is founded on faith produced some rather strong reactions—which you can read in a conversation that took place at the Edge. The responses highlighted three important points.

First, many of the responses seemed determined to sever any connection between the practice of scientific and religious faith. For example, Jerry Coyne replies that scientists’ belief in the reliability of the laws of physics is “not a matter of faith. It’s a matter of experience. In contrast, the tenets of religion are truly based on faith, since there is no empirical data to support them.” He further states that “the lack of a current explanation for why the laws are as they are, however, does not make physics a faith. It only means that we don’t have the answer.”

Second, Coyne’s response (as well as others) shows that many scientists misunderstand the true definition of Christian faith. Lawrence Krauss echoes Coyne’s sentiments and declares that “the scientific method continually refines and changes our understanding of physical law, whereas religious ‘truths’ have remained largely unchanged.” Both of these scientists imply that science operates on logic and facts, whereas religion operates on feeling and belief.

However, as my colleague Ken Samples says, “biblical faith is confident trust in a credible or reliable source.” Testing and probing is part of the process of determining the credibility and reliability of a source. Contrary to Coyne’s assertion, the reliability of the Bible is supported by empirical data. For a couple of examples, investigate the big bang and early Earth.

Third, clearly many non-Christians have an inaccurate view of biblical faith. However, I think Christians should be responsible for articulating an accurate description of the Christian faith. Let me provide an example that clarifies how talking about God’s work in our lives can help dispel this misunderstanding.

A job interview brought me to California for the first time. Two months later, my family and I moved into an apartment I rented—sight unseen—over the phone. Before we even began the journey from the Midwest (where we were living at the time), we had some concerns. All of our family and friends lived in the Midwest. On top of all that, neither of us wanted to live in California, plus my pregnant wife was suffering back problems. Yet we made the move. One could call this blind faith since we were moving to an unknown place, dealing with significant health issues, and leaving the support of our extended family—all because God told us to.

However, this would miss the point that I had great confidence in God’s plan for our family. I had seen his work in my parents, and they trained us in the Christian faith. I had personally encountered God numerous times on mission trips and skiing trips, in my time at college, and during graduate school. I had studied under intelligent, knowledgeable Christians and had learned how to defend the reliability of the Bible. And I had seen Christ transform various aspects of my life as I sought to follow him. In other words, I had an abundance of evidence saying that following God’s direction in my life was the best way to live. Rather than blind faith, I was exercising confident trust in a credible source.

As I read the responses to the article by Paul Davies, I sense people rejecting Christianity, at least in part, because they see faith as ignoring the evidence. This provides an opportunity for Christians to show the rational, evidence-based nature of the Christian faith. And it allows us to make the case that God (and his revelation in the Bible) is a credible, reliable source worthy of our confident trust.

As I have explained in posts one and two, our present brief (13,000-year) warm interglacial and even briefer (9,000-year) period of extreme climate stability will end. Another ice age is coming. Though for a number of reasons (as I will explain) we cannot prevent the onset of an ice age, there are some things we can do to delay it.

Primary Natural Drivers of the Ice Age Cycle
As I describe in some detail in my book, Improbable Planet, the primary natural drivers of the ice age cycle are (1) cyclical variations in Earth’s rotation axis tilt (aka obliquity), and (2) cyclical variations in the elliptical shape or eccentricity of Earth’s orbit about the Sun.¹

Earth’s obliquity varies from 22.1° to 24.5°. The predominant periodicity of this variation is 41,000 years. Presently, Earth’s obliquity = 23.439281°. It is decreasing at a rate of 47 arc seconds per century (0.0130° per century). Lower obliquity favors ice ages because summers are cooler and seasonal differences at high latitudes (where ice resides) are less pronounced, reducing the amount of winter snow and ice that melts. Earth’s obliquity is projected to reach its minimum value around 10,000 AD.

The eccentricity of Earth’s orbit varies from 0.000055 to 0.0679^2, where a value of 0.0 equals a perfect circle and 1.0 describes an orbit where the maximum orbital diameter divided by the minimum orbital diameter = infinity (that is, the minimum orbital diameter = 0.0). The predominant periodicities are 413,000, 125,000, and 95,000 years. Presently, Earth’s orbital eccentricity = 0.01670986, and it is decreasing. The last maximum (0.019) was about 10,000 years ago, and the previous minimum was 40,000 years ago (0.010). Lower eccentricity favors ice ages and a minimal value of Earth’s eccentricity is projected to occur roughly around 60,000 AD.

Delaying the Next Ice Age
If the primary natural drivers of the ice age cycle were the only significant factors driving the cycle, we should be in an ice age right now. Both Earth’s obliquity and orbital eccentricity are declining. Both are operating to cool our global climate. If Earth’s obliquity and orbital eccentricity were the only significant factors, the next ice age should have begun roughly 5,000 years ago.

Figure 1 shows the global mean temperatures over the past 300,000 years. Some unknown event or unique combination of obliquity and eccentricity cycles, circa 5,000 years ago, prevented the global mean temperature from rising high enough and long enough to melt the polar ice cap and bring on a subsequent ice age.

Figure 1: Global Mean Temperatures for the Past 300,000 Years. The temperature scale (y-axis) is in degrees Centigrade relative to the present global mean temperature. Image credit:Adapted by author from image produced by Robert A. Rohde, Global Warming Art Project, CC by SA.

The domestication of cows began about 10,500 years ago but remained a small component of animal husbandry until 7,000–6,000 years ago.³ The dramatic rise in the domesticated cow population that began during the sixth millennium BC substantially enhanced the emission of greenhouse gases into Earth’s atmosphere. This emission compensated for the cooling generated by Earth’s declining obliquity and orbital eccentricity.

Additional compensation for the cooling arising from Earth’s declining obliquity and orbital eccentricity came from the domestication of rice and the deforestation of Eurasia to make room for intensive crop cultivation and pasture land.⁴ Before the advent of the industrial revolution, the combination of the growth of animal husbandry, irrigation for rice farming, and the transformation of forests into cultivated fields and pasture lands raised the atmospheric carbon dioxide level from 245 parts per million to 285 parts per million, and the atmospheric methane level from 450 parts per billion to 700 parts per billion.

These three features of anthropogenic activity (human activity that affects nature) operating over the past 7,000 years played a major role, not only in delaying the onset of the next ice age, but also in producing an unprecedented period of extreme global climate stability. As figure 2 shows, the global mean temperature throughout the past 9,000 years has not varied by more than 2°Celsius (3.5°Fahrenheit). As I explained in Improbable Planet,⁵ it is due in large part to this brief period of extreme climate stability that humanity has been able to launch and sustain global, high-technology civilization and grow a human population numbering in the billions.

Figure 2: Global Mean Temperatures during the Last 80,000 Years. The blue lines show the global mean temperature as determined from the GRIP Greenland deep ice core while the purple lines show the global mean temperature as determined by the NGRIP Greenland deep ice core. Image credit: adapted by author from image produced by Leland McKinnes/Wikipedia Commons, CC-by-3.0.

Since the advent of the industrial revolution and especially during the explosion of human wealth and technology that has occurred since the end of World War II, anthropogenic activity has overcompensated for the global cooling arising from the currently ongoing decline in Earth’s obliquity and orbital eccentricity. As I explained in my previous two blogs, it is this overcompensation that is threatening to accelerate the onset of the next ice age.

Many scientists and many more politicians are calling for draconian economic sacrifices in order to rectify this overcompensation of human activity. These scientists and politicians, in my opinion, are failing to fully consider the biblical principle of the universality of human sin and selfishness. In light of this biblical principle, as I explained in Hidden Treasures in the Book of Job,⁶ the only practical remedies for reducing the overcompensation are remedies that simultaneously boost peoples’ economic well-being and lower the impact of human activity. I discussed several such remedies in Hidden Treasures in the Book of Job, including restoring the whale populations,⁷ reducing the Sahara and Gobi deserts to the sizes they manifested two millennia ago,⁸ and substituting ostrich meat for beef.⁹

In addition to remedies achievable with existing resources and technology, there are a number of foreseeable technological advances that promise to reduce the over-compensation and restore the extreme climate stability we have been enjoying for the past 9,000 years. A prominent example is nuclear fusion. For several decades, physicists around the world have been working hard to develop nuclear fusion (as opposed to fission) reactors. If such reactors could be developed and produced in quantity, we would no longer need to use fossil fuels to generate energy to sustain the global economy.

While we can take steps to significantly delay the onset of the next ice age and restore extreme climate stability, such steps could have a severe impact on agricultural productivity. One reason why we are able to grow enough food to feed 7.5 billion humans, plus all the world’s domesticated animals, is that we depend on the melting of glaciers left over from the last ice age to provide the necessary water to irrigate our vast cultivated fields. Thus, a substantial delay in the onset of the next ice age could confront us with another potentially catastrophic problem—the complete melting away of the glaciers that currently are supplying water to our agricultural plains.

Preparing for the Next Ice Age
I am not saying it is infeasible for humanity to find a way to delay the onset of the next ice age by one or two millennia. Nuclear fusion reactors, for example, conceivably could provide a means to desalinate huge quantities of ocean water. However, to cite another biblical principle and a famous Christian hymn, this world is not our home.

In chapters 15 and 16 of Improbable Planet, I explain how the ice age cycle is a marvel of divine design. It is designed to enable our planet to sustain several billion people at one time. It is designed to enable these several billion humans to develop the wealth and technology to make possible the completion of the Great Commission (Matthew 28:18–20) within the next few decades.

I describe how it is possible—with existing resources—for Christians today to take the good news of salvation through Jesus Christ to all the people groups of the world where, within each people group, a large minority of them would become disciples of Jesus Christ. With sufficient motivation on the part of existing evangelical Christians, I demonstrate in Improbable Planet how the task of “making disciples of all nations” could be completed in less than a few decades.¹⁰

The Bible promises (Romans 8, Revelation 20–22) us that when the full number of human beings that God intends to redeem is in fact redeemed, the universe and our planet Earth will have fulfilled the purpose for which God created them. God will then replace them with a brand new creation—the new heavens and the new earth, a realm where “the old order of things” will pass away and where God says about the new creation, “I am making everything new.” As I explain in Beyond the Cosmos¹¹ and in Why the Universe Is the Way It Is,¹² the new creation will be governed by completely different laws of physics and dimensions. In the new creation we will not need to be concerned about the ice age cycle, global warming, or climate stability. God has promised to make the new creation a perfect realm for all eternity.

To be clear, I am not saying that because it appears the Great Commission can be fulfilled within a few decades, that we can ignore the climate problems we currently face. Many Christians, including myself, believe that the Bible teaches a literal reign of Jesus Christ here on planet Earth for a one-thousand-year period following the completion of the Great Commission. For Christians who do not hold to a millennial reign of Christ on Earth, there are still the exhortations from our Savior to “occupy until I come” (Luke 19:13) and the creation care mandate described in Genesis 1:28–30 and Job 37–39.

What I am saying is that God generously granted us an extremely beneficial ice age cycle and a brief period of extreme climate stability within that cycle so that we could not only enjoy a brief period of unprecedented wealth and technology but also, far more importantly, to use that wealth and technology to fulfill an eternal spiritual destiny. Yes, let’s do everything we can to wisely and economically sustain this remarkable period of terrestrial blessing in which we currently reside. However, let us do much more to partner with God to bring about the redemption of untold human beings, the eradication of all evil, and our preparation for eternal life and our careers in the new creation.

Back in the summer of 1950, famed physicist Enrico Fermi visited Los Alamos National Laboratory and discussed the possibility of interstellar travel with his colleagues as they walked to have lunch. In the brief exchange, some thought faster-than-light (FTL) travel was possible while others thought not. During lunch Fermi posed his now legendary question: “Where is everybody?” Remarkably, although the question came out of the blue, everyone understood its implications.

Fermi’s Paradox

At least one impetus for the conversation involved a query about how to explain a rash of UFO sightings. If aliens pervade the universe, some of them should have visited Earth already. However, all the observations at the time provided no substantial evidence for alien visitors (a conclusion still true today). Assuming the possibility of FTL travel, the existence of alien life and the lack of any evidence became known as the Fermi paradox.

The Drake Equation

Roughly a decade later, astronomer Frank Drake developed an equation that helps organize the scientific process by which we might determine the number of advanced alien civilizations in our galaxy. Known as the Drake Equation, it has 7 factors that break the huge problem of finding alien life into smaller, more manageable categories.

N = R_* • f_p • n_e • f_l • f_i • f_c • L

N:       number of detectable civilizations throughout the Milky Way Galaxy

R*:      rate of formation of stars suitable for intelligent life

f_p:        fraction of stars suitable for intelligent life that have planetary systems

n_e:       number of planets in those planetary systems

f_l:         fraction of those planets that develop life

f_i:         fraction of those life-forms that develop intelligence

f_c:        fraction of those intelligent life-forms that send signals into space

L:        length of time those civilizations emit the signals into space

To determine all these factors will require research in disciplines including astronomy, physics, planetary science, geology, biology, biochemistry, and many others. In fact, scientists have formed a discipline called astrobiology that encompasses the specific aspects of all these other disciplines that pertain to life’s existence. A major component of astrobiology research entails the search for other planets that might host life. Until the discovery of the first exoplanet in the 1990s, this was a largely “data-free” endeavor. Research since then indicates that as many as 20% of stars might have habitable planets. We have no hard data driving the values of the last four factors and any one of these could easily be zero (meaning no civilization exists beyond Earth). Some research even suggests that as many as 22% of Sun-like stars harbor Earth-sized planets in some sort of habitable zone.¹ However, scientists are likely underestimating the difficulty of making a truly habitable planet.

Resolving the Paradox?

Some people see that the number of civilizations predicted by the Drake Equation is zero (because the last four factors are really small). Others predict really large numbers by assuming, for example, that all the factors are around 0.1. These really large numbers lead to the paradox. According to the authors of a recent paper, replacing specific probabilities normally used for each factor with ranges that account for the uncertainty in each factor resolves (or rather “dissolves”) the issue.² If one uses a uniform range between 0 and 0.2 for each number, the Drake equation predicts that we are alone in the galaxy over 21% of the time. With this relatively large probability that no other civilizations exist in the galaxy, Fermi’s paradox disappears.

I would point out that this analysis glosses over a more fundamental point: we have no idea what the values for the last four factors should be. And we have good reason to think some, like f_l, are probably zero! In reality, most scientists consider the Drake equation, not as a tool to predict the number of detectable civilizations, but as a way to organize our approach to the search for life in the universe. We don’t know the answer we will find, but we can bear in mind that maybe life exists here on Earth (and anywhere else we might find it) because God created it to reflect his glory!

Endnotes:

1. Erik A. Petigura, Andrew W. Howard, and Geoffrey W. Marcy, “Prevalence of Earth-Size Planets Orbiting Sun-Like Star,” Proceedings of the National Academy of Sciences 110 (November 26, 2013): 19273–78, https://doi.org/10.1073/pnas.1319909110.
2. Anders Sandberg, Eric Drexler, and Toby Ord, “Dissolving the Fermi Paradox,” Future of Humanity Institute, Oxford University (June 8, 2018): https://arxiv.org/pdf/1806.02404.pdf.