Connections 2006, Vol. 8, No. 4
- Habitable Planets Rarer than Originally Thought
- An Inordinate Fondness
- A Dime's Worth of Difference
- Faith and Reason
- Beating the Odds in Monte Carlo
Habitable Planets Rarer than Originally Thought
Jeff Zweerink, Ph.D.
Tradesmen get a lot of business from people who start projects that appear simple. ("How hard can it be to install a new shower?") What initially looks like a straightforward task ends up requiring much more skill, time, and financial resources than expected. After many hours of frustration, and often many dollars spent, the exasperated homeowner calls the expert. In those circumstances, the skill and resourcefulness of the craftsman is readily appreciated.
Scientists encounter a similar situation as they study the process of building a life-supporting planet. Some people, usually the nonexperts, believe the conditions for producing life-supporting planets are neither rare nor terribly complex. However, as planetary scientists-the experts-make planetary system formation models more realistic, the evidence for fine-tuning in our solar system continues to grow.
Twenty years ago, the nine solar system planets (the International Astronomical Union recently disqualified Pluto, reducing the total to eight1) were the only known planets in the universe. Lacking the ability to make direct observations, most astronomers assumed that any extrasolar planetary systems would bear a strong resemblance to ours and would be rather abundant. But in recent years, direct observations began pouring in. As of August 2006, astronomers had discovered just over 200 extrasolar planets (including 148 stars with single planets and 20 stars with multiple planets). Virtually all are gas giants similar to Jupiter. Detection of these Jupiter-class planets has enabled scientists to assess the possibility that an Earth-like planet, capable of supporting long-standing liquid water, could exist around these stars.
Contrary to expectations, none of these planetary systems resemble the one where we live. All of the extrasolar "Jupiters" orbit their stars more closely or have a more eccentric orbit than Jupiter. Consequently, the gravitational instabilities resulting from the gas-giant orbits in most of the planetary systems would eject any Earth-like planet into interstellar space. Still, astronomers found that in a few planetary systems, Earth-like planets would be stable for a long time.
Since a hypothetical habitable planet might be stable in a small fraction of known systems, astronomers added more realism by investigating whether an Earth-like planet could even form in such systems. Using Monte Carlo simulations,2 a University of Colorado astrophysicist studied how the existence of gas giants with specific orbits influences the subsequent formation of any habitable terrestrial planets.3 The simulations revealed that any gas giant orbiting slightly closer to its star than Jupiter's location prevented the formation of watery, Earth-like planets. Additionally, if the gas-giant orbit was not circular, its orbit had to be even farther from the star to permit formation of a watery, terrestrial planet. However, this position makes the terrestrial planet less habitable, as increasing the gas-giant distance from the star diminishes its capacity to shield the terrestrial planet from comet and asteroid impacts.
Even this picture is not complete, though. Astronomers know from the calculated orbits of the gas-giant planets that they must have migrated from the location where they formed to their current orbit. A group of astrophysicists simulated how this migration would affect the formation of habitable terrestrial planets in four systems where a terrestrial planet appears stable.4 The simulations showed that the migration completely disrupted habitable-planet formation in three systems. In the fourth system, planets up to six-tenths the mass of Earth could form if 1) the gas-giant migration occurred very early, 2) the known gas-giant orbits are well determined, and 3) no other gas giants exist in the system. (A terrestrial planet just over half an Earth mass likely cannot support the long-standing plate tectonics that are critical for advanced life, but no planets larger than 0.63 Earth masses formed in the simulations.) However, the chance of forming any potentially habitable terrestrial planet diminishes dramatically if any of the three conditions are not met, particularly if the migration does not occur very rapidly.
Such exquisite fine-tuning provides a sobering reminder of the difficulty of the task. The naturalist is clearly seeing that "it's not as easy as it looks."
The bottom line is that as scientists' understanding of planetary formation increases and their simulations become more realistic, the naturalistic expectation of finding habitable terrestrial planets around other stars continues to fade. In contrast, the latest scientific findings continue to reveal the fingerprints of a supernatural Creator who intervened in cosmic history to ensure a life-supporting environment such as Earth.
2. For more information on Monte Carlo simulations, see Dave Rogstad's article, "Beating the Odds in Monte Carlo," on page 8 of this issue.
3. Sean N. Raymond, "The Search for Other Earths: Limits on the Giant Planet Orbits that Allow Habitable Terrestrial Planets to Form," Astrophysical Journal 643 (2006): L131-34.
4. Sean N. Raymond, Rory Barnes, and Nathan A. Kaib, "Predicting Planets in Known Extrasolar Planetary Systems. III. Forming Terrestrial Planets," Astrophysical Journal 644 (2006): 1223-31.
An Inordinate Fondness
Fazale (Fuz) R. Rana, Ph.D.
When asked what the study of nature told him about God, the legendary biologist J. B. S. Haldane quipped, "The Creator must have an inordinate fondness for beetles. He made so many of them."
For Haldane-an atheist-the existence of a large number of beetle species was prima facie evidence for evolution. If God exists, why would He produce over 450,000 seemingly unnecessary beetle species? An evolutionary perspective seems to make more sense, as this type of wanton biodiversity merely represents the outworking of undirected evolutionary processes.
When challenged along these lines, Christians often try to identify reasons why God created 450,000 beetle species. There is nothing wrong with this approach. In fact, it's possible to offer plausible reasons why God made nearly one million insect species. For example, one study shows that insects are worth $57 billion to the U.S. economy each year.1
In accord with this approach Scripture teaches that God created with specific goals in mind. Psalm 104-a creation account that mirrors Genesis 1-communicates that God created in a purposeful, progressive fashion, with the Creator's activity on each creation day setting the stage for His subsequent work.
The tendency, however, is to think of God exclusively as an Engineer who creates with only one specific purpose or function in mind. Is it possible that God is not just an Engineer, but also a divine Artist who creates at times solely for His enjoyment? Maybe the Creator really does like beetles. And that's why He made 450,000 beetle species.
Scripture supports this idea. Psalm 104:25 states that God formed the leviathan (which in this passage seems to refer to whales) on Day Five to frolic in the vast, spacious seas. In other words, God created the great sea mammals for no other purpose than to play! If God made the leviathan for merriment, could it be true for other creatures throughout life's history?
If not for the fossil record, people alive today would have no idea of the vast history of life on Earth. The fossil record gives an incomplete and often imperfect view of life's distant past, much of which is lost forever. Still, this record provides enough of a window to reveal a menagerie of unusual and interesting animals. Why did the Creator make such a diverse array of creatures at differing points in Earth's history? Could it be that one of the reasons God created so many remarkable animals-like the dinosaurs, creatures that fascinate children and paleontologists alike-was for His amusement?
Artistry and engineering are not mutually exclusive. Human engineers often design cars and buildings to be both functionally efficient and aesthetically pleasing. But sometimes humans create for no other reasons than for their pleasure and for others to enjoy their work. Could not the Creator do the same, for no other reason than an inordinate fondness?
1. Michael Hopkin, "What's the Point of Insects?" email@example.com (March 31, 2006), http://www.nature.com/news/2006/060327/pf/060327-19_pf.html, accessed April 5, 2006.
A Dime's Worth of Difference
Hugh Ross, Ph.D.
The universe is incredibly massive. Nevertheless, its mass must be spectacularly fine-tuned for life to be possible. Exactly how massive the universe is remained unknown until astronomers focused the Hubble Space Telescope on a patch of sky no bigger than a tenth the Moon's (angular) diameter, and held it there for some 278 hours. This Ultra Deep Field (see figure) successfully imaged all the galaxies (at least those bigger than dwarfs) that exist in that region.
The field contains roughly 10,000 galaxies. By extrapolation, then, astronomers determine that the entire observable universe contains at least 200 billion galaxies. These galaxies contain an estimated average of 200 billion stars each. The total number of stars in these galaxies, then, is 40 billion trillion. The unobserved dwarf galaxies would contribute an estimated additional 10 billion trillion. Thus, the total number of stars in the observable universe adds up to about 50 billion trillion.
Fifty billion trillion stars-that's an unimaginably enormous universe. And yet the universe is more massive by far. The stars, both those that are still shining and those that have burned out, account for just one percent of the universe's total mass!
One reason the universe must be so massive is that life requires it. The density of protons and neutrons determines how much of the universe's hydrogen fuses into heavier elements. With a slightly lower density (producing fewer than about 50 billion trillion observable stars), nuclear fusion would be less productive and at no time in cosmic history (either in the big bang or in stars) would elements heavier than helium be produced. Or, if the density were slightly higher (producing more than about 50 billion trillion observable stars), nuclear fusion would be so productive that only heavier-than-iron elements would exist. Either way, life-essential elements such as carbon, nitrogen, oxygen, and phosphorous would be too scarce or nonexistent.
Another life-related reason the universe must be so massive is that the cosmic mass critically influences the universe's expansion rate. If the mass density were smaller, the influence of gravity would be too weak for stars like the Sun and planets like Earth to form. On the other hand, if the mass density were greater, only stars much larger than the Sun would form. Either way, the universe would contain no stars like the Sun or planets like Earth, and life would have no possible home. The required fine-tuning is so extreme (one part in a quadrillion quadrillion quadrillion quadrillion) that if one were to remove or add a single dime's worth of mass to this vast cosmos, the balance of the observable universe would be thrown off and physical life would not be possible. Such amazing fine-tuning suggests the involvement of a supernatural, superintelligent Creator.
1. Job 9:8; Psalm 104:2; Isaiah 40:22, 42:5, 44:24, 45:12, 48:13, 51:13; Jeremiah 10:12, 51:15; and Zechariah 12:1.
2. Jonathan Coles, “A New Estimate of the Hubble Time with Improved Modeling of Gravitational Lenses,” Astrophysical Journal 679 (May 20, 2008): 17-24.
3. For a description of the technique and its applications, see R.D. Blandford and R. Narayan, “Cosmological Applications of Gravitational Lensing,” Annual Reviews of Astronomy and Astrophysics 30 (1992): 311-58, powerpoint available at www.asu.edu/clas/hst/classes/ast494+591/2007-04-06/grav_lens.pdf; and http://www.answers.com/topic/gravitational-lens.
4. E. Komatsu et al., “Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretations,” Astrophysical Journal Supplement Series (2008), in press.
Faith and Reason
Kenneth Richard Samples
Skeptics often charge Christians with "blind faith." And at times even believers have spoken of faith in less-than-rational terms. However, historic Christianity affirms a necessary and proper relationship between faith and reason. There has been a broad measure of agreement in Christian history that the two are indeed compatible. The Christian faith is reasonable in four distinct ways.
First, the Christian faith affirms that there is an objective source and foundation for knowledge, reason, and rationality. That source and foundation is found in a personal and rational God who is infinitely wise and all-knowing. This God created the universe to reflect a coherent order, and he made man in his image (with rational capacities) to discover that intelligible organization. Logic and rationality are then expected features in the Christian theistic worldview.
Second, Christian truth-claims do not violate the basic laws or principles of reason. Christian faith and doctrines (for example, the Trinity and the Incarnation), though they often transcend our finite human comprehension, are not irrational or absurd.
Third, the Bible itself encourages the attainment of knowledge, wisdom, and understanding (Job 28:28; Prov. 1:7) and promotes such intellectual virtues as discernment, testing, and reflection (Acts 17:11; Col. 2:8; 1 Thess. 5:21).
Fourth, the truths of the Christian faith correspond to, and are supported by, such things as evidence, facts, and reasons. Biblical faith (Greek: pisteuō, the verb "believe," and pistis, the noun "faith") can be defined as confident trust in a reliable, reasonable, and viable source (God or Christ). Faith (or belief) is a necessary component of knowledge and reason since a person must believe something in order to know it. Yet reason can be properly used to evaluate, confirm, and buttress faith. Faith and reason therefore function in a complementary fashion. While reason in and of itself, apart from God's special grace, cannot cause faith, the use of reason is normally a part of a person's coming to faith, and serves to support faith in innumerable ways. In summary, faith is foundational to reason and reason can serve to evaluate or confirm faith.
In the New Testament, faith is always focused upon an object. And the trustworthy object of a person's faith, according to Scripture, is God or the Lord Jesus Christ. Even the very faith that results in salvation involves knowledge (of the facts surrounding the life, death, and resurrection of Jesus Christ) and discursive reasoning (as to what the facts about Jesus Christ really mean). Saving faith then includes knowledge (of the gospel), assent (to its truth and importance), and confident trust and reliance (upon the Lord and Savior Jesus Christ). Such faith engages all the human faculties: mind (knowledge), will (assent), and heart (trust).
Christian faith and reason can also be connected in another important way. The Christian life should be marked by what the Apostle Paul calls the renewing of the mind (Rom. 12:2). This involves the use of our cognitive faculties to their fullest extent in our devotion to God. Augustine of Hippo (AD 354-430) called this indispensable intellectual and spiritual activity "faith seeking understanding." Believers should strongly endeavor to use God-given reason to explore the depths of their faith and to discover its doctrinal truth. Stretching mental and spiritual muscles to apprehend (yet never fully to comprehend) such doctrines as the Triune nature of God and the Incarnation of Jesus Christ moves one from an initial stage of faith to a deeper stage of reflection and a greater sense of God's majesty. Loving God with the mind is part of fulfilling the overarching commandment to love and honor God with our entire being (Matt. 22:37).
Thus, Christian faith, far from being arbitrary and blind, is grounded in knowledge and reason. It is the believer's task to represent this historic faith graciously and accurately in an age of hardened skepticism.
1. See Avery Dulles, A History of Apologetics, 2nd ed. (San Francisco: Ignatius, 2005).
2. For a defense of the Trinity and the Incarnation, see Kenneth Richard Samples, Without a Doubt (Grand Rapids, MI: Baker, 2004), 63-76; 120-33.
3. Saving faith is the gift of God (Acts 13:48; 1 Cor. 12:3; Eph. 2:8-9; Heb. 12:2). For a helpful biblical discussion of how faith is a sovereign gift of God, see Anthony A. Hoekema, Saved by Grace (Grand Rapids, MI: Eerdmans, 1989), 143-45.
4. For a discussion of Augustine's expression of "faith seeking understanding," see Ed L. Miller, God and Reason: An Invitation to Philosophical Theology, 2nd ed. (Upper Saddle River, NJ: Prentice Hall, 1995), 134-37.
Historic Christian View of Faith and Reason
There exists a diversity of views in Christian church history regarding the proper relationship between faith and reason, but the views have much in common.
|Crede ut intelligas
Fides quaerens intellectum
|"Believe in order that you may understand."
"Faith seeking understanding" ("For faith is understanding's step; and understanding faith's attainment.")
|Augustine (354-430)||Relationship of belief and authority to reason
For Augustine, faith and reason have an interdependent relationship and both are uniquely enabled by divine grace.
|Credo ut intelligam||"I believe in order that I might understand."||Anselm (1033-1109)||Anselm was an Augustinian and laid emphasis upon faith being prior to reason and understanding.|
|Intelligo et credo||"I understand and I believe."
"Grace presupposes nature and perfects it."
|Thomas Aquinas (1225-1274)||Aquinas was also an Augustinian and believed that some truths are discovered through both faith and reason, whereas other truths are known exclusively through faith (special revelation). Nevertheless, human reason is finite and negatively impacted by sin so grace buttresses both.|
|Credo quia absurdum est||"I believe because it is absurd."||Soren Kierkegaard (1813-1855)||Kierkegaard emphasized that the gospel message (God becoming a man to atone for human sin) is an affront to human reason, but his views need not imply an outright rejection of reason or that Christianity is actually absurd|
These approaches to faith and reason are explored and explained in Ed L. Miller, God and Reason: An Invitation to Philosophical Theology, 2nd ed. (Upper Saddle River, NJ: Prentice Hall, 1995), 129-53, and in Kenneth D. Boa and Robert M. Bowman Jr., Faith has Its Reasons: Integrative Approaches to Defending Christian Faith, 2nd ed. (Waynesboro, GA: Authentic Media; Milton Keynes, UK: Paternoster, 2006).
Beating the Odds in Monte Carlo
David H. Rogstad, Ph.D.
What does science have in common with games of chance? Is RTB now hooking up with gamblers to establish its creation model? You may be surprised to learn that many of the most difficult problems facing the scientist can be solved using the same approach a gambler takes in trying to improve his odds at the craps table or the roulette wheel. This technique is known as the Monte Carlo method and was invented in the late 1940s by mathematicians Stan Ulam and Nicholas Metropolis.1
By way of illustration: We've all experienced the frustration of waiting in lines to obtain some service, like cashing a check at the bank. On average the bank knows that it must service, say, one customer per minute, based on its long-term average of customers. However, at any particular time there may be more or fewer customers waiting in line because of the random nature of their arrival at the bank. If you wanted to know what the peak wait time would be, you could sit to the side for a long time and keep track of the wait times using a stopwatch.
Another approach is to set up a Monte Carlo simulation by programming a spreadsheet running on a personal computer. This simulation process makes use of a random-number generator (the computer equivalent of throwing a die to get a random integer between 1 and 6) by designating the random number to correspond to the time during the day when a given customer arrives (e.g., in the range 10 a.m. - 6 p.m.). An accurate peak wait time can be derived because of long-term statistical averages. For a more sophisticated simulation, one could use a second, independent random-number generator to estimate the time the teller takes to process a customer. Before the advent of digital computers, performing such a simulation would have been extremely difficult, but now it is fairly easy.
Scientists in all fields tackle a variety of problems with this method, many of them difficult or impossible to solve in any other way.2 One of the biggest breakthroughs using Monte Carlo simulations has come in astrophysics.3 Scientists have been able to simulate the conditions of the early universe (that is, just a few minutes after the big bang event). During this time, it is thought, the various light elements beyond hydrogen (deuterium, helium, and lithium) condensed out of the energy field as the universe expanded and cooled. The Monte Carlo simulations estimated these primordial element abundances, and the results were in remarkable agreement with observations, providing an early confirmation of big bang cosmology.
Even though the name derives from a resort casino, Monte Carlo simulations offer far better odds and results. As scientists employ this technique to understand the universe, the odds that RTB's cosmic creation model is correct stand to improve.
1. Nicholas Metropolis and S. Ulam, "The Monte Carlo Method," Journal of the American Statistical Association, 44 (1949): 335-41.
3. Gary Steigman, "Primordial Nucleosynthesis: Successes and Challenges," International Journal of Modern Physics, E15 (2006): 1-36.