Ultimately, however, the authors are in a poor position to argue that Earth is optimally located for both habitability and measurability. They try to establish habitability requirements by comparing Earth with other locations in the galaxy.Unfortunately, we lack the data required for a well-reasoned comparison. If we had many examples of planets that do and do not bear life, and an explanation for why the conditions on some planets led to life while those on others did not,we might be able to establish an accurate metric of habitability. Until then, we are forced to extrapolate measures of habitability from a sample of one inhabited planet.and
Caution seems especially in order given that the authors have intentionally limited themselves to our knowledge of the Universe gained through selected observational sciences, such as comparative planetary geology, solar physics and astronomy, rather than including more laboratory-based sciences. Similarly, although the authors attempted to avoid cherry picking instances of measurability that support their position by focusing on important observations in these fields, the vagueness of such a criterion makes their selection rather subjective.[size=200%]The Wedge: Or the apologetic side of PP[/size] Website of Michael KeasSenior Fellow at the Center for (
Revise US 311 to accommodate a new main textbook: Guillermo Gonzalez and Jay W. Richards, The Privileged Planet: How Our Place in the Cosmos is Designed for Discovery. The authors of this book have allowed me to use the book in manuscript form. It will appear in print in 2003. I am developing a study guide to go with the book.and
Organize an "Authors meet Critics" session for the August 2003 meeting of the American Scientific Affiliation that focuses on the book, The Privileged Planet: How Our Place in the Cosmos is Designed for Discovery (forthcoming, 2003). Mike Keas (chair): Introduction (2 minutes) Guillermo Gonzalez (author #1, astronomer) presents (20 minutes) Astronomer critic presents (20 minutes) 5 minute rebuttals each Break Jay W. Richards (author #2, philosopher/theologian) presents (20 minutes) Philosopher/theologian critic presents (20 minutes) 5 minute rebuttals each Mike Keas: "Teaching the 'significance-of-Earth' controversy in science and liberal arts courses." (10 minutes) Closing comments from each of the participants (2 minutes each)From the actual program it seems that the philosophical presentation was combined with Gonzalez's presentation and that the rebuttal by a philosopher/theologian did not take place. In the November-December 2001 issue of the Skeptical Inquirer published an article "Was the 'Rare Earth' Hypothesis Influenced by a Creationist?" by Darling. Darling investigated and discovered how "he's [Gonzalez's] been instrumental in tying the various strains of the Rare Earth argument together and energetically promoting the thesis across a broad front.". But this is not where Darling's discovery ended. Darling uncovered several articles by Gonzalez in creationist literature.
In fact, Gonzalez is a regular contributor to Reasons to Believe pamphlets. In a 1997 piece, he concluded: "The personal involvement of a supernatural Creator seems scientifically reasonable to me." A 1998 article ends this way: "Scientists are left to wonder how Earth came to exist and persist for so long in the zone where life is possible. The impression of design could hardly be more distinct."After Darling ran across these articles by Gonzalez in creationist literature he decided to contact Ward and Brownlee assuming that these authors were aware of their colleagues theological beliefs.
Darling assumed that Ward and Brownlee must be aware of their colleague Gonzalez's deep theological convictions. But when he asked Ward about this eight months after their book's publication, he found otherwise. "That is news to me. I have never seen or even heard that Gonzalez does this... Are you sure you have the right Gonzales?" Ward responded to Darling. Darling assured Ward there was no doubt. "I think I need an explanation," Ward told Gonzalez in forwarding the e-mail exchange about this between Darling and Ward.Gonzalez responded to the email
Gonzalez responded this way to Ward (as quoted in Darling's book): Regarding his [Darling's] statement about my "secret agenda" as a design advocate, it is not such a secret, as my writing on the design issue is rather public and widely distributed. I recently received a grant from the John Templeton Foundation to study habitability from a design perspective--several people in the department know about it. I have not been more open about my pro-design views here at the UW because of the open hostility to such views among the faculty. But I will not apologize for admitting that my theistic theological views motivate my science and vice-versa.The Privilege of Life on Earth The latest discoveries in astrophysics support the notion that our world was created for a special purpose by Benjamin Wiker Wiker interviews Gonzalez in this 2001 article and presents some remarkable claims and comments.
If so, think again, advises astrophysicist Guillermo Gonzalez. Our sun, our solar system, and our galaxy are quite extraordinary--so extraordinary, he contends, that they must have had an Intelligent Designer. This, he emphasizes, is a statement based not on religious faith, but on the latest findings of astrophysics.I would argue that the jump from function to purpose IS a statement of religious faith and not based on scientific findings.
My work, in part, deals with astrobiology from an astronomer's viewpoint. I simply follow the empirical evidence wherever it will lead me, and I try not to let philosophical preconceptions color my interpretations. Over the past decade, I have amassed a body of data that continues to reveal the Earth's uncommon qualities.A more balanced view of the evidence may show that universe may not be as inhospitable to life as proposed by Gonzalez. Perhaps philosophical preconceptions, remember Gonzalez's email above
But I will not apologize for admitting that my theistic theological views motivate my science and vice-versa.plays a larger role?
Having been on the other side of this issue for many years, I know what kinds of arguments people put forth to defend their views of ETI. They are extremely weak arguments, and the motivation comes mostly from wishful thinking. Many researchers involved in the search for ETI, called "SETI," simply don't want to accept evidence that will reduce the probability of their success. In addition, there is a very deep and open hostility to religious views (especially Christian ones) among many SETI researchers. I don't like to name names, but the rantings of the late Carl Sagan are in evidence in the many books he wrote on the subject. He was particularly fond of revising history to fit his anti-religious ideological agenda.Accusing SETI researchers of wishful thinking and yet purpose in the universe is what? More fascinating is how Gonzalez accuses these researchers of unwilling to accept evidence that will reduce the probability of success? But is Gonzalez willing to accept the data that reduces the probability of success of HIS arguments? Gonzalez's statements about Sagan (rants, ideological agenda) appear somewhat ironic to me.
Gonzalez: I am not in complete agreement with a couple of aspects of their version of the Rare Earth hypothesis. First, I am more skeptical than Brownlee and Ward about the existence of simple life on other worlds. They seem to downplay the great difficulty origin-of-life researchers are having in understanding how life first arose from a naturalistic perspective. Second, I believe the most important implication of this hypothesis is that the cosmos is designed. Brownlee and Ward conclude that their hypothesis should move us to have greater concern for the environment since "good planets are hard to come by." While I agree this is a worthwhile implication, it is hardly the most significant one.This supports my argument that while the Rare Earth is about the weak Anthropic argument, Privileged Planet is about the strong Anthropic argument.
Gonzalez: If we are right, then ours is the strongest empirical evidence for purpose in the universe to date. And what purpose is it? It is simply that the universe was designed for scientific discovery by intelligent life.Yep Does Science Point to God - Part One by Benjamin Wiker
e scientists are coming to a conclusion they never expected: The universe was designed. And if it was designed, there must be a Designer. Benjamin D. Wiker shows you what the Intelligent Design movement could mean for the future of science and religion. This is part one of a two part series.Does Science Point to God? - Part II
e second of a two-part series on the problem of evolution and Darwinian materialism. This article examines the wider consequences to philosophy, theology and morality of the uncritical acceptance of Darwinism.[size=200%]Guillermo Gonzalez and Reasons to Believe[/size] Science and CHRISTIANITY in Harmony by Pat Lewis
In an article describing up-to-the-minute research about our Sun, astronomer Guillermo Gonzalez explains a number of ways in which our star seems to have been designed to make life possible on Planet Earth. In several respects, the Sun is unlike the majority of stars; its uncommon mass, stability, position in the Galaxy, and especially its chemical makeup.*Scroll down to "The Uncommon Composition of the Sun" by Guillermo Gonzalez
As astronomers are learning more about the solar system's surroundings and are able to better place the Sun in its proper context, they are showing the Sun to be rare indeed. They are also discovering that the conditions required for life are far more numerous and narrow than commonly believed. These findings, along with the many examples of fine-tuning in chemistry, biochemistry, physics, and cosmology, argue against chance explanations. A non-chance explanation called intentional design implies both mind and will. And I call that intentionality a God thing.New Evidence for Faith: Live Here or Nowhere by Hugh Ross and Guillermo Gonzalez
As people in the real estate business say, "Location is everything." The fact that the sun's location is fine-tuned to permit the possibility of life - and even more precisely fine-tuned to keep the location fixed in that unique spot where life is possible - powerfully suggests divine design.Guillermo Gonzalez, "Solar System Bounces in the Right Range for Life," Facts & Faith, v. 11, n. 1 (1997), pp. 4-5. Who is the Designer: Reasons to Believe 2003 Conference
Friday Afternoon What we can learn about the Designer from -- The Privileged Planet Guillermo Gonzalez and Jay RichardsExcerpted from G. Gonzalez, "Rare Sun," Facts for Faith 2 (2002) 14-21 Metal Matters By Hugh Ross
The star of such a planet would need to have been formed more recently than five billion years ago (see "Search for Planets Draws a Blank," page 8). Therefore, the number of stars that might be candidates to possess a planet with the capacity to support advanced life is just a tiny percentage of the total stars in existence. Stars that formed significantly earlier than about five billion years ago or later than about 4.5 billion years ago would not be candidates.The abuse of probabilities Close encounters of a deadly kind
This drift pattern is exactly what we see in the orbits of the forty extra-solar planets discovered so far. This drift pattern, caused by close stellar encounters, is the norm for planetary systems, the team concludes. Our solar system had the extraordinary "good fortune" of forming in a very small and loose star cluster situated well away from a spiral arm where stars are more densely packed. And, because our solar system revolves around our galaxy's core at just the right distance/rate, it remains in this safe zone, this sparsely populated area of our galaxy.2 2. Guillermo Gonzalez and Hugh Ross, "You Must Be Here," Facts for Faith, vol. 1, no. 1 (2000), pp. 36-Rare sun by Guillermo Gonzalez
Power Points To assert that some of the Sun's parameters must be fine-tuned to within a narrow range to permit life on Earth is reasonable. This assertion is called the Weak Anthropic Principle. Earth's Sun is unlike other stars in these characteristics: Mass - The Sun's mass helps determine its lifespan. The Sun delivers fewer and less intense transient radiation events than do lower mass stars. Initial composition - Not only is the Sun's metallicity atypical compared to the general field population (most of which lack giant planets), but it is also atypical compared to nearby stars with giant planets. Stability - As a star, the Sun is highly stable, which prevents wild climate changes. Observer viewpoint cannot explain the low brightness variations of the Sun. Location - The Sun holds a surprising position in the galaxy. It is between spiral arms in a circular orbit. A location very close to the so-called co-rotation circle prevents it from crossing spiral arms too frequently. Because these parameters must fall within a certain narrow range for Earth life to be possible, their convergence within that range argues for fine-tuning. Adding these examples to many additional ones from chemistry, cosmology, and physics greatly increases the overall required degree of fine-tuning for life. And fine-tuning argues for a Fine-Tuner, more frequently referred to as God, the Creator.The Measurability of the Universe--a Record of the Creator's Design By Guillermo Gonzalez
Since measurability is not a requirement for habitability, one cannot invoke the Anthropic Principle7 to make the remarkable measurability of the universe seem less remarkable. Evidence suggests that the universe was designed not only for human habitability but also for human measurability and comprehensibility. The same processes and features that make Earth habitable also make and preserve a record of activity and provide a means for measurement. Those very places in the Milky Way that would be most dangerous to humans (e. g., the galactic center, globular clusters, and spiral arms) also offer the poorest visibility and opportunity to make measurements. Does it seem a mere coincidence that Earth's location in the Milky Way affords an optimal view of most of the universe? Humanity's home planet is a comfortable porch from which curious humans can gaze out to the ends of time and space. 7 Hugh Ross, The Creator and the Cosmos 2d ed. (Colorado Springs, CO: Navpress, 1995), 92, 121-25, 128.The claim that measurability is not a requirement for habitability and thus one cannot invoke the Anthropic principle misses the point that habitability may be a subset of measurability or a superset. In other words habitability certainly could be a requirement for measurability since without habitability, there would be nobody present to measure A Spectrum of Views on ETI by Sam Conner, Guillermo Gonzalez, and Hugh Ross
So far, the search for ETI (commonly referred to as SETI) has yielded one significant finding. As an article in the most recent issue of Facts & Faith indicates, SETI has virtually eliminated the possibility that our galaxy contains hundreds of thousands of planets populated by technologically advanced societies.9 This limit, though it tells us little, at least poses a serious challenge to Mormon teachings about life on planets all around us.Guillermo Gonzalez, "Solar System Bounces in the Right Range for Life," Facts & Faith 11, no. 1 (1997): pp. 4-5. Guillermo Gonzalez, "Mini-Comets Write New Chapter in Earth-Science," Facts & Faith 11, no. 3 (1997): pp. 6-7. Guillermo Gonzalez, "The Measurability of the Universe: A Record of the Creator's Design," Facts for Faith 4 (Q4 2000), 42-48. Guillermo Gonzalez, "New Planets Hurt Chances for ETI," Facts & Faith, vol. 12, no. 4 (1998), pp. 2-4. The Extrasolar Planets Encyclopaedia
There are hundreds of billions of galaxies in the observable Universe, with each galaxy such as our own containing some 1011 stars. Surrounded by this seemingly limitless ocean of stars, mankind has long speculated about the existence of planetary systems other than our own, and the possibility of the development of life elsewhere in the Universe. Only recently has evidence become available to begin to distinguish the extremes of thinking that has pervaded for more than 2000 years, typified by opinions ranging from `There are infinite worlds both like and unlike this world of ours' (Epicurus, 341-270 BC) to `There cannot be more worlds than one' (Aristotle, 384-322 BC).
Based on present knowledge from the radial velocity surveys, about 5% of solar-type stars may harbour massive planets, and an even higher percentage may have planets of lower mass or with larger orbital radii. If these numbers can be extrapolated, the number of planets in our Galaxy alone would be of order 1 billion.Extrasolar planets Review article
It is not surprising that the Sun lies within the GHZ because we have used our local conditions as a template for finding similar systems. The Sun's value of x, solar metallicity and Earth's biological time scale were used to help define the GHZ. However, independent information comes from extrasolar planet host metallicities, the supernova rate and the metallicity evolution of the Galaxy. Our procedure is solar-centric but not to the extent of putting the Sun in the center of the GHZ."The Galactic Habitable Zone and the Age Distribution of Complex Life in the Milky Way", Charles H. Lineweaver,ï¿½ Yeshe Fenner* & Brad K. Gibson, Published in Science Jan 2, 2004
Our Sun is a very common and ordinary star. There is really nothing to distinguish it from a myriad of other similar stars in this region of the Galaxy. Yet, the Sun possesses a marvelous system of nine diverse planets. This has led us to believe that the formation of planetary systems should be a natural, common result of the process of star formation. We expect that a significant fraction of Solar-type stars should have some type of planetary system in orbit around them. The discovery by the HST of disks of dust around many stars in the Orion nebulae certainly reinforces that feeling.Extrasolar Planets Around Main Sequence Stars To appear in Protostars and Planets IV, ed. V. Mannings, A.Boss, and S.Russell Geoffrey W. Marcy San Francisco State University & U.C. Berkeley William D. Cochran University of Texas and Michel Mayor Geneva Observatory FORMATION OF TERRESTRIAL PLANETS IN THE UNIVERSE: THE FIRST CRITICAL TRANSITION LINEWEAVER, Charles H., Physics, Univ of New South Wales, Sydney 2052 Australia, firstname.lastname@example.org.
Planets like the Earth cannot form unless elements heavier than helium are available. These heavy elements, or `metals', were not produced in the big bang. They result from fusion inside stars and have been gradually building up over the lifetime of the Universe. Recent observations indicate that the presence of giant extrasolar planets at small distances from their host stars, is strongly correlated with high metallicity of the host stars. The presence of these close-orbiting giants is incompatible with the existence of earth-like planets. Thus, there may be a Goldilocks selection effect: with too little metallicity, earths are unable to form for lack of material, with too much metallicity giant planets destroy earths. Here I quantify these effects and obtain the probability, as a function of metallicity, for a stellar system to harbour an earth-like planet. I combine this probability with current estimates of the star formation rate and of the gradual build up of metals in the Universe to obtain an estimate of the age distribution of earth-like planets in the Universe. The analysis done here indicates that three quarters of the earth-like planets in the Universe are older than the Earth and that their average age is 1.8 0.9 billion years older than the Earth. If life forms readily on earth-like planets -- as suggested by the rapid appearance of life on Earth -- this analysis gives us an age distribution for life on such planets and a rare clue about how we compare to other life which may inhabit the Universe.
The 50 or so huge extrasolar planets that we know about are in orbits that would destroy any Earth-like planets. Dr. Charles H. Lineweaver, Research Fellow at the University of New South Wales, calls this a Goldilocks effect: "with too few ingredients Earths are unable to form, with too many, giant planets destroy any Earths trying to form. Edinburgh - June 27, 2001 Although the Earth is 4.55 billion years old, by cosmic standards the Earth is the new kid on the block. By combining observations of extrasolar planets and the rate of star formation in the Universe, Lineweaver has discovered that compared to other Earth-like planets in the Universe, our Earth is extremely young. In a paper in press at the planetary science journal Icarus, Lineweaver reported that "three quarters of the Earth-like planets in the Universe are older than the Earth and their average age is 1.8 (plus or minus 0.9) billion years older than the Earth." Although the analysis is about terrestrial planets, not the life on them, Lineweaver concluded that "If life forms readily on Earth-like planets--as suggested by the rapid appearance of life on Earth--this analysis gives us an age distribution for life on such planets and a rare clue about how we compare to other life which may inhabit the Universe." The "rare clue" is this: most of the life forms in the Universe have had two billion years longer to evolve than we have. (To put this time span in perspective, two billion years ago our ancestors were amoebas.)EXOWORLDS The Goldilocks Effect: How Other Earths Form Just Right See also An Estimate of the Age Distribution of Terrestrial Planets in the Universe: Quantifying Metallicity as a Selection Effect
Planets like the Earth cannot form unless elements heavier than helium are available. These heavy elements, or `metals', were not produced in the big bang. They result from fusion inside stars and have been gradually building up over the lifetime of the Universe. Recent observations indicate that the presence of giant extrasolar planets at small distances from their host stars, is strongly correlated with high metallicity of the host stars. The presence of these close-orbiting giants is incompatible with the existence of earth-like planets. Thus, there may be a Goldilocks selection effect: with too little metallicity, earths are unable to form for lack of material, with too much metallicity giant planets destroy earths. Here I quantify these effects and obtain the probability, as a function of metallicity, for a stellar system to harbour an earth-like planet. I combine this probability with current estimates of the star formation rate and of the gradual build up of metals in the Universe to obtain an estimate of the age distribution of earth-like planets in the Universe. The analysis done here indicates that three quarters of the earth-like planets in the Universe are older than the Earth and that their average age is 1.8 +/- 0.9 billion years older than the Earth. If life forms readily on earth-like planets - as suggested by the rapid appearance of life on Earth - this analysis gives us an age distribution for life on such planets and a rare clue about how we compare to other life which may inhabit the Universe.Habitability of Earth-like planets and extrasolar planetary systems
A general modelling scheme for assessing the suitability for life on any Earth-like extrasolar planet is presented. This approach is based on an integrated Earth system analysis in order to calculate the habitable zone in main-sequence-star planetary systems. A new attempt by Lineweaver (2001) to estimate the formation rate of Earth-like planets over cosmological time scales is applied to calculate the average number of habitable planets in the Milky Way as a function of time. The combination of this results with our estimations of extrasolar habitable zones yields the average number of habitable planets over cosmological time scales. We find that there was a maximum number of habitable planets at the time of Earth's origin.The number of habitable planets in the Milky Way over cosmological time scales The habitable zone of Earth-like planets around 47 UMa Werner von Bloh, Manfred Cuntz,Christine Bounama, and Siegfried Franck
The system of 47 UMa consists of two Jupiter-size planets beyond the outer edge of the stellar habitable zone, and thus resembles our own Solar System rather closely. The habitability of this system for Earth-like planets is investigated following a concept, which assumes the long-term possibility of photosynthetic biomass production under geodynamic conditions. In particular, the stellar luminosity and the age of the star/planet system are of fundamental importance for planetary habitability. Our study considers different types of planetary continental growth models. In the event of successful formation, we find that Earth-like habitable planets around 47 UMa are in principle possible
Abstract. Is there life beyond planet Earth? This is one of the grand enigmas which humankind tries to solve through scientific research. Recent progress in astronomical measurement techniques has confirmed the existence of a multitude of extra-solar planets. On the other hand, enormous efforts are being made to assess the possibility of life on Mars. All these activities have stimulated several investigations about the habitability of cosmic bodies. The habitable zone (HZ) around a given central star is defined as the region within which an Earth-like planet might enjoy the moderate surface temperatures required for advanced life forms. At present, there are several models determining the HZ. One class of models utilises climate constraints for the existence of liquid water on a planetary surface. Another approach is based on an integrated Earth system analysis that relates the boundaries of the HZ to the limits of photosynthetic processes. Within the latter approach, the evolution of the HZ for our solar system over geological time scales is calculated straightforwardly, and a convenient filter can be constructed that picks the candidates for photosynthesis-based life from all the extra-solar planets discovered by novel observational methods. These results can then be used to determine the average number of planets per planetary system that are within the HZ. With the help of a segment of the Drake equation, the number of "Gaias" (i.e. extra-solar terrestrial planets with a globally acting biosphere) is estimated. This leads to the thoroughly educated guess that there should exist half a million Gaias in the Milky Way.Planetary habitability: is Earth commonplace in the Milky Way? S. Franck, A. Block, W. Bloh, C. Bounama, I. Garrido, H.-J. Schellnhuber : Naturwissenschaften Volume 88, Number 10 p 416-426 [size=200%]Known examples of ï¿½bad' measurability[/size] Oort cloud Kuiper Belt Dark Matter Neutrinos to be continued...