Today’s New Reason To Believe

David H. Rogstad, Ph.D.

Since its inception 22 years ago, Reasons To Believe has held the position that our Solar System is extremely unusual, probably unique in the observable universe. We base this view on the Solar System’s various characteristics required to provide the long-term conditions necessary for life in general and especially for the advanced life on Earth. On the other hand, it is the contention of the naturalistic scientific community, for the most part, that there is nothing unique about our Solar System or Earth. This viewpoint is usually referred to as the Principle of Mediocrity (an extension of the Copernican Principle), the idea being that since the Earth is not at the center of the Solar System, we are not special like once thought. In the words of Carl Sagan from his PBS series Cosmos,

For most of human history we have searched for our place in the cosmos. Who are we? What are we? We find that we inhabit an insignificant planet of a hum-drum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people.

While this is the prevalent view, there are some nontheist scientists who have argued an approach not too different from that of Reasons To Believe; namely that Earth is rare. However, the growing body of evidence for exoplanets—planets orbiting stars other than our Sun—seemed to provide support for the non-uniqueness of our Solar System.

A recent report on computer simulations of the birth of planetary systems appears to put the ball back into the “uniqueness” court. E. Thommes and his colleagues at Northwestern University examined the more than 250 planetary systems, including our own, and developed a sophisticated model for the formation of planetary systems from beginning to end. They have numerically simulated this model using a variety of boundary conditions to reproduce results that are in agreement with some of the key trends observed in the properties of the exoplanets. These same simulations demonstrate that our own Solar System represents a rare case where the gas giants form but do not migrate into the inner parts of the planetary system, and all the planets achieve stable circular orbits. In the words of one of the authors,

We now better understand the process of planet formation and can explain the properties of the strange exoplanets we’ve observed. We also know that the Solar System is special and understand at some level what makes it special.

Undoubtedly, skeptics will remain and certainly this model will require development and improvement, but RTB scholars remain convinced that the more we learn about the special characteristics of our Solar System, the more we will discover the “fingerprints” of its Designer.

David H. Rogstad, Ph.D.

What if we could exchange our Sun for another star? Would we still have an environment that supports advanced life? Or would the change prevent the continuation of that life?

A few months ago, Hugh Ross discussed efforts by various astronomers to find a twin of the Sun using six different star properties. Only four or five stars out of more than 100,000 had characteristics similar enough to fit this category, and those few still had differences that disqualified them. I was so impressed with this work that I voiced the opinion on our Creation Update webcast that it wouldn’t surprise me if, as more data came in, the uniqueness of the Sun would be more firmly established, providing us with another fine-tuned characteristic for our solar system. (Hugh made the same argument.)

My enthusiasm was somewhat dampened, however, by a soon-to-be-published study by J. Robles and colleagues where they performed a comprehensive comparison of the Sun to other stars. In this study the authors established 11 relatively independent star properties that are thought to affect whether a planet orbiting the star can support simple (as opposed to advanced) life for a short time (as opposed to simple life for billions of years). In such cases, the likeness of a supposed twin can be more relaxed.

Ideally, one would like to measure these properties for a large collection of stars in order to obtain the distributions in each property. The Sun would then appear as a point in this 11-dimensional distribution and measurements would show whether the Sun was out on the edge of this distribution (indicating rarity) or somewhere in its middle (indicating ordinariness). Of course, to get a proper measure of the uniqueness of the Sun, some kind of a chi-squared statistical test should be applied, from which various probabilities can be derived.

Unfortunately, the number of stars possessing all 11 of the properties is very limited, so the authors of the study had to use limited sets of stars that were parts of other surveys, and in many cases these sets were not overlapping. To see what this limitation could do to bias the study, imagine a comparison for just two properties with the stars being completely nonoverlapping so we don’t know if the stars in one set have skewed values for the other property. It is possible for the Sun to appear in the middle of both property distributions but not be in the middle of the joint distribution for stars where we can obtain both properties. In practice the nonoverlapping distributions are not likely to be so skewed, but it does reveal a weakness in the conclusions of the study.

The authors conclude that the Sun is not unique. If the study is free from the non-overlapping bias, one would expect to be able to find stars that are twins of the Sun in many, if not all, of the 11 properties. However, based on the studies Hugh Ross mentioned above, finding such a twin, even for a limited number of properties, has proved difficult, at least for the more restrictive advanced-life case.

Perhaps in the end the Sun will not prove to be unique, but based on the results so far, that appears to be the case. Future deep surveys with accurate measurements for all the relevant stellar parameters hold promise to help settle the matter.

David H. Rogstad, Ph.D.

More than once, scientists and philosophers have noted how mathematics can describe, with remarkable precision, the laws that govern our universe. An example of this is found in the article The Unreasonable Effectiveness of Mathematics in the Natural Sciences by the Nobel Prize-winning physicist, Eugene Wigner. (See also a discussion here.) Mathematics is largely a product of human minds, using reason and logic, while the laws of physics are a description of how the cosmos operates. Why should there be any relationship between the two? Why, for instance, should the motion of Earth around the Sun follow a pattern that derives precisely from an inverse square law, a purely algebraic expression? As a naturalist with some Hindu leanings, Wigner commented:

The miracle of the appropriateness of the language of mathematics for the formulation of the laws of physics is a wonderful gift which we neither understand nor deserve. We should be grateful for it and hope that it will remain valid in future research and that it will extend, for better or for worse, to our pleasure, even though perhaps also to our bafflement, to wide branches of learning.

A further example of the correspondence between mathematics and physics has been published in the Notices of the American Mathematical Society by D. Khavinson and G. Neumann, and described in less technical terms in a press release here. These authors were working on an extension of a fundamental theorem in their particular field of mathematics. Without going into the details of their work, Khavinson and Neumann were able to derive an upper bound for the number of solutions to a certain type of equation. They posted their result on the Web, expecting no one outside the field of mathematics would be interested.

To their great surprise, they received a response from an astrophysicist S. Rhie, who had been studying gravitational lensing, where light from a distant celestial object, such as a star or galaxy, is deflected by a massive object between the source of light and the observer. This phenomenon was originally predicted using Newtonian mechanics, and refined using Einstein’s general relativity. The first gravitational lensing was discovered in 1979. Rhie was working on certain idealized situations where the number of images that could be seen due to gravitational lensing could be calculated mathematically. He used the same forms investigated by Khavinson and Neumann and obtained the same result, with some additional improvements.

While such a connection between mathematics and physics is hardly new, it supplies one more reminder of this amazing relationship. The atheist says matter created mind, providing no explanation for this correspondence. The theist says mind created matter, in which case the correspondence makes perfect sense. Humans are capable of thinking some of God’s thoughts after Him, the one who used His mind to create the wonderful cosmos in which we live.