Saturday, June 17, 2017

The Six Days of Creation


Does the Bible teach that the universe was created a few thousand years ago? I know many people, both secular and religious, who believe that it does and, therefore, insist that the Bible is in conflict with the claims of Big Bang cosmology which require a universe that is about 13.8 billion years old. Of course the Bible does not say how old the universe is, so why do some people believe it teaches a "young" earth, only thousands of years old.  Such a claim is based on three propositions, all of which can be shown to be false, or at least not necessarily true. If the propositions are not correct, then there is no information in the Bible about the age of the universe. The propositions are (1) the genealogies in the Bible are basically complete, (2) the six days of creation in Genesis are consecutive 24 hour days, and (3) no time passes between the creation of the earth and the universe (as described in Genesis 1:1), and the subsequent six days of creation.

Monday, May 29, 2017

Some Proposals about the Beginning of our Universe


The theoretical physicist from Caltech, Sean Carroll gave a talk to the American Astronomical Society in January 2017 on the topic of what we know and don't know about the beginning of the universe. He has generously posted a copy of his presentation on his blog, preposterousuniverse.com. In this talk, Dr. Carroll speculates about how the gaps in what we don't know may be filled in by presenting a systematic classification of the main ideas developed over the last few years about what may have occurred before our universe began and brought our universe into existence. (Dr. Carroll does point out that to say our universe "came into existence" sounds like a process within time, but that time as we know it actually had a beginning with our universe.) In previous posts I have already discussed many of the things Dr. Carroll covers in his talk including (1) that our universe was in a state with very low entropy at its beginning, (2) that something like the Big Bang occurred about 13.8 billion years ago but we don't know what actually happened in the first trillionth of a trillionth of a trillionth of a second because (3) we don't have a quantum theory of gravity which may describe the initial conditions of our universe, even though (4) the equations of classical general relativity predict that our universe had an actual beginning.

Let's review what we do know: (1) About 13.8 billion years ago the universe was very hot and dense and was expanding rapidly while decelerating; (2) classical general relativity predicts that there was an actual beginning of our universe in a singularity; and (3) our early universe was in a very low entropy state which is quite hard to explain since low entropy is associated with an ordered, and improbable state. The last point presents tremendous challenges for any naturalistic proposal about how our universe came into existence.

In regards to what we don't know, Dr. Carroll presents four different classes of models about the space-time origin of our universe: (1) a bouncing model, (2) a cyclic model, (3) a hibernating model, or (4) a reproducing model.

Sunday, May 21, 2017

Extraordinary Claims and Extraordinary Evidence

"Extraordinary claims require extraordinary evidence" is a phrase that was popularized by Carl Sagan but has its roots from at least the 18th century Enlightenment when the miracles of Christianity were being questioned by certain intellectual thinkers of the day. The most famous Enlightenment critic of Christianity was probably David Hume who wrote an essay called Of Miracles in 1748 where he states, "Suppose, for instance, that the fact, which the testimony endeavours to establish, partakes of the extraordinary and the marvellous; in that case, the evidence, resulting from the testimony, admits of a diminution, greater or less, in proportion as the fact is more or less unusual."

At first this statement may sound reasonable. For instance, I am more likely to believe you if you tell me you had breakfast this morning than I would believe you if you told me that you levitated off the ground this morning without anything holding you up. But does the fact that I believe you if you say you did something ordinary and I don't believe you if you say you did something extraordinary support the statement that "Extraordinary claims require extraordinary evidence?" Actually, it doesn't. Although I may believe that you ate breakfast this morning, I must obtain supporting evidence if I want to actually determine whether or not that fact is true. If you have cleaned up your kitchen, such evidence may be hard to find. I might have to pump out the contents of your stomach, for instance to see what you ate and when you ate it. It is one thing to say that I believe you ate breakfast because it is an "ordinary" event, but it is quite another to actually find enough evidence to validate your claim. My point is that actual validation of any event requires sufficient evidence.

Sunday, April 30, 2017

Some Thoughts on a Multiverse

     
It may sound more like science fiction than serious science, but many scientists have recently embraced the idea that there may be many more universes than just our own.  Such an idea can produce a great science fiction story, such as that in the original Star Trek episode "Mirror Mirror" where a transporter accident causes Captain Kirk to move to an alternative universe that is more brutal and savage aboard its version of the Starship Enterprise.

There are a few different scenarios for producing many universes (or a "multiverse") within proposed scientific theories.  One mechanism is the probabilistic nature of quantum mechanics. The "many worlds" interpretation of quantum mechanics proposes that every time a quantum event occurs that has multiple possible outcomes, all outcomes are produced in some universe. This is similar to saying something like every time I flip a coin, if a "heads" shows up, then an additional universe branches off from ours in which everything is the same except the coin shows "tails." Not many scientists actually believe that quantum mechanics produces these universes, but some do.

A different scenario that produces many universes is called "eternal inflation" in which our universe is somewhat like one bubble in a boiling pot of water, but there are many other bubble universes that are also produced. This theory of eternal inflation1 is an extension of the inflationary big bang model in which our universe had a period of rapid expansion in the first 10-35 seconds. In the eternal inflation model, the rapid expansion may have stopped in our universe but continued in others producing many other universes.
     
Perhaps the most popular theory that includes a multiverse is string theory, that postulates the fundamental particles we know of, like quarks and leptons, are composed of "vibrating strings of energy."  String theory requires that the universe is actually composed of 10 dimensions, rather than just the three dimensions of space and one dimension of time that we are familiar with.  Different string theories can be derived from an even more exotic theory, called "M-theory" which requires an 11 dimensional universe.  I'm not an expert on string theory so I don't understand all of the calculations that produce the string theory landscape, but my understanding is that there are many different minimum energy states (vacua) within string theory and any universe could occupy one of those states.  Depending on certain assumptions the number of possible vacua is often estimated at something like 10500. This means that there are 10500 different kinds of possible universes, but since every one of these universes could be duplicated many times within string theory, there could even be many more universes than that unimaginably large number.

Sunday, April 9, 2017

An Introduction to the Anthropic Principle and Fine Tuning

Most of the readers of this blog have probably heard about the anthropic principle and the fine-tuning of the universe.  However, because future posts will discuss the ramifications and speculations about fine-tuning, I thought it would be prudent to give a brief overview of these topics. Although not identical, the anthropic principle and the fine-tuning are definitely related.

The anthropic principle takes different forms, but is basically the idea that the universe has the necessary conditions for the existence of any conscious being that is able to observe the universe.  These conditions could, in principle, be very narrow or very broad in their scope. Many of the observations about the anthropic nature of our universe were developed beginning in the 1960's and continue to this day. Perhaps the most definitive book on the subject was written in 1986 by John Barrow and Frank Tipler, The Anthropic Cosmological Principle. The authors actually develop four anthropic principles with the first one, the Weak Anthropic Principle, being the most well known and uncontroversial principle, "The observed values of all physical and cosmological quantities are not equally probable but they take on values restricted by the requirement that there exist sites where carbon-based life can evolve and by the requirements that the universe be old enough for it to have already done so"1

Although the parameters required for life to exist could, in theory, span a large or small range, it turns out that many of the parameters necessary for life to exist in our universe must fall within a very narrow region, or the universe would either not exist or not be able to support life. The fact that the conditions for life fall into such a narrow range, plus the many incredible mechanisms that give rise to the needed building blocks of life, constitute the fine-tuning of the universe.

I liken the finely-tuned universe to a panel that controls the parameters of the universe with about 100 knobs that can be set to certain values. If you turn any knob just a little to the right or to the left the result is either a universe that is inhospitable to life or no universe at all.

Saturday, March 25, 2017

The Second Law of Thermodynamics: An excerpt from the Dictionary of Christianity and Science

On April 25, 2017, Zondervan will publish the Dictionary of Christianity and Science. This is the definitive reference book discussing the intersection of Christian faith and contemporary science.  It has been a project that has taken over five years to complete. The four general editors, Paul Copan, Tremper Longman III, Christopher L. Reese, and myself have worked with over 100 outstanding contributors and our amazing editor, Madison Trammel, to bring this book to fruition.

There are a few features of this book that separate it from other such works. While most articles in the dictionary are unbiased, for topics that are controversial among Christians, the Dictionary presents various advocacy articles with opposing views. For instance, different views on evolution and the length of the days of creation are included. These articles represent the viewpoint of the author and are not completely unbiased. This multiple presentation model serves as a great resource for each reader to understand the complexities of the issue and come to his or her own conclusions.

Most of the articles in the Dictionary relate the particular subject to some aspect of Christian thought. For instance, articles on Special Relativity or Conservation of Energy have a concluding paragraph that mentions how some aspect of that subject relates to the character of God. This feature that explicitly discusses the intersection of science and faith distinguishes this reference book from others.

I have written 22 of the 450 or so articles. If you preorder the Dictionary you will get a number of bonus features including a presentation slide deck discussing String Theory which includes one of the articles I wrote on that subject. As an introduction to the Dictionary the rest of this post reproduces the entry I have written on the Second Law of Thermodynamics. This reprint is copyrighted by Zondervan and the four general editors and is used by permission. At the end of this article I briefly discuss the relationship of the second law of thermodynamics to biological evolution. I want to point out that I am not advocating for evolution but just stating facts regarding whether or not evolution violates the second law of thermodynamics.