Tag Archives: Big Bang

Sean Carroll debates William Lane Craig on cosmology and God’s existence

British Spitfire and German Messerschmitt Me 109 locked in a dogfight
British Spitfire and German Messerschmitt Me 109 locked in a dogfight

Here’s the video of the debate:

Carroll was as good of a speaker as Craig in terms of style. Very easy to listen to, very quick on his feet, very civil. There was no clear winner on style.

It was difficult to assess the truth value of scientific points being made, especially for the layperson. I explained a few of them in my posts earlier this week, but I think laypeople might struggle with them if they are hearing about these things for the first time.

A couple of Craig’s slides: (click for larger images)

Slide 1 of 2:

Dr. Craig slide #1 of 2
Dr. Craig slide #1 of 2

Slide 2 of 2:

Dr. Craig slide #2 of 2
Dr. Craig slide #2 of 2

Quick summary: (this is not complete, because I couldn’t get everything they were saying noted)

Dr. Craig defended two arguments: 1) the kalam cosmological argument and the fine-tuning argument.

Dr. Craig supported the origin of the universe with 1) the expansion of the universe and 2) the second law of thermodynamics.

Dr. Craig said that the BGV theorem supports a beginning for the universe.

Dr. Craig said that the consensus of scientists did not accept Carroll’s naturalistic cosmology, quoting Stephen Hawking in support.

Dr. Craig said that multiverse models fall victim to the Boltzmann brain problem, where we should observe Boltzmann brains coming into existence and then phasing out again far more probably than embodied minds. But we observe embodied minds, and no Boltzmann brains.

Dr. Carroll said that science cannot study metaphysical questions.

Dr. Carroll said that science is about making models that may or may not be consistent with the experimental data.

Dr. Carroll said that the BGV theorem does not support a beginning for the universe.

Dr. Carroll proposed 17 alternative cosmologies, but did not provide a shred of scientific evidence for any of them, the way that Craig did for the standard model.

Dr. Carroll refuted Dr. Craig’s citation of Stephen Hawking, and Craig yielded the point.

Dr. Carroll speculated that science might progress to the point where the fine-tuning can be explained without an intelligent cause, and he gave an example of where that happened (inflation).

Dr. Craig argued that all 17 of the models suggested by Carroll either conflicted with evidence, had serious problems or did require a beginning.

Dr. Craig argued that Carroll’s own model required a beginning.

Dr. Craig argued that Carroll’s own model fell victim to the Boltzmann brain problem.

Dr. Craig argued that Carroll’s own model violated the second law of thermodynamics.

Dr. Craig re-stated his point that the baby universe spawning in Carroll’s model was speculative and incomplete, and cited Christopher Weaver’s work.

Dr. Carroll denied that things that pop into being out of nothing require a transcendent cause.

Dr. Carroll reiterated that science can only make naturalistic models, and that he did not have to answer questions about ultimate causes.

Dr. Carroll showed a photo of Alan Guth expressing his opinion that the universe is “probably” eternal. No evidence was given for this assertion.

Dr. Carroll said that the fine-tuning was not done in an optimal way, because one fine-tuned value was lower than it needed to be, and it should be exactly what it needed to be if God did it.

Dr. Carroll said that a finely-tuned universe is more probably in naturalism than in theism, because God can do anything he wants and doesn’t need a fine-tuned universe.

Dr. Carroll said he would stop defending his model now, and would instead defend Aguirre-Gratton.

Dr. Craig gave three reasons why the universe popping into being out of nothing requires a transcendent cause.

First, he said that nothing cannot cause anything to happen, because nothing is nothing.

Second, he said that if things pop into being out of nothing, then why don’t we see it happening all the time with other things.

Third, he said that we have no reason to dismiss the causal principle, especially when it is the basis of scientific inquiry and has been so fruitful in the progress of science.

Dr. Craig reiterated that baby universes in Carroll’s model would be dominated by Boltzmann brains, and we don’t observe that.

Dr. Craig said that even on the quantum gravity models that Carroll mentioned, there would still be a beginning.

Dr. Carroll said that Craig mustn’t say “popped into being” but instead that “there was a first moment of time”.

Dr. Carroll said that his model does indeed violate the second law of thermodynamics “YES!”.

At this point Carroll stopped talking about the topic of the debate and started expressing personal opinions about religion. It’s funny how often atheists do this in debates.

Dr. Carroll said that most theists don’t believe in God because of cosmology, but because of community and feelings.

Dr. Carroll said that science had learned a lot in the last 2000 years, so theism was false.

Dr. Carroll said that most philosophers don’t think that God exists, so theism was false.

Dr. Carroll said microscopes and telescopes were absent 2000 years ago, so theism was false.

Dr. Carroll said that religion should be about community and feelings, not about what is true.

Conclusion:

My conclusion was that Carroll lost because he is just satisfied to throw theories out and not to argue that they are true by citing evidence. Carroll never seemed to be interested in finding out what is true, but instead he just wanted to tell a story that didn’t include God, and assert that by Occam’s Razor, his story was a better explanation. I am not impressed with theoretical speculations, although the layperson might be. I kept waiting for him to respond to Craig’s points about how his model was falsified by experimental evidence and observations, e.g. – the Boltzmann brains or the baby universe generation, and he never cited the evidence I wanted him to cite. Craig did have some evidence for his views, but he could have been stronger in making his case. He could have shown the e-mail from Vilenkin that stated that he had understood the BGV theorem, and was using it correctly, for example.

For me the winning side comes down to evidence. The standard model is the standard model because of scientific evidence. Until that evidence is overturned, then speculative models are of no interest to anyone who is evidence-driven. Speculations are not science. A philosophical presupposition of metaphysical naturalism is not science.

If you want to see a good lecture on scientific evidence related to cosmology, then there is the particle physicist Michael Strauss lecture on cosmology and fine-tuning at Stanford University and his more recent lecture at the University of Texas. Note that Strauss is an experimental physicist, not a theoretical physicist like Carroll.

Here’s another review of the debate by Randy Everist of Possible Worlds blog. He explains the back-and-forth over Boltzmann brains and the BGV theorem in more detail.

MIT physicist Alan Lightman on fine-tuning and the multiverse

Christianity and the progress of science
Christianity and the progress of science

Here’s the article from Harper’s magazine.

The MIT physicist says that the fine-tuning is real, and is best explained by positing the existence of an infinite number of universes that are not fine-tuned – the so-called multiverse.

Excerpt:

While challenging the Platonic dream of theoretical physicists, the multiverse idea does explain one aspect of our universe that has unsettled some scientists for years: according to various calculations, if the values of some of the fundamental parameters of our universe were a little larger or a little smaller, life could not have arisen. For example, if the nuclear force were a few percentage points stronger than it actually is, then all the hydrogen atoms in the infant universe would have fused with other hydrogen atoms to make helium, and there would be no hydrogen left. No hydrogen means no water. Although we are far from certain about what conditions are necessary for life, most biologists believe that water is necessary. On the other hand, if the nuclear force were substantially weaker than what it actually is, then the complex atoms needed for biology could not hold together. As another example, if the relationship between the strengths of the gravitational force and the electromagnetic force were not close to what it is, then the cosmos would not harbor any stars that explode and spew out life-supporting chemical elements into space or any other stars that form planets. Both kinds of stars are required for the emergence of life. The strengths of the basic forces and certain other fundamental parameters in our universe appear to be “fine-tuned” to allow the existence of life. The recognition of this fine-­tuning led British physicist Brandon Carter to articulate what he called the anthropic principle, which states that the universe must have the parameters it does because we are here to observe it. Actually, the word anthropic, from the Greek for “man,” is a misnomer: if these fundamental parameters were much different from what they are, it is not only human beings who would not exist. No life of any kind would exist.

If such conclusions are correct, the great question, of course, is why these fundamental parameters happen to lie within the range needed for life. Does the universe care about life? Intelligent design is one answer. Indeed, a fair number of theologians, philosophers, and even some scientists have used fine-tuning and the anthropic principle as evidence of the existence of God. For example, at the 2011 Christian Scholars’ Conference at Pepperdine University, Francis Collins, a leading geneticist and director of the National Institutes of Health, said, “To get our universe, with all of its potential for complexities or any kind of potential for any kind of life-form, everything has to be precisely defined on this knife edge of improbability…. [Y]ou have to see the hands of a creator who set the parameters to be just so because the creator was interested in something a little more complicated than random particles.”

Intelligent design, however, is an answer to fine-tuning that does not appeal to most scientists. The multiverse offers another explanation. If there are countless different universes with different properties—for example, some with nuclear forces much stronger than in our universe and some with nuclear forces much weaker—then some of those universes will allow the emergence of life and some will not. Some of those universes will be dead, lifeless hulks of matter and energy, and others will permit the emergence of cells, plants and animals, minds. From the huge range of possible universes predicted by the theories, the fraction of universes with life is undoubtedly small. But that doesn’t matter. We live in one of the universes that permits life because otherwise we wouldn’t be here to ask the question.

I thought I was going to have to go outside this article to refute the multiverse, but Lightman is honest enough to refute it himself:

The… conjecture that there are many other worlds… [T]here is no way they can prove this conjecture. That same uncertainty disturbs many physicists who are adjusting to the idea of the multiverse. Not only must we accept that basic properties of our universe are accidental and uncalculable. In addition, we must believe in the existence of many other universes. But we have no conceivable way of observing these other universes and cannot prove their existence. Thus, to explain what we see in the world and in our mental deductions, we must believe in what we cannot prove.

Sound familiar? Theologians are accustomed to taking some beliefs on faith. Scientists are not. All we can do is hope that the same theories that predict the multiverse also produce many other predictions that we can test here in our own universe. But the other universes themselves will almost certainly remain a conjecture.

The multiverse is not pure nonsense, it is theoretically possible. The problem is that the multiverse generator itself would require fine-tuning, so the multiverse doesn’t get rid of the problem. And, as Lightman indicates, we have no independent experimental evidence for the existence of the multiverse in any case. Atheists just have to take it on faith, and hope that their speculations will be proved right. Meanwhile, the fine-tuning is just as easily explained by postulating God, and we have independent evidence for God’s existence, like the the origin of biological information, the sudden appearance of animal body plans, the argument from consciousness, and so on. Even if the naturalists could explain the fine-tuning, they would still have a lot of explaining to do. Theism (intelligent causation) is the simplest explanation for all of the things we learn from the progress of science.

We need to be frank about atheists and their objections to the progress of science. Within the last 100 years, we have discovered that the physical universe came into being out of nothing 15 billion years ago, and we have discovered that this one universe is fine-tuned for intelligent life. I don’t think it’s like that the last 100 years of scientific progress on the origins question are going to be overturned so that science once again affirms what atheists believe about the universe. Things are going the wrong way for atheists – at least with respect to science.

See it in action

To see these arguments examined in a debate with a famous atheist, simply watch the debate between William Lane Craig and Christopher Hitchens, and judge which debater is willing to form his beliefs on scientific progress, and which debater is forming his beliefs against the science we have today, and hoping that the good science we have today based on experiments will be overturned by speculative theories at some point in the future. When you watch that debate, it becomes very clear that Christian theists are interested in conforming their beliefs to science, and atheists are very interested in speculating against what science has shown in order to maintain their current pre-scientific view. That’s not what rational people ought to do when confronted with evidence.

Positive arguments for Christian theism

How the WMAP satellite confirmed nucleosynthesis predictions and falsified atheism

Christianity and the progress of science
Christianity and the progress of science

Prior to certain scientific discoveries, most people thought that the universe had always been here, and no need to ask who or what may have caused it. But today, that’s all changed. Today, the standard model of the origin of the universe is that all the matter and energy in the universe came into being in an event scientists call “The Big Bang”. At the creation event, space and time themselves began to exist, and there is no material reality that preceded them.

So a couple of quotes to show that.

An initial cosmological singularity… forms a past temporal extremity to the universe. We cannot continue physical reasoning, or even the concept of spacetime, through such an extremity… On this view the big bang represents the creation event; the creation not only of all the matter and energy in the universe, but also of spacetime itself.

Source: P. C. W. Davies, “Spacetime Singularities in Cosmology,” in The Study of Time III, ed. J. T. Fraser (Berlin: Springer Verlag ).

And another quote:

[A]lmost everyone now believes that the universe, and time itself, had a beginning at the big bang.

Source: Stephen Hawking and Roger Penrose, The Nature of Space and Time, The Isaac Newton Institute Series of Lectures (Princeton, N. J.: Princeton University Press, 1996), p. 20.

So, there are several scientific discoveries that led scientists to accept the creation event, and one of the most interesting and famous is the discovery of how elements heavier than hydrogen were formed.

Nucleosynthesis: forming heavier elements by fusion
Nucleosynthesis: forming heavier elements by fusion

Here’s the history of how that discovery happened, from the National Aeronautics and Space Administration (NASA) web site:

The term nucleosynthesis refers to the formation of heavier elements, atomic nuclei with many protons and neutrons, from the fusion of lighter elements. The Big Bang theory predicts that the early universe was a very hot place. One second after the Big Bang, the temperature of the universe was roughly 10 billion degrees and was filled with a sea of neutrons, protons, electrons, anti-electrons (positrons), photons and neutrinos. As the universe cooled, the neutrons either decayed into protons and electrons or combined with protons to make deuterium (an isotope of hydrogen). During the first three minutes of the universe, most of the deuterium combined to make helium. Trace amounts of lithium were also produced at this time. This process of light element formation in the early universe is called “Big Bang nucleosynthesis” (BBN).

The creation hypothesis predicts that there will be specific amounts of these light elements formed as the universe cools down. Do the predictions match with observations?

Yes they do:

The predicted abundance of deuterium, helium and lithium depends on the density of ordinary matter in the early universe, as shown in the figure at left. These results indicate that the yield of helium is relatively insensitive to the abundance of ordinary matter, above a certain threshold. We generically expect about 24% of the ordinary matter in the universe to be helium produced in the Big Bang. This is in very good agreement with observations and is another major triumph for the Big Bang theory.

Moreover, WMAP satellite measurements of mass density agree with our observations of these light element abundances.

Here are the observations from the WMAP satellite:

Scientific observations match predictions
Scientific observations match predictions

And here is how those WMAP measurements confirm the Big Bang creation event:

However, the Big Bang model can be tested further. Given a precise measurement of the abundance of ordinary matter, the predicted abundances of the other light elements becomes highly constrained. The WMAP satellite is able to directly measure the ordinary matter density and finds a value of 4.6% (±0.2%), indicated by the vertical red line in the graph. This leads to predicted abundances shown by the circles in the graph, which are in good agreement with observed abundances. This is an important and detailed test of nucleosynthesis and is further evidence in support of the Big Bang theory. 

“An important and detailed test”.

For completeness, we should learn how elements heavier than these light elements are formed:

Elements heavier than lithium are all synthesized in stars. During the late stages of stellar evolution, massive stars burn helium to carbon, oxygen, silicon, sulfur, and iron. Elements heavier than iron are produced in two ways: in the outer envelopes of super-giant stars and in the explosion of a supernovae. All carbon-based life on Earth is literally composed of stardust.

That’s a wonderful thing to tell a young lady when you are on a date: “your body is made of stardust”. In fact, as I have argued before, this star formation, which creates the elements necessary for intelligent life, can only be built if the fundamental constants and quantities in the universe are finely-tuned.

Now, you would think that atheists would be happy to find observations that confirm the origin of the universe out of nothing, but they are not. Actually, they are in denial.

Here’s a statement from the Secular Humanist Manifesto, which explains what atheists believe about the universe:

Religious humanists regard the universe as self-existing and not created.

For a couple of examples of how atheistic scientists respond to the evidence for a cosmic beginning, you can check out this post, where we get responses from cosmologist Lawrence Krauss, and physical chemist Peter Atkins.

You cannot have the creation of the universe be true AND a self-existing, eternal universe ALSO be true. Someone has to be wrong. Either the science is wrong, or the atheist manifesto is wrong. I know where I stand.

Positive arguments for Christian theism