Atheist Luke Muehlhauser interviews well-respect cosmologist Luke Barnes about the fine-tuning argument, and the naturalistic response to it.
Luke M. did a good job explaining what was in the podcast. (I wish more people who put out podcasts would do that).
Details:
In one of my funniest and most useful episodes yet, I interview astronomer Luke Barnes about the plausibility of 11 responses to the fine-tuning of the universe. Frankly, once you listen to this episode you will be better equipped to discuss fine-tuning than 90% of the people who discuss it on the internet. This episode will help clarify the thinking of anyone – including and perhaps especially professional philosophers – about the fine-tuning of the universe.
The 11 responses to fine-tuning we discuss are:
“It’s just a coincidence.”
“We’ve only observed one universe, and it’s got life. So as far as we know, the probability that a universe will support life is one out of one!”
“However the universe was configured, evolution would have eventually found a way.”
“There could be other forms of life.”
“It’s impossible for life to observe a universe not fine-tuned for life.”
“Maybe there are deeper laws; the universe must be this way, even though it looks like it could be other ways.”
“Maybe there are bajillions of universes, and we happen to be in one of the few that supports life.”
“Maybe a physics student in another universe created our universe in an attempt to design a universe that would evolve intelligent life.”
“This universe with intelligent life is just as unlikely as any other universe, so what’s the big deal?”
“The universe doesn’t look like it was designed for life, but rather for empty space or maybe black holes.”
“Fine-tuning shows there must be an intelligent designer beyond physical reality that tuned the universe so it would produce intelligent life.”
Download CPBD episode 040 with Luke Barnes. Total time is 1:16:31.
There is a very good explanation of some of the cases of fine-tuning that I talk about most on this blog – the force of gravity, the strong force, etc. as well as many other examples. Dr. Barnes is an expert, but he is also very very easy to listen to even when talking about difficult issues. Luke M. is very likeable as the interviewer.
I thought I would turn to the atheist theoretical physicist Sean Carroll, who has previously debated William Lane Craig, to explain to us what a Boltzmann brain is, and what threat it posts to the multiverse hypothesis.
Ludwig Boltzmann was one of the founders of the field of thermodynamics in the nineteenth century.
One of the key concepts was the second law of thermodynamics, which says that the entropy of a closed system always increases. Since the universe is a closed system, we would expect the entropy to increase over time. This means that, given enough time, the most likely state of the universe is one where everything is the in thermodynamic equilibrium … but we clearly don’t exist in a universe of this type since, after all, there is order all around us in various forms, not the least of which is the fact that we exist.
With this in mind, we can apply the anthropic principle to inform our reasoning by taking into account that we do, in fact, exist.
Here the logic gets a little confusing, so I’m going to borrow the words from a couple of more detailed looks at the situation. As described by cosmologist Sean Carroll in From Eternity to Here:
Boltzmann invoked the anthropic principle (although he didn’t call it that) to explain why we wouldn’t find ourselves in one of the very common equilibrium phases: In equilibrium, life cannot exist. Clearly, what we want to do is find the most common conditions within such a universe that are hospitable to life. Or, if we want to be more careful, perhaps we should look for conditions that are not only hospitable to life, but hospitable to the particular kind of intelligent and self-aware life that we like to think we are….
We can take this logic to its ultimate conclusion. If what we want is a single planet, we certainly don’t need a hundred billion galaxies with a hundred billion stars each. And if what we want is a single person, we certainly don’t need an entire planet. But if in fact what we want is a single intelligence, able to think about the world, we don’t even need an entire person–we just need his or her brain.
So the reductio ad absurdum of this scenario is that the overwhelming majority of intelligences in this multiverse will be lonely, disembodied brains, who fluctuate gradually out of the surrounding chaos and then gradually dissolve back into it. Such sad creatures have been dubbed “Boltzmann brains” by Andreas Albrecht and Lorenzo Sorbo….
In a 2004 paper, Albrecht and Sorbo discussed “Boltzmann brains” in their essay:
A century ago Boltzmann considered a “cosmology” where the observed universe should be regarded as a rare fluctuation out of some equilibrium state. The prediction of this point of view, quite generically, is that we live in a universe which maximizes the total entropy of the system consistent with existing observations. Other universes simply occur as much more rare fluctuations. This means as much as possible of the system should be found in equilibrium as often as possible.
From this point of view, it is very surprising that we find the universe around us in such a low entropy state. In fact, the logical conclusion of this line of reasoning is utterly solipsistic. The most likely fluctuation consistent with everything you know is simply your brain (complete with “memories” of the Hubble Deep fields, WMAP data, etc) fluctuating briefly out of chaos and then immediately equilibrating back into chaos again. This is sometimes called the “Boltzmann’s Brain” paradox.
[…]Now that you understand Boltzmann brains as a concept, though, you have to proceed a bit to understanding the “Boltzmann brain paradox” that is caused by applying this thinking to this absurd degree. Again, as formulated by Carroll:
Why do we find ourselves in a universe evolving gradually from a state of incredibly low entropy, rather than being isolated creatures that recently fluctuated from the surrounding chaos?
Unfortunately, there is no clear explanation to resolve this … thus why it’s still classified as a paradox.
Naturalists like to propose the multiverse as a way of explaining away the fine-tuning that we see, and explaining why complex, embodied intelligent beings like ourselves exist. But even if the multiverse hypothesis were true, we still would not expect to observe stars, planets, and conscious embodied intelligent beings. It is far more likely on a multiverse scenario that any observers we had would be “Boltzmann” brains in an empty universe. The multiverse hypothesis doesn’t explain the universe we have, which contains “a hundred billion galaxies with a hundred billion stars each” – not to mention our bodies which are composed of heavy elements, all of which require fine-tuning piled on fine-tuning piled on fine-tuning.
William Lane Craig answered a question about Boltzmann brains a while back, so let’s look at his answer since we saw what his debate opponent said above.
He writes:
Incredible as it may sound, today the principal–almost the only–alternative to a Cosmic Designer to explain the incomprehensibly precise fine tuning of nature’s constants and fundamental quantities is the postulate of a World Ensemble of (a preferably infinite number of) randomly ordered universes. By thus multiplying one’s probabilistic resources, one ensures that by chance alone somewhere in this infinite ensemble finely tuned universes like ours will appear.
Now comes the key move: since observers can exist only in worlds fine-tuned for their existence, OF COURSE we observe our world to be fine-tuned! The worlds which aren’t finely tuned have no observers in them and so cannot be observed! Hence, our observing the universe to be fine-tuned for our existence is no surprise: if it weren’t, we wouldn’t be here to be surprised. So this explanation of fine tuning relies on (i) the hypothesis of a World Ensemble and (ii) an observer self-selection effect.
Now apart from objections to (i) of a direct sort, this alternative faces a very formidable objection to (ii), namely, if we were just a random member of a World Ensemble, then we ought to be observing a very different universe. Roger Penrose has calculated that the odds of our solar system’s forming instantaneously through the random collision of particles is incomprehensibly more probable that the universe’s being fine-tuned, as it is. So if we were a random member of a World Ensemble, we should be observing a patch of order no larger than our solar system in a sea of chaos. Worlds like that are simply incomprehensibly more plentiful in the World Ensemble than worlds like ours and so ought to be observed by us if we were but a random member of such an ensemble.
Here’s where the Boltzmann Brains come into the picture. In order to be observable the patch of order needn’t be even as large as the solar system. The most probable observable world would be one in which a single brain fluctuates into existence out of the quantum vacuum and observes its otherwise empty world. The idea isn’t that the brain is the whole universe, but just a patch of order in the midst of disorder. Don’t worry that the brain couldn’t persist long: it just has to exist long enough to have an observation, and the improbability of the quantum fluctuations necessary for it to exist that long will be trivial in comparison to the improbability of fine tuning.
In other words, the observer self-selection effect is explanatorily vacuous. It does not suffice to show that only finely tuned worlds are observable. As Robin Collins has noted, what needs to be explained is not just intelligent life, but embodied, interactive, intelligent agents like ourselves. Appeal to an observer self-selection effect accomplishes nothing because there is no reason whatever to think that most observable worlds are worlds in which that kind of observer exists. Indeed, the opposite appears to be true: most observable worlds will be Boltzmann Brain worlds.
Allen Hainline explained some of the OTHER problems with the multiverse in a post on Cross Examined’s blog. I recommend taking a look at those as well, because I feel funny even talking about Boltzmann brains. I would rather just say that there is no experimental evidence for the multiverse hypothesis, as I blogged before, and leave it at that. But if the person you are talking to fights you on it, you can disprove the multiverse with the Boltzmann brains.
Radical feminists complain a lot about sexism, but damage is self-inflicted
One problem with feminism is that it produces the very outcomes that feminists then turn around and complain about. For example, consider the women’s studies major that is favored by feminists. Does it produce a good financial return on investment?
Here is an article from the Daily Signal to answer that.
Excerpt:
While only 23 percent of American women identify as feminists, 47 percent of millennial women do.
But unfortunately, the policies supported by modern feminists have been particularly bad for young women.
[…]Today, millennial women struggle with significant student loan debt and often have a hard time finding a job that will get them out of mom and dad’s basement. About 42 percent of women have more than $30,000 in student loan debt, compared than just 27 percent of men.
This could be a function of more women pursuing higher levels of learning. But significant student loan defaults among this group indicate that women may not be getting the return on investment they had hoped for.
Women are vastly overrepresented in majors that are known to have low returns on investment, such as gender studies or social work. Yet the feminist movement encourages more young women to pursue these degrees.
Their solution is to advocate further government assistance through policies such as free public college, loan forgiveness, and income-based repayment policies that drag out the life of a loan while doing nothing to put pressure on colleges to keep prices in check.
Hmm. Perhaps instead of taxing working men to pay for the poor academic decisions of women, we can shame and blame women who prefer useless degrees in women’s studies to useful degrees in computer science?
According to the National Center for Education Statistics, the number of women’s and gender studies degrees in the United States has increased by more than 300% since 1990, and in 2015, there were more than 2,000 degrees conferred.
These days, women’s studies programs include gender and sexuality studies, and many of the programs explore and question the relationship of race, class, sexuality, ethnicity and more to encourage students to investigate in the broader field of gender.
THREE HUNDRED PERCENT. It would never occur to me – as a child of poor non-white immigrants – that I could spend tens of thousands of dollars, and even go into debt, for a degree that would not pay for itself. Whether I liked computer science or not, that’s what I had to study – or something like that.
What about the idea that women are paid less than men for the same work, because of discrimination?
Liberal feminist Hanna Rosin takes a look at this question in the far-left Slate, of all places.
Excerpt:
The official Bureau of Labor Department statistics show that the median earnings of full-time female workers is 77 percent of the median earnings of full-time male workers. But that is very different than “77 cents on the dollar for doing the same work as men.” The latter gives the impression that a man and a woman standing next to each other doing the same job for the same number of hours get paid different salaries. That’s not at all the case. “Full time” officially means 35 hours, but men work more hours than women. That’s the first problem: We could be comparing men working 40 hours to women working 35.
How to get a more accurate measure? First, instead of comparing annual wages, start by comparing average weekly wages. This is considered a slightly more accurate measure because it eliminates variables like time off during the year or annual bonuses (and yes, men get higher bonuses, but let’s shelve that for a moment in our quest for a pure wage gap number). By this measure, women earn 81 percent of what men earn, although it varies widely by race. African-American women, for example, earn 94 percent of what African-American men earn in a typical week. Then, when you restrict the comparison to men and women working 40 hours a week, the gap narrows to 87 percent.
But we’re still not close to measuring women “doing the same work as men.” For that, we’d have to adjust for many other factors that go into determining salary. Economists Francine Blau and Lawrence Kahn did that in a recent paper, “The Gender Pay Gap.”.”They first accounted for education and experience. That didn’t shift the gap very much, because women generally have at least as much and usually more education than men, and since the 1980s they have been gaining the experience. The fact that men are more likely to be in unions and have their salaries protected accounts for about 4 percent of the gap. The big differences are in occupation and industry. Women congregate in different professions than men do, and the largely male professions tend to be higher-paying. If you account for those differences, and then compare a woman and a man doing the same job, the pay gap narrows to 91 percent. So, you could accurately say in that Obama ad that, “women get paid 91 cents on the dollar for doing the same work as men.”
I believe that the remainder of the gap can be accounted for by looking at other voluntary factors that differentiate men and women.
The Heritage Foundation says that a recent study puts the number at 95 cents per dollar.
Excerpt:
Women are more likely than men to work in industries with more flexible schedules. Women are also more likely to spend time outside the labor force to care for children. These choices have benefits, but they also reduce pay—for both men and women. When economists control for such factors, they find the gender gap largely disappears.
A 2009 study commissioned by the Department of Labor found that after controlling for occupation, experience, and other choices, women earn 95 percent as much as men do. In 2005, June O’Neil, the former director of the Congressional Budget Office, found that “There is no gender gap in wages among men and women with similar family roles.” Different choices—not discrimination—account for different employment and wage outcomes.
If women choose to study women’s studies, why should they be surprised that they are paid less than men who study computer science? I wish the people who teach women’s studies understood what it means to create something for a customer that they are willing to pay for. Then maybe they could tell women how to get paid more. People who learn hard things, create value for customers, and work longer hours make more money. Teaching young women useless prejudices against men does not help them to make more money.
