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Are We Alone? Fine-Tuning the Universe, with Barnes, Keating, and Richards
“Are we alone in the universe?” That’s the central question we put to astrophysicist Dr. Luke Barnes, cosmologist Dr. Brian Keating, and philosopher Dr. Jay Richards. Our guests delve into the probabilities and challenges of finding extraterrestrial life, considering the vastness of the cosmos and the fine-tuning necessary for life to exist. They explore the implications of the SETI project, the rarity of Earth-like conditions, and the potential for habitable planets in other solar systems. This discussion is set against the backdrop of broader scientific and philosophical inquiries, including the Big Bang, the multiverse theory, and the role of humanity in the cosmic order. The conversation offers a deep and nuanced perspective on the search for life beyond Earth and what it could mean for our understanding of the universe and our place within it.
Published in Uncommon Knowledge
Whenever the topic of the so-called “fine tuning” of the universe comes up I brace myself to hear what I think are poorly reasoned arguments leading to metaphysical destinations. Including Dr. Keating helped, I think, to provide the balance that may have discouraged that particular detour. Kudos for having a diversity of viewpoints on the show.
It’s perfectly okay to use the matter of the universe’s apparent fine-tuning as a jumping off point for speculation as to why it might be the way it is: that’s fun, and may even, someday, be productive. But there’s at least one obvious and thus-far irrefutable explanation that would render such apparent fine-tuning unremarkable: that, for all we know, universes do what ours appears to have done — spring into being — all the time. After all, we know nothing about the context in which our universe began (if it began), nor about the processes that precipitated it. The only reason we have to believe that ours is the only one that began in that manner is the same reason our ancestors had for believing that Earth is the only planet. Given that, drawing any large conclusions from the apparent fine-tuning is probably imprudent.
This was an ambitious program. Topics don’t get much bigger than these.
Excellent post and discussion. However, the number of fine-tuning factors identified for the existence of life on Earth is at least an order of magnitude more than the 31 Luke Barnes mentions. Was he limiting himself to the cosmologcial fine tuning factors on a large scale? I suppose I must read his book to find out.
And no, Henry. There is no multiverse. Universes don’t appear all the time. There is zero evidence of this, only bad interpretations of quantum theory. Furthermore, if there were a multiverse, it would only make the fine tuning problem worse, not resolve it.
First, I’m not talking about the stuff Sean Carroll et al talk about with their endless quantum bifurcation. That’s what most people hear when they hear “multiverse,” which is why I didn’t use the phrase.
Secondly, you don’t know what, if anything, existed before our universe came into being — if it actually came into being. You don’t know what the pre-universe was like prior to the start of the expansion of the universe we have. You don’t know why or how our universe came into being — again, if it came into being.
No one knows. We have no evidence of anything earlier than ~13.7 billion years ago; we have no evidence that would support or contradict the idea that the universe simply popped into existence in some context that predated space, time, and matter.
That’s why I said it is “thus-far irrefutable.” It remains a conceptually simple, seemingly plausible, untested explanation.
Thirdly, no, it needn’t make the fine-tuning problem worse (accepting for the sake of discussion that there is a “fine-tuning problem”). If all those endless universes inflating randomly out of nothing[?] differ from one another, if their laws and/or constants can vary, then it stands to reason that the only universes containing intelligences pondering the fine-tuning of their own universes will be those compatible with life.
I’m not saying that that is the explanation. I’m just saying that you can’t, that no one can, refute it.
Here’s an interesting thing. The interview touched on two topics that seem intuitively improbable and suggestive of… well, of something unnatural or paradoxical.
One is the oft-discussed “fine-tuning,” the seemingly nearly-impossible exactitude with which some natural constants match the apparently arbitrary values which we think they would have to have in order for us to exist. The other is the so-called “Fermi paradox,” the idea that, given the vastness of the universe and the incomprehensible number of stars and planets, many undoubtedly like our own, it’s extraordinary bordering on miraculous that we’ve yet found no evidence of life anywhere other than here on good old terra firma.
While both of these seem intuitively to be remarkable, they’re actually example of reasoning from mathematical ignorance in two slightly different but complementary ways.
In the case of the fine-tuning problem, we’re faced with what appears to be an extremely low-probability event, and we marvel that it occurred.
In the case of the Fermi paradox, we’re faced with what appears to be an extremely large number of opportunities for an event to occur, and marvel that we see only a single occurrence.
But here’s the thing. The expected number of occurrences of any particular chance outcome can be calculated as the probability, the likelihood, of that outcome occurring times the number of opportunities, or tries, we have for reaching that outcome.
The likelihood of the universe being “fine-tuned” the way it appears to be seems very, very small. But we don’t have any idea how many opportunities there have been for such a universe to arise. If the latter number is very, very large, then it really isn’t surprising that we live in such a universe.
Similarly, regarding the Fermi paradox, the number of opportunities for life to form in the universe seems very, very large. But we don’t have any idea how likely it is for life to form, or for life to become intelligent. If that probability is very, very small, then, again, it really isn’t surprising that we haven’t seen any more of it.
In both cases we’re letting one stunningly small (tuning) or large (Fermi) number overwhelm our senses, despite having absolutely no basis for estimating the magnitude of the other critical term in the equation.
It is a quite natural, intuitive/emotional response to an extreme number. It’s the product of the same impulse that causes otherwise prudent people to buy lottery tickets when the payoff becomes numbingly large — despite the possibility that skyrocketing ticket sales have actually depressed their mathematically expected return.
And, of course, we wouldn’t BE alive in any universe that DIDN’T.
It’s not just the initial likelihood, either. While not specifically mentioned in your comment, the time overlap must be considered. Even if millions of civilizations were formed in the universe over billions of years, the combinations of how far they would be from us, and the likelihood that we would be in a position to – for example – receive signals from them during the relatively brief span of OUR world civilization, is still small.
A civilization even relatively nearby – say, 1,000 light-years – might have risen, sent out all their radio and TV shows etc, and then fallen, before we were able to receive such signals. Or, if they’re 2,000 light-years away and sent their signals 1,000 years ago, we may be gone before their signals get here. And even if we were still around then, THEY might have already disappeared. Either way, we would be unable to communicate with them, or travel to them…
To be clear, the number of ticket buyers doesn’t change the odds of any one person winning, but it does affect how much they would win IF they won. Because of the increased likelihood that they would share the prize.
But I don’t think the prospect of having to divide possibly over $1 Billion among even 100 people, if there were that many winners, would deter many people from spending $1 or $10 on a ticket. That’s still $10 Million each for the winners. People don’t buy a ticket in a $1 Billion lottery just because they expect to be the only big winner.
Well done.
I haven’t listened to this remarkable interview yet but plan on it.
I just discovered that some of the reliable people looking into the big bang also believe that there were situations that preceded it. Did this aspect of it get discussed?
Carol,
No, not really. As I recall, there was one reference made to the ambiguity of it — to the fact that we don’t know that time, etc., actually started with what we think is the initial expansion of the universe.
I said this was an ambitious program. In fact, the topic is so large and multi-faceted that all one can take out of an hour-long interview like this is a smattering of seemingly unrelated bits. Consider what’s contained in the program’s title: Fine-Tuning and Are We Alone, two unrelated topics either of which is worth hours of discussion.
They touch on anthropocentricity as it relates to our ability to perform science — that is, the degree to which our astronomical location and situation impacts our ability to observe and measure the universe — which is a really interesting idea worthy of deeper examination and, perhaps, refutation. But there’s simply too little time.
It was a pleasant interview, but I think it fails to deliver anything beyond a cursory mention of several interesting topics.
H.
Thanks for your observations.
Big topics often require more than a hour.
Even if it is Robinson handing the interview.
In any case, as soon as I put the work project to bed, I’ll be listening in.
Henry, can you recommend a starting point or bibliography for those interested in this topic.
Sis,
I’m sorry, but I don’t have anything for you. I have what is probably an odd perspective on theoretical physics and cosmology. I’m interested in knowing what we think we know about the universe, about the particles and fields and laws we think define the world we see, but I have little interest in the more speculative takes on physics that run on ahead of what we can test experimentally.
Relativity and quantum mechanics have a rich body of supporting evidence. They make predictions that, when we finally develop the means to test them, prove to be astoundingly accurate.
Other things, like string theory, quantum multiverses, stuff like that, I find less interesting. Maybe that’s because I don’t feel a need to understand the mathematical underpinning of reality (I wouldn’t understand it anyway). Maybe because I want to absorb relatively settled knowledge, and not soak up a bunch of highly speculative hypotheses. I’m just interested in appreciating the awe-inspiring intricacies of our world.
The fine-tuning problem is real. The answers offered for it, some more plausible than others, are speculative in nature and currently untestable, and so they don’t interest me very much. I’m content to know that there are plausible answers to the fine-tuning problem that don’t require that we abandon physics in favor of metaphysics, nor that we embrace some specific speculative hypothesis (e.g., string theory).
I have a particular dislike for what I believe to be the reckless mixing of physical and metaphysical paradigms. That’s why I make it a point to respond to those who attempt to use science to prove, or to disprove, the existence of G-d and/or a metaphysical universe. As I’ve written elsewhere, I think doing so weakens both scientific and religious integrity, and ultimately serves no one well.
Unfortunately, most of the popular literature that attempts to deal specifically with the fine-tuning problem tends to do one of two things I’d rather it didn’t: delve into speculative theoretical physics, or focus more heavily than I’d like on rebuking the G-d hypothesis.
I wish I could recommend a book that wasn’t a heavy lift in terms of math, and that didn’t lean too heavily into speculative physics. Barbara Ryden’s Introduction to Cosmology textbook is very good, clear, and comprehensive, but also requires more math than most of us have — certainly more than I have, though I enjoyed it nonetheless. Leonard Susskind’s The Cosmic Landscape is often fascinating, but he’s the big name in string theory and that was the least interesting aspect of the book to me.
I’d really like to find a book that says, basically, “Here is what we’re pretty confident we know, and why — and here are, briefly, some of the speculative things people are considering to fill in the gaps.” I think such a book, pitched at the layman reader, would be terrific. It would be a great answer to books like Stephen Meyer’s Return of the God Hypothesis, which really does deserve a readable but challenging response — specifically, challenging to Meyer’s overly confident (in my opinion) exclusion of scientific alternatives to metaphysics.
Now you’ve got me interested in going out to see what’s available. If I find anything, I’ll let you know.
H.
Incidentally, if you’d like to see an example of the bad things that happen when people try to combine science and religion, I’ll refer you to another recent Uncommon Knowledge episode from a couple of weeks ago.
Beyond Evolution: Unraveling the Origins of Life with Stephen Meyer and James Tour
I have enormous respect for Peter Robinson, but Peter, for all his substantial intelligence and decency, isn’t sufficiently versed in science as to be able to defend it against two gentlemen so willing to selectively omit the arguments Peter should, but is unable to, make.
I think everyone, not least Peter, would be better served if he avoided having such one-sided collections of guests when dealing with this topic (as he did with the interview that is the topic of the current post, for example).