The Big Picture: On the Origins of Life, Meaning, and the Universe Itself

"Sean is a cosmologist. He and I have similar backgrounds, though he’s a little more on the relativity side and I’m a little more on the particle physics side. I’ve always liked Sean’s writing. I used to read his blog regularly and now I listen to his podcast . He’s a really great science communicator. His first books two books were about physics. The Big Picture is about physics and cosmology, but with a big dose of philosophy on top of that. I read a lot of philosophy and it’s really refreshing to read a physicist writing about philosophy in a reasonably competent way. Most physicists think they’re good at philosophy when they’re actually terrible at it. That’s why I thought The Big Picture really stood out. It’s asking questions that philosophers of science might ask, from the perspective of a physicist who is also informed as a philosopher. Sean writes a lot about the anthropic principle. This is an idea that goes back several decades, but stated in its simplest form it’s that an observer will always find themselves living in a situation where observers are possible. It sounds uncontroversial and it’s basically a tautology. It just has to be true by definition, but it actually leads to some really interesting conclusions. First I’ll give you a really uncontroversial usage of the anthropic principle and then I’ll give you a controversial one. The non-controversial one is we find ourselves living on a planet that has the chemistry and temperature to potentially support life. By definition we couldn’t find ourselves living on a planet that couldn’t support life, so we’re not surprised that 0.00001 (etc.) per cent of the volume of the universe is a planet with life-supporting conditions, and we happen to be on it—even though it seems unlikely, when you put it that way. Support Five Books Five Books interviews are expensive to produce. If you're enjoying this interview, please support us by donating a small amount . The more controversial version of the anthropic principle is maybe looking at something like the strength of the electromagnetic force. We notice that if the electromagnetic force had been a little bit stronger or a little bit weaker, life couldn’t exist in this universe. I forget the details, but I think if it were a little bit stronger than certain processes happen among nuclei that would cause stars to implode and if they were a little bit weaker, you couldn’t have certain kinds of key stable atoms. The details aside, the basic idea is that this number fits the value you need for intelligent life—or any kind of organized life or biology to exist at all. So some physicists have said this is probably because there are many universes, and in most of those universes life doesn’t exist because this number isn’t the right number. But of those many, many universes we of course find ourselves in one where things seem tuned to life. This doesn’t require a designer or any theistic explanation, it’s just something that we shouldn’t be surprised about—in the same way that we’re not surprised we live on a life-supporting planet. There’s a lot of interesting philosophy behind this question and Sean does a very good job of exploring those sorts of issues. Different people respond to these discoveries in different ways. I gave a talk earlier today where one of the questions I got in the Q&A session was, ‘If there are an infinite number of universes or space goes on for an infinite distance (which it may or may not) then doesn’t that mean everything is pointless?’ I don’t think I’d reach the same conclusion, but for him a profound sense of pointlessness came from that discovery. My advice to him was, ‘Then you shouldn’t think about it very much.’ But I don’t know. The psychology is really interesting. I definitely get that sense of awe and wonder that people talk about when they’re thinking about these sorts of things. I experience that profoundly, and not just at cosmology. When I learned about relativity or quantum physics for the first time, it was the most amazing stuff I’d ever encountered in my life. It really motivated me to become a physicist. So I get that. I’ve never felt that by learning more about the universe things seem more pointless. I don’t think the universe provides meaning, but human beings create their own meaning, when they value things. It’s nothing about any law of physics, but the way that I feel about my friends and loved ones, the way I feel about fellow human beings, the reason I love certain kinds of music or some of the experiences I’ve had, you can’t take all that away from me by saying there’s a multiverse. That doesn’t change that at all. Those feelings are profound and real. No fact I could ever learn about the universe would take them away from me."