In 30 seconds
Lee Smolin tells Lex Fridman that he is a realist: he believes there is a real world behind our brain-constructed experience, and that science is a community's way of getting closer to describing it. He argues that the scientific method is not a simple recipe but a set of ethical norms and checking habits, and that fundamental physics since the 1970s has lacked the triumphs of the early 20th century. He also discusses Bohr's anti-realism and whether human minds can ever fully understand reality.
- 1We experience a heavily processed world, but Smolin still believes a real one stands behind itOur brains actively construct experience, yet he remains curious about what lies beyond that veil.
- 2Being right is a matter of degreeFor a realist, theories are more or less right depending on how close they come to an exact description of the real world.
- 3There is no single scientific methodFollowing the philosopher Paul Feyerabend, Smolin argues that any rule one proposes for science, such as always agreeing with all existing data, will sometimes have to be broken for science to progress.
- 4Science is a community bound by ethical norms and training in checkingDon't lie, report all results, and learn to defend your case against every objection your colleagues can raise.
- 5Galileo's tower experiment shows how evidence and theory entangleThe same falling ball supported both Aristotle and the principle of inertia, so the shift to the new physics took centuries and was not complete until Newton.
- 6Realism and anti-realism divide even the founders of quantum theorySmolin cites Bohr's view that science describes our interactions with nature, not nature in our absence, while he hopes our stories converge on the real world.
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We see a processed world, but behind it Smolin believes in a real one
Fridman opens by asking how we know what is real and what is merely a creation of human perception. Smolin answers that we do not know, and that this is the business of science. He says he believes there is a world independent of his existence, experience and knowledge of it, which he calls the real world.
Pressed on whether it is crazy to think everything is a creation of the mind, Smolin says a version of that idea is not crazy at all. What we experience is constructed by our brains in an active mode, so we do not see the raw world but a very processed one. Even so, he still believes a real world lies behind that veil, and says he is curious about it.
Fridman asks whether we reach the real world through the tools of physics or through some more intuitive grasp inherited from our ape ancestors. Smolin replies that we are in the same position as our ancestors, finding ourselves in a world we are naturally curious about and need to explain.
Humans judge fast and tell stories, so being right means getting closer
Smolin says two things are true of being human. We make judgments fast, because we have to act quickly on incomplete information, as in deciding whether something is a tiger. So we are often wrong, and we fool ourselves and other people readily, which leads to many stories, some of which bring concrete benefits and some of which do not.
Fridman asks what it means to be right. Smolin says a realist should see right and wrong not as binary but as a relative scale: you are more right the closer you come to an exact, objective description of the real world.
There is no single scientific method, only a community with ethical rules and checking habits
Smolin says he does not believe in a scientific method, a view shaped in graduate school by philosopher Paul Feyerabend. Feyerabend argued by logic and historical example that for any rule proposed for science, such as always making sure your theories agree with all the data already taken, there must be times when a scientist breaks it for science to progress. So it is not a simple matter.
He thinks of science instead as a community of people bound by ethical precepts: do not lie, and report all your results whether or not they support your hypothesis. A scientist's training consists mostly of methods of checking, because people make many mistakes, and mathematics and experiment provide tools to check, double-check and triple-check.
The test at the end of training, he says, is whether you can build a convincing case that colleagues cannot shout down by asking whether you checked this or that, and what about an apparent contradiction. When you can produce that defense you receive a PhD, which licenses you but does not make you immune to mistakes; the community just has to waste less time fixing them.
Galileo's tower shows why evidence never settles a theory on its own
Fridman asks about the gap between that community practice and the ideal of repeatable experiments. Smolin says the relationship between experiment and theory is not simple. He gives Galileo's experiment of dropping a ball from a tower, where the ball lands at the base.
An Aristotelian reads the result as proof that the earth is not moving, since the ball falls straight down. Galileo, using the principle of inertia, says the ball and the tower move together with the earth, so it lands at the base for that reason as well. Each side reads the same result as confirming its own view.
Smolin concludes that you need an interconnected set of cases and many years of work to make such a transition. The move from Aristotelian physics to the new physics, he says, took centuries and was not completed until Newton in 1687.
Early 20th-century physics delivered a revolution; fundamental physics since the 1970s has not
Fridman asks why science seems to produce ideas engineers can turn into technology, from rockets to the iPhone. Smolin wants to be more precise about when and where. He says there was a scientific revolution that partly succeeded from the late 1890s through the 1930s and 1940s, with some stretch into the 1970s.
That revolution included relativity, developments in electromagnetism, the confirmation that matter is made of atoms with electrons around nuclei, and quantum mechanics, which began in 1905 and reached final form in the late 1920s. It became the basis of the technologies Fridman mentioned, and electrical technology developed in close relation with the science.
By contrast, Smolin says the fundamental physics since the early 1970s has no similar story so far: no series of triumphs and no practical application. Asked how the early 20th-century community judged right from wrong, he says experimental validation is ultimately the final test and is absolutely necessary, and that key predictions of quantum mechanics and electromagnetism were confirmed.
Realism means an objective description exists, and consciousness remains the open problem
Smolin defines realism as belief in an external world independent of our existence, perception, belief and knowledge. For a realist physicist, it should be possible in principle to give a completely objective description of every fundamental process, explaining exactly what happens and why. He adds that he is not that interested in determinism and could live with a fundamental world that has some chance in it.
Fridman asks whether God plays dice, and Smolin says the truth is probably much worse: theories can change without warning and the future is open. Asked about the role of the human mind, he separates two questions. The first is whether our perceptions play a role in making things real, which he thinks they do not, and the second is whether a realist, naturalist view can make room for the existence of perception, consciousness and mind.
The second question is one he thinks about a lot, and he says a realist view certainly cannot yet explain consciousness, though he hopes it eventually will. He notes that his answer to the first question depends on the second.
Bohr's anti-realism challenges the storytelling, and the limits of understanding are a question for the distant future
Asked about the camps of anti-realists, Smolin says he is not a good scholar of them, but notes that many of quantum physics' inventors were not realists. They lived through a perilous time between the world wars. Niels Bohr, he says, held that science's purpose is not to give an objective description of nature in our absence but, as an extension of our conversations, to describe our interactions with nature.
On this view we are free to invent and use terms like particle, wave, causality, time or space if they are useful, without believing they say anything about nature in our absence. Fridman asks whether Smolin finds this storyteller picture compelling. Smolin says he would like to believe the realist aspiration that our stories will eventually lead to the real world, though we are certainly nowhere near there and that question is for people 5,000 years in the future.
Asked whether human minds might hit a cognitive limit in grasping reality, Smolin again calls it a question for the far future. He admires David Deutsch's argument about the universality of explanation, mathematics and computing, built on symbolic systems that can refer to themselves. Smolin does not claim to agree with Deutsch on everything, but says we are doing okay so far and have plenty to play with.
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