Lee Smolin on Quantum Gravity, the Nature of Reality, and Einstein's Unfinished Revolution

Lee Smolin, a theoretical physicist and co-inventor of loop quantum gravity, engages in a deep discussion with Lex Fridman about the fundamental nature of reality, the scientific method, and the ongoing challenges in theoretical physics. Smolin champions a "realist" perspective, asserting his belief in an external world that exists independently of human perception, knowledge, or experience. He argues that the ultimate goal of science is to progressively refine our description of this objective reality, acknowledging that absolute certainty might remain elusive. Drawing influence from Paul Feyerabend, Smolin challenges the conventional notion of a singular "scientific method," suggesting that scientific progress often necessitates deviating from established rules and is more accurately characterized by a community bound by ethical precepts and rigorous training in verification and scrutiny.

A central focus of the conversation is "Einstein's Unfinished Revolution," which refers to the persistent and unresolved conflict between general relativity, our best theory for describing large-scale phenomena like space-time and gravity, and quantum theory, which governs the microscopic world. Smolin, echoing Einstein's skepticism, views quantum mechanics as "consistent but incomplete," positing that it requires additional degrees of freedom or a more comprehensive framework to fully describe all physical phenomena. A key distinction he makes is that time is fundamental, defined by the "continual creation of events from existing events," and that the future, therefore, does not yet exist. In contrast, space and the combined concept of space-time are presented as emergent, intellectual constructions rather than intrinsic, fundamental components of reality. He contrasts his realist stance with anti-realist views, such as those attributed to Niels Bohr, which suggest science primarily serves to describe our interactions with nature rather than nature itself.

While the discussion is largely theoretical, Smolin offers profound insights into the psychology and process of scientific discovery. He highlights the critical roles of innate curiosity, intellectual stubbornness, and an unwavering commitment to understanding, exemplified by figures like Einstein. Smolin uses Eric Weinstein's "wheels on luggage" metaphor to illustrate that groundbreaking innovations often lie in plain sight, overlooked by even brilliant minds due to ingrained conventional thinking. This underscores the importance of cultivating a mindset that actively questions assumptions and resists established paradigms, even if such an approach carries inherent risks of error or arrogance. The rigorous training of scientists, emphasizing meticulous checking and the ability to defend arguments against intense peer scrutiny, is presented as an essential mechanism for ensuring scientific integrity and progress.

The implications of Smolin's work extend significantly beyond the confines of theoretical physics, touching upon the philosophy of science, the inherent limits of human cognition, and the potential for future scientific revolutions. His critique regarding the perceived stagnation in fundamental physics since the 1970s, particularly the lack of practical applications stemming from theories like string theory, prompts critical reflection on the current trajectory and effectiveness of research paradigms. The profound ideas concerning the fundamental nature of time and causality carry deep philosophical weight, influencing our understanding of existence, determinism, and the very structure of the universe, suggesting a dynamic, ever-evolving reality rather than a static, predetermined one. Lex Fridman also frames the conversation within the broader context of Artificial Intelligence, suggesting that developing advanced AI requires a return to exploring the first principles of the universe and the human mind.

I believe that there is a world that is independent of my existence in my experience about it my knowledge of it and this I call the real world.

What we experienced is constructed by our brains and by our brains in an active mode so we don't see the raw world we see a very processed world.

Paul Farben or he was a student of popper who taught opera Karl Popper and Farben argued both by logic and by historical exam well that you named anything that should be part of the practice of science say you should always make sure that your theories agree with all the data that's always meant it's already been taken and he'll prove to you that there have to be times when science contradicts when some scientist contradicts that advice for science to progress overall so it's not a simple matter.

A realist as a physicist is somebody who believes that there should be possible some completely objective description of each and every process at the fundamental level which which describes and explains exactly what happens and why it happened.

I think that theories can change and theories unchanged without warning I think the future is open.

The purpose of science is not to give an objective realist description of nature's it would be in our absence this movie might be saying Niels Bohr the purpose of science is as an extension of our conversations with each other to describe our interactions with nature.

Einstein's unfinished revolution is the twin revolutions which invented relativity theory special and especially general relativity and quantum theory which he was the first person to realize in 1905 there would have to be a radically different theory which somehow realized to resolve the paradox of the duality of particle wave for photons.

I think the time is fundamental and quote goes all the way down and space does not and the combination of them we use in general relativity that we call space-time also it is not.

I believe that history universe has a history which goes to the past I believe that a future does not exist there's a notion of a present and a notion of the past and the past consists of is a story about events that took place to our past.

An event is where something changes or where to I it's hard to say because it's a primitive concept in the event is a moment of time within space this is the the view and general relativity where two particles intersect in their paths or something changes in the path of the particle.

Einstein carried his luggage Freud carried his luggage Marx carried his luggage Martha Graham carried her luggage etcetera Edison carried his luggage all these geniuses carry their luggage and not once before relatively recently did it occur to anybody to put a wheel on luggage and pull it and it was right there waiting to be invented for centuries.