Lee Smolin on Einstein's Unfinished Revolution: Unifying Quantum Mechanics and General Relativity, the Nature of Time, and Challenges to Locality

Lee Smolin discusses "Einstein's Unfinished Revolution," which refers to the unresolved conflict between general relativity, our best theory of space, time, and gravitation for large-scale phenomena, and quantum theory, which describes the microscopic world. Einstein, a founder of quantum mechanics, later viewed it as incomplete, a perspective Smolin shares. The core problem lies in the measurement problem within quantum mechanics and the lack of a coherent relationship between these two fundamental theories. Smolin argues that rather than solely attempting to quantize gravity within the existing quantum framework, a more promising path involves completing quantum mechanics by introducing additional degrees of freedom that inherently incorporate space-time and gravity.

Smolin elaborates on his view that space-time is an "intellectual construction" and not fundamental to reality. Instead, he posits that time is fundamental, characterized by a continual creation of events from existing ones, implying that the future does not exist, only the present and the past. Space, in this view, is an emergent property that arises from the complex relationships between events. He distinguishes between two notions of locality: the well-tested locality in quantum field theory and "Bell locality," which has been experimentally disproven by phenomena like entanglement. Entanglement, where two particles share a property without it being intrinsic to either, demonstrates that the reality of one particle can be instantaneously affected by a measurement choice made on a distant, entangled particle, challenging classical notions of local causality.

Addressing the path forward, Smolin describes the current state of theoretical physics as both "terrifying for students" and "full of opportunity." He advocates for a more collaborative and less siloed approach within the physics community, encouraging researchers to move beyond defending specific theoretical "hills" and instead engage in interdisciplinary dialogue to combine ideas and advance understanding. He emphasizes the importance of foundational principles in science, stating that his own work is guided by the principle that "there is just one world that happens once," directly contrasting with the Many-Worlds Interpretation (MWI).

Smolin critically analyzes the Many-Worlds Interpretation, acknowledging its realist appeal but highlighting its significant challenges, particularly regarding the derivation of the Born rule and the concept of probability. He notes that MWI, by discarding the measurement postulate, loses the mechanism for probability, and while post-Everett developments like decoherence and decision theory have attempted to address this, even experts in the field, such as those at Oxford, express uncertainty about their complete success. Smolin's work, often in collaboration with Marina Cortes, Carlos Set, and Roberto Mangabeira Unger, seeks to build a theory where causality and events are primary, leading to an emergent understanding of space, thereby offering an alternative framework to resolve the unfinished revolution.

Einsteins unfinished revolution is the twin revolutions which invented relativity theory special and especially general relativity and quantum theory...

...he didn't believe that the quantum mechanics as it was developed in the late 19th middle late 1920s was completely corrected first he didn't believe it at all then he was convinced that it's consistent but incomplete and that also is my view.

The basic formulation of quantum mechanics gives you two ways to evolve situations in time one of them is explicitly when no observer is observing or no taking place and the other is when a measurement or an observation is taking place and they country they basically contradict each other.

Space-time you talked about a construction so I believe the space-time is a intellectual construction that we make of the events in the universe.

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 does 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...

One thing that's really weird about quantum mechanics is a property called entanglement you can have two particles interact and then share a property without it being a property of either one of the two particles.

We need people to get off the hill and come down into valleys and party and talk and become friendly and learn to say not know but but yes and yes your idea goes this far but maybe if we put it together with my idea we can go further.

When we started looking for principles we made our first principle there is just one world that happens once.

...there is a branch in which everything that might happen does happen with probability 1 in that branch you might think you could count the number of branches in which things do and don't happen and get numbers that you can define as something like frequentist probabilities...