
The Last Theory
The Last Theory is an easy-to-follow exploration of what might be the last theory of physics. In 2020, Stephen Wolfram launched the Wolfram Physics Project to find the elusive fundamental theory that explains everything. On The Last Theory podcast, I investigate the implications of Wolfram's ideas and dig into the details of how his universe works. Join me for fresh insights into Wolfram Physics every other week.
Latest episodes

Apr 27, 2025 • 9min
Aggregation – how the Wolfram model weaves the future – with Stephen Wolfram
In the previous excerpt from my conversation with Stephen Wolfram, I asked him how I can remain a single, coherent, persistent consciousness in a branching universe.In this excerpt, we went deeper into this question. As a conscious observer, I have a single thread of experience. So if the universe branches into many timelines, why don’t I branch into many versions of me?Stephen’s answer touched on many profound aspects of the Wolfram model.He started with the failure of the Many Worlds interpretation of quantum mechanics to consider the possibility that different branches of history can merge, in other words, come back together again. This failure is rooted in assumption that the universe is continuous; as soon as we start thinking of the universe as discrete, such merging seems not only possible, but inevitable.He went on to consider the concept of causal invariance, the idea that it doesn’t matter which of countless similar paths you take through the multiway graph, you end up in the same place. In the Ruliad, he said, causal invariance is inevitable.Then we got to the core of the concept of the observer. According to Stephen Wolfram, an observer equivalences many different states and experiences the aggregate of these states.I did not expect Stephen’s next move, to apply the concept of aggregation not just to observers, but to the universe itself.He made the profound proposal that in the Wolfram model of physics, in addition to the computation of the hypergraph through the application of rules, there’s a process of aggregation of possible paths through the multiway graph to weave the future.—Stephen WolframStephen WolframThe Wolfram Physics ProjectWolfram InstituteWolfram Institute Community DiscordConcepts mentioned by StephenMany Worlds interpretation of quantum mechanicsComputational irreducibilityCausal invarianceThe RuliadSequentializationEquivalencing—The Last Theory is hosted by Mark Jeffery founder of Open Web MindI release The Last Theory as a video too! Watch here.Kootenay Village Ventures Inc.

Mar 15, 2025 • 13min
When the universe branches, what happens to me? with Stephen Wolfram
Stephen Wolfram, Co-founder and CEO of Wolfram Research, delves into the fascinating concept of consciousness in a branching universe. He explores how we navigate multiple versions of ourselves that eventually merge back together, allowing for a coherent experience of reality. Wolfram introduces ideas like branchial space and equivalencing in the context of quantum mechanics and statistical mechanics. He reveals how this interplay influences our understanding of consciousness and existence, connecting complex theories to our daily perceptions.

Mar 2, 2025 • 16min
What is the causal graph in Wolfram Physics?
Dive into the fascinating realm of the causal graph, a pivotal component of Wolfram Physics that reshapes our understanding of the universe. Explore how this tool interlinks special relativity, general relativity, and quantum mechanics while challenging traditional views of causality and free will. It’s a mind-bending discussion on the nature of reality and objectivity, inviting listeners to rethink what causality truly means. Prepare for a thought-provoking journey into the physics of existence!

Feb 13, 2025 • 8min
Is everything determined? with Stephen Wolfram
Stephen Wolfram, a renowned scientist and creator of the Wolfram Physics Project, dives deep into the concept of determinism in the universe. He introduces the intriguing idea of the 'ruliad,' suggesting everything is predetermined, but our perception of it varies based on our position within this framework. Wolfram wrestles with profound philosophical questions, exploring the nature of reality and the observer's role in the evolution of the universe. Prepare for a mind-bending discussion that challenges our understanding of free will and objective reality!

Jan 15, 2025 • 20min
Why is space three-dimensional? with Stephen Wolfram
Stephen Wolfram, a distinguished computer scientist and physicist known for creating Mathematica and Wolfram Alpha, delves into the intriguing concept of why space is three-dimensional. He discusses how our familiar three-dimensional experience emerges from hypergraphs, a key structure in his model of the universe. Wolfram challenges traditional views by exploring the role of observers in shaping our perception of space and time. He also hints at a more complex underlying structure that could redefine our understanding of dimensionality and computation.

Jan 9, 2025 • 9min
The first wow for Stephen Wolfram
Stephen Wolfram, a groundbreaking scientist and innovator behind Mathematica and Wolfram Alpha, shares his intriguing insights on uniting General Relativity and Quantum Mechanics. He unwraps his early ‘wow’ moment when he recognized these two theories as manifestations of the same underlying principles. Wolfram discusses the role of hypergraphs in understanding the universe, revealing a path towards a unified theory of physics. With enthusiasm, he highlights the unexpected coherence found in merging these critical aspects of modern science, reshaping our grasp of the universe.

Dec 23, 2024 • 7min
5 reasons to take Wolfram Physics seriously
Explore the intriguing world of Wolfram Physics through five compelling reasons that elevate its importance in theoretical physics. Discover how a discrete hypergraph model could transform our grasp of space, time, and matter. The discussion emphasizes the potential to unify existing theories and offers fresh insights that challenge conventional thinking. Get ready for a thought-provoking journey that may just shift your understanding of the universe!

Oct 30, 2024 • 17min
Why does the universe exist?
What if the universe is just a hypergraph? This intriguing exploration challenges the way we perceive existence. The discussion delves into the philosophical implications of Stephen Wolfram's revolutionary theory. Can mathematical concepts truly define our reality? Listeners are invited to rethink the connection between consciousness and the universe. It's a captivating journey that blends science and philosophy, all while addressing the profound question of why there's something rather than nothing.

Sep 15, 2024 • 18min
Causality ain't what you think it is
Explore the slippery nature of causality and its implications for free will. Discover how our everyday understanding clashes with the universe’s unpredictability. Dive into a rethinking of causality as the episode examines the Wolfram physics model. This new perspective suggests that the universe may operate on discrete computations, reshaping our interpretations of cause and effect. Get ready to question everything you thought you knew about how events unfold in our cosmos!

Jul 28, 2024 • 15min
What precisely is causal invariance?
Dive into the intriguing world of causal invariance and its vital role in Wolfram Physics. Discover how this concept elegantly connects special relativity and quantum mechanics through complex multi-way graphs. Explore the significance of node histories and the branching paths that shape our universe. Unpack the layers of causality and how multiple reality branches can converge, unlocking profound insights into the nature of existence. It's a fascinating journey into the depths of our understanding of the cosmos!
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