From: mk_thisisit
Roger Penrose, a Nobel Prize winner in physics, has dedicated a significant part of his life to fundamental questions about the universe, including the nature of consciousness and the search for a grand unification theory [00:04:21]. His work is characterized by a multidisciplinary approach, combining mathematics, physics, and philosophy [00:02:03].
Black Holes and Singularities
Penrose’s Nobel Prize in 2020 was awarded for explaining how the existence of black holes results from the theory of relativity [00:04:40]. Despite their enigmatic nature, Penrose does not consider black holes the “greatest mystery of humanity” [00:04:55]. We have a good understanding of what they look like, their rotation (Ker solution), and how they produce gravitational waves when they collide [00:05:07]. Detailed calculations and observations from detectors like LIGO have greatly advanced our knowledge [00:05:25].
A key concept in Penrose’s work, and in general relativity more broadly, is the singularity [00:06:44]. A singularity is a region in spacetime where curvature is large, and preferred curved lines (geodesics) have a beginning but no end, falling into a point that does not belong to spacetime [00:06:52]. In such singularities, the physics as we know it ends [00:07:17].
Penrose notes that in black holes, the mathematics we know “breaks down at the point of singularity” [00:11:56]. He clarifies that it is not mathematics that fails, but rather our understanding of the physical theory (Einstein’s general theory of relativity) becomes inadequate at this point [00:12:09]. This suggests a need for a theory that connects to quantum mechanics, often referred to as quantum gravity [00:12:30].
The Challenge of Quantum Gravity
The search for quantum gravity aims to describe the evolution of what happens inside a black hole, going beyond Einstein’s theory [00:12:41]. Penrose expresses skepticism about current approaches to quantum gravity, specifically string theory, stating, “I do not believe them” [00:13:01].
For Penrose, the more important question is how to “eat” quantum mechanics, rather than focusing solely on quantum gravity [00:17:20]. He highlights the “absurdity” of quantum mechanics with its Schrödinger equation and the collapse of the wave function [00:17:31]. He argues that a gravitational effect within quantum mechanics could explain the collapse of the wave function, a concept explored by Hungarian physicist Lajos Diósi before him [00:17:55]. This perspective is considered more directly observable and relevant to how the universe behaves “here and now” [00:18:13].
Classical vs. Quantum Reality
Penrose distinguishes between classical reality and quantum reality [00:32:21].
- Classical Reality: Allows for a specific description of an object’s properties (e.g., shape, color) [00:32:51]. You can ask a classical object “what you are” and it will have a definite answer [00:32:58].
- Quantum Reality: Does not allow for such direct questioning [00:33:08]. Using the example of a proton’s spin, Penrose explains that while you can confirm if a spin is oriented in a particular direction without disturbing the system (Einstein’s element of reality), you cannot simply ask the particle “In which direction are you rotating?” and expect a definitive answer [00:33:48]. Instead, quantum reality provides probabilistic answers [00:35:46]. The “bridge” between these two worlds exists, but it cannot be simply defined by asking for a definite state [00:35:13].
Consciousness and Quantum Effects
Penrose investigates how human consciousness is born from matter [00:18:29]. He connects the quality of understanding, a feature of conscious beings, to this question [00:00:45]. He frequently suggests that conscious information is transformed into consciousness as a result of a quantum effect [00:18:55].
Penrose argues that the brain must be quantum, based on a mathematical argument connected to Gödel’s theorem [00:19:09]. He uses examples from mathematics to illustrate that conscious thinking is not like computer processing [00:19:18]. While rules can be encoded for computers, Gödel’s theorem shows that there are mathematical truths that cannot be proven by those rules [00:22:05]. For Penrose, knowing why something is true involves “understanding,” which he links directly to consciousness [00:23:04].
He discusses the idea that the choice of quantum state might take place in the consciousness of the observer, a concept famously put forth by Hungarian Nobel Prize winner Eugene Wigner [00:26:03]. Penrose himself sees the source of consciousness in the phenomenon of quantum effects within the brain, potentially related to microtubules in the neural network [00:26:24]. While microtubules are ubiquitous in living systems, specific types or their quantum signaling capabilities might be relevant to consciousness [00:26:44].
The Future of Physics: A New Approach
Penrose advises young scientists to “Combine general relativity with quantum mechanics, but not in the way people talk” [00:46:48]. He asserts that the “Great Challenge” and the “new Physics” lie in understanding how to “eat” quantum mechanics [00:46:57].
This perspective suggests that the fundamental breakthroughs might not come from string theory, which Penrose considers a “dead end,” but from a deeper understanding of the inherent complexities and apparent absurdities of quantum mechanics itself, especially in relation to gravity [00:31:08].