From: mk_thisisit
Sir Roger Penrose is a Nobel Prize winner in physics and is regarded as one of the greatest minds of all time, known for the multidisciplinarity of his research, which has been compared to that of Newton, Einstein, or Darwin [00:01:50]. He is not only an outstanding mathematician and physicist but also a philosopher who is not afraid to ask often controversial questions [00:02:03].
Nobel Prize in Physics
On October 6, 2020, the Nobel Prize in Physics was announced, and Sir Roger Penrose was the first name heard by the world [00:01:23], [00:01:32]. The prize was awarded “supposedly” for explaining how the existence of black holes results from the theory of relativity [00:04:36]. Penrose had to wait almost 60 years for his Nobel Prize, although his theory was considered indisputable [00:05:43]. He received the phone call about the Nobel Prize while stepping out of the shower and initially told his assistant that he couldn’t talk [00:02:53]. It took a third call before he finally understood he was a Nobel Prize winner [00:03:51].
Black Holes and Singularities
Penrose’s work on the subject of black holes was published in the mid-1960s [00:04:28]. He does not consider black holes to be the “greatest mystery of humanity,” as there is a very good understanding of them, including their appearance when rotating (Kerr solution), computational algorithms for observing their collisions, and the gravitational waves they produce [00:04:55]. Observations of gravitational waves by the LIGO detector further support this understanding [00:05:27].
A key concept in his work is the “singularity,” a region in spacetime where curvature is large, or where “geodesics” (preferred curved lines in the universe) have a beginning but no end, terminating outside spacetime [00:06:46]. Physics, as currently known, ends in such singularities [00:07:17].
Collaboration with Stephen Hawking
Penrose first lectured on singularities in 1964 at King’s College in London, a lecture Stephen Hawking did not attend [00:07:22]. However, Denis Sciama, a close colleague, convinced Penrose to repeat the lecture in Cambridge, where Hawking was present [00:07:41]. More importantly, Penrose had a detailed private discussion with Stephen Hawking and his colleague George Ellis [00:07:56]. Hawking quickly grasped the details and saw how to apply Penrose’s solution in a different cosmic context, which he developed extensively in his doctoral thesis [00:08:11].
Penrose developed the singularity theorem for black holes [00:09:03]. He and Stephen Hawking later co-authored a paper covering their combined results [00:09:12]. Despite their differences, their shared ground was mathematics [00:11:41]. Through their research, it is understood that the mathematics known to us breaks down at the singularity point within black holes [00:11:46]. It is not mathematics itself that fails, but rather the physical theory it describes, particularly Einstein’s general theory of relativity, which becomes inadequate at these points [00:12:09]. A future theory, often called quantum gravity, will be needed to describe the evolution of what happens inside a black hole [00:12:30].
Cyclic Universe Theory
Penrose feels like an “outsider” when it comes to cosmology [00:06:10]. His concept of the cyclic universe (Conformal Cyclic Cosmology - CCC) was first introduced around 2004 [00:06:23]. This theory suggests that the universe has no beginning or end, but rather goes through continuous cycles [00:39:48]. The Big Bang, in this model, is like the final phase of a previous universe [00:40:04].
In this model, our current “eon” has a distant future of exponential expansion, which is consistent with observations [00:37:58]. Penrose initially did not believe in an exponential expansion, assuming the cosmological constant must be zero, but changed his mind after being convinced by cosmologist Jerry Ostriker [00:38:13].
Inflationary Theory
Penrose believes inflationary theory is a “dead end” [00:31:08]. He argues that inflation is not needed in his model and “ruins cosmology” [00:37:17]. The effects that resemble inflation, in his view, do not result from inflation but from looking back through the Big Bang at the expansion of a previous aeon [00:37:40].
The “Boring Era”
In his book Cycles of Time, Penrose describes how the universe evolves into a “boring era” where only specific types of particles, like photons, remain [00:40:15]. Mathematically, this extremely expanded and empty state can be scaled down to become identical to the Big Bang, leading to the next explosion and the start of a new universe [00:40:29].
Our galaxy, the Milky Way, is on a collision course with the Andromeda galaxy, and they will eventually merge [00:41:10]. The supermassive black hole in Andromeda, being larger, will absorb the Milky Way’s black hole [00:41:41]. This process will continue with larger galactic clusters being absorbed by supermassive black holes [00:42:14]. The “boring era” is the incredibly long period (about 10^100 years) during which these black holes gradually evaporate via Hawking radiation [00:42:38]. This radiated energy then contributes to the next aeon [00:43:00].
Consciousness and Quantum Mechanics
Penrose has dedicated a significant part of his life to answering fundamental questions about how human consciousness is born from matter and where our ability to understand the laws of nature comes from [00:00:36], [00:01:01], [00:18:29]. He often mentions that conscious information is transformed into consciousness as a result of a quantum effect [00:18:46].
He argues that conscious thinking is not like computer processing, using Gödel’s theorem as a mathematical argument [00:19:11]. Gödel’s theorem suggests that there are true statements that cannot be proven by a given set of rules, which implies that human understanding goes beyond mere computation [00:22:05]. Understanding, for Penrose, involves consciousness [00:23:12]. He believes that the quality of understanding ultimately came into being thanks to natural selection [00:24:29].
Microtubules
Penrose explores the idea that the quantum world on a micro scale might react to itself on a macro scale, particularly through microtubules in the neural network of the human brain [00:26:30]. While microtubules are common in all living systems, some special types might be related to consciousness [00:26:44]. Recent observations suggest that microtubules may be able to communicate through super-radiation or other means and could be responsible for the formation of “light thoughts” in the brain [00:27:39].
Grand Unification Theory
Penrose’s research aims to connect classical physics with quantum physics [00:29:07]. For him, a “grand unification theory” is a mathematical formula that shows the point of contact between what is classical and what is quantum [00:29:21]. This differs from what particle physicists usually mean by the term, which is a theory that unifies all fundamental forces [00:29:37]. He considers string theory, which claims to achieve this, to be a “dead end” [00:31:01].
Three Worlds/Realities
In his understanding of reality, Penrose proposes a new division into “three worlds” or “three realities” [00:31:37]. He distinguishes between classical reality and quantum reality [00:32:18].
- Classical reality describes objects with definite structures and properties that can be directly asked about (e.g., the shape or color of a cup) [00:32:53].
- Quantum reality, based on Einstein’s “element of reality,” means that a state can be confirmed if you propose a specific property, but it cannot be directly determined what its property is without disturbing the system [00:33:18]. For example, a proton’s spin cannot be asked “Which way are you rotating?” but if you ask “Are you rotating around this rod?”, it can answer “yes” with 100% certainty if that’s its state [00:33:48]. This gives it quantum reality, but not classical reality [00:35:58]. The “bridge” between these two worlds exists, but it cannot be used to determine the quantum state, only to confirm it probabilistically [00:35:13], [00:35:46].
Advice to Young Scientists
Penrose advises young scientists to “combine general relativity with quantum mechanics, but not in the way people talk” [00:46:48]. He emphasizes the “Great Challenge” of understanding how to interpret quantum mechanics, as “there lies the new Physics” [00:46:57]. He believes that the rapid communication enabled by modern technology could lead to significant scientific progress, much like how Kepler and Galileo might have advanced science if they could have easily communicated [00:47:07].
Sir Roger Penrose holds the status of emeritus professor of mathematics at the University of Oxford [00:50:11].