What’s inside a black hole?

 The correct answer is no one knows, but I’m going to make a wild, speculative, not fully-informed guess and suggest, possibly nothing. But first, a detour, to provide some context.
 
I came across an interview with very successful, multi-award-winning, Australian-Canadian actor, Pamela Rabe, who is best known (in Australia, at least) for her role in Wentworth (about a fictional female prison). She was interviewed by Benjamin Law in The Age Good Weekend magazine, a few weekends ago, where among many other questions, he asked, Is there a skill you wish you could acquire? She said there were so many, including singing better, speaking more languages and that she wished she was more patient. Many decades ago, I remember someone asking me a similar question, and I can still remember the answer: I said that I wish I was more intelligent, and I think that’s still true.
 
Some people might be surprised by this, and perhaps it’s a good thing I’m not, because I think I would be insufferable. Firstly, I’ve always found myself in the company of people who are much cleverer than me, right from when I started school, and right through my working life. The reason I wish I was more intelligent is that I’ve always been conscious of trying to understand things that are beyond my intellectual abilities. My aspirations don’t match my capabilities.
 
And this brings me to a discussion on black holes, which must, in some respects, represent the limits of what we know about the Universe and maybe what is even possible to know. Not surprisingly, Marcus du Sautoy spent quite a few pages discussing black holes in his excellent book, What We Cannot Know. But there is a short YouTube video by one of the world’s leading exponents on black holes, Kip Thorne, which provides a potted history. I also, not that long ago, read his excellent book, Black Holes and Time Warps; Einstein’s Outrageous Legacy (1994), which gives a very comprehensive history, in which he was not just an observer, but one of the actors.
 
It's worth watching the video because it highlights the role mathematics has played in physics, not only since Galileo, Kepler and Newton, but increasingly so in the 20th Century, following the twin revolutions of quantum mechanics and relativity theory. In fact, relativity theory predicted black holes, yet most scientists (including Einstein, initially) preferred to believe that they couldn’t exist; that Nature wouldn’t allow it.
 
We all suffer from these prejudices, including myself (and even Einstein). I discussed in a recent post how we create mathematical models in an attempt to explain things we observe. But more and more, in physics, we use mathematical models to explain things that we don’t observe, and black holes are the perfect example. If you watch the video interview with Thorne, this becomes obvious, because scientists were gradually won over by the mathematical arguments, before there was any incontrovertible physical evidence that they existed.
 
And since no one can observe what’s inside a black hole, we totally rely on mathematical models to give us a clue. Which brings me to the title of the post. The best known equation in reference to black holes in the Bekenstein-Hawking equation which give us the entropy of a black hole and predicts Hawking radiation. This is yet to be observed, but this is not surprising, as it’s virtually impossible. It’s simply not ‘hot’ enough to distinguish from the CMBR (cosmic microwave background radiation) which permeates the entire universe. 

Here is the formula:

S(BH) = kA/4(lp)^2 

Where S is the entropy of the black hole, A is the surface area of the sphere at the event horizon, and lp is the Planck length given by this formula:

√(Gh/2πc^3) 

Where G is the gravitational constant, h is Planck’s constant and c is the constant for lightspeed.

Hawking liked the idea that it’s the only equation in physics to incorporate the 4 fundamental natural constants: k, G, h and c; in one formula.

So, once again, mathematics predicts something that’s never been observed, yet most scientists believe it to be true. This led to what was called the ‘information paradox’ that all information falling into a black hole would be lost, but what intrigues me is that if a black hole can, in principle, completely evaporate by converting all its mass into radiation, then it infers that the mass is not in fact lost – it must be still there, even if we can’t see it. This means, by inference, that it can’t have disappeared down a wormhole, which is one of the scenarios conjectured.

One of the mathematical models proposed is the 'holographic principle' for black holes, for which I’ll quote directly from Wikipedia, because it specifically references what I’ve already discussed.

The holographic principle was inspired by the Bekenstein bound of black hole thermodynamics, which conjectures that the maximum entropy in any region scales with the radius squared, rather than cubed as might be expected. In the case of a black hole, the insight was that the information content of all the objects that have fallen into the hole might be entirely contained in surface fluctuations of the event horizon. The holographic principle resolves the black hole information paradox within the framework of string theory.

I know this is a long hop to make but what if the horizon not only contains the information but actually contains all the mass. In other words, what if everything is frozen at the event horizon because that’s where time ‘stops’. Most probably not true, and I don’t know enough to make a cogent argument. However, it would mean that the singularity predicted to exist at the centre of a black hole would not include its mass, but only spacetime.

Back in the 70s, I remember reading an article in Scientific American by a philosopher, who effectively argued that a black hole couldn’t exist. Now this was when their purported existence was mostly mathematical, and no one could unequivocally state that they existed physically. I admit I’m hazy about the details but, from what I can remember, he argued that it was self-referencing because it ‘swallowed itself’. Obviously, his argument was much more elaborate than that one-liner suggests. But I do remember thinking his argument flawed and I even wrote a letter to Scientific American challenging it. Basically, I think it’s a case of conflating the language used to describe a phenomenon with the physicality of it.

I only raise it now, because, as a philosopher, I’m just as ignorant of the subject as he was, so I could be completely wrong.

Addendum 1: I was of 2 minds whether to write this, but it kept bugging me - wouldn't leave me alone, so I wrote it down. I've no idea how true it might be, hence all the caveats and qualifications. It's absolutely at the limit of what we can know at this point in time. As I've said before, philosophy exists at the boundary of science and ignorance. It ultimately appealed to my aesthetics and belief in Nature’s aversion to perversity.

Addendum 2: Another reason why I'm most likely wrong is that there is a little known quirk of Newton's theory of gravity that the gravitational 'force' anywhere inside a perfectly symmetrical hollow sphere is zero. So the inside of a black hole exerting zero gravitational force would have to be the ultimate irony, which makes it highly improbable. I've no idea how that relates to the 'holographic principle' for a black hole. But I still don't think all the mass gets sucked into a singularity or down a wormhole. My conjecture is based purely on the idea that 'time' might well become 'zero' at the event horizon, though, from what I've read, no physicist thinks so. From an outsider's perspective, time dilation becomes asymptotically infinite (effective going to zero, but perhaps taking the Universe's lifetime to reach it). In this link, it begs a series of questions that seem to have no definitive answers. The alternative idea is that it's spacetime that 'falls' into a black hole, therefore taking all the mass with it.

Addendum 3: I came across this video by Tibbees (from a year ago), whom I recommend. She cites a book by Carlo Rovelli, White Holes, which is also the title of her video. Now, you can't talk about white holes without talking about black holes; they are just black holes time reversed (as she explicates). We have no evidence they actually exist, unless the Big Bang is a white hole (also mentioned). I have a lot of time for Carlo Rovelli, even though we have philosophical differences (what a surprise). Basically, he argues that, at a fundamental level, time doesn't exist, but it's introduced into the universe as a consequence of entropy (not the current topic). 

Tibbees gives a totally different perspective to my post, which is why I bring it up. Nevertheless, towards the end, she mentions that our view of a hypothetical person (she suggests Rovelli) entering a black hole is that their existence becomes assymptotically infinite. But what, if in this case, what we perceive is what actually happens. Then my scenario makes sense. No one else believes that, so it's probably incorrect.

Do we make reality?

 I’ve read 2 articles, one in New Scientist (12 Oct 2024) and one in Philosophy Now (Issue 164, Oct/Nov 2024), which, on the surface, seem unrelated, yet both deal with human exceptionalism (my term) in the context of evolution and the cosmos at large.
 
Staring with New Scientist, there is an interview with theoretical physicist, Daniele Oriti, under the heading, “We have to embrace the fact that we make reality” (quotation marks in the original). In some respects, this continues on with themes I raised in my last post, but with different emphases.
 
This helps to explain the title of the post, but, even if it’s true, there are degrees of possibilities – it’s not all or nothing. Having said that, Donald Hoffman would argue that it is all or nothing, because, according to him, even ‘space and time don’t exist unperceived’. On the other hand, Oriti’s argument is closer to Paul Davies’ ‘participatory universe’ that I referenced in my last post.
 
Where Oriti and I possibly depart, philosophically speaking, is that he calls the idea of an independent reality to us ‘observers’, “naïve realism”. He acknowledges that this is ‘provocative’, but like many provocative ideas it provides food-for-thought. Firstly, I will delineate how his position differs from Hoffman’s, even though he never mentions Hoffman, but I think it’s important.
 
Both Oriti and Hoffman argue that there seems to be something even more fundamental than space and time, and there is even a recent YouTube video where Hoffman claims that he’s shown mathematically that consciousness produces the mathematical components that give rise to spacetime; he has published a paper on this (which I haven’t read). But, in both cases (by Hoffman and Oriti), the something ‘more fundamental’ is mathematical, and one needs to be careful about reifying mathematical expressions, which I once discussed with physicist, Mark John Fernee (Qld University).
 
The main issue I have with Hoffman’s approach is that space-time is dependent on conscious agents creating it, whereas, from my perspective and that of most scientists (although I’m not a scientist), space and time exists external to the mind. There is an exception, of course, and that is when we dream.
 
If I was to meet Hoffman, I would ask him if he’s heard of proprioception, which I’m sure he has. I describe it as the 6th sense we are mostly unaware of, but which we couldn’t live without. Actually, we could, but with great difficulty. Proprioception is the sense that tells us where our body extremities are in space, independently of sight and touch. Why would we need it, if space is created by us? On the other hand, Hoffman talks about a ‘H sapiens interface’, which he likens to ‘desktop icons on a computer screen’. So, somehow our proprioception relates to a ‘spacetime interface’ (his term) that doesn’t exist outside the mind.
 
A detour, but relevant, because space is something we inhabit, along with the rest of the Universe, and so is time. In relativity theory there is absolute space-time, as opposed to absolute space and time separately. It’s called the fabric of the universe, which is more than a metaphor. As Viktor Toth points out, even QFT seems to work ‘just fine’ with spacetime as its background.
 
We can do quantum field theory just fine on the curved spacetime background of general relativity.
 
[However] what we have so far been unable to do in a convincing manner is turn gravity itself into a quantum field theory.
 
And this is where Oriti argues we need to find something deeper. To quote:
 
Modern approaches to quantum gravity say that space-time emerges from something deeper – and this could offer a new foundation for physical laws.
 
He elaborates: I work with quantum gravity models in which you don’t start with a space-time geometry, but from more abstract “atomic” objects described in purely mathematical language. (Quotation marks in the original.)
 
And this is the nub of the argument: all our theories are mathematical models and none of them are complete, in as much as they all have limitations. If one looks at the history of physics, we have uncovered new ‘laws’ and new ‘models’ when we’ve looked beyond the limitations of an existing theory. And some mathematical models even turned out to be incorrect, despite giving answers to what was ‘known’ at the time. The best example being Ptolemy’s Earth-centric model of the solar system. Whether string theory falls into the same category, only future historians will know.
 
In addition, different models work at different scales. As someone pointed out (Mile Gu at the University of Queensland), mathematical models of phenomena at one scale are different to mathematical models at an underlying scale. He gave the example of magnetism, demonstrating that mathematical modelling of the magnetic forces in iron could not predict the pattern of atoms in a 3D lattice as one might expect. In other words, there should be a causal link between individual atoms and the overall effect, but it could not be determined mathematically. To quote Gu: “We were able to find a number of properties that were simply decoupled from the fundamental interactions.” Furthermore, “This result shows that some of the models scientists use to simulate physical systems have properties that cannot be linked to the behaviour of their parts.”
 
This makes me sceptical that we will find an overriding mathematical model that will entail the Universe at all scales, which is what theories of quantum gravity attempt to do. One of the issues that some people raise is that a feature of QM is superposition, and the superposition of a gravitational field seems inherently problematic.
 
Personally, I think superposition only makes sense if it’s describing something that is yet to happen, which is why I agree with Freeman Dyson that QM can only describe the future, which is why it only gives us probabilities.
 
Also, in quantum cosmology, time disappears (according to Paul Davies, among others) and this makes sense (to me), if it’s attempting to describe the entire universe into the future. John Barrow once made a similar point, albeit more eruditely.
 
Getting off track, but one of the points that Oriti makes is whether the laws and the mathematics that describes them are epistemic or ontic. In other words, are they reality or just descriptions of reality. I think it gets blurred, because while they are epistemic by design, there is still an ontology that exists without them, whereas Oriti calls that ‘naïve realism’. He contends that reality doesn’t exist independently of us. This is where I always cite Kant: that we may never know the ‘thing-in-itself,’ but only our perception of it. Where I diverge from Kant is that the mathematical models are part of our perception. Where I depart from Oriti is that I argue there is a reality independently of us.
 
Both QM and relativity theory are observer-dependent, which means they could both be describing an underlying reality that continually eludes us. Whereas Oriti argues that ‘reality is made by our models, not just described by them’, which would make it subjective.
 
As I pointed out in my last post, there is an epistemological loop, whereby the Universe created the means to understand itself, through us. Whether there is also an ontological loop as both Davies and Oriti infer, is another matter: do we determine reality through our quantum mechanical observations? I will park that while I elaborate on the epistemic loop.
 
And this finally brings me to the article in Philosophy Now by James Miles titled, We’re as Smart as the Universe gets. He argues that, from an evolutionary perspective, there is a one-in-one-billion possibility that a species with our cognitive abilities could arise by natural selection, and there is no logical reason why we would evolve further, from an evolutionary standpoint. I have touched on this before, where I pointed out that our cultural evolution has overtaken our biological evolution and that would also happen to any other potential species in the Universe who developed cognitive abilities to the same level. Dawkins coined the term, ‘meme’, to describe cultural traits that have ‘survived’, which now, of course, has currency on social media way beyond its original intention. Basically, Dawkins saw memes as analogous to genes, which get selected; not by a natural process but by a cultural process.
 
I’ve argued elsewhere that mathematical theorems and scientific theories are not inherently memetic. This is because they are chosen because they are successful, whereas memes are successful because they are chosen. Nevertheless, such theorems and theories only exist because a culture has developed over millennia which explores them and builds on them.
 
Miles talks about ‘the high intelligence paradox’, which he associates with Darwin’s ‘highest and most interesting problem’. He then discusses the inherent selection advantage of co-operation, not to mention specialisation. He talks about the role that language has played, which is arguably what really separates us from other species. I’ve argued that it’s our inherent ability to nest concepts within concepts ad-infinitum (which is most obvious in our facility for language, like I’m doing now) that allows us to, not only tell stories, compose symphonies, explore an abstract mathematical landscape, but build motor cars, aeroplanes and fly men to the moon. Are we the only species in the Universe with this super-power? I don’t know, but it’s possible.
 
There are 2 quotes I keep returning to:
 
The most incomprehensible thing about the Universe is that it’s comprehensible. (Einstein)
 
The Universe gave rise to consciousness and consciousness gives meaning to the Universe. (Wheeler)
 
I haven’t elaborated, but Miles makes the point, while referencing historical antecedents, that there appears no evolutionary 'reason’ that a species should make this ‘one-in-one-billion transition’ (his nomenclature). Yet, without this transition, the Universe would have no meaning that could be comprehended. As I say, that’s the epistemic loop.
 
As for an ontic loop, that is harder to argue. Photons exist in zero time, which is why I contend they are always in the future of whatever they interact with, even if they were generated in the CMBR some 13.5 billion years ago. So how do we resolve that paradox? I don’t know, but maybe that’s the link that Davies and Oriti are talking about, though neither of them mention it. But here’s the thing: when you do detect such a photon (for which time is zero) you instantaneously ‘see’ back to 380,000 years after the Universe’s birth.

How scale demonstrates that mathematics is intrinsically entailed in the Universe

 I momentarily contemplated another title: Is the Planck limit an epistemology or an ontology? Because that’s basically the topic of a YouTube video that’s the trigger for this post. I wrote a post some time ago where I discussed whether the Universe is continuous or discrete, and basically concluded that it was continuous. Based on what I’ve learned from this video, I might well change my position. But I should point out that my former opposition was based more on the idea that it could be quantised into ‘bits’ of information, whereas now I’m willing to acknowledge that it could be granular at the Planck scale, which I’ll elaborate on towards the end. I still don’t think that the underlying reality of the Universe is in ‘bits’ of information, therefore potentially created and operated by a computer.
 
Earlier this year, I discussed the problem of reification of mathematics so I want to avoid that if possible. By reification, I mean making a mathematical entity reality. Basically, physics works by formulating mathematical models that we then compare to reality through observations. But as Freeman Dyson pointed out, the wave function (Ψ), for example, is a mathematical entity and not a physical entity, which is sometimes debated. The fact is that if it does exist physically, it’s never observed, and my contention is that it ‘exists’ in the future; a view that is consistent with Dyson’s own philosophical viewpoint that QM can only describe the future and not the past.
 
And this brings me to the video, which has nothing to say about wave functions or reified mathematical entities, but uses high school mathematics to explore such esoteric and exotic topics as black holes and quantum gravity. There is one step involving integral calculus, which is about as esoteric as the maths becomes, and if you allow that 1/∞ = 0, it leads to the formula for the escape velocity from any astronomical body (including Earth). Note that the escape velocity literally allows an object to escape a gravitational field to infinity (∞). And the escape velocity for a black hole is c (the speed of light).
 
All the other mathematics is basic algebra using some basic physics equations, like Newton’s equation for gravity, Planck’s equation for energy, Heisenberg’s Uncertainty Principle using Planck’s Constant (h), Einstein’s famous equation for the equivalence of energy and mass, and the equation for the Coulomb Force between 2 point electric charges (electrons). There is also the equation for the Schwarzschild radius of a black hole, which is far easier to derive than you might imagine (despite the fact that Schwarzschild originally derived it from Einstein’s field equations).
 
Back in May 2019, I wrote a post on the Universe’s natural units, which involves the fundamental natural constants, h, c and G. This was originally done by Planck himself, which I describe in that post, while providing a link to a more detailed exposition. In the video (embedded below), the narrator takes a completely different path to deriving the same Planck units before describing a method that Planck himself would have used. In so doing, he explains how at the Planck level, space and time are not only impossible to observe, even in principle, but may well be impossible to remain continuous in reality. You need to watch the video, as he explains it far better than I can, just using high school mathematics.
 
Regarding the title I chose for this post, Roger Penrose’s Conformal Cyclic Cosmology (CCC) model of the Universe, exploits the fact that a universe without matter (just radiation) is scale invariant, which is essential for the ‘conformal’ part of his theory. However, that all changes when one includes matter. I’ve argued in other posts that different forces become dominant at different scales, from the cosmological to the subatomic. The point made in this video is that at the Planck scale all the forces, including gravity, become comparable. Now, as I pointed out at the beginning, physics is about applying mathematical models and comparing them to reality. We can’t, and quite possibly never will, be able to observe reality at the Planck scale, yet the mathematics tells us that it’s where all the physics we currently know is compatible. It tells me that not only is the physics of the Universe scale-dependent, but it's also mathematically dependent (because scale is inherently mathematical). In essence, the Universe’s dynamics are determined by mathematical parameters at all scales, including the Planck scale.
 
Note that the mathematical relationships in the video use ~ not = which means that they are approximate, not exact. But this doesn’t detract from the significance that 2 different approaches arrive at the same conclusion, which is that the Planck scale coincides with the origin of the Universe incorporating all forces equivalently.
 
 
Addendum: I should point out that Viktor T Toth, who knows a great deal more about this than me, argues that there is, in fact, no limit to what we can measure in principle. Even the narrator in the video frames his conclusion cautiously and with caveats. In other words, we are in the realm of speculative physics. Nevertheless, I find it interesting to contemplate where the maths leads us.

More on radical ideas

 As you can tell from the title, this post carries on from the last one, because I got a bit bogged down on one issue, when I really wanted to discuss more. One of the things that prompted me was watching a 1hr presentation by cosmologist, Claudia de Rahm, whom I’ve mentioned before, when I had the pleasure of listening to an on-line lecture she gave, care of New Scientist, during the COVID lockdown.
 
Claudia’s particular field of study is gravity, and, by her own admission, she has a ‘crazy idea’. Now here’s the thing: I meet a lot of people on Quora and in the blogosphere, who like me, live (in a virtual sense) on the fringes of knowledge rather than as academic or professional participants. And what I find is that they often have an almost zealous confidence in their ideas. To give one example, I recently came across someone who argued quite adamantly that the Universe is static, not expanding, and has even written a book on the subject. This is contrary to virtually everyone else I’m aware of who works in the field of cosmology and astrophysics. And I can’t help but compare this to Claudia de Rahm who is well aware that her idea is ‘crazy’, even though she’s fully qualified to argue it.
 
In other words, it’s a case of the more you know about a subject, the less you claim to know, because experts are more aware of their limitations than non-experts. I should point out, in case you didn’t already know, I’m not one of the experts.
 
Specifically, Claudia’s crazy idea is that not only are there gravitational waves, but gravitons and that gravitons have an extremely tiny amount of mass, which would alter the effect of gravity at very long range. I should say that at present, the evidence is against her, because if she’s right, gravity waves would travel not at the speed of light, as predicted by Einstein, but ever-so-slightly less than light.
 
Freeman Dyson, by the way, has argued that if gravitons do exist, they would be impossible to detect, but if Claudia is right, then they would be.
 
In her talk, Claudia also discusses the vacuum energy, which according to particle physics, should be 28 orders of magnitude greater than the relativistic effect of ‘dark energy’. She calls it ‘the biggest discrepancy in the entire history of science’. This suggests that there is something rotten in the state of theoretical physics, along with the fact, that what we can physically observe, only accounts for 5% of the Universe.
 
It should be pointed out that at the end of the 19th Century no one saw or predicted the 2 revolutions in physics that were just around the corner – relativity theory and quantum mechanics. They were an example of what Thomas Kuhn called The Structure of Scientific Revolutions (the title of his book expounding on this). And I’d suggest that these current empirical aberrations in cosmology are harbingers of the next Kuhnian revolution.
 
Roger Penrose, whom I’ve referenced a number of times on this blog, is someone else with some ‘crazy’ ideas compared to the status quo, for which I admire him even if I don’t agree with him. One of Penrose’s hobby horses is his own particular inference from Godel’s Incompleteness Theorem, which he learned as a graduate (under Steen, at Cambridge) and which he discusses in this video. He argues that it provides evidence that humans don’t think like computers. If one takes the example of Riemann’s Hypothesis (really a conjecture) we know that a computer can’t tell us if it’s true or not (my example, not Penrose’s).* However, most mathematicians believe it is true, and it would be an enormous shock if it was proven untrue, or a contra-example was found by a computer. This is the case with other conjectures that have been proven true, like Fermat’s Last Theorem and Poincare’s conjecture. Penrose’s point, if I understand him correctly, is that it takes a human mind and not a computer to make this leap into the unknown and grasp a ‘truth’ out of the aether.
 
Anyone who has engaged in some artistic endeavour can identify with this, even if it’s not mathematical truths they are seeking but the key to unravelling a plot in a story.
 
Penrose makes the point in the video that he’s a ‘visual’ person, which he thinks is unusual in his field. Penrose is an excellent artist, by the way, and does all his own graphics. This is something else I can identify with, as I was quite precocious as a very young child at drawing (I could draw in perspective, though no one taught me) even though it never went anywhere.
 
Finally, some crazy ideas of my own. I’ve pointed out on other posts that I have a predilection (for want of a better term) for Kant’s philosophical proposition that we can never know the ‘thing-in-itself’ but only a perception of it.
 
With this in mind, I contend that this philosophical premise not only applies to what we can physically detect via instruments, but what we theoretically infer from the mathematics we use to explore nature. As heretical an idea as it may seem, I argue that mathematics is yet another 'instrument' we use to probe the secrets of the Universe. Quantum mechanics and relativity theory being the most obvious.
 
As I’ve tried to expound on other posts, relativity theory is observer-dependent, in as much as different observers will both measure and calculate different values of time and space, dependent on their specific frame of reference. I believe this is a pertinent example of Kant’s proposition that the thing-in-itself escapes our perception. In particular, physicists (including Penrose) will tell you that events that are ostensibly simultaneous to us (in a galaxy far, far away) will be perceived as both past and future by 2 observers who are simply crossing a street in opposite directions. I’ve written about this elsewhere as ‘the impossible thought experiment’.
 
The fact is that relativity theory rules out the event being observed at all. In other words, simultaneous events can’t be observed (according to relativity). For this reason, virtually all physicists will tell you that simultaneity is an illusion – there is no universal now.
 
But here’s the thing: if there is an edge in either space or time, it can only be observed from outside the Universe. Relativity theory, logically enough, can only tell us what we can observe from within the Universe.
 
But to extend this crazy idea, what’s stopping the Universe existing within a higher dimension that we can’t perceive. Imagine being a fish and you spend your entire existence in a massive body of water, which is your entire universe. But then one day you are plucked out of that environment and you suddenly become aware that there is another, even bigger universe that exists right alongside yours.
 
There is a tendency for us to think that everything that exists we can learn and know about – it’s what separates us from every other living thing on the planet. But perhaps there are other dimensions, or even worlds, that lie forever beyond our comprehension.

*Footnote: Actually, Penrose in his book, The Emperor’s New Mind, discusses this in depth and at length over a number of chapters. He makes the point that Turing’s ‘proof’ that it’s impossible to predict whether a machine attempting to compute all the Riemann zeros (for example) will stop, is a practical demonstration of the difference between ‘truth’ and ‘proof’ (as Godel’s Incompleteness Theorem tell us). Quite simply, if the theorem is true, the computer will never stop, so it can never be proven algorithmically. It can only be proven (or disproven) if one goes ‘outside the [current] rules’ to use Penrose’s own nomenclature.

What does physics really tell us about reality?

 A little while ago I got into another discussion with Mark John Fernee (see previous post), but this time dealing with the relationship between ontology and epistemology as determined by physics. It came about in reference to a paper in Physics Today that someone cited, by N. David Nermin, a retired Professor of physics in Ithaca, New York, titled What’s bad about this habit. In particular, he talked about our tendency to ‘reify’ mathematically determined theories into reality. It helps if we have some definitions, which Fernee conveniently provided that were both succinct and precise.

Epistemology - concerning knowledge.

Ontology - concerning reality.

Reify - to think of an idea as real.

It so happens that around the same time I read an article in New Scientist (25 Mar 2024, pp.32-5) Strange but true? by philosopher, Eric Schwitzgebel, which covers similar territory. The title tells you little, but it’s really about how modern theories in physics don’t really tell us what reality is; instead giving us a range of possibilities to choose from.

I will start with Nermin, who spends the first page talking about quantum mechanics (QM), as it’s the most obvious candidate for a mathematical theory that gets reified by almost everyone who encounters it. This selected quote gives a good feel for what he’s talking about.

When I was a graduate student learning quantum field theory, I had a friend who was enchanted by the revelation that quantum fields were the real stuff that makes up the world. He reified quantum fields. But I hope you will agree that you are not a continuous field of operators on an infinite-dimensional Hilbert space. Nor, for that matter, is the page you are reading or the chair you are sitting in. Quantum fields are useful mathematical tools. They enable us to calculate things.

I found another quote by Freeman Dyson (2014), who makes a similar point to Nermin about the wave function (Ψ).

Unfortunately, people writing about quantum mechanics often use the phrase "collapse of the wave-function" to describe what happens when an object is observed. This phrase gives a misleading idea that the wave-function itself is a physical object. A physical object can collapse when it bumps into an obstacle. But a wave-function cannot be a physical object. A wave-function is a description of a probability, and a probability is a statement of ignorance. Ignorance is not a physical object, and neither is a wave-function. When new knowledge displaces ignorance, the wave-function does not collapse; it merely becomes irrelevant.

But Nermin goes on to challenge even the reality of space and time. Arguing that it is a mathematical abstraction. 

What about spacetime itself? Is that real? Spacetime is a (3+1) dimensional mathematical continuum. Even if you are a mathematical Platonist, I would urge you to consider that this continuum is nothing more than an extremely effective way to represent relations between distinct events.

He then goes on to explain that ‘an event… can be represented as a mathematical point in spacetime.’

He elaborates how this has become so reified into ordinary language that we’re no longer aware that it is an abstraction.

So spacetime is an abstract four-dimensional mathematical continuum of points that approximately represent phenomena whose spatial and temporal extension we find it useful or necessary to ignore. The device of spacetime has been so powerful that we often reify that abstract bookkeeping structure, saying that we inhabit a world that is such a four (or, for some of us, ten) dimensional continuum. The reification of abstract time and space is built into the very languages we speak, making it easy to miss the intellectual sleight of hand.

And this is where I start to have issues with his overall thesis, whereas Fernee said, ‘I completely concur with what he has written, and it is well articulated.’ 

When I challenged Fernee specifically on Nermin’s points about space-time, Fernee argued:

His contention was that even events in space-time are an abstraction. We all assume the existence of an objective reality, and I don't know of anyone who would seriously challenge that idea. Yet our descriptions are abstractions. All we ask of them is that they are consistent, describe the observed phenomena, and can be used to make predictions.

I would make an interesting observation on this very point, that distinguishes an AI’s apparent perspective of space and time compared to ours. Even using the word, ‘apparent’, infers there is a difference that we don’t think about.

I’ve made the point in other posts, including one on Kant, that we create a model of space and time in our heads which we use to interact with the physical space and time that exists outside our heads, and so do all living creatures with eyes, ears and touch. In fact, the model is so realistic that we think it is the external reality.

When we throw or catch a ball on the sporting field, we know that our brains don’t work out the quadratic equations that determine where it’s going to land. But imagine an AI controlled artillery device, which would make those calculations and use a 3-dimensional grid to determine where its ordinance was going to hit. Likewise, imagine an AI controlled drone using GPS co-ordinates – in other words, a mathematical abstraction of space and time – to navigate its way to a target. And that demonstrates the fundamental difference that I think Nermin is trying to delineate. The point is that, from our perspective, there is no difference.

This quote gives a clearer description of Nermin’s philosophical point of view.

Space and time and spacetime are not properties of the world we live in but concepts we have invented to help us organize classical events. Notions like dimension or interval, or curvature or geodesics, are properties not of the world we live in but of the abstract geometric constructions we have invented to help us organize events. As Einstein once again put it, “Space and time are modes by which we think, not conditions under which we live.”

Whereas I’d argue that they are both, and the mathematics tells us things about the ‘properties of the world [universe]’ which we can’t directly perceive with our senses – like ‘geodesics’ and the ‘curvature’ of spacetime. Yet they can be measured as well as calculated, which is why we know GR (Einstein’s general theory of relativity) works.

My approach to understanding physics, which may be misguided and would definitely be the wrong approach according to Nermin and Fernee, is to try and visualise the concepts that the maths describes. The concept of a geodesic is a good example. I’ve elaborated on this in another post, but I can remember doing Newtonian-based physics in high school, where gravity made no sense to me. I couldn’t understand why the force of gravity seemed to be self-adjusting so that the acceleration (g) was the same for all objects, irrespective of their mass.

It was only many years later, when I understood the concept of a geodesic using the principle of least action, that it all made sense. The objects don’t experience a force per se, but travel along the path of least action which is also the path of maximum relativistic time. (I’ve described this phenomenon elsewhere.) The point is that, in GR, mass is not in the equations (unlike Newton’s mathematical representation) and the force we all experience is from whatever it is that stops us falling, which could be a chair you’re sitting on or the Earth.

So, the abstract ‘geodesic’ explains what Newton couldn’t, even though Newton gave us the right answers for most purposes.

And this leads me to extend the discussion to include the New Scientist article. The author, Eric Schwitzgebel, ponders 3 areas of scientific inquiry: quantum mechanics (are there many worlds?); consciousness (is it innate in all matter?) and computer simulations (do we live in one?). I’ll address them in reverse order, because that’s easiest.

As Paul Davies pointed out in The Goldilocks Enigma, the so-called computer-simulation hypothesis is a variant on Intelligent Design. If you don’t believe in ID, you shouldn’t believe that the universe is a computer simulation, because some entity had to design it and produce the code.

'Is consciousness innate?' is the same as pansychism, as Schwitzgebel concurs, and I’d say there is no evidence for it, so not worth arguing about. Basically, I don’t want to waste time on these 2 questions, and, to be fair, Schwitzgebel’s not saying he’s an advocate for either of them.

Which brings me to QM, and that’s relevant. Schwitzbegel makes the point that all the scientific interpretations have bizarre or non-common-sensical qualities, of which MWI (many worlds interpretation) is just one. Its relevance to this discussion is that they are all reifications that are independent of the mathematics, because the mathematics doesn’t discern between them. And this gets to the nub of the issue for me. Most physicists would agree that physics, in a nutshell, is about creating mathematical models that are then tested by experimentation and observation, often using extremely high-tech, not-to-mention behemoth instruments, like the LHC and the James Webb telescope.

It needs to be pointed out that, without exception, all these mathematical models have limitations and, historically, some have led us astray. The most obvious being Ptolemy’s model of the solar system involving epicycles. String theory, with its 10 dimensions and 10^500 possible universes, is a potential modern-day contender, but we don’t really know.

Nevertheless, as I explained with my brief discourse on geodesics (above), there are occasions when the mathematics provides an insight we would otherwise be ignorant of.

Basically, I think what Schwitzgebel is really touching on is the boundary between philosophy and science, which I believe has always existed and is an essential dynamic, despite the fact that many scientists are dismissive of its role.

Returning to Nermin, it’s worth quoting his final passage.

Quantum mechanics has brought home to us the necessity of separating that irreducibly real experience from the remarkable, beautiful, and highly abstract super-structure we have found to tie it all together.

The ‘real experience’ includes the flow of time; the universality of now which requires memory for us to know it exists; the subjective experience of free will. All of these are considered ‘illusions’ by many scientists, not least Sabine Hossenfelder in her excellent book, Existential Physics. I tend to agree with another physicist, Richard Muller, that what this tells us is that there is a problem with our theories and not our reality.

In an attempt to reify QM with reality, I like the notion proposed by Freeman Dyson that it’s a mathematical model that describes the future. As he points out, it gives us probabilities, and it provides a logical reason why Feynman’s abstraction of an infinite number of ‘paths’ are never observed.

Curiously, Fernee provides tacit support for the idea that the so-called ‘measurement’ or ‘observation’ provides an ‘abstract’ distinction between past and future in physics, though he doesn’t use those specific words.

In quantum mechanics, the measurement hypothesis, which includes the collapse of the wave function, is an irreversible process. As we perceive the world through measurements, time will naturally seem irreversible to us.

Very similar to something Davies said in another context:

The very act of measurement breaks the time symmetry of quantum mechanics in a process sometimes described as the collapse of the wave function…. the rewind button is destroyed as soon as that measurement is made.

Lastly, I would like to mention magnetism, because, according to SR, it’s mathematically dependent on a moving electric charge. Only it’s not always, as this video explicates. You can get a magnetic field from electric spin, which is an abstraction, as no one suggests that electrons do physically spin, even though they produce measurable magnetic moments.

What most people don’t know is that our most common experience of a magnetic field, which is a bar magnet, is created purely by electron spin and not moving electrons.

Does simultaneity have any meaning?

 Someone on Quora asked me a question about simultaneity with respect to Einstein’s special theory of relativity (SR), so I referenced a 30min video of a lecture on the subject, which I’ve cited before on this blog. It not only provides a qualitative explanation or description, but also provides the calculations which demonstrate the subjectivity of simultaneity as seen by different observers.
 
Below I’ve copied exactly what I posted on Quora, including the imbedded video. I’ll truncate the question to make things simpler. The questioner (Piet Venter) asked if there is experimental evidence, which I ignored, partly because I don’t know if there is, but also because it’s mathematically well understood and it’s a logical consequence of SR. Afterwards, I’ll discuss the philosophical ramifications.
 
Does the train embankment thought experiment of Einstein really demonstrate relativity of simultaneity?
 
Actually, there’s a very good YouTube video, which explains this much better than I can. It’s a lecture on the special theory of relativity (SR) and you might find the mathematics a bit daunting, but it’s worth persevering with. He gives the perspective from both a ‘stationary’ observer and a ‘moving’ observer. Note that he also allows for space-contraction for the ‘moving’ case to arrive at the correct answer.

 
To be specific, he uses the Bob and Alice scenario with Bob in a spaceship, so Bob’s ‘stationary’ with respect to the light signals, while he’s ‘moving’ with respect to Alice. What I find interesting is that from Bob’s perspective, he sees what I call a ‘true simultaneity’ (though no one uses that term) because everything is in the same frame of reference for Bob. The lecturer explains both their perspectives qualitatively in the first 6 mins, before he gets into the calculations.
 
When he does the calculations, Bob sees no difference in the signals, while Alice does. This infers that Bob has a special status as an observer compared to Alice. This is consistent with the calculations if you watch the whole video. The other point that no one mentions, is that Alice can tell that the signal on Bob’s ship is moving with respect to her reference-frame because of the Doppler shift of the light, whereas Bob sees no Doppler shift.

 
I commit a heresy by talking about a ‘true simultaneity’, while physicists will tell you there’s no such thing. But even the lecturer in the video makes the point that, according to Bob, he sees the two events recorded by his ‘clocks’ as happening at the same time, because everything is stationary in his frame of reference. Even though his frame of reference is moving relative to others, including Alice, and also compared to anyone on Earth, presumably (since he’s in a spaceship).
 
I contend that Bob has a special status and this is reflected in the mathematics. So is this a special case or can we generalise this to other events? People will argue that a core tenet of Einstein’s relativity is that there are no observers with a ‘special status’. But actually, the core tenet, as iterated by the lecturer in the video, is that the speed of light is the same for all observers, irrespective of their frame of reference. This means that even if an observer is falling into a black hole at the speed of light, they would still see any radiation travelling at the speed of light relative to them. So relativity creates paradoxes, and I gave a plausible resolution to that particular paradox in a recent post, as did David Finkelstein in 1958. (The ‘special status’ is that Bob is in the same frame of reference, his spaceship, as the light source and the 2 resultant events.)
 
In another even more recent post, I cited Kip Thorne explaining how, when one looks at the curvature of spacetime, one gets the same results if spacetime is flat and it’s the ruler that distorts. If one goes back to the Bob and Alice thought experiment in the video, Alice sees (or measures) a distortion, in as much as the front clock in Bob’s spaceship ‘lags’ his rear clock, where for Bob they are the same. This is because, from Alice’s perspective, the light signal takes longer to reach the front because it’s travelling away from her (from Bob’s perspective, it’s stationary). On the other hand, the rear clock is travelling towards the light signal (from her perspective).
 
When I was first trying to get my head around relativity, I took an unusual and novel approach. Because we are dealing with light waves, it occurred to me that both observers would ‘see’ the same number of waves, but the waves would be longer or shorter, which also determines the time and distance that they measure, because waves have wavelength (corresponding to distance) and frequency (corresponding to time).
 
If I apply this visualisation trick to Alice’s perception, then the waves going to the front clock must get longer and the waves going to the rear must get shorter, if they are to agree with the number of waves that Bob ‘sees’, whereby from his perspective, there’s no change in wavelength or frequency. And if the number of waves correspond to a ‘ruler’, then Alice’s ruler becomes distorted while Bob’s doesn’t. So she ‘measures’ a longer distance to the front from the light source than the rear, and because it takes longer for the light to reach the front clock, then it ‘lags’ (relative to Bob’s recording) according to her observation, using her own clocks (refer video).
 
So, does this mean that there is a universal simultaneity that we can all agree on? No, it doesn’t. For a start, using the thought experiment in the video, Bob is travelling relative to a frame of reference, which is the spacetime of the Universe. In fact, if there is a gravitational gradient in his space ship then that would be enough to put his clocks out of sync, so his frame of reference is idealised.
 
But I would make the point that not all observations of simultaneity are equal. While observers in different locations in the Universe would see the same events happening in different sequences; for events having a causal relationship, then all observers would see the same sequence, irrespective of their frame of reference. Since everything that happens is causally related to past events, then everything exists in a sequence that is unchangeable. It’s just that there is no observer who can see all causal sequences – it’s impossible. This brings me back to Kant, whom I reference in my last post, that there is an epistemological gap between what we can observe and what really is. If there is a hypothetical ‘universal now’ for the entire universe, no single observer within the universe can see it. Current wisdom is that it doesn’t exist, but I contend that, if it does, we can’t know.

What would Kant say?

Even though this is a philosophy blog, my knowledge of Western philosophy is far from comprehensive. I’ve read some of the classic texts, like Aristotle’s Nicomachean Ethics, Descartes Meditations, Hume’s A treatise of Human Nature, Kant’s Critique of Pure Reason; all a long time ago. I’ve read extracts from Plato, as well as Sartre’s Existentialism is a Humanism and Mill’s Utilitarianism. As you can imagine, I only recollect fragments, since I haven’t revisited them in years.
 
Nevertheless, there are a few essays on this blog that go back to the time when I did. One of those is an essay on Kant, which I retitled, Is Kant relevant to the modern world? Not so long ago, I wrote a post that proposed Kant as an unwitting bridge between Plato and modern physics. I say, ‘unwitting’, because, as far as I know, Kant never referenced a connection to Plato, and it’s quite possible that I’m the only person who has. Basically, I contend that the Platonic realm, which is still alive and well in mathematics, is a good candidate for Kant’s transcendental idealism, while acknowledging Kant meant something else. Specifically, Kant argued that time and space, like sensory experiences of colour, taste and sound, only exist in the mind.
 
Here is a good video, which explains Kant’s viewpoint better than me. If you watch it to the end, you’ll find the guy who plays Devil’s advocate to the guy expounding on Kant’s views makes the most compelling arguments (they’re both animated icons).

But there’s a couple of points they don’t make which I do. We ‘sense’ time and space in the same way we sense light, sound and smell to create a model inside our heads that attempts to match the world outside our heads, so we can interact with it without getting killed. In fact, our modelling of time and space is arguably more important than any other aspect of it.
 
I’ve always had a mixed, even contradictory, appreciation of Kant. I consider his insight that we may never know the things-in-themselves to be his greatest contribution to epistemology, and was arguably affirmed by 20th Century physics. Both relativity and quantum mechanics (QM) have demonstrated that what we observe does not necessarily reflect reality. Specifically, different observers can see and even measure different parameters of the same event. This is especially true when relativistic effects come into play.
 
In relativity, different observers not only disagree on time and space durations, but they can’t agree on simultaneity. As the Kant advocate in the video points out, surely this is evidence that space and time only exist in the mind, as Kant originally proposed. The Devil’s advocate resorts to an argument of 'continuity', meaning that without time as a property independent of the mind, objects and phenomena (like a candle burning) couldn’t continue to happen without an observer present.
 
But I would argue that Einstein’s general theory of relativity, which tells us that different observers can measure different durations of space and time (I’ll come back to this later), also tells us that the entire universe requires a framework of space and time for the objects to exist at all. In other words, GR tells us, mathematically, that there is an interdependence between the gravitational field that permeates and determines the motion of objects throughout the entire universe, and the spacetime metric those same objects inhabit. In fact, they are literally on opposite sides of the same equation.
 
And this brings me to the other point that I think is missing in the video’s discussion. Towards the end, the Devil’s advocate introduces ‘the veil of perception’ and argues:
 
We can only perceive the world indirectly; we have no idea what the world is beyond this veil… How can we then theorise about the world beyond our perceptions? …Kant basically claims that things-in-themselves exist but we do not know and cannot know anything about these things-in-themselves… This far-reaching world starts to feel like a fantasy.
 
But every physicist has an answer to this, because 20th Century physics has taken us further into this so-called ‘fantasy’ than Kant could possibly have imagined, even though it appears to be a neverending endeavour. And it’s specifically mathematics that has provided the means, which the 2 Socratic-dialogue icons have ignored. Which is why I contend that it’s mathematical Platonism that has replaced Kant’s transcendental idealism. It’s rendered by the mind yet it models reality better than anything else we have available. It’s the only means we have available to take us behind ‘the veil of perception’ and reveal the things-in-themselves.
 
And this leads me to a related point that was actually the trigger for me writing this in the first place.
 
In my last post, I mentioned I’m currently reading Kip A. Thorne’s book, Black Holes and Time Warps; Einstein’s Outrageous Legacy (1994). It’s an excellent book on many levels, because it not only gives a comprehensive history, involving both Western and Soviet science, it also provides insights and explanations most of us are unfamiliar with.
 
To give an example that’s relevant to this post, Thorne explains how making measurements at the extreme curvature of spacetime near the event horizon of a black hole, gives the exact same answer whether it’s the spacetime that distorts while the ‘rulers’ remain unchanged, or it’s the rulers that change while it’s the spacetime that remains ‘flat’. We can’t tell the difference. And this effectively confirms Kant’s thesis that we can never know the things-in-themselves.
 
To quote Thorne:
 
What is the genuine truth? Is spacetime really flat, or is it really curved? To a physicist like me this is an uninteresting question because it has no physical consequences (my emphasis). Both viewpoints, curved spacetime and flat, give the same predictions for any measurements performed with perfect rulers and clocks… (Earlier he defines ‘perfect rulers and clocks’ as being derived at the atomic scale)
 
Ian Miller (a physicist who used to be active on Quora) once made the point, regarding space-contraction, that it’s the ruler that deforms and not the space. And I’ve made the point myself that a clock can effectively be a ruler, because a clock that runs slower measures a shorter distance for a given velocity, compared to another so-called stationary observer who will measure the same distance as longer. This happens in the twin paradox thought experiment, though it’s rarely mentioned (even by me).

The role of prejudice in scientific progress

 I’m currently reading Black Holes and Time Warps; Einstein’s Outrageous Legacy by Kip A. Thorne, published in 1994. Despite the subject matter, it’s very readable, and virtually gives a history of the topic by someone who was more than just an observer, but a participant.
 
What I find curious is how everyone involved, including Einstein, Oppenheimer and Wheeler, had their own prejudices, some of which were later proven incorrect. None of these great minds were infallible. And one shouldn’t be surprised by this, given they were all working on the very frontier of physics and astrophysics in particular.
 
And surely that means that some of my prejudices will eventually be proven wrong. I expect so, even if I’m not around to acknowledge them. Science works because people’s prejudices can be overturned, which always requires a certain cognitive dissonance. As Freeman Dyson remarked in one his Closer-to-Truth interviews with Robert Lawrence Kuhn, every question answered by science invariably poses more questions, so it’s part of the process.
 
Of course, I’m not even a scientist, but a self-described spectator on the boundary of ideas. So why should I take myself seriously? Because, over time, my ideas have evolved and I’ve occasionally had insights that turned out to be true. One of these was confirmed in the reading of Thorne’s book. In a not-so-recent post, The fabric of the Universe, I attempted to resolve the paradox that an external observer to someone falling into a black hole sees them frozen in time, whereas the infalling subject experiences no such anomaly. I concluded that space itself falls into the black hole at the speed of light.
 
It so happens that a little-known postdoc, David Finkelstein, wrote a paper effectively coming to the same conclusion – only a lot more rigorously – in 1958, when I was still in primary school. The thing is that people like Penrose, Oppenheimer and Wheeler were convinced, though it had stumped them. In fact, according to Thorne, Wheeler took longer to be convinced. Thorne himself wrote an article in Scientific American in 1967, describing it by using diagrams showing a 2-D ‘fabric’ dragging ants into the hole, while they 'rolled balls’ away at the speed-of-light. At the event horizon the balls were exactly the same speed as the fabric, but in the opposite direction. Therefore, to the external observer, they were never ‘received’, but to the ants, the balls were travelling at the speed-of-light relative to them. Paradox solved. Note it was solved more than 60 years before I worked it out for myself.
 
And this is the thing: I need to work things out for myself, which is why I stick to my prejudices until I’m convinced that I’m wrong. But, to be honest, that’s what scientists do (I emphasise, I’m not a scientist) and that’s how science works. I contend that there is a dialectic between science and philosophy, where philosophy addresses questions that science can’t currently answer, but when it does, it asks more questions, so it’s neverending.

 

The mystery of reality

Many will say, ‘What mystery? Surely, reality just is.’ So, where to start? I’ll start with an essay by Raymond Tallis, who has a regular column in Philosophy Now called, Tallis in Wonderland – sometimes contentious, often provocative, always thought-expanding. His latest in Issue 157, Aug/Sep 2023 (new one must be due) is called Reflections on Reality, and it’s all of the above.
 
I’ve written on this topic many times before, so I’m sure to repeat myself. But Tallis’s essay, I felt, deserved both consideration and a response, partly because he starts with the one aspect of reality that we hardly ever ponder, which is doubting its existence.
 
Actually, not so much its existence, but whether our senses fool us, which they sometimes do, like when we dream (a point Tallis makes himself). And this brings me to the first point about reality that no one ever seems to discuss, and that is its dependence on consciousness, because when you’re unconscious, reality ceases to exist, for You. Now, you might argue that you’re unconscious when you dream, but I disagree; it’s just that your consciousness is misled. The point is that we sometimes remember our dreams, and I can’t see how that’s possible unless there is consciousness involved. If you think about it, everything you remember was laid down by a conscious thought or experience.
 
So, just to be clear, I’m not saying that the objective material world ceases to exist without consciousness – a philosophical position called idealism (advocated by Donald Hoffman) – but that the material objective world is ‘unknown’ and, to all intents and purposes, might as well not exist if it’s unperceived by conscious agents (like us). Try to imagine the Universe if no one observed it. It’s impossible, because the word, ‘imagine’, axiomatically requires a conscious agent.
 
Tallis proffers a quote from celebrated sci-fi author, Philip K Dick: 'Reality is that which, when you stop believing in it, doesn’t go away' (from The Shifting Realities of Philip K Dick, 1955). And this allows me to segue into the world of fiction, which Tallis doesn’t really discuss, but it’s another arena where we willingly ‘suspend disbelief' to temporarily and deliberately conflate reality with non-reality. This is something I have in common with Dick, because we have both created imaginary worlds that are more than distorted versions of the reality we experience every day; they’re entirely new worlds that no one has ever experienced in real life. But Dick’s aphorism expresses this succinctly. The so-called reality of these worlds, in these stories, only exist while we believe in them.
 
I’ve discussed elsewhere how the brain (not just human but animal brains, generally) creates a model of reality that is so ‘realistic’, we actually believe it exists outside our head.
 
I recently had a cataract operation, which was most illuminating when I took the bandage off, because my vision in that eye was so distorted, it made me feel sea sick. Everything had a lean to it and it really did feel like I was looking through a lens; I thought they had botched the operation. With both eyes open, it looked like objects were peeling apart. So I put a new eye patch on, and distracted myself for an hour by doing a Sudoku problem. When I had finished it, I took the patch off and my vision was restored. The brain had made the necessary adjustments to restore the illusion of reality as I normally interacted with it. And that’s the key point: the brain creates a model so accurately, integrating all our senses, but especially, sight, sound and touch, that we think the model is the reality. And all creatures have evolved that facility simply so they can survive; it’s a matter of life-and-death.
 
But having said all that, there are some aspects of reality that really do only exist in your mind, and not ‘out there’. Colour is the most obvious, but so is sound and smell, which all may be experienced differently by other species – how are we to know? Actually, we do know that some animals can hear sounds that we can’t and see colours that we don’t, and vice versa. And I contend that these sensory experiences are among the attributes that keep us distinct from AI.
 
Tallis makes a passing reference to Kant, who argued that space and time are also aspects of reality that are produced by the mind. I have always struggled to understand how Kant got that so wrong. Mind you, he lived more than a century before Einstein all-but proved that space and time are fundamental parameters of the Universe. Nevertheless, there are more than a few physicists who argue that the ‘flow of time’ is a purely psychological phenomenon. They may be right (but arguably for different reasons). If consciousness exists in a constant present (as expounded by Schrodinger) and everything else becomes the past as soon as it happens, then the flow of time is guaranteed for any entity with consciousness. However, many physicists (like Sabine Hossenfelder), if not most, argue that there is no ‘now’ – it’s an illusion.
 
Speaking of Schrodinger, he pointed out that there are fundamental differences between how we sense sight and sound, even though they are both waves. In the case of colour, we can blend them to get a new colour, and in fact, as we all know, all the colours we can see can be generated by just 3 colours, which is how the screens on all your devices work. However, that’s not the case with sound, otherwise we wouldn’t be able to distinguish all the different instruments in an orchestra. Just think: all the complexity is generated by a vibrating membrane (in the case of a speaker) and somehow our hearing separates it all. Of course, it can be done mathematically with a Fourier transform, but I don’t think that’s how our brains work, though I could be wrong.
 
And this leads me to discuss the role of science, and how it challenges our everyday experience of reality. Not surprisingly, Tallis also took his discussion in that direction. Quantum mechanics (QM) is the logical starting point, and Tallis references Bohr’s Copenhagen interpretation, ‘the view that the world has no definite state in the absence of observation.’ Now, I happen to think that there is a logical explanation for this, though I’m not sure anyone else agrees. If we go back to Schrodinger again, but this time his eponymous equation, it describes events before the ‘observation’ takes place, albeit with probabilities. What’s more, all the weird aspects of QM, like the Uncertainty Principle, superposition and entanglement, are all mathematically entailed in that equation. What’s missing is relativity theory, which has since been incorporated into QED or QFT.
 
But here’s the thing: once an observation or ‘measurement’ has taken place, Schrodinger’s equation no longer applies. In other words, you can’t use Schrodinger’s equation to describe something that has already happened. This is known as the ‘measurement problem’, because no one can explain it. But if QM only describes things that are yet to happen, then all the weird aspects aren’t so weird.
 
Tallis also mentions Einstein’s 'block universe', which infers past, present and future all exist simultaneously. In fact, that’s what Sabine Hossenfelder says in her book, Existential Physics:
 
The idea that the past and future exist in the same way as the present is compatible with all we currently know.
 
And:


Once you agree that anything exists now elsewhere, even though you see it only later, you are forced to accept that everything in the universe exists now. (Her emphasis.)
 
I’m not sure how she resolves this with cosmological history, but it does explain why she believes in superdeterminism (meaning the future is fixed), which axiomatically leads to her other strongly held belief that free will is an illusion; but so did Einstein, so she’s in good company.
 
In a passing remark, Tallis says, ‘science is entirely based on measurement’. I know from other essays that Tallis has written, that he believes the entire edifice of mathematics only exists because we can measure things, which we then applied to the natural world, which is why we have so-called ‘natural laws’. I’ve discussed his ideas on this elsewhere, but I think he has it back-to-front, whilst acknowledging that our ability to measure things, which is an extension of counting, is how humanity was introduced to mathematics. In fact, the ancient Greeks put geometry above arithmetic because it’s so physical. This is why there were no negative numbers in their mathematics, because the idea of a negative volume or area made no sense.
 
But, in the intervening 2 millennia, mathematics took on a life of its own, with such exotic entities like negative square roots and non-Euclidean geometry, which in turn suddenly found an unexpected home in QM and relativity theory respectively. All of a sudden, mathematics was informing us about reality before measurements were even made. Take Schrodinger’s wavefunction, which lies at the heart of his equation, and can’t be measured because it only exists in the future, assuming what I said above is correct.
 
But I think Tallis has a point, and I would argue that consciousness can’t be measured, which is why it might remain inexplicable to science, correlation with brain waves and their like notwithstanding.
 
So what is the mystery? Well, there’s more than one. For a start there is consciousness, without which reality would not be perceived or even be known, which seems to me to be pretty fundamental. Then there are the aspects of reality which have only recently been discovered, like the fact that time and space can have different ‘measurements’ dependent on the observer’s frame of reference. Then there is the increasing role of mathematics in our comprehension of reality at scales both cosmic and subatomic. In fact, given the role of numbers and mathematical relationships in determining fundamental constants and natural laws of the Universe, it would seem that mathematics is an inherent facet of reality.

 

Addendum:

As it happens, I wrote a letter to Philosophy Now on this topic, which they published, and also passed onto Raymond Tallis. As a consequence, we had a short correspondence - all very cordial and mutually respectful.

One of his responses can be found, along with my letter, under Letters, Issue 160. Scroll down to Lucky Guesses.
 

Can relativity theory be reconciled with common sense?

 You might think I write enough posts on Einstein’s theories of relativity, including the last one, but this one is less esoteric. It arose from a question I answered on Quora. Like a lot of questions on Quora, it’s provocative and you wonder whether the questioner is serious or not.
 
Before I came up with the title, I rejected 2 others: Relativity theory for dummies (which seemed patronising) and Relativity explained without equations or twins (which is better). But I settled on the one above, because it contains a thought experiment, which does exactly that. It’s a thought experiment I’ve considered numerous times in the past, but never expressed in writing.
 
I feel that the post also deals with some misconceptions: that SR arose from the failure of the Michelson-Morley experiments to measure the aether, and that GR has no relationship to Newton’s theory of gravity.
 
If the theories of relativity are so "revolutionary," why are they so incompatible with the 'real' world? In others(sic), why are the theories based on multiple assumptions in mathematics rather than the physical world?
 
You got one thing right, which is ‘theories’ plural – there is the special theory (SR) and the general theory (GR). As for ‘multiple assumptions in mathematics’, there was really only one fundamental assumption and that determined the mathematical formulation of both theories, but SR in particular (GR followed 10 years later).
 
The fundamental assumption was that the speed of light, c, is the same for all observers irrespective of their frame of reference, so not dependent on how fast they’re travelling relative to someone else, or, more importantly, the source of the light. This is completely counter-intuitive but is true based on all observations, including from the far reaches of the Universe. Imagine if, as per our common sense view of the world, that light travelled slower from a source receding from us and faster from a source approaching us.
 
That means that observing a galaxy far far away, the spiral arm travelling away from us would become increasingly out-of-sync with the arm travelling towards us. It’s hard to come up with a more graphic illustration that SR is true. The alternative is that the galaxy arms are travelling through an aether that permeates all of space. This was the accepted view before Einstein’s ‘revolutionary’ idea.
 
True: Einstein’s idea was premised on mathematics (not observation), but the mathematics of Maxwell’s equations, which ‘predicts’ the constant speed of light and provides a value for it. As someone said (Heinrich Hertz): “we get more out of [these equations] than was originally put into them.”
 
But SR didn’t take into account gravity, which unlike the fictitious aether, does permeate the whole universe, so Einstein developed GR. This was a mathematical theory, so not based on empirical observations, but it had to satisfy 3 criteria, established by Einstein at the outset.
 
1)    It had to satisfy the conservation laws of energy, momentum and angular momentum
2)    It had to allow for the equivalence of gravitational and inertial mass.
3)    It had to reduce mathematically to Newton’s formula when relativistic effects were negligible.
 
Many people overlook the last one, when they claim that Einstein’s theory made Newton’s theory obsolete, when in fact, it extended it into realms it couldn’t compute. Likewise, Einstein’s theory also has limitations, yet to be resolved. Observations that confirmed the theory followed its mathematical formulation, which was probably a first in physics.

Note that the curvature of spacetime is a consequence of Einstein’s theory and not a presupposition, and was one of the earliest observational confirmations of said theory.
 
 
Source: The Road to Relativity; The History and Meaning of Einstein’s “The Foundation of General Relativity” (the original title of his paper) by Hanoch Gutfreund and Jurgen Renn.
 

Addendum: I elaborate on the relationship between Newton's and Einstein's theories on another post, in the context of How does science work?

The fabric of the Universe

Brian Greene wrote an excellent book with a similar title (The Fabric of the Cosmos) which I briefly touched on here. Basically, it’s space and time, and the discipline of physics can’t avoid it. In fact, if you add mass and charge, you’ve got the whole gamut that we’re aware of. I know there’s the standard model along with dark energy and dark matter, but as someone said, if you throw everything into a black hole, the only thing you know about it is its mass, charge and angular momentum. Which is why they say, ‘a black hole has no hair.’ That was before Stephen Hawking applied the laws of thermodynamics and quantum mechanics and came up with Hawking radiation, but I’ve gone off-track, so I’ll come back to the topic-at-hand.
 
I like to tell people that I read a lot of books by people a lot smarter than me, and one of those books that I keep returning to is The Constants of Nature by John D Barrow. He makes a very compelling case that the only Universe that could be both stable and predictable enough to support complex life would be one with 3 dimensions of space and 1 of time. A 2-dimensional universe means that any animal with a digestive tract (from mouth to anus) would fall apart. Only a 3-dimensional universe allows planets to maintain orbits for millions of years. As Barrow points out in his aforementioned tome, Einstein’s friend, Paul Ehrenfest (1890-1933) was able to demonstrate this mathematically. It’s the inverse square law of gravity that keeps planets in orbit and that’s a direct consequence of everything happening in 3 dimensions. Interestingly, Kant thought it was the other way around – that 3 dimensions were a consequence of Newton’s universal law of gravity being an inverse square law. Mind you, Kant thought that both space and time were a priori concepts that only exist in the mind:
 
But this space and this time, and with them all appearances, are not in themselves things; they are nothing but representations and cannot exist outside our minds.
 
And this gets to the nub of the topic alluded to in the title of this post: are space and time ‘things’ that are fundamental to everything else we observe?
 
I’ll start with space, because, believe it or not, there is an argument among physicists that space is not an entity per se, but just dimensions between bodies that we measure. I’m going to leave aside, for the time being, that said ‘measurements’ can vary from observer to observer, as per Einstein’s special theory of relativity (SR).
 
This argument arises because we know that the Universe is expanding (by measuring the Doppler-shift of stars); but does space itself expand or is it just objects moving apart? In another post, I referenced a paper by Tamara M. Davis and Charles H. Lineweaver from UNSW (Expanding Confusion: Common Misconceptions of Cosmological Horizons and the Superluminal Expansion of the Universe), which I think puts an end to this argument, when they explain the difference between an SR and GR Doppler shift interpretation of an expanding universe.
 
The general relativistic interpretation of the expansion interprets cosmological redshifts as an indication of velocity since the proper distance between comoving objects increases. However, the velocity is due to the rate of expansion of space, not movement through space, and therefore cannot be calculated with the special relativistic Doppler shift formula. (My emphasis)
 
I’m now going to use a sleight-of-hand and attempt a description of GR (general theory of relativity) without gravity, based on my conclusion from their exposition.
 
The Universe has a horizon that’s directly analogous to the horizon one observes at sea, because it ‘moves’ as the observer moves. In other words, other hypothetical ‘observers’ in other parts of the Universe would observe a different horizon to us, including hypothetical observers who are ‘over-the-horizon’ relative to us.
 
But the horizon of the Universe is a direct consequence of bodies (or space) moving faster-than-light (FTL) over the horizon, as expounded upon in detail in Davis’s and Lineweaver’s paper. But here’s the thing: if you were an observer on one of these bodies moving FTL relative to Earth, the speed of light would still be c. How is that possible? My answer is that the light travels at c relative to the ‘space’* (in which it’s observed), but the space itself can travel faster than light.
 
There are, of course, other horizons in the Universe, which are event horizons of black holes. Now, you have the same dilemma at these horizons as you do at the Universe’s horizon. According to an external observer, time appears to ‘stop’ at the event horizon, because the light emitted by an object can’t reach us. However, for an observer at the event horizon, the speed of light is still c, and if the black hole is big enough, it’s believed (obviously no one can know) that someone could cross the event horizon without knowing they had. But what if it’s spacetime that crosses the event horizon? Then both the external observer’s perception and the comoving observer’s perception would be no different if the latter was at the horizon of the entire universe.
 
But what happens to time? Well, if you measure time by the frequency of light being emitted from an object at any of these horizons, it gets Doppler-shifted to zero, so time ‘stops’ for the ‘local’ observer (on Earth) but not for the observer at the horizon.
 
So far, I’ve avoided talking about quantum mechanics (QM), but something curious happens when you apply QM to cosmology: time disappears. According to Paul Davies in The Goldilocks Enigma: ‘…vanishing of time for the entire universe becomes very explicit in quantum cosmology, where the time variable simply drops out of the quantum description.’ This is consistent with Freeman Dyson’s argument that QM can only describe the future. Thus, if you apply a description of the future to the entire cosmos, there would be no time.
 
 
* Note: you can still apply SR within that ‘space’.

 

Addendum: I've since learned that in 1958, David Finkelstein (a postdoc with the Stevens Institute of Technology in Hoboken, New Jersey) wrote an article in Physical Review that gave the same explanation for how time appears different to different observers of a black hole, as I do above. It immediately grabbed the attention (and approval) of Oppenheimer, Wheeler and Penrose (among others), who had struggled to resolve this paradox. (Ref. Black Holes And Time Warps; Einstein's Outrageous Legacy, Kip S. Thorne, 1994)
 

Consciousness, free will, determinism, chaos theory – all connected

 I’ve said many times that philosophy is all about argument. And if you’re serious about philosophy, you want to be challenged. And if you want to be challenged you should seek out people who are both smarter and more knowledgeable than you. And, in my case, Sabine Hossenfelder fits the bill.
 
When I read people like Sabine, and others whom I interact with on Quora, I’m aware of how limited my knowledge is. I don’t even have a university degree, though I’ve attempted a number of times. I’ve spent my whole life in the company of people smarter than me, including at school. Believe it or not, I still have occasional contact with them, through social media and school reunions. I grew up in a small rural town, where the people you went to school with feel like siblings.
 
Likewise, in my professional life, I have always encountered people cleverer than me – it provides perspective.
 
In her book, Existential Physics; A Scientist’s Guide to Life’s Biggest Questions, Sabine interviews people who are possibly even smarter than she is, and I sometimes found their conversations difficult to follow. To be fair to Sabine, she also sought out people who have different philosophical views to her, and also have the intellect to match her.
 
I’m telling you all this to put things in perspective. Sabine has her prejudices like everyone else, some of which she defends better than others. I concede that my views are probably more simplistic than hers, and I support my challenges with examples that are hopefully easy to follow. Our points of disagreement can be distilled down to a few pertinent topics, which are time, consciousness, free will and chaos. Not surprisingly, they are all related – what you believe about one, affects what you believe about the others.
 
Sabine is very strict about what constitutes a scientific theory. She argues that so-called theories like the multiverse have ‘no explanatory power’, because they can’t be verified or rejected by evidence, and she calls them ‘ascientific’. She’s critical of popularisers like Brian Cox who tell us that there could be an infinite number of ‘you(s)’ in an infinite multiverse. She distinguishes between beliefs and knowledge, which is a point I’ve made myself. Having said that, I’ve also argued that beliefs matter in science. She puts all interpretations of quantum mechanics (QM) in this category. She keeps emphasising that it doesn’t mean they are wrong, but they are ‘ascientific’. It’s part of the distinction that I make between philosophy and science, and why I perceive science as having a dialectical relationship with philosophy.
 
I’ll start with time, as Sabine does, because it affects everything else. In fact, the first chapter in her book is titled, Does The Past Still Exist? Basically, she argues for Einstein’s ‘block universe’ model of time, but it’s her conclusion that ‘now is an illusion’ that is probably the most contentious. This critique will cite a lot of her declarations, so I will start with her description of the block universe:
 
The idea that the past and future exist in the same way as the present is compatible with all we currently know.
 
This viewpoint arises from the fact that, according to relativity theory, simultaneity is completely observer-dependent. I’ve discussed this before, whereby I argue that for an observer who is moving relative to a source, or stationary relative to a moving source, like the observer who is standing on the platform of Einstein’s original thought experiment, while a train goes past, knows this because of the Doppler effect. In other words, an observer who doesn’t see a Doppler effect is in a privileged position, because they are in the same frame of reference as the source of the signal. This is why we know the Universe is expanding with respect to us, and why we can work out our movement with respect to the CMBR (cosmic microwave background radiation), hence to the overall universe (just think about that).
 
Sabine clinches her argument by drawing a spacetime diagram, where 2 independent observers moving away from each other, observe a pulsar with 2 different simultaneities. One, who is traveling towards the pulsar, sees the pulsar simultaneously with someone’s birth on Earth, while the one travelling away from the pulsar sees it simultaneously with the same person’s death. This is her slam-dunk argument that ‘now’ is an illusion, if it can produce such a dramatic contradiction.
 
However, I drew up my own spacetime diagram of the exact same scenario, where no one is travelling relative to anyone one else, yet create the same apparent contradiction.

 My diagram follows the convention in that the horizontal axis represents space (all 3 dimensions) and the vertical axis represents time. So the 4 dotted lines represent 4 observers who are ‘stationary’ but ‘travelling through time’ (vertically). As per convention, light and other signals are represented as diagonal lines of 45 degrees, as they are travelling through both space and time, and nothing can travel faster than them. So they also represent the ‘edge’ of their light cones.
 
So notice that observer A sees the birth of Albert when he sees the pulsar and observer B sees the death of Albert when he sees the pulsar, which is exactly the same as Sabine’s scenario, with no relativity theory required. Albert, by the way, for the sake of scalability, must have lived for thousands of years, so he might be a tree or a robot.
 
But I’ve also added 2 other observers, C and D, who see the pulsar before Albert is born and after Albert dies respectively. But, of course, there’s no contradiction, because it’s completely dependent on how far away they are from the sources of the signals (the pulsar and Earth).
 
This is Sabine’s perspective:
 
Once you agree that anything exists now elsewhere, even though you see it only later, you are forced to accept that everything in the universe exists now. (Her emphasis.)
 
I actually find this statement illogical. If you take it to its logical conclusion, then the Big Bang exists now and so does everything in the universe that’s yet to happen. If you look at the first quote I cited, she effectively argues that the past and future exist alongside the present.
 
One of the points she makes is that, for events with causal relationships, all observers see the events happening in the same sequence. The scenario where different observers see different sequences of events have no causal relationships. But this begs a question: what makes causal events exceptional? What’s more, this is fundamental, because the whole of physics is premised on the principle of causality. In addition, I fail to see how you can have causality without time. In fact, causality is governed by the constant speed of light – it’s literally what stops everything from happening at once.
 
Einstein also believed in the block universe, and like Sabine, he argued that, as a consequence, there is no free will. Sabine is adamant that both ‘now’ and ‘free will’ are illusions. She argues that the now we all experience is a consequence of memory. She quotes Carnap that our experience of ‘past, present and future can be described and explained by psychology’ – a point also made by Paul Davies. Basically, she argues that what separates our experience of now from the reality of no-now (my expression, not hers) is our memory.
 
Whereas, I think she has it back-to-front, because, as I’ve pointed out before, without memory, we wouldn’t know we are conscious. Our brains are effectively a storage device that allows us to have a continuity of self through time, otherwise we would not even be aware that we exist. Memory doesn’t create the sense of now; it records it just like a photograph does. The photograph is evidence that the present becomes the past as soon as it happens. And our thoughts become memories as soon as they happen, otherwise we wouldn’t know we think.
 
Sabine spends an entire chapter on free will, where she persistently iterates variations on the following mantra:
 
The future is fixed except for occasional quantum events that we cannot influence.
 
But she acknowledges that while the future is ‘fixed’, it’s not predictable. And this brings us to chaos theory. Sabine discusses chaos late in the book and not in relation to free will. She explicates what she calls the ‘real butterfly effect’.
 
The real butterfly effect… means that even arbitrarily precise initial data allow predictions for only a finite amount of time. A system with this behaviour would be deterministic and yet unpredictable.
 
Now, if deterministic means everything physically manifest has a causal relationship with something prior, then I agree with her. If she means that therefore ‘the future is fixed’, I’m not so sure, and I’ll explain why. By specifying ‘physically manifest’, I’m excluding thoughts and computer algorithms that can have an effect on something physical, whereas the cause is not so easily determined. For example, In the case of the algorithm, does it go back to the coder who wrote it?
 
My go-to example for chaos is tossing coins, because it’s so easy to demonstrate and it’s linked to probability theory, as well as being the very essence of a random event. One of the key, if not definitive, features of a chaotic phenomenon is that, if you were to rerun it, you’d get a different result, and that’s fundamental to probability theory – every coin toss is independent of any previous toss – they are causally independent. Unrepeatability is common among chaotic systems (like the weather). Even the Earth and Moon were created from a chaotic event.
 
I recently read another book called Quantum Physics Made Me Do It by Jeremie Harris, who argues that tossing a coin is not random – in fact, he’s very confident about it. He’s not alone. Mark John Fernee, a physicist with Qld Uni, in a personal exchange on Quora argued that, in principle, it should be possible to devise a robot to perform perfectly predictable tosses every time, like a tennis ball launcher. But, as another Quora contributor and physicist, Richard Muller, pointed out: it’s not dependent on the throw but the surface it lands on. Marcus du Sautoy makes the same point about throwing dice and provides evidence to support it.
 
Getting back to Sabine. She doesn’t discuss tossing coins, but she might think that the ‘imprecise initial data’ is the actual act of tossing, and after that the outcome is determined, even if can’t be predicted. However, the deterministic chain is broken as soon as it hits a surface.
 
Just before she gets to chaos theory, she talks about computability, with respect to Godel’s Theorem and a discussion she had with Roger Penrose (included in the book), where she says:
 
The current laws of nature are computable, except for that random element from quantum mechanics.
 
Now, I’m quoting this out of context, because she then argues that if they were uncomputable, they open the door to unpredictability.
 
My point is that the laws of nature are uncomputable because of chaos theory, and I cite Ian Stewart’s book, Does God Play Dice? In fact, Stewart even wonders if QM could be explained using chaos (I don’t think so). Chaos theory has mathematical roots, because not only are the ‘initial conditions’ of a chaotic event impossible to measure, they are impossible to compute – you have to calculate to infinite decimal places. And this is why I disagree with Sabine that the ‘future is fixed’.
 
It's impossible to discuss everything in a 223 page book on a blog post, but there is one other topic she raises where we disagree, and that’s the Mary’s Room thought experiment. As she explains it was proposed by philosopher, Frank Jackson, in 1982, but she also claims that he abandoned his own argument. After describing the experiment (refer this video, if you’re not familiar with it), she says:
 
The flaw in this argument is that it confuses knowledge about the perception of colour with the actual perception of it.
 
Whereas, I thought the scenario actually delineated the difference – that perception of colour is not the same as knowledge. A person who was severely colour-blind might never have experienced the colour red (the specified colour in the thought experiment) but they could be told what objects might be red. It’s well known that some animals are colour-blind compared to us and some animals specifically can’t discern red. Colour is totally a subjective experience. But I think the Mary’s room thought experiment distinguishes the difference between human perception and AI. An AI can be designed to delineate colours by wavelength, but it would not experience colour the way we do. I wrote a separate post on this.
 
Sabine gives the impression that she thinks consciousness is a non-issue. She talks about the brain like it’s a computer.
 
You feel you have free will, but… really, you’re running a sophisticated computation on your neural processor.
 
Now, many people, including most scientists, think that, because our brains are just like computers, then it’s only a matter of time before AI also shows signs of consciousness. Sabine doesn’t make this connection, even when she talks about AI. Nevertheless, she discusses one of the leading theories of neuroscience (IIT, Information Integration Theory), based on calculating the amount of information processed, which gives a number called phi (Φ). I came across this when I did an online course on consciousness through New Scientist, during COVID lockdown. According to the theory, this number provides a ‘measure of consciousness’, which suggests that it could also be used with AI, though Sabine doesn’t pursue that possibility.
 
Instead, Sabine cites an interview in New Scientist with Daniel Bor from the University of Cambridge: “Phi should decrease when you go to sleep or are sedated… but work in Bor’s laboratory has shown that it doesn’t.”
 
Sabine’s own view:
 
Personally, I am highly skeptical that any measure consisting of a single number will ever adequately represent something as complex as human consciousness.
 
Sabine discusses consciousness at length, especially following her interview with Penrose, and she gives one of the best arguments against panpsychism I’ve read. Her interview with Penrose, along with a discussion on Godel’s Theorem, which is another topic, discusses whether consciousness is computable or not. I don’t think it is and I don’t think it’s algorithmic.
 
She makes a very strong argument for reductionism: that the properties we observe of a system can be understood from studying the properties of its underlying parts. In other words, that emergent properties can be understood in terms of the properties that it emerges from. And this includes consciousness. I’m one of those who really thinks that consciousness is the exception. Thoughts can cause actions, which is known as ‘agency’.
 
I don’t claim to understand consciousness, but I’m not averse to the idea that it could exist outside the Universe – that it’s something we tap into. This is completely ascientific, to borrow from Sabine. As I said, our brains are storage devices and sometimes they let us down, and, without which, we wouldn’t even know we are conscious. I don’t believe in a soul. I think the continuity of the self is a function of memory – just read The Lost Mariner chapter in Oliver Sacks’ book, The Man Who Mistook His Wife For A Hat. It’s about a man suffering from retrograde amnesia, so his life is stuck in the past because he’s unable to create new memories.
 
At the end of her book, Sabine surprises us by talking about religion, and how she agrees with Stephen Jay Gould ‘that religion and science are two “nonoverlapping magisteria!”. She makes the point that a lot of scientists have religious beliefs but won’t discuss them in public because it’s taboo.
 
I don’t doubt that Sabine has answers to all my challenges.
 
There is one more thing: Sabine talks about an epiphany, following her introduction to physics in middle school, which started in frustration.
 
Wasn’t there some minimal set of equations, I wanted to know, from which all the rest could be derived?
 
When the principle of least action was introduced, it was a revelation: there was indeed a procedure to arrive at all these equations! Why hadn’t anybody told me?
 
The principle of least action is one concept common to both the general theory of relativity and quantum mechanics. It’s arguably the most fundamental principle in physics. And yes, I posted on that too.