The edge of time

This is a contentious idea, despite the fact that we all believe we experience it all the time. Many physicists, including ones I admire, and whom I readily admit know a lot more than me (like Sabine Hossenfelder), believe that ‘now’ is an illusion; or (in the case of Paul Davies) that it requires a neurological explanation rather than a physical one. I will go further and claim there is an edge of time for the entire universe.
 
I made the point in a previous post that if you go on YouTube, you’ll find discussions with physicists who all have their own pet theories that are at odds with virtually everyone else, and to be honest, I can’t fault them, and I’m pleased that they’re willing to share their views.
 
Well, I’m not a physicist, but this is my particular heretical viewpoint that virtually no one else agrees with, with the additional caveat that they all have more expertise than me. They will tell you that I’m stuck in 19th Century physics, but I believe I can defend myself against that simple rebut.
 
During COVID lockdown in 2021, I did a series of online courses through New Scientist, including one on The Cosmos, where one of the lecturers was Chris Impey (Distinguished Professor, Department of Astronomy, University of Arizona) who made the point that the Universe has an ‘edge in time’, but not an edge in space. He might have used the word ‘boundary’ instead of ‘edge’, which would be more appropriate for space. In fact, it’s possible that space is infinite while time is finite, which means that the concept of spacetime might have limited application, but I’m getting ahead of myself.
 
The one other person I’ve read who might (partly) agree with me is Richard Muller, who cowrote a paper with Shaun Maguire, titled Now, and the Flow of Time, as well as a book, NOW; The Physics of Time, which I’ve read more than once. Basically, the edge of time on a cosmic scale is the edge of the Big Bang (which is still happening). What I’m saying is that there is a universal ‘Now’ for the entire universe, which is one of the most heretical ideas you can hold. According to modern physics, ‘Now’ is completely subjective and dependent on the observer – there is no objective Now, which is what I challenge.
 
There is a way in which this is correct, in that different observers in different parts of the Universe see completely different things (if they’re far enough apart) and would even see different horizons for the Universe. In fact, it’s possible that an observer who is over the horizon to us will see objects we can’t see, and of course, wouldn’t see us at all. This is because objects over the horizon are travelling away from us faster than the speed of light.
 
Because the speed of light is finite, the objects that we ‘observe’ millions or billions of light years away, are commensurately that much older than we are. And it follows from this logic, that if anyone could observe Earth from these same objects, they would see it equally old compared to what we see. This means that everyone sees a different now. This leads to the logical question: how could an objective ‘now’ exist? I like to invoke Kant that we cannot know the ‘thing-in-itself’, only our perception of it.
 
And I invoke Kant when I look at relativity theory, because it’s inherently an observer-dependent theory. I would contend that all physics theories are epistemic, meaning they deal with knowledge, rather than ontic, which is what is really there. Some argue that even space and time are epistemic, not ontic, but I disagree. The dimensions of space and time determine to a large extent what sort of universe we can live in. A point made by John Barrow in his book, The Constants of Nature.
 
In a not-so-recent post, I explained the famous pole-in-the-barn paradox, where 2 different observers see different things (in fact, measure different things) yet, in both cases, there is no clash between the pole and the barn (or in the example I describe, a spaceship and a tunnel). One of my conclusions is that it’s only the time that changes for the 2 observers, and not the space. Instead, they measure a different ‘length’ or ‘distance travelled’ by using their clocks as rulers. But it also implies that one of the observers is more ‘privileged’ than the other, which seems to contradict the equivalence principle. But I can make this claim because there is a reference frame for the entire universe, which is provided by the CMBR (cosmic microwave background radiation). This is not contentious, because we can even measure our velocity relative to it by using the Doppler effect, hence our velocity relative to the entire universe.
 
But there is another famous and simple experiment that provides evidence that there is an overall frame of reference for the Universe, which philosopher of science, Tim Maudlin, called ‘the most important experiment in physics’. If you were to go to the International Space Station and spin an object, it would be subject to the same inertial forces as it would on Earth. So what’s it spinning in reference to? The spaceship, its orbit around Earth, or the entire cosmos? I’d say, the entire universe, which is obviously not spinning itself, otherwise it would have a centre. Of course, Einstein knew this, and his answer was there is no absolute time or space but absolute spacetime.
 
I raised this earlier, because, if time is finite and space infinite, the concept of absolute spacetime breaks down, at least conceptually. But space doesn’t have to be infinite to have no boundary. In fact, it’s either open and infinite or closed and finite, albeit in 3 dimensions. To provide a relatable analogy, the Earth’s surface is finite and closed, but in 2 dimensions. Marcus du Sautoy made the point that, if the Universe is spatially infinite, we might never know.
 
The other point is that you could have clocks running at different rates dependent on where they are in the Universe, yet there could still be a universal Now. This is implicit in the famous twin paradox thought experiment. I like to point out that when the twins reunite they have lived different durations of time, yet agree where they are in time together. This means you can have a universal Now for the universe while disagreeing on its age; if you lived near a massive black hole, for instance.
 
In the same way observers can travel different distances to arrive at the same destination, they can travel different time intervals as well. In fact, they would agree they’ve travelled the exact same spacetime, which is why relativity theory argues you can only talk about spacetime combined rather than space and time separately. But I argue that it’s the clock that changes and not space, where the clock is the ruler for space.

The fly-in-the-ointment is simultaneity. According to relativity theory, simultaneity is completely dependent on the observer, but again, I invoke Kant. There could be an objective simultaneity that can’t be observed. I’ve written on this before, so I’ll keep it brief, but basically, you can have a ‘true’ simultaneity, if both the observer and the events are in the same frame of reference. And you can tell if you’re not, by using the Doppler effect. Basically, the Doppler effect tells you if the source of the signals (that are apparently simultaneous) are in the same frame of reference as you. If they’re not, then they’re not simultaneous, which infers there is an objective simultaneity. Whether this applies to the entire universe is another matter.

You may be familiar with this diagram.

 

 
I want to make a couple of points that no one else does. Firstly, everything outside the past light cone is unobservable (by definition), which means relativity theory can’t be applied, yet people do. As I said earlier, relativity is epistemic and all epistemic theories (or models) have limitations. In other words, I contend that there is an ontology outside the light cones that relativity theory can’t tell us anything about (I discuss this in more detail in a post appositely titled, The impossible thought experiment).
 
Secondly, the so-called ‘hypersurface’ is a fiction, or at best, a metaphor. Yet Brian Greene, to give one example, discusses it and graphically represents it as if it’s physically real. If ‘Now’ is the edge of the Big Bang, it suffuses the entire universe (even if it’s physically infinite), which means it’s impossible to visualise.
 
Let’s talk about another epistemic theory, quantum mechanics. In fact, the ontology of QM has been an open debate for more than a century. I recently watched a discussion between Matt (from PBS Space Time) and Mithuna Yoganathan (of Looking Glass Universe), which is excellent. It turns out they’re both from Melbourne, which is where I’m writing this. I figured Mithuna was Aussie, even though she’s based in London, but I didn’t pick Matt’s accent. I have to admit he sounds more Australian in his conversation with her. Towards the end of the video, they readily admit they get very speculative (meaning philosophical) but Mithuna provides compelling arguments for the multiple worlds interpretation (MWI) of QM. Personally, I argue that MWI doesn’t address the probabilities which is intrinsic to QM. Why are some worlds more probabilistic than others? If all outcomes happen in some universe somewhere, then they all have a probability of ONE in that universe. If there are an infinite number of universes then probabilities are nonsensical.
 
If you go to 37.10m of the video where Mithuna talks about the Schrodinger equation and the ‘2 rules’, I think she gets to the nub of the problem, and at 38.10 puts it into plain English. Basically, she says that there are either 2 rules for the Universe or you need to reject the ‘measurement’ or ‘collapse’ of the wave function, which means accepting MWI (the wave function continues in another universe), which she implies without saying. She says the 2 rules makes ‘the Copenhagen interpretation untenable’. I find this interesting, because I concluded many years ago that the Universe obeys 2 sets of rules.
 
My argument is that one set of rules, determined epistemically by the Schrodinger equation, describes the future and the other set of rules, which is classical physics and is determined by what we observe, describes the past.
 
A feature of QM, which separates it from classical physics, is entanglement and non-locality. Non-locality means it doesn’t strictly obey relativity theory, yet they remain compatible (because you can’t use entanglement to transmit information faster-than-light). In fact, Schrodinger himself said that “entanglement is the characteristic trait of quantum mechanics, the one that enforces its entire departure from classical lines of thought.” In other words, it obeys different rules to classical physics, with or without ‘measurement’.
 
MWI effectively argues that superposition exists in reality, albeit in parallel universes, whereas I contend that it only exists in the future. The wave function describes all of these possibilities, and via the Born rule, gives them probabilities. But when we observe it, which axiomatically puts it in the past, there is only ONE and there is no longer any superposition.
 
All physicists agree that entanglement, in principle, can apply to objects on opposite sides of the Universe. In fact, Schrodinger’s equation, in principle, can describe a wave function for the entire universe, which is why I’ve half-jokingly called it God’s equation, and have it tattooed on my arm.
 
I contend (though, as far as I know, no one agrees with me) that entanglement across the entire universe only makes sense if there is a universal Now for the entire universe. A Now that separates QM future superpositions (described by the wave function in Schrodinger’s equation) from past ‘observables’ in classical physics.

Writing and philosophy

 I’ve been watching a lot of YouTube videos of Alan Moore, who’s probably best known for his graphic novels, Watchmen and V for Vendetta, both of which were turned into movies. He also wrote a Batman graphic novel, The Killing Joke, which was turned into an R rated animated movie (due to Batman having sex with Batgirl) with Mark Hamill voicing the Joker. I’m unsure if it has any fidelity to Moore’s work, which was critically acclaimed, whereas the movie received mixed reviews. I haven’t read the graphic novel, so I can’t comment.
 
On the other hand, I read Watchmen and saw the movie, which I reviewed on this blog, and thought they were both very good. I also saw V for Vendetta, starring Natalie Portman and Hugo Weaving, without having read Moore’s original. Moore also wrote a novel, Jerusalem, which I haven’t read, but is referenced frequently by Robin Ince in a video I cite below.
 
All that aside, it’s hard to know where to start with Alan Moore’s philosophy on writing, but the 8 Alan Moore quotes video is as good a place as any if you want a quick overview. For a more elaborate dialogue, there is a 3-way interview, obviously done over a video link, between Moore and Brian Catling, hosted by Robin Ince, with the online YouTube channel, How to Academy. They start off talking about imagination, but get into philosophy when all 3 of them start questioning what reality is, or if there is an objective reality at all.
 
My views on this are well known, and it’s a side-issue in the context of writing or creating imaginary worlds. Nevertheless, had I been party to the discussion, I would have simply mentioned Kant, and how he distinguishes between the ‘thing-in-itself’ and our perception of it. Implicit in that concept is the belief that there is an independent reality to our internal model of it, which is mostly created by a visual representation, but other senses, like hearing, touch and smell, also play a role. This is actually important when one gets into a discussion on fiction, but I don’t want to get ahead of myself. I just wish to make the point that we know there is an external objective reality because it can kill you. Note that a dream can’t kill you, which is a fundamental distinction between reality and a dreamscape. I make this point because I think a story, which takes place in your imagination, is like a dreamscape; so that difference carries over into fiction.
 
And on the subject of life-and-death, Moore references something he’d read on how evolution selects for ‘survivability’ not ‘truth’, though he couldn’t remember the source or the authors. However, I can, because I wrote about that too. He’s obviously referring to the joint paper written by Donald Hoffman and Chetan Prakash called Objects of Consciousness (Frontiers of Psychology, 2014). This depends on what one means by ‘truth’. If you’re talking about mathematical truths then yes, it has little to do with survivability (our modern-day dependence on technical infrastructure notwithstanding). On the other hand, if you’re talking about the accuracy of the internal model in your mind matching the objective reality external to your body, then your survivability is very much dependent on it.
 
Speaking of mathematics, Ince mentions Bertrand Russell giving up on mathematics and embracing philosophy because he failed to find a foundation that ensured its truth (my wording interpretating his interpretation). Basically, that’s correct, but it was Godel who put the spanner in the works with his famous Incompleteness Theorem, which effectively tells us that there will always exist mathematical truths that can’t be proven true. In other words, he concretely demonstrated (proved, in fact) that there is a distinction between truth and proof in mathematics. Proofs rely on axioms and all axioms have limitations in what they can prove, so you need to keep finding new axioms, and this infers that mathematics is a neverending endeavour. So it’s not the end of mathematics as we know it, but the exact opposite.
 
All of this has nothing to do with writing per se, but since they raised these issues, I felt compelled to deal with them.
 
At the core of this part of their discussion, is the unstated tenet that fiction and non-fiction are distinct, even if the boundary sometimes becomes blurred. A lot of fiction, if not all, contains factual elements. I like to cite Ian Fleming’s James Bond novels containing details like the gun Bond used (a Walther PPK) and the Bentley he drove, which had an Amherst Villiers supercharger. Bizarrely, I remember these trivial facts from a teenage obsession with all things Bond.
 
And this allows me to segue into something that Moore says towards the end of this 3-way discussion, when he talks specifically about fantasy. He says it needs to be rooted in some form of reality (my words), otherwise the reader won’t be able to imagine it at all. I’ve made this point myself, and give the example of my own novel, Elvene, which contains numerous fantasy elements, including both creatures that don’t exist on our world and technology that’s yet to be invented, if ever.
 
I’ve written about imagination before, because I argue it’s essential to free will, which is not limited to humans, though others may disagree. Imagination is a form of time travel, into the past, but more significantly, into the future. Episodic memories and imagination use the same part of the brain (so we are told); but only humans seem to have the facility to time travel into realms that don’t exist anywhere else other than the imagination. And this is why storytelling is a uniquely human activity.
 
I mentioned earlier how we create an internal world that’s effectively a simulation of the external world we interact with. In fact, my entire philosophy is rooted in the idea that we each of us have an internal and external world, which is how I can separate religion from science, because one is completely internal and the other is an epistemology of the physical universe from the cosmic scale to the infinitesimal. Mathematics is a medium that bridges them, and contributes to the Kantian notion that our perception may never completely match the objective reality. Mathematics provides models that increase our understanding while never quite completing it. Godel’s incompleteness theorem (referenced earlier) effectively limits physics as well. Totally off-topic, but philosophically important.
 
Its relevance to storytelling is that it’s a visual medium even when there are no visuals presented, which is why I contend that if we didn’t dream, stories wouldn’t work. In response to a question, Moore pointed out that, because he worked on graphic novels, he had to think about the story visually. I’ve made the point before that the best thing I ever did for my own writing was to take some screenwriting courses, because one is forced to think visually and imagine the story being projected onto a screen. In a screenplay, you can only write down what is seen and heard. In other words, you can’t write what a character is thinking. On the other hand, you can write an entire novel from inside a character’s head, and usually more than one. But if you tell a story from a character’s POV (point-of-view) you axiomatically feel what they’re feeling and see what they’re witnessing. This is the whole secret to novel-writing. It’s intrinsically visual, because we automatically create images even if the writer doesn’t provide them. So my method is to provide cues, knowing that the reader will fill in the blanks. No one specifically mentions this in the video, so it’s my contribution.
 
Something else that Moore, Catling and Ince discuss is how writing something down effectively changes the way they think. This is something I can identify with, both in fiction and non-fiction, but fiction specifically. It’s hard to explain this if you haven’t experienced it, but they spend a lot of time on it, so it’s obviously significant to them. In fiction, there needs to be a spontaneity – I’ve often compared it to playing jazz, even though I’m not a musician. So most of the time, you don’t know what you’re going to write until it appears on the screen or on paper, depending which medium you’re using. Moore says it’s like it’s in your hands instead of your head, which is certainly not true. But the act of writing, as opposed to speaking, is a different process, at least for Moore, and also for me.
 
I remember many years ago (decades) when I told someone (a dentist, actually) that I was writing a book. He said he assumed that novelists must dictate it, because he couldn’t imagine someone writing down thousands upon thousands of words. At the time, I thought his suggestion just as weird as he thought mine to be. I suspect some writers do. Philip Adams (Australian broadcaster and columnist) once confessed that he dictated everything he wrote. In my professional life, I have written reports for lawyers in contractual disputes, both in Australia and the US, for which I’ve received the odd kudos. In one instance, someone I was working with was using a cassette-like dictaphone and insisted I do the same, believing it would save time. So I did, in spite of my better judgement, and it was just terrible. Based on that one example, you’d be forgiven for thinking that I had no talent or expertise in that role. Of course, I re-wrote the whole thing, and was never asked to do it again.
 
I originally became interested in Moore’s YouTube videos because he talked about how writing affects you as a person and can also affect the world. I think to be a good writer of fiction you need to know yourself very well, and I suspect that is what he meant without actually saying it. The paradox with this is that you are always creating characters who are not you. I’ve said many times that the best fiction you write is where you’re completely detached – in a Zen state – sometimes called ‘flow’. Virtuoso musicians and top sportspersons will often make the same admission.
 
I believe having an existential philosophical approach to life is an important aspect to my writing, because it requires an authenticity that’s hard to explain. To be true to your characters you need to leave yourself out of it. Virtually all writers, including Moore, talk about treating their characters like real people, and you need to extend that to your villains if you want them to be realistic and believable, not stereotypes. Moore talks about giving multiple dimensions to his characters, which I won’t go into. Not because I don’t agree, but because I don’t over-analyse it. Characters just come to me and reveal themselves as the story unfolds; the same as they do for the reader.
 
What I’ve learned from writing fiction (which I’d self-describe as sci-fi/fantasy) – as opposed to what I didn’t know – is that, at the end of the day (or story), it’s all about relationships. Not just intimate relationships, but relationships between family members, between colleagues, between protagonists and AI, and between protagonists and antagonists. This is the fundamental grist for all stories.
 
Philosophy is arguably more closely related to writing than any other artform: there is a crossover and interdependency; because fiction deals with issues relevant to living and being.

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.

Radical ideas

 It’s hard to think of anyone I admire in physics and philosophy who doesn’t have at least one radical idea. Even Richard Feynman, who avoided hyperbole and embraced doubt as part of his credo: "I’d rather have doubt and be uncertain, than be certain and wrong."
 
But then you have this quote from his good friend and collaborator, Freeman Dyson:


Thirty-one years ago, Dick Feynman told me about his ‘sum over histories’ version of quantum mechanics. ‘The electron does anything it likes’, he said. ‘It goes in any direction at any speed, forward and backward in time, however it likes, and then you add up the amplitudes and it gives you the wave-function.’ I said, ‘You’re crazy.’ But he wasn’t.
 
In fact, his crazy idea led him to a Nobel Prize. That exception aside, most radical ideas are either still-born or yet to bear fruit, and that includes mine. No, I don’t compare myself to Feynman – I’m not even a physicist - and the truth is I’m unsure if I even have an original idea to begin with, be they radical or otherwise. I just read a lot of books by people much smarter than me, and cobble together a philosophical approach that I hope is consistent, even if sometimes unconventional. My only consolation is that I’m not alone. Most, if not all, the people smarter than me, also hold unconventional ideas.
 
Recently, I re-read Robert M. Pirsig’s iconoclastic book, Zen and the Art of Motorcycle Maintenance, which I originally read in the late 70s or early 80s, so within a decade of its publication (1974). It wasn’t how I remembered it, not that I remembered much at all, except it had a huge impact on a lot of people who would never normally read a book that was mostly about philosophy, albeit disguised as a road-trip. I think it keyed into a zeitgeist at the time, where people were questioning everything. You might say that was more the 60s than the 70s, but it was nearly all written in the late 60s, so yes, the same zeitgeist, for those of us who lived through it.
 
Its relevance to this post is that Pirsig had some radical ideas of his own – at least, radical to me and to virtually anyone with a science background. I’ll give you a flavour with some selective quotes. But first some context: the story’s protagonist, whom we assume is Pirsig himself, telling the story in first-person, is having a discussion with his fellow travellers, a husband and wife, who have their own motorcycle (Pirsig is travelling with his teenage son as pillion), so there are 2 motorcycles and 4 companions for at least part of the journey.
 
Pirsig refers to a time (in Western culture) when ghosts were considered a normal part of life. But then introduces his iconoclastic idea that we have our own ghosts.
 
Modern man has his own ghosts and spirits too, you know.
The laws of physics and logic… the number system… the principle of algebraic substitution. These are ghosts. We just believe in them so thoroughly they seem real.
 
Then he specifically cites the law of gravity, saying provocatively:
 
The law of gravity and gravity itself did not exist before Isaac Newton. No other conclusion makes sense.
And what that means, is that the law of gravity exists nowhere except in people’s heads! It’s a ghost! We are all of us very arrogant and conceited about running down other people’s ghosts but just as ignorant and barbaric and superstitious about our own.
Why does everybody believe in the law of gravity then?
Mass hypnosis. In a very orthodox form known as “education”.
 
He then goes from the specific to the general:
 
Laws of nature are human inventions, like ghosts. Laws of logic, of mathematics are also human inventions, like ghosts. The whole blessed thing is a human invention, including the idea it isn’t a human invention. (His emphasis)
 
And this is philosophy in action: someone challenges one of your deeply held beliefs, which forces you to defend it. Of course, I’ve argued the exact opposite, claiming that ‘in the beginning there was logic’. And it occurred to me right then, that this in itself, is a radical idea, and possibly one that no one else holds. So, one person’s radical idea can be the antithesis of someone else’s radical idea.
 
Then there is this, which I believe holds the key to our disparate points of view:
 
We believe the disembodied 'words' of Sir Isaac Newton were sitting in the middle of nowhere billions of years before he was born and that magically he discovered these words. They were always there, even when they applied to nothing. Gradually the world came into being and then they applied to it. In fact, those words themselves were what formed the world. (again, his emphasis)
 
Note his emphasis on 'words', as if they alone make some phenomenon physically manifest.
 
My response: don’t confuse or conflate the language one uses to describe some physical entity, phenomena or manifestation with what it describes. The natural laws, including gravity, are mathematical in nature, obeying sometimes obtuse and esoteric mathematical relationships, which we have uncovered over eons of time, which doesn’t mean they only came into existence when we discovered them and created the language to describe them. Mathematical notation only exists in the mind, correct, including the number system we adopt, but the mathematical relationships that notation describes, exist independently of mind in the same way that nature’s laws do.
 
John Barrow, cosmologist and Fellow of the Royal Society, made the following point about the mathematical ‘laws’ we formulated to describe the first moments of the Universe’s genesis (Pi in the Sky, 1992).
 
Specifically, he says our mathematical theories describing the first three minutes of the Universe predict specific ratios of the earliest ‘heavier’ elements: deuterium, 2 isotopes of helium and lithium, which are 1/1000, 1/1000, 22 and 1/100,000,000 respectively; with the remaining (roughly 78%) being hydrogen. And this has been confirmed by astronomical observations. He then makes the following salient point:



It confirms that the mathematical notions that we employ here and now apply to the state of the Universe during the first three minutes of its expansion history at which time there existed no mathematicians… This offers strong support for the belief that the mathematical properties that are necessary to arrive at a detailed understanding of events during those first few minutes of the early Universe exist independently of the presence of minds to appreciate them.
 
As you can see this effectively repudiates Pirsig’s argument; but to be fair to Pirsig, Barrow wrote this almost 2 decades after Pirsig’s book.
 
In the same vein, Pirsig then goes on to discuss Poincare’s Foundations of Science (which I haven’t read), specifically talking about Euclid’s famous fifth postulate concerning parallel lines never meeting, and how it created problems because it couldn’t be derived from more basic axioms and yet didn’t, of itself, function as an axiom. Euclid himself was aware of this, and never used it as an axiom to prove any of his theorems.
 
It was only in the 19th Century, with the advent of Riemann and other non-Euclidean geometries on curved surfaces that this was resolved. According to Pirsig, it led Poincare to question the very nature of axioms.
 
Are they synthetic a priori judgements, as Kant said? That is, do they exist as a fixed part of man’s consciousness, independently of experience and uncreated by experience? Poincare thought not…
Should we therefore conclude that the axioms of geometry are experimental verities? Poincare didn’t think that was so either…
Poincare concluded that the axioms of geometry are conventions, our choice among all possible conventions is guided by experimental facts, but it remains free and is limited only by the necessity of avoiding all contradiction.
 
I have my own view on this, but it’s worth seeing where Pirsig goes with it:
 
Then, having identified the nature of geometric axioms, [Poincare] turned to the question, Is Euclidean geometry true or is Riemann geometry true?
He answered, The question has no meaning.
[One might] as well as ask whether the metric system is true and the avoirdupois system is false; whether Cartesian coordinates are true and polar coordinates are false. One geometry can not be more true than another; it can only be more convenient. Geometry is not true, it is advantageous.
 
I think this is a false analogy, because the adoption of a system of measurement (i.e. units) and even the adoption of which base arithmetic one uses (decimal, binary, hexadecimal being the most common) are all conventions.
 
So why wouldn’t I say the same about axioms? Pirsig and Poincare are right in as much that both Euclidean and Riemann geometry are true because they’re dependent on the topology that one is describing. They are both used to describe physical phenomena. In fact, in a twist that Pirsig probably wasn’t aware of, Einstein used Riemann geometry to describe gravity in a way that Newton could never have envisaged, because Newton only had Euclidean geometry at his disposal. Einstein formulated a mathematical expression of gravity that is dependent on the geometry of spacetime, and has been empirically verified to explain phenomena that Newton couldn’t. Of course, there are also limits to what Einstein’s equations can explain, so there are more mathematical laws still to uncover.
 
But where Pirsig states that we adopt the axiom that is convenient, I contend that we adopt the axiom that is necessary, because axioms inherently expand the area of mathematics we are investigating. This is a consequence of Godel’s Incompleteness Theorem that states there are limits to what any axiom-based, consistent, formal system of mathematics can prove to be true. Godel himself pointed out that that the resolution lies in expanding the system by adopting further axioms. The expansion of Euclidean to non-Euclidean geometry is a case in point. The example I like to give is the adoption of √-1 = i, which gave us complex algebra and the means to mathematically describe quantum mechanics. In both cases, the axioms allowed us to solve problems that had hitherto been impossible to solve. So it’s not just a convenience but a necessity.
 
I know I’ve belaboured a point, but both of these: non-Euclidean geometry and complex algebra; were at one time radical ideas in the mathematical world that ultimately led to radical ideas: general relativity and quantum mechanics; in the scientific world. Are they ghosts? Perhaps ghost is an apt metaphor, given that they appear timeless and have outlived their discoverers, not to mention the rest of us. Most physicists and mathematicians tacitly believe that they not only continue to exist beyond us, but existed prior to us, and possibly the Universe itself.
 
I will briefly mention another radical idea, which I borrowed from Schrodinger but drew conclusions that he didn’t formulate. That consciousness exists in a constant present, and hence creates the psychological experience of the flow of time, because everything else becomes the past as soon as it happens. I contend that only consciousness provides a reference point for past, present and future that we all take for granted.

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.

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).

From Plato to Kant to physics

 I recently wrote a post titled Kant and modern physics, plus I’d written a much more extensive essay on Kant previously, as well as an essay on Plato, whose famous Academy was arguably the origin of Western philosophy, science and mathematics.
 
This is in answer to a question on Quora. The first thing I did was turn the question inside out or upside down, as I explain in the opening paragraph. It was upvoted by Kip Wheeler, who describes himself as “Been teaching medieval stuff at Uni since 1993.” He provided his own answer to the same question, giving a contrary response to mine, so I thought his upvote very generous.
 
There are actually a lot of answers on Quora addressing this theme, and I only reference one of them. But, as far as I can tell, I’m the only one who links Plato to Kant to modern physics.
 
Why could Plato's theory of forms not help us to know things better?
 
I think this question is back-to-front. If you change ‘could’ to ‘would’ and eliminate ‘not’, the question makes more sense – at least, to me. Nevertheless, it ‘could… not help us to know things better’ if it’s misconstrued or if it’s merely considered a religious artefact with no relevance to contemporary epistemology.
 
There are some good answers to similar questions, with Paul Robinson’s answer to Is Plato’s “Theory of Ideas” True? being among the more erudite and scholarly. I won’t attempt to emulate him, but take a different tack using a different starting point, which is more widely known.
 
Robinson, among others, makes reference to Plato’s famous shadows on the wall of a cave allegory (or analogy in modern parlance), and that’s a good place to start. Basically, the shadows represent our perceptions of reality whilst ‘true’ reality remains unknown to us. Plato believed that there was a world of ‘forms’, which were perfect compared to the imperfect world we inhabit. This is similar to the Christian idea of Heaven as distinct from Earth, hence the religious connotation, which is still referenced today.
 
But there is another way to look at this, which is closer to Kant’s idea of the thing-in-itself. Basically, we may never know the true nature of something just based on our perceptions, and I’d contend that modern science, especially physics, has proved Kant correct, specifically in ways he couldn’t foresee.
 
That’s partly because we now have instruments and technologies that can change what we can perceive at all scales, from the cosmological to the infinitesimal. But there’s another development which has happened apace and contributed to both the technology and the perception in a self-reinforcing dialectic between theory and observation. I’m talking about physics, which is arguably the epitome of epistemological endeavour.
 
And the key to physics is mathematics, only there appears to be more mathematics than we need. Ever since the Scientific Revolution, mathematics has proven fundamental in our quest for the elusive thing-in-itself. And this has resulted in a resurgence in the idea of a Platonic realm, only now it’s exclusive to mathematics. I expect Plato would approve, since his famous Academy was based on Pythagoras’s quadrivium of arithmetic, geometry, astronomy and music, all of which involve mathematics.

Kant and modern physics

 I wrote a post on Kant back in February 2020, but it was actually an essay I wrote more than 20 years earlier, when I was a student of philosophy. I would not be able to improve on that essay, and I’m not about to try now. In that essay, I argue that Kant’s great contribution to philosophy, and epistemology in particular, was his idea of the ‘thing-in-itself’, which may remain forever unknowable, as we only have our perceptions of ‘things’.
 
In other posts, I have sometimes argued that the ‘thing-in-itself’ is dependent on the scale that we can observe it, but there is something deeper that I think only became apparent in the so-called golden age of physics in the 20th Century. In a more recent post, I pointed out that both relativity theory and quantum mechanics (the 2 pillars of modern physics) are both observer dependent. I argue that there could be an objective ontology that they can’t describe. I think this is more obvious in the case of special relativity, where different observers literally measure different durations of both space and time, but I’m getting ahead of myself.
 
On Quora, there are 4 physicists whom I ‘follow’ and read regularly. They are Viktor T Toth, Richard Muller, Mark John Fernee and Ian Miller. Out of these, Miller is possibly the most contentious as he argues against non-locality in QM (quantum mechanics), which I’m not aware of any other physicist concurring with. Of course, it’s Bell’s Inequality that provides the definitive answer to this, of which Miller has this to say:
 
If you say it must because of violations of Bell’s Inequality, first note that the inequality is a mathematical relationship that contains only numbers; no physical concept is included.
 
But the ‘numbers’ compare classical statistical outcomes with Born statistical outcomes and experiments verify Born’s results, so I disagree. Having said that, Miller makes pertinent points that I find insightful and, like all those mentioned, he knows a lot more about this topic than me.
 
For example, concerning relativity, he argues that it’s the ruler that changes dimension and not the space being measured. He also points out, regarding the twin paradox, that only one twin gains energy, which is the one whose clock slows down. Note that clocks are also a form of ‘ruler’, but they measure time instead of space. So you can have 2 observers who ‘measure’ different durations of space and time, but agree on ‘now’, when they reunite, as is the case with the twin paradox thought experiment.
 
This point is slightly off-track, but not irrelevant to the main focus of this post. The main focus is an academic paper jointly written by Shaun Maguire and Richard Muller, titled Now, and the Flow of Time. This paper is arguably as contentious as Miller’s take on non-locality and Bell, because Muller and Maguire argue that ‘space’ can be created.
 
Now, Viktor T Toth is quite adamant that space is not created because space is not an entity, but a ‘measurement’ between entities called ‘objects’. Now, it has to be said, that Muller has stated publicly on Quora that he has utmost respect for Toth and neither of them have called each other out over this issue.
 
Toth argues that people confound the mathematical metric with ‘space’ or ‘spacetime’, but I’d argue that this mathematical metric has physical consequences. In another post, I reference another paper, recommended to me by Mark John Fernee (authored by Tamara M. Davis and Charles H. Lineweaver at the University of New South Wales) which describes how a GR Doppler shift intrinsically measures the expansion of space.
 
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)
 
As I explain in that post: ‘What they are effectively saying is that there is a distinction between the movement of objects in space and the movement of space itself.’
 
The spacetime metric that Toth refers to provides a reference frame for c, the speed of light. So, whilst a spacetime metric (‘space’ by another name) can travel faster than light with respect to us (so over the horizon of the observable universe), an observer situated in that metric would still measure light as c relative to them.
 
Muller’s and Maguire’s paper goes even further, saying that space is created along with time, and they believe this can be measured as ‘a predicted lag in the emergence of gravitational radiation when two black holes merge.’ I won’t go into the details; you would need to read the paper.
 
A conclusion implicit in their theory is that there could be a universal now.
 
A natural question arises: why are the new nows created at the end of time, rather than uniformly throughout time, in the same way that new space is uniformly created throughout the universe.
 
The authors then provide alternative arguments, which I won’t go into, but they do ponder the fundamental difference between space and time, where one is uni-directional and the other is not. As far as we know, there is no ‘edge’ in space but there is in time. Muller and Maguire do wonder if space is ‘created’ throughout the Universe (as quoted above) or at an ‘edge’.
 
You may wonder how does Kant fit into all this? It’s because all these discussions are dependent on what we observe and what we theorise, both of which are perceptions. And, in physics, theorising involves mathematics. I’ve argued that mathematics can be seen as another medium determining perceptions, along with all the instruments we’ve built that now include the LHC and the Hubble and Webb telescopes.
 
Sabine Hossenfelder, whom I often reference on this blog these days, wrote a book, called Lost in Math, where she interviews some of the brightest minds in physics and challenges the pervading paradigm that mathematics can provide answers to questions that experimentation can’t – string theory being the most obvious.

Before the revolution in cosmology, created by Copernicus and built on by Galileo, Kepler and Newton, people believed that the Sun went round the Earth and that some objects in the night sky would occasionally backtrack in their orbits, which was explained by epicycles. That was overturned, and now it seems obvious that, in fact, the Earth rotates on its axis and orbits the sun along with all the other planets, which explains our ‘perception’ that sometimes the planets go ‘backwards.’
 
I wonder if the next revolution in science and cosmology may also provide a ‘simpler’ picture, where there is a ‘universal now’ that explains the age of the Universe, the edge of time that we all experience and non-locality in QM.
 
Of course, I’m probably wrong.

Addendum: This is Richard Muller talking about time on Quora.

Ontology and epistemology; the twin pillars of philosophy

 I remember in my introduction to formal philosophy that there were 5 branches: ontology, epistemology, logic, aesthetics and ethics. Logic is arguably subsumed under mathematics, which has a connection with ontology and epistemology through physics, and ethics is part of all our lives, from politics to education to social and work-related relations to how one should individually live. Aesthetics is like an orphan in this company, yet art is imbued in all cultures in so many ways, it is unavoidable.
 
However, if you read about Western philosophy, the focus is often on epistemology and its close relation, if not utter dependence, on ontology. Why dependence? Because you can’t have knowledge of something without inferring its existence, even if the existence is purely abstract.
 
There are so many facets to this, that it’s difficult to know where to start, but I will start with Kant because he argued that we can never know ‘the-thing-in-itself’, only a perception of it, which, in a nutshell, is the difference between ontology and epistemology.
 
We need some definitions, and ontology is dictionary defined as the ‘nature of being’, while epistemology is ‘theory of knowledge’, and with these definitions, one can see straightaway the relationship, and Kant’s distillation of it.
 
Of course, one can also see how science becomes involved, because science, at its core, is an epistemological endeavour. In reading and researching this topic, I’ve come to the conclusion that, though science and philosophy have common origins in Western scholarship, going back to Plato, they’ve gone down different paths.
 
If one looks at the last century, which included the ‘golden age of physics’, in parallel with the dominant philosophical paradigm, heavily influenced, if not initiated, by Wittgenstein, we see that the difference can be definitively understood in terms of language. Wittgenstein effectively redefined epistemology as how we frame the world with language, while science, and physics in particular, frames the world in mathematics. I’ll return to this fundamental distinction later.
 
In my last post, I went to some lengths to argue that a fundamental assumption among scientists is that there is an ‘objective reality’. By this, I mean that they generally don’t believe in ‘idealism’ (like Donald Hoffman) which is the belief that objects don’t exist when you don’t perceive them (Hoffman describes it as the same experience as using virtual-reality goggles). As I’ve pointed out before, this is what we all experience when we dream, which I contend is different to the experience of our collective waking lives. It’s the word, ‘collective’, that is the key to understanding the difference – we share waking experiences in a way that is impossible to corroborate in a dream.
 
However, I’ve been reading a lot of posts on Quora by physicists, Viktor T Toth and Mark John Fernee (both of whom I’ve cited before and both of whom I have a lot of respect for). And they both point out that much of what we call reality is observer dependent, which makes me think of Kant.
 
Fernee, when discussing quantum mechanics (QM) keeps coming back to the ‘measurement problem’ and the role of the observer, and how it’s hard to avoid. He discusses the famous ‘Wigner’s friend’ thought experiment, which is an extension of the famous Schrodinger’s cat thought experiment, which infers you have the cat in 2 superpositional states: dead and alive. Eugne Wigner developed a thought experiment, whereby 2 experimenters could get contradictory results. Its relevance to this topic is that the ontology is completely dependent on the observer. My understanding of the scenario is that it subverts the distinction between QM and classical physics.
 
I’ve made the point before that a photon travelling across the Universe from some place and time closer to its beginning (like the CMBR) is always in the future of whatever it interacts with, like, for example, an ‘observer’ on Earth. The point I’d make is that billions of years of cosmological time have passed, so in another sense, the photon comes from the observer’s past, who became classical a long time ago. For the photon, time is always zero, but it links the past to the present across almost the entire lifetime of the observable universe.
 
Quantum mechanics, more than any other field, demonstrates the difference between ontology and epistemology, and this was discussed in another post by Fernee. Epistemologically, QM is described mathematically, and is so successful that we can ignore what it means ontologically. This has led to diverse interpretations from the multiple worlds interpretation (MWI) to so-called ‘hidden variables’ to the well known ‘Copenhagen interpretation’.
 
Fernee, in particular, discusses MWI, not that he’s an advocate, but because it represents an ontology that no one can actually observe. Both Toth and Fernee point out that the wave function, which arguably lies at the heart of QM is never observed and neither is its ‘decoherence’ (which is the measurement problem by another name), which leads many to contend that it’s a mathematical fiction. I argue that it exists in the future, and that only classical physics is actually observed. QM deals with probabilities, which is purely epistemological. After the ‘observation’, Schrodinger’s equation, which describes the wave function ceases to have any meaning. One is in the future and the observation becomes the past as soon as it happens.
 
I don’t know enough about it, but I think entanglement is the key to its ontology. Fernee points out in another post that entanglement is to do with conservation, whether it be the conservation of momentum or, more usually, the conservation of spin. It leads to what is called non-locality, according to Bell’s Theorem, which means it appears to break with relativistic physics. I say ‘appears’, because it’s well known that it can’t be used to send information faster than light; so, in reality, it doesn’t break relativity. Nevertheless, it led to Einstein’s famous quote about ‘spooky action at a distance’ (which is what non-locality means in layperson’s terms).
 
But entanglement is tied to the wave function decoherence, because that’s when it becomes manifest. It’s crucial to appreciate that entangled particles are described by the same wave function and that’s the inherent connection. It led Schrodinger to claim that entanglement is THE defining feature of QM; in effect, it’s what separates QM from classical physics.
 
I think QM is the best demonstration of Kant’s prescient claim that we can never know the-thing-in-itself, but only our perception of it. QM is a purely epistemological theory – the ontology it describes still eludes us.
 
But relativity theory also suggests that reality is observer dependent. Toth points out that even the number of particles that are detected in some scenarios are dependent on the frame of reference of the observer. This has led at least one physicist (on Quora) to argue that the word ‘particle’ should be banned from all physics text books – there are only fields. (Toth is an expert on QFT, quantum field theory, and argues that particles are a manifestation of QFT.) I won’t elaborate as I don’t really know enough, but what’s relevant to this topic is that time and space are observer dependent in relativity, or appear to be.
 
In a not-so-recent post, I described how different ‘observers’ could hypothetically ‘see’ the same event happening hundreds of years apart, just because they are walking across a street in opposite directions. I use quotation marks, because it’s all postulated mathematically, and, in fact, relativity theory prevents them from observing anything outside their past and future light cones. I actually discussed this with Fernee, and he pointed out that it’s to do with causality. Where there is no causal relation between events, we can’t determine an objective sequence let alone one relevant to a time frame independent of us (like a cosmic time frame). And this is where I personally have an issue, because, even though we can’t observe it or determine it, I argue that there is still an objective reality independently of us.
 
In relativity there is something called true time (τ) which is the time in the frame of reference of the observer. If spacetime is invariant, then it would logically follow that where you have true time you should have an analogous ‘true space’, yet I’ve never come across it. I also think there is a ‘true simultaneity’ but no one else does, so maybe I’m wrong.
 
There is, however, something called the Planck length, and someone asked Toth if this changed relativistically with the Lorenz transformation, like all other ‘rulers’ in relativity physics. He said that a version of relativity was formulated that made the Planck length invariant but it created problems and didn’t agree with experimental data. What I find interesting about this is that Planck’s constant, h, literally determines the size of atoms, and one doesn’t expect atoms to change size relativistically (but maybe they do). The point I’d make is that these changes are observer dependent, and I’d argue that there is a Planck length that is observer independent, which is the case when there is no observer.
 
This has become a longwinded way of explaining how 20th Century science has effectively taken this discussion away from philosophy, but it’s rarely acknowledged by philosophers, who take refuge in Wittgenstein’s conclusion that language effectively determines what we can understand of the world, because we think in a language and that limits what we can conceptualise. And he’s right, until we come up with new concepts requiring new language. Everything I’ve just discussed was completely unknown more than 120 years ago, for which we had no language, let alone concepts.
 
Some years ago, I reviewed a book by Don Cupitt titled, Above Us Only Sky, which was really about religion in a secular world. But, in it, Cupitt repeatedly argued that things only have meaning when they are ‘language-wrapped’ (his term) and I now realise that he was echoing Wittgenstein. However, there is a context in which language is magical, and that is when it creates a world inside your head, called a story.
 
I’ve been reading Bryan Magee’s The Great Philosophers, based on a series of podcasts with various academics in 1987, which started with Plato and ended with Wittgenstein. He discussed Plato with Myles Burnyeat, Professor of Ancient Philosophy at Oxford. Naturally, they discussed Socrates, the famous dialogues and the more famous Republic, but towards the end they turned to the Timaeus, which was a work on ‘mathematical science’, according to Burnyeat, that influenced Aristotle and Ptolemy.
 
It's worth quoting their last exchange verbatim:
 
Magee: For us in the twentieth century there is something peculiarly contemporary about the fact that, in the programme it puts forward for acquiring an understanding of the world, Plato’s philosophy gives a central role to mathematical physics.
 
Burnyeat: Yes. What Plato aspired to do, modern science has actually done. And so there is a sort of innate sympathy between the two which does not hold for Aristotle’s philosophy. (My emphasis)

Addendum: This is a very good exposition on the 'measurement problem' by Sabine Hossenfelder, which also provides a very good synopsis of the wave function (ψ), Schrodinger's equation and the Born rule.

Did the Universe see us coming?

 I recently read The Grand Design by Stephen Hawking (2010), co-authored by Leonard Mlodinow, who gets ‘second billing’ (with much smaller font) on the cover, so one is unsure what his contribution was. Having said that, other titles listed by Mlodinow (Euclid’s Window and Feynman’s Rainbow) make me want to search him out. But the prose style does appear to be quintessential Hawking, with liberal lashings of one-liners that we’ve come to know him for. Also, I think one can confidently assume that everything in the book has Hawking’s imprimatur.

 

I found this book so thought-provoking that, on finishing it, I went back to the beginning, so I could re-read his earlier chapters in the context of his later ones. On the very first page he says, rather provocatively, ‘philosophy is dead’. He then spends the rest of the book giving his account of ‘life, the universe and everything’ (which, in one of his early quips, ‘is not 42’). He ends the first chapter (introduction, really) with 3 questions:

 

1)    Why is there something rather than nothing?

2)    Why do we exist?

3)    Why this particular set of laws and not some other?

It’s hard to get more philosophical than this.

 

I haven’t read everything he’s written, but I’m familiar with his ideas and achievements, as well as some of his philosophy and personal prejudices. ‘Prejudice’ is a word that is usually used pejoratively, but I use it in the same sense I use it on myself, regarding my ‘pet’ theories or beliefs. For example, one of my prejudices (contrary to accepted philosophical wisdom) is that AI will not achieve consciousness.

 

Nevertheless, Hawking expresses some ideas that I would not have expected of him. His chapter titled, What is Reality? is where he first challenges the accepted wisdom of the general populace. He argues, rather convincingly, that there are only ‘models of reality’, including the ones we all create inside our heads. He doesn’t say there is no objective reality, but he says that, if we have 2 or more ‘models of reality’ that agree with the evidence, then one cannot say that one is ‘more true’ than another.

 

For example, he says, ‘although it is not uncommon for people to say that Copernicus proved Ptolemy wrong, that is not true’. He elaborates: ‘one can use either picture as a model of the universe, for our observations of the heavens can be explained by assuming either the earth or the sun is at rest’.

 

However, as I’ve pointed out in other posts, either the Sun goes around the Earth or the Earth goes around the Sun. It has to be one or the other, so one of those models is wrong.

 

He argues that we only ‘believe’ there is an ‘objective reality’ because it’s the easiest model to live with. For example, we don’t know whether an object disappears or not when go into another room, nevertheless he cites Hume, ‘who wrote that although we have no rational grounds for believing in an objective reality, we also have no choice but to act as if it’s true’.

 

I’ve written about this before. It’s a well known conundrum (in philosophy) that you don’t know if you’re a ‘brain-in-a-vat’. But I don’t know of a single philosopher who thinks that they are. The proof is in dreams. We all have dreams that we can’t distinguish from reality until we wake up. Hawking also referenced dreams as an example of a ‘reality’ that doesn’t exist objectively. So dreams are completely solipsistic to the extent that all our senses will play along, including taste.

 

Considering Hawking’s confessed aversion to philosophy, this is all very Kantian. We can never know the thing-in-itself. Kant even argued that time and space are a priori constructs of the mind. And if we return to the ‘model of reality’ that exists in your mind: if it didn’t accurately reflect the external objective reality outside your mind, the consequences would be fatal. To me, this is evidence that there is an objective reality independent of one’s mind - it can kill you. However, if you die in a dream, you just wake up.

 

Of course, this all leads to subatomic physics, where the only models of reality are mathematical. But even in this realm, we rely on predictions made by these models to determine if they reflect an objective reality that we can’t see. To return to Kant, the thing-in-itself is dependent on the scale at which we ‘observe’ it. So, at the subatomic scale, our observations may be tracks of particles captured in images, not what we see with the naked eye. The same can be said on the cosmic scale; observations dependent on instruments that may not even be stationed on Earth.

 

To get a different perspective, I recently read an article on ‘reality’ written by Roger Penrose (New Scientist, 16 May 2020) which was updated from one he wrote in 2006. Penrose has no problem with an ‘objective independent reality’, and he goes to some lengths (with examples) to show the extraordinary agreement between our mathematical models and physical reality. 

 

Our mathematical models of physical reality are far from complete, but they provide us with schemes that model reality with great precision – a precision enormously exceeding that of any description free of mathematics.

 

(It should be pointed out that Penrose and Hawking won a joint prize in physics for their work in cosmology.)

 

But Penrose gets to the nub of the issue when he says, ‘...the “reality” that quantum theory seems to be telling us to believe in is so far removed from what we are used to that many quantum theorists would tell us to abandon the very notion of reality’. But then he says in the spirit of an internal dialogue, ‘Where does quantum non-reality leave off and the physical reality that we actually experience begin to take over? Present day quantum theory has no satisfactory answer to this question’. (I try to answer this below.)

 

Hawking spends an entire chapter on this subject, called Alternative Histories. For me, this was the most revealing chapter in his book. He discusses at length Richard Feynman’s ‘sum over histories’ methodology, called QED or quantum electrodynamics. I say methodology instead of theory, because it’s a mathematical method that has proved extraordinarily accurate in concordance with Penrose’s claim above. Feynman compared it to measuring the distance between New York and Seattle (from memory) to within the width dimension of a human hair.

 

Basically, as Hawking expounds, in Feynman’s theory, a quantum particle can take every path imaginable (in the famous double-slit experiment, say) and then he adds them altogether, but because they’re waves, most of them cancel each other out. This leads to the principle of superposition, where a particle can be in 2 places or 2 states at once. However, as soon as it’s ‘observed’ or ‘measured’ it becomes one particle in one state. In fact, according to standard quantum theory, it’s possible for a single photon to be split into 2 paths and be ‘observed’ to interfere with itself, as described in this video. (I've edited this after Wes Hansen from Quora challenged it). I've added a couple of Wes's comments in an addendum below. Personally, I believe 'superposition' is part of the QM description of the future, as alluded to by Freeman Dyson (see  below). So I don't think superposition really occurs.

 

Hawking contends that the ‘alternative histories’ inherent in Feynman’s mathematical method, not only affect the future but also the past. What he is implying is that when an observation is made it determines the past as well as the future. He talks about a ‘top down’ history in lieu of a ‘bottom up’ history, which is the traditional way of looking at things. In other words, cosmological history is one of many ‘alternative histories’ (his terminology) that evolve from QM.

 

This leads to a radically different view of cosmology, and the relation between cause and effect. The histories that contribute to the Feynman sum don’t have an independent existence, but depend on what is being measured. We create history by our observation, rather than history creating us (my emphasis).

 

As it happens, John Wheeler made the exact same contention, and proposed that it could happen on a cosmic scale when we observed light from a distant quasar being ‘gravitationally lensed’ by an intervening galaxy or black hole (refer Davies paper, linked below). Hawking makes specific reference to Wheeler’s conjecture at the end of his chapter. It should be pointed out that Wheeler was a mentor to Feynman, and Feynman even referenced Wheeler’s influence in his Nobel Prize acceptance speech.

 

A contemporary champion of Wheeler’s ideas is Paul Davies, and he even dedicates his book, The Goldilocks Enigma, to Wheeler.

 

Davies wrote a paper which is available on-line, where he describes Wheeler’s idea as the “…participatory universe” in which observers—minds, if you like—are inextricably tied to the concretization of the physical universe emerging from quantum fuzziness over cosmological durations.

 

In the same paper, Davies references and attaches an essay by Freeman Dyson, where he says, “Dyson concludes that a quantum description cannot be applied to past events.”

 

And this leads me back to Penrose’s question: how do we get the ‘reality’ we are familiar with from the mathematically modelled quantum world that strains our credulousness? If Dyson is correct, and the past can only be described by classical physics then QM only describes the future. So how does one reconcile this with Hawking’s alternative histories?

 

I’ve argued elsewhere that the path from the infinitely many paths of Feynman’s theory, is only revealed when an ‘observation’ is made, which is consistent with Hawking’s point, quoted above. But it’s worth quoting Dyson, as well, because Dyson argues that the observer is not the trigger.

 

... the “role of the observer” in quantum mechanics is solely to make the distinction between past and future...

 

What really happens is that the quantum-mechanical description of an event ceases to be meaningful as the observer changes the point of reference from before the event to after it. We do not need a human observer to make quantum mechanics work. All we need is a point of reference, to separate past from future, to separate what has happened from what may happen, to separate facts from probabilities.

 

But, as I’ve pointed out in other posts, consciousness exists in a constant present. The time for ‘us’ is always ‘now’, so the ‘point of reference’, that is key to Dyson’s argument, correlates with the ‘now’ of a conscious observer.

 

We know that ‘decoherence’ is not necessarily dependent on an observer, but dependent on the wave function interacting with ‘classical physics’ objects, like a laboratory apparatus or any ‘macro’ object. Dyson’s distinction between past and future makes sense in this context. Having said that, the interaction could still determine the ‘history’ of the quantum event (like a photon), even it traversed the entire Universe, as in the cosmic background radiation (for example).

 

In Hawking’s subsequent chapters, including one titled, Choosing Our Universe, he invokes the anthropic principle. In fact, there are 2 anthropic principles called the ‘weak’ and the ‘strong’. As Hawking points out, the weak anthropic principle is trivial, because, as I’ve pointed out, it’s a tautology: Only universes that produce observers can be observed.

 

On the other hand, the strong anthropic principle (which Hawking invokes) effectively says, Only universes that produce observers can ‘exist’. One can see that this is consistent with Davies’ ‘participatory universe’.

 

Hawking doesn’t say anything about a ‘participatory universe’, but goes into some detail about the fine-tuning of our universe for life, in particular the ‘miracle’ of how carbon can exist (predicted by Fred Hoyle). There are many such ‘flukes’ in our universe, including the cosmological constant, which Hawking also discusses at some length.

 

Hawking also explains how an entire universe could come into being out of ‘nothing’ because the ‘negative’ gravitational energy cancels all the ‘positive’ matter and radiation energy that we observe (I assume this also includes dark energy and dark matter). Dark energy is really the cosmological constant. Its effect increases with the age of the Universe, because, as the Universe expands, gravitational attraction over cosmological distances decreases while ‘dark energy’ (which repulses) doesn’t. Dark matter explains the stable rotation of galaxies, without which, they’d fly apart.

 

Hawking also describes the Hartle-Hawking model of cosmology (without mentioning James Hartle) whereby he argues that in a QM only universe (at its birth), time was actually a 4^th spatial dimension. He calls this the ‘no-boundary’ universe, because, as John Barrow once quipped, ‘Once upon a time, there was no time’. I admit that this ‘model’ appeals to me, because in quantum cosmology, time disappears mathematically.

 

Hawking’s philosophical view is the orthodox one that, if there is a multiverse, then the anthropic principle (weak or strong) ensures that there must be a universe where we can exist. I think there are very good arguments for the multiverse (the cosmological variety, not the QM multiple worlds variety) but I have a prejudice against an infinity of them because then there would be an infinity of me.

 

Hawking is a well known atheist, so, not surprisingly, he provides good arguments against the God hypothesis. There could be a demiurge, but if there is, there is no reason to believe it coincides with any of the Gods of mythology. Every God I know of has cultural ties and that includes the Abrahamic God.

 

For someone who claims that ‘philosophy is dead’, Hawking’s book is surprisingly philosophical and thought-provoking, as all good philosophy should be. In his conclusions, he argues strongly for ‘M theory’, believing it will provide the theory(s) of everything that physicists strive for. M theory, as Hawking acknowledges, requires ‘supersymmetry’, and from what I know and read, there is little or no evidence of it thus far. But I agree with Socrates that every mystery resolved only uncovers more mysteries, which history, thus far, has confirmed over and over.

 

My views have evolved and, along with the ‘strong anthropic principle’, I’m becoming increasingly attracted to Wheeler’s ‘participatory universe’, because the more of its secrets we learn, the more it appears as if ‘the Universe saw us coming’, to paraphrase Freeman Dyson.

Addendum (23Apr2021): Wes Hansen, whom I met on Quora, and who has strong views on this topic, told me outright that he's not a fan of Hawking or Feynman. Not surprisingly, he challenged some of my views and I'm not in a position to say if he's right or wrong. Here are some of his comments:

You know, I would add, the problem with the whole “we create history by observation” thing is, it takes a whole lot of history for light to travel to us from distant galaxies, so it leads to a logical fallacy. Consider:

Suppose we create the past with our observations, then prior to observation the galaxies in the Hubble Deep Fields did not exist. Then where does the light come from? You see, we are actually seeing those galaxies as they existed long ago, some over 10 billion years ago.

We have never observed a single photon interfering with itself, quite the opposite actually: Ian Miller's answer to Can a particle really be in several places at the same time in the subatomic world, or is this just modern mysticism?. This is precisely why I cannot tolerate Hawking or Feynman, it’s absolute nonsense!

Regarding his last point, I think Ian Miller has a point. I don't always agree with Miller, but he has more knowledge on this topic than me. I argue that the superposition, which we infer from the interference pattern, is in the future. The idea of a single photon taking 2 paths and interfering with itself is deduced solely from the interference pattern (see linked video in main text). My view is that superposition doesn't really happen - it's part of the QM description of the future. I admit that I effectively contradicted myself, and I've made an edit to the original post to correct that.