Paul P. Mealing

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Showing posts with label Epistemology. Show all posts
Showing posts with label Epistemology. Show all posts

Monday 26 February 2024

Does simultaneity have any meaning?

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


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

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

Sunday 18 February 2024

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).

Monday 12 February 2024

The role of prejudice in scientific progress

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

 

Sunday 31 December 2023

What are the limits of knowledge?

 This was the Question of the Month in Philosophy Now (Issue 157, August/September 2023) and 11 answers were published in Issue 159, December 2023/January 2024, including mine, which I now post complete with minor edits.

 

Some people think that language determines the limits of knowledge, yet it merely describes what we know rather than limits it, and humans have always had the facility to create new language to depict new knowledge.

There are many types of knowledge, but I’m going to restrict myself to knowledge of the natural world. The ancient Greeks were possibly the first to intuit that the natural world had its own code. The Pythagoreans appreciated that musical pitch had a mathematical relationship, and that some geometrical figures contained numerical ratios. They made the giant conceptual leap that this could possibly be a key to understanding the Cosmos itself.

Jump forward two millennia, and their insight has borne more fruit than they could possibly have imagined. Richard Feynman made the following observation about mathematics in The Character of Physical Law: “Physicists cannot make a conversation in any other language. If you want to learn about nature, to appreciate nature, it is necessary to understand the language that she speaks in. She offers her information only in one form.”

Meanwhile, the twentieth century logician Kurt Gödel proved that in any self-consistent, axiom-based, formal mathematical system, there will always be mathematical truths that can’t be proved true using that system. However, they potentially can be proved if one expands the axioms of the system. This infers that there is no limit to mathematical truths.

Alonso Church’s ‘paradox of unknowability’ states, “unless you know it all, there will always be truths that are by their very nature unknowable.” This applies to the physical universe itself. Specifically, since the vast majority of the Universe is unobservable, and possibly infinite in extent, most of it will remain forever unknowable. Given that the limits of knowledge are either infinite or unknowable in both the mathematical and physical worlds, then those limits are like a horizon that retreats as we advance towards it.

Friday 17 November 2023

On the philosophy of reality

 This follows on from my last post, after I saw a YouTube interview with Raymond Tallis on Closer to Truth. He’s all but saying that physics has lost the plot, or at least that’s my takeaway. I happen to know that he’s also writing a book on ‘reality’ – might even have finished it – which is why he can’t stop talking about it, and, it seems, neither can I.
 
I think there are 3 aspects to this discussion, even though they are not clearly delineated. Nevertheless, it might be worth watching the video to better appreciate what I’m talking about. While I agree with some of his points, I think Tallis’s main thrust that physicists contend that ‘reality dissolves’ is a strawman argument as I’ve never heard or read a physicist make that claim. Robert Lawrence Kuhn, who hosts all the talks on Closer To Truth, appears to get uncharacteristically flustered, but I suspect it’s because he intuitively thought the argument facile but couldn’t easily counter it. It would have been far more interesting and edifying if Tallis was debating with someone like Paul Davies, who is not only a physicist, but knows some philosophy.
 
At one point they get onto evolution, as Kuhn attempts to make the distinction between how we’ve evolved to understand the world but culturally moved beyond that. This leads to the 3 aspects I alluded to earlier.
 
The first aspect is that there is an objective reality independent of us, which we need to take seriously because it can kill us. As Tallis points out, this is what we’ve evolved to avoid, otherwise we wouldn’t be here. As I’ve pointed out many times, our brains create a model of that reality so we can interact with it. This is the second aspect, and is part of our evolutionary heritage.
 
The third aspect appears to be completely at odds with this and that appears to be what Tallis has an issue with. The third aspect is that we make mathematical models of reality, which seem, on the surface at least, to have no bearing on the reality that we experience. We don’t see wavefunctions of particles or twins aging at different rates when one goes on a journey somewhere.
 
It doesn’t help that different physicists attempt to give different accounts of what’s happening. For example, a lot of physicists believe that the wavefunction is just a useful mathematical fiction. Others believe that it carries on in another universe after the ‘observation’ or ‘measurement’. All acknowledge that we can’t explain exactly what happens, which is why it’s called the ‘measurement problem’.
 
What many people don’t tell you is that QM only makes predictions about events, which is why it deals in probabilities, and logically, observations require a time lapse, no matter how small, before it’s recorded, so it axiomatically happens in the past. As Paul Davies points out there is an irreversibility in time once the ‘observation’ has been made.
 
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.
 
So, nothing ‘dissolves’, it’s just not observable until after the event, and the event could be a photon hitting a photo-sensitive surface or an isotope undergoing some form of radioactive decay or an electron hitting a screen and emitting light. Even Sabine Hossenfleder (in one of her videos) points out that the multiple paths of Feynman’s ‘sum-over-histories path-integral’ are in the future of the measurement that they predict via calculation.
 
Tallis apparently thinks that QM infers that there is nothing solid in the world, yet it was Freeman Dyson, in collaboration with Andrew Leonard, who used Wolfgang Pauli’s Exclusion Principle to demonstrate why solid objects don’t meld into each other. Dyson acknowledged that ‘the proof was extraordinarily complicated, difficult and opaque’, which might explain why it took so long for someone to calculate it (1967).
 
Humans are unique within the animal kingdom in that we’ve developed tools that allow us to ‘sense’ phenomena that can’t be detected through our biological senses. It’s this very attribute that has led to the discipline of science, and in the last century it has taken giant strides beyond anything our predecessors could have imagined. Not only have we learned that we live in a galaxy that is one among trillions and that the Universe is roughly 14 billion years old, but we can ‘sense’ radiation only 380,000 years after its birth. Who would have thought? At the other end of the scale, we’ve built a giant underground synchrotron that ‘senses’ the smallest known particle in nature, called quarks. They are sub-sub-atomic.
 
But, in conjunction with these miracle technologies, we have discovered, or developed (a combination of both), mathematical tools that allow us to describe these phenomena. In fact, as Richard Feynman pointed out, mathematics is the only language in which ‘nature speaks’. It’s like the mathematical models are another tool in addition to the technological ones that extend our natural senses.
 
Having said that, sometimes these mathematical models don’t actually reflect the real world. A good example is Ptolemy’s model of the solar system using epicycles, that had Earth at its centre. A possible modern example is String Theory, which predicts up to 10 spatial dimensions when we are only aware of 3.
 
Sabine Hossenfelder (already mentioned) wrote a book called Lost in Math, where she challenges this paradigm. I think that this is where Tallis is coming from, though he doesn’t specifically say so. He mentions a wavefunction (in passing), and I’ve already pointed out that some physicists see it as a convenient and useful mathematical fiction. One is Viktor T Toth (on Quora) who says:
 
The mathematical fiction of wavefunction collapse was “invented” to deal with the inconvenient fact that otherwise, we’d have to accept what the equations tell us, namely that quantum mechanics is nonlocal (as per Bell’s theorem)…

 
But it’s this very ‘wavefunction collapse’ that Davies was referring to when he pointed out that it ‘destroys the rewind button’. Toth has a different perspective:
 
As others pointed out, wavefunction collapse is, first and foremost, a mathematical abstraction, not a physical process. If it were a physical process, it would be even weirder. Rather than subdividing spacetime with an arbitrarily chosen hypersurface called “now” into a “before observation” and an “after observation” half, connected by the non-unitary transformation of the “collapse”, wavefunction collapse basically implies throwing away the entire universe, replacing it with a different one (past, present, and future included) containing the collapsed wavefunction instead of the original.
 
Most likely, it’s expositions like this that make Tallis throw up his hands (figuratively speaking), even though I expect he’s never read anything by Toth. Just to address Toth’s remark, I would contend that the ‘arbitrarily chosen hypersurface called “now”’ is actually the edge in time of the entire universe. A conundrum that is rarely acknowledged, let alone addressed, is that the Universe appears to have no edge in space while having an edge in time. Notice how different his ‘visualisation’ is to Davies’, yet both of them are highly qualified and respected physicists.
 
So, while there are philosophical differences among physicists, one can possibly empathise with the frustrations of a self-identified philosopher. (Tallis’s professional background is in neuroscience.)
 
Nevertheless, Tallis uses quantum mechanics just like the rest of us, because all electronic devices are dependent on it, and we all exploit Einstein’s relativity theories when we use our smartphones to tell us where we are.
 
So the mathematical models, by and large, work. And they work so well, that we don’t need to know anything about them, in the same way you don’t need to know anything about all the technology your car uses in order for you to drive it.
 
Tallis, like many philosophers, sees mathematics as a consequence of our ability to measure things, which we then turn into equations that conveniently describe natural phenomena. But the history of Western science reveals a different story, where highly abstract mathematical discoveries later provide an epistemological key to our comprehension of the most esoteric natural phenomena. The wavefunction is a good example: using an unexpected mathematical relationship discovered by Euler in the 1700s, it encapsulates in one formula (Shrodinger’s), superposition, entanglement and Heisenberg’s Uncertainty Principle. So it may just be a mathematical abstraction, yet it describes the most enigmatic features discovered in the natural world thus far.
 
From what I read and watch (on YouTube), I don’t think you can do theoretical physics without doing philosophy. Philosophy (specifically, epistemology) looks at questions that don’t have answers using our current bank of knowledge. Examples include the multiverse, determinism and free will. Philosophers with a limited knowledge of physics (and that includes me) are not in the same position as practicing physicists to address questions about reality. This puts Tallis at a disadvantage. Physicists can’t agree on topics like the multiverse, superdeterminism, free will or the anthropic principle, yet often hold strong views regardless.
 
I’m always reminded of John Wheeler’s metaphor of science as an island of knowledge in a sea of ignorance, with the shoreline being philosophy. Note that as the island expands so does the shoreline of our ignorance.

Monday 23 October 2023

The mystery of reality

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

 
And:

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

Sunday 10 September 2023

A philosophical school of thought with a 2500 year legacy

I’ve written about this before, but revisited it with a recent post I published on Quora in response to a question, where I didn’t provide the answer expected, but ended up giving a very brief history of philosophy as seen through the lens of science.
 
I’ve long contended that philosophy and science are joined at the hip, and one might extend the metaphor by saying the metaphysical bond is mathematics.
 
When I say a very brief history, what I mean is that I have selected a few specific figures, albeit historically prominent, who provide links in a 2500 year chain, while leaving out countless others. I explain how I see this as a ‘school of thought’, analogous to how some people might see a religion that also goes back centuries. The point is that we in the West have inherited this, and it’s determined the technological world that we currently live in, which would have been unimaginable even as recently as the renaissance or the industrial revolution, let alone in ancient Greece or Alexandria.
 
Which philosopher can you best relate yourself to?
 
It would take a certain hubris to claim that I relate to any philosopher whom I admire, but there are some whom I feel, not so much a kinship with, but an agreement in spirit and principle. Philosophers, like scientists and mathematicians, stand on the shoulders of those who went before.
 
I go back to Socrates because I think he was ahead of his time, and he effectively brought argument into philosophy, which is what separates it from dogma.
 
Plato was so influenced by Socrates that he gave us the ‘Socratic dialogue’ method of analysing an issue, whereby fictional characters (albeit with historical names) discuss hypotheticals in the form of arguments.
 
But Plato was also heavily influenced by Pythagorean philosophy, and even adopted its quadrivium of arithmetic, geometry, astronomy and music for his famous Academy. This tradition was carried over to the famous school or Library of Alexandria, from which sprang such luminaries as Euclid, Eratosthenes, who famously ‘measured’ the circumference of the Earth (around 230BC) and Hypatia, the female mathematician, mentor to a Bishop and a Roman Prefect, as well as speaker in the Senate, who was killed for her sins by a Christian mob in 414AD.
 
Plato is most famously known for his cave allegory, whereby we observe shadows on a wall, without knowing that there is another reality beyond our kin, consequently called the Platonic realm. In later years, this was associated with the Christian ideal of ‘heaven’, but was otherwise considered an outdated notion.
 
Then, jumping forward a couple of centuries from Plato, we come to Kant, who inadvertently resurrected the idea with his concept of ‘transcendental idealism’. Kant famously postulated that there is a difference between what we observe and the ‘thing-in-itself’, which we may never know. I find this reminiscent of Plato’s cave analogy.
 
Even before Kant there was a scientific revolution led by Galileo, Kepler and Newton, who took Pythagorean ideals to a new level when they used geometry and a new mathematical method called calculus to describe the motions of the planets that had otherwise escaped a proper and consistent exposition.
 
Then came the golden age of physics that not only built on Newton, but also Faraday and Maxwell, whereby newly discovered mathematical tools like complex algebra and non-Euclidean geometry opened up a Pandora’s box called quantum mechanics and relativity theory, which have led the way for over a hundred years in our understanding of the infinitesimally small and the cosmologically large, respectively.
 
But here’s the thing: since the start of the last century, all our foundational theories have been led by mathematics rather than experimentation, though the latter is required to validate the former.
 
To quote Richard Feynman from a chapter in his book, The Character of Physical Law, titled, The Relation of Mathematics to Physics:


Physicists cannot make a conversation in any other language. If you want to learn about nature, to appreciate nature, it is necessary to understand the language that she speaks in. She offers her information only in one form.
 
And this leads me to conclude that Kant's ‘transcendental idealism’ is mathematics*, which has its roots going back to Plato and possibly Pythagoras before him.
 
In answer to the question, I don’t think there is any specific philosopher that I ‘best relate to’, but there is a school of thought going back 2500 years that I have an affinity for.
 
 
*Note: Kant didn’t know that most of mathematics is uncomputable and unknown.
 

Friday 18 August 2023

The fabric of the Universe

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

 

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

Thursday 25 May 2023

Philosophy’s 2 disparate strands: what can we know; how can we live

The question I’d like to ask, is there a philosophical view that encompasses both? Some may argue that Aristotle attempted that, but I’m going to take a different approach.
 
For a start, the first part can arguably be broken into 2 further strands: physics and metaphysics. And even this divide is contentious, with some arguing that metaphysics is an ‘abstract theory with no basis in reality’ (one dictionary definition).
 
I wrote an earlier post arguing that we are ‘metaphysical animals’ after discussing a book of the same name, though it was really a biography of 4 Oxford women in the 20th Century: Elizabeth Anscombe, Mary Midgley, Philippa Foot and Iris Murdoch. But I’ll start with this quote from said book.
 
Poetry, art, religion, history, literature and comedy are all metaphysical tools. They are how metaphysical animals explore, discover and describe what is real (and beautiful and good). (My emphasis.)
 
So, arguably, metaphysics could give us a connection between the 2 ‘strands’ in the title. Now here’s the thing: I contend that mathematics should be part of that list, hence part of metaphysics. And, of course, we all know that mathematics is essential to physics as an epistemology. So physics and metaphysics, in my philosophy, are linked in a rather intimate  way.
 
The curious thing about mathematics, or anything metaphysical for that matter, is that, without human consciousness, they don’t really exist, or are certainly not manifest. Everything on that list is a product of human consciousness, notwithstanding that there could be other conscious entities somewhere in the universe with the same capacity.
 
But again, I would argue that mathematics is an exception. I agree with a lot of mathematicians and physicists that while we create the symbols and language of mathematics, we don’t create the intrinsic relationships that said language describes. And furthermore, some of those relationships seem to govern the universe itself.
 
And completely relevant to the first part of this discussion, the limits of our knowledge of mathematics seems to determine the limits of our knowledge of the physical world.
 
I’ve written other posts on how to live, specifically, 3 rules for humans and How should I live? But I’m going to go via metaphysics again, specifically storytelling, because that’s something I do. Storytelling requires an inner and outer world, manifest as character and plot, which is analogous to free will and fate in the real world. Now, even these concepts are contentious, especially free will, because many scientists tell us it’s an illusion. Again, I’ve written about this many times, but it’s relevance to my approach to fiction is that I try and give my characters free will. An important part of my fiction is that the characters are independent of me. If my characters don’t take on a life of their own, then I know I’m wasting my time, and I’ll ditch that story.
 
Its relevance to ‘how to live’ is authenticity. Artists understand better than most the importance of authenticity in their work, which really means keeping themselves out of it. But authenticity has ramifications, as any existentialist will tell you. To live authentically requires an honesty to oneself that is integral to one’s being. And ‘being’ in this sense is about being human rather than its broader ontological meaning. In other words, it’s a fundamental aspect of our psychology, because it evolves and changes according to our environment and milieu. Also, in the world of fiction, it's a fundamental dynamic.
 
What's more, if you can maintain this authenticity (and it’s genuine), then you gain people’s trust, and that becomes your currency, whether in your professional life or your social life. However, there is nothing more fake than false authenticity; examples abound.
 
I’ll give the last word to Socrates; arguably the first existentialist.
 
To live with honour in this world, actually be what you try to appear to be.


Saturday 29 April 2023

Can philosophy be an antidote to dogma?

 This is similar to another post I wrote recently, both of which are answers to questions I found on Quora. The reason I’m posting this is because I think it’s better than the previous one. Not surprisingly, it also references Socrates and the role of argument in philosophical discourse.
 
What qualities are needed to be a good philosopher?
 
I expect you could ask 100 different philosophers and get 100 different answers. Someone (Gregory Scott), in answer to a similar question, claimed that everyone is a philosopher, but not necessarily a good one.
 
I will suggest 2 traits that I try to cultivate in myself: to be intellectually curious and to be analytical. But I’m getting ahead of myself.
 
For a start, there are many ‘branches’ or categories of philosophy: epistemology and ethics, being the best known and most commonly associated with philosophy. Some might include ontology as well, which has a close relationship with epistemology, like 2 sides of the same coin. There is also logic and aesthetics but then the discussion becomes interminable.
 
But perhaps the best way to answer this question is to look at philosophers you admire and ask yourself, what qualities do they possess that merit your admiration?
 
Before I answer that for myself, I’m going to provide some context. Sandy Grant (philosopher at the University of Cambridge) published an essay titled Dogmas (Philosophy Now, Issue 127, Aug/Sep 2018), whereby she points out the pitfalls of accepting points of view on ‘authority’ without affording them critical analysis. And I would argue that philosophy is an antidote to dogma going back to Socrates, who famously challenged the ‘dogmas’ of his day. Prior to Socrates, philosophy was very prescriptive where you followed someone’s sayings, be they from the Bible, or Confucius or the Upanishads. Socrates revolutionary idea was to introduce argument, and philosophy has been based on argument ever since.
 
Socrates is famously attributed with the saying, The unexamined life is not worth living, which he apparently said before he was forced to take his own life. But there is another saying attributed to Socrates, which is more germane, given the context of his death.
 
To live with honour in this world, actually be what you try to appear to be.
 
Socrates also acquitted himself well in battle, apparently, so he wasn’t afraid of dying for a cause and a principle. Therefore, I would include integrity as the ‘quality’ of a good person, let alone a philosopher.
 
We currently live in an age where the very idea of truth is questioned, whether it be in the realm of science or politics or media. Which is why I think that critical thinking is essential, whereby one looks at evidence and the expertise behind that evidence. I’ve spent a working lifetime in engineering, where, out of necessity, one looks to expertise that one doesn’t have oneself. Trust has gone AWOL in our current social media environment and the ability to analyse without emotion and ideology is paramount. To accept evidence when it goes against your belief system is the mark of a good philosopher. Evidence is the keystone to scientific endeavour and also in administering justice. But perhaps the greatest quality required of a philosopher is to admit, I don’t know, which is also famously attributed to Socrates.

Sunday 16 April 2023

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.

Tuesday 28 March 2023

Why do philosophers think differently?

 This was a question on Quora, and this is my answer, which, hopefully, explains the shameless self-referencing to this blog.

 

Who says they do? I think this is one of those questions that should be reworded: what distinguishes a philosopher’s thinking from most other people’s? I’m not sure there is a definitive answer to this, because, like other individuals, every philosopher is unique. The major difference is that they spend more time writing down what they’re thinking than most people, and I’m a case in point.
 
Not that I’m a proper philosopher, in that it’s not my profession – I’m an amateur, a dilettante. I wrote a little aphorism at the head of my blog that might provide a clue.

Philosophy, at its best, challenges our long held views, such that we examine them more deeply than we might otherwise consider.

Philosophy, going back to Socrates, is all about argument. Basically, Socrates challenged the dogma of his day and it ultimately cost him his life. I write a philosophy blog and it’s full of arguments, not that I believe I can convince everyone to agree with my point of view. But basically, I hope to make people think outside their comfort zone, and that’s the best I can do.
 
Socrates is my role model, because he was the first (that we know of) who challenged the perceived wisdom provided by figures of authority. In Western traditions tracing the more than 2 millennia since Socrates, figures of authority were associated with the Church, in all its manifestations, where challenging them could result in death or torture or both.
 
That’s no longer the case - well, not quite true - try following that path if you’re a woman in Saudi Arabia or Iran. But, for most of us, living in a Western society, one can challenge anything at all, including whether the Earth is a sphere.
 
Back to the question, I don’t think it can be answered, even in the transcribed form that I substituted. Personally, I think philosophy in the modern world requires analysis and a healthy dose of humility. The one thing I’ve learned from reading and listening to many people much smarter than me is that the knowledge we actually know is but a blip and it always will be. Nowhere is this more evident than in mathematics. There are infinitely more incomputable numbers than computable numbers. So, if our knowledge of maths is just the tip of a universe-sized iceberg, what does that say about anything else we can possibly know.
 
Perhaps what separates a philosopher’s thinking from most other people’s is that they are acutely aware of how little we know. Come to think of it, Socrates famously made the same point.

Friday 17 March 2023

In the beginning there was logic

 I recently read an article in Philosophy Now (Issue 154, Feb/Mar 2023), jointly written by Owen Griffith and A.C. Paseau, titled One Logic, Or Many? Apparently, they’ve written a book on this topic (One True Logic, Oxford University Press, May 2022).
 
One of the things that struck me was that they differentiate between logic and reason, because ‘reason is something we do’. This is interesting because I’ve argued previously that logic should be a verb, but I concede they have a point. In the past I saw logic as something that’s performed, by animals and machines as well as humans. And one of the reasons I took this approach was to distinguish logic from mathematics. I contend that we use logic to access mathematics via proofs, which we then call theorems. But here’s the thing: Kurt Godel proved, in effect, that there will always be mathematical ‘truths’ that we can’t prove within any formal system of mathematics that is consistent. The word ‘consistent’ is important (as someone once pointed out to me) because, if it’s inconsistent, then all bets are off.
 
What this means is that there is potentially mathematics that can’t be accessed by logic, and that’s what we’ve found, in practice, as well as in principle. Matt Parker provides a very good overview in this YouTube video on what numbers we know and what we don’t know. And what we don’t know is infinitely greater than what we do know. Gregory Chaitin has managed to prove that there are infinitely greater incomputable numbers than computable numbers, arguing that Godel’s Incompleteness Theorem goes to the very foundation of mathematics.
 
This detour is slightly off-topic, but very relevant. There was a time when people believed that mathematics was just logic, because that’s how we learned it, and certainly there is a strong relationship. Without our prodigious powers of logic, mathematics would be an unexplored territory to us, and remain forever unknown. There are even scholars today who argue that mathematics that can’t be computed is not mathematics, which rules out infinity. That’s another discussion which I won’t get into, except to say that infinity is unavoidable in mathematics. Euclid (~300 BC) proved (using very simple logic) that you can have an infinite number of primes, and primes are the atoms of arithmetic, because all other numbers can be derived therefrom.
 
The authors pose the question in their title: is there a pluralism of logic? And compare a logic relativism with moral relativism, arguing that they both require an absolutism, because moral relativism is a form of morality and logic relativism is a form of logic, neither of which are relative in themselves. In other words, they always apply by self-definition, so contradict the principle that they endorse – they are outside any set of rules of morality or logic, respectively.
 
That’s their argument. My argument is that there are tenets that always apply, like you can’t have a contradiction. They make this point themselves, but one only has to look at mathematics again. If you could allow contradictions, an extraordinary number of accepted proofs in mathematics would no longer apply, including Euclid’s proof that there are an infinity of primes. The proof starts with the premise that you have the largest prime number and then proves that it isn’t.
 
I agree with their point that reason and logic are not synonymous, because we can use reason that’s not logical. We make assumptions that can’t be confirmed and draw conclusions that rely on heuristics or past experiences, out of necessity and expediency. I wrote another post that compared analytical thinking with intuition and I don’t want to repeat myself, but all of us take mental shortcuts based on experience, and we wouldn’t function efficiently if we didn’t.
 
One of the things that the authors don’t discuss (maybe they do in their book) is that the Universe obeys rules of logic. In fact, the more we learn about the machinations of the Universe, on all scales, the more we realise that its laws are fundamentally mathematical. Galileo expressed this succinctly in the 17th Century, and Richard Feynman reiterated the exact same sentiment in the last century.
 
Cliffard A Pickover wrote an excellent book, The Paradox of God And the Science of Omniscience, where he points out that even God’s omniscience has limits. To give a very trivial example, even God doesn’t know the last digit of pi, because it doesn’t exist. What this tells me is that even God has to obey the rules of logic. Now, I’ve come across someone (Sye Ten Bruggencate) who argued that the existence of logic proves the existence of God, but I think he has it back-to-front (if God can’t breach the rules of logic). In other words, if God invented logic, ‘He’ had no choice. And God can’t make a prime number nonprime or vice versa. There are things an omnipotent God can’t do and there are things an omniscient God can’t know. So, basically, even if there is a God, logic came first, hence the title of this essay.

Saturday 14 January 2023

Why do we read?

This is the almost-same title of a book I bought recently (Why We Read), containing 70 short essays on the subject, featuring scholars of all stripes: historians, philosophers, and of course, authors. It even includes scientists: Paul Davies, Richard Dawkins and Carlo Rovelli, being 3 I’m familiar with.
 
One really can’t overstate the importance of the written word, because, oral histories aside, it allows us to extend memories across generations and accumulate knowledge over centuries that has led to civilisations and technologies that we all take for granted. By ‘we’, I mean anyone reading this post.
 
Many of the essayists write from their personal experiences and I’ll do the same. The book, edited by Josephine Greywoode and published by Penguin, specifically says on the cover in small print: 70 Writers on Non-Fiction; yet many couldn’t help but discuss fiction as well.
 
And books are generally divided between fiction and non-fiction, and I believe we read them for different reasons, and I wouldn’t necessarily consider one less important than the other. I also write fiction and non-fiction, so I have a particular view on this. Basically, I read non-fiction in order to learn and I read fiction for escapism. Both started early for me and I believe the motivation hasn’t changed.
 
I started reading extra-curricular books from about the age of 7 or 8, involving creatures mostly, and I even asked for an encyclopaedia for Christmas at around that time, which I read enthusiastically. I devoured non-fiction books, especially if they dealt with the natural world. But at the same time, I read comics, remembering that we didn’t have TV at that time, which was only just beginning to emerge.
 
I think one of the reasons that boys read less fiction than girls these days is because comics have effectively disappeared, being replaced by video games. And the modern comics that I have seen don’t even contain a complete narrative. Nevertheless, there are graphic novels that I consider brilliant. Neil Gaiman’s Sandman series and Hayao Miyazake’s Nausicaa of the Valley of the Wind, being standouts. Watchmen by Alan Moore also deserves a mention.
 
So the escapism also started early for me, in the world of superhero comics, and I started writing my own scripts and drawing my own characters pre-high school.
 
One of the essayists in the collection, Niall Ferguson (author of Doom) starts off by challenging a modern paradigm (or is it a meme?) that we live in a ‘simulation’, citing Oxford philosopher, Nick Bostrom, writing in the Philosophical Quarterly in 2003. Ferguson makes the point that reading fiction is akin to immersing the mind in a simulation (my phrasing, not his).
 
In fact, a dream is very much like a simulation, and, as I’ve often said, the language of stories is the language of dreams. But here’s the thing; the motivation for writing fiction, for me, is the same as the motivation for reading it: escapism. Whether reading or writing, you enter a world that only exists inside your head. The ultimate solipsism.

And this surely is a miracle of written language: that we can conjure a world with characters who feel real and elicit emotional responses, while we follow their exploits, failures, love life and dilemmas. It takes empathy to read a novel, and tests have shown that people’s empathy increases after they read fiction. You engage with the character and put yourself in their shoes. It’s one of the reasons we read.
 
 
Addendum: I would recommend the book, by the way, which contains better essays than mine, all with disparate, insightful perspectives.
 

Monday 14 November 2022

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.

Sunday 25 September 2022

What we observe and what is reality are distinct in physics

 I’ve been doing this blog for 15 years now, and in that time some of my ideas have changed or evolved, and, in some areas, my knowledge has increased. As I’ve said on Quora a few times, I read a lot of books by people who know a lot more than me, especially in physics.
 
There is a boundary between physics and philosophy, the shoreline of John Wheeler’s metaphorical ‘island of knowledge in the infinite sea of ignorance’. To quote: “As the island grows so does the shoreline of our ignorance.” And I think ignorance is the key word here, because it’s basically speculation, which means some of us are wrong, including me, most likely. As I’ve often said, ‘Only future generations can tell us how ignorant the current generation is’. I can say that with a lot of confidence, just by looking at the history of science.
 
If this blog has a purpose beyond promoting my own pet theories and prejudices, it is to make people think.
 
Recently, I’ve been pre-occupied with determinism and something called superdeterminism, which has become one of those pet prejudices among physicists in the belief that it’s the only conclusion one can draw from combining relativity theory, quantum mechanics, entanglement and Bell’s theorem. Sabine Hossenfelder is one such advocate, who went so far as to predict that one day all other physicists will agree with her. I elaborate on this below.
 
Mark John Fernee (physicist with Qld Uni), with whom I’ve had some correspondence, is one who disagrees with her. I believe that John Bell himself proposed that superdeterminism was possibly the only resolution to the quandaries posed by his theorem. There are two other videos worth watching, one by Elijah Lew-Smith and a 50min one by Brian Greene, who doesn’t discuss superdeterminism. Nevertheless, Greene’s video gives the best and easiest to understand description of Bell’s theorem and its profound implications for reality.
 
So what is super-determinism, and how is it distinct from common or garden determinism? Well, if you watch the two relevant videos, you get two different answers. According to Sabine, there is no difference and it’s not really to do with Bell’s theorem, but with the measurement problem in QM. She argues that it’s best explained by looking at the double-slit experiment. Interestingly, Richard Feynman argued that all the problems associated with QM can be analysed, if not understood, by studying the double-slit experiment.
 
Sabine wrote an academic paper on the ‘measurement problem’, co-authored with Jonte R. Hance from the University of Bristol, which I’ve read and is surprisingly free of equations (not completely) but uses the odd term I’m unfamiliar with. I expect I was given a link by Fernee which I’ve since lost (I really can’t remember), but I still have a copy. One of her points is that as long as we have unsolved problems in QM, there is always room for different philosophical interpretations, and she and Hance discuss the most well-known ones. This is slightly off-topic, but only slightly, because even superdeterminism and its apparent elimination of free will is a philosophical issue.
 
Sabine argues that it’s the measurement that creates superdeterminism in QM, which is why she uses the double-slit experiment to demonstrate it. It’s because the ‘measurement’ ‘collapses’ the wave function and ‘determines’ the outcome, that it must have been ‘deterministic’ all along. It’s just that we don’t know it until a measurement is made. At least, this is my understanding of her argument.
 
The video by Elijah Lew-Smith gives a different explanation, focusing solely on Bell’s theorem. I found that it also required more than one viewing, but he makes a couple of points, which I believe go to the heart of the matter. (Greene’s video gives an easier-to-follow description, despite its length).
 
We can’t talk about an objective reality independent of measurement.
(Which echoes Sabine’s salient point in her video.)
 
And this point: There really are instantaneous interactions; we just can’t access them.
 
This is known as ‘non-locality’, and Brian Greene provides the best exposition I’ve seen, and explains how it’s central to Bell’s theorem and to our understanding of reality.
 
On the other hand, Lew-Smith explains non-locality without placing it at the centre of the discussion.
 
If I can momentarily go back to Sabine’s key argument, I addressed this in a post I wrote a few years back. Basically, I argued that you can only know the path an electron or photon takes retrospectively, after the measurement or observation has been made. Prior to that, QM tells us it’s in a superposition of states and we only have probabilities of where it will land. Curiously, I referenced a video by Sabine in a footnote, where she makes this point in her conclusion:
 
You don’t need to know what happens in the future because the particle goes to all points anyway. Except…  It doesn’t. In reality, it goes to only one point. So maybe the reason we need the measurement postulate is because we don’t take this dependency on the future seriously enough.
 
And to me, that’s what this is all about: the measurement is in the future of the wave function, and the path it takes is in the past. This, of course, is what Freeman Dyson claims: that QM cannot describe the past, only the future.
 
And if you combine this perspective with Lew-Smith’s comment about objective reality NOT being independent of the measurement, then objective reality only exists in the past, while the wave function and all its superpositional states exist in the future.
 
So how does entanglement fit into this? Well, this is the second point I highlighted, which is that ‘there really are instantaneous reactions, which we can’t access’, which is ‘non-locality’. And this, as Schrodinger himself proclaimed, is what distinguishes QM from classical physics. In classical physics, ‘locality’ means there is a relativistic causal connection and in entanglement there is not, which is why Einstein called it ‘spooky action at a distance’.
 
Bell’s theorem effectively tells us that non-locality is real, supported by experiment many times over, but you can’t use it to transmit information faster-than-light, so relativity is not violated in practical terms. But it does ask questions about simultaneity, which is discussed in Lew-Smith’s video. He demonstrates graphically that different observers will observe a different sequence of measurement, so we have disagreement, even a contradiction about which ‘measurement’ collapsed the wave function. And this is leads to superdeterminism, because, if the outcome is predetermined, then the sequence of measurement doesn’t matter.
 
And this gets to the nub of the issue, because it ‘appears’ that ‘objective reality’ is observer dependent. Relativity theory always gives the result from a specific observer’s point of view and different observers in different frames of reference can epistemically disagree. Is there a frame of reference that is observer independent? I always like to go back to the twin paradox, because I believe it provides an answer. When the twins reunite, they disagree on how much time has passed, yet they agree on where they are in space-time. There is not absolute time, but there is absolute space-time.
 
Did you know we can deduce the velocity that Earth travels relative to absolute space-time, meaning the overall observable Universe? By measuring the Doppler shift of the CMBR (cosmic microwave background radiation) in all directions, it’s been calculated that we are travelling at 350km/s in the direction of Pisces (ref., Paul Davies, About Time; Einstein’s Unfinished Revolution, 1995). They should teach this in schools.
 
Given this context, is it possible that entanglement is a manifestation of objective simultaneity? Not according to Einstein, who argued that: ‘The past, present and future is only a stubbornly persistent illusion’; which is based on the ‘fact’ that simultaneity is observer dependent. But Einstein didn’t live to see Bell’s theorem experimentally verified. Richard Muller, a prize-winning physicist and author (also on Quora) was asked what question he’d ask Einstein if he could hypothetically meet him NOW. I haven’t got a direct copy, but essentially Muller said he’d ask Einstein if he now accepted a ‘super-luminal connection’, given experimental confirmation of Bell’s theorem. In other words, entanglement is like an exception to the rule, where relativity strictly doesn’t apply.
 
Sabine with her co-author, Jonte Hance, make a passing comment that the discussion really hasn’t progressed much since Bohr and Einstein a century ago, and I think they have a point.
 
Mark Fernee, whom I keep mentioning on the sidelines, does make a distinction between determinism and superdeterminism, where determinism simply means that everything is causally connected to something, even if it’s not predictable. Chaos being a case-in-point, which he describes thus:
 
Where this determinism breaks down is with chaotic systems, such as three body dynamics. Chaotic systems are so sensitive to the initial parameters that even a slight inaccuracy can result in wildly different predictions. That's why predicting the weather is so difficult.
Overall, complexity limits the ability to predict the future, even in a causal universe.

 
On the other hand, superdeterminism effectively means the end of free will, and, in his own words, ‘free will is a contentious issue, even among physicists’.
 
Fernee provided a link to another document by Sabine, where she created an online forum specifically to deal with less than knowledgeable people about their disillusioned ideas on physics – crackpots and cranks. It occurred to me that I might fall into this category, but it’s for others to judge. I’m constantly reminded of how little I really know, and that I’m only fiddling around the edges, or on the ‘shoreline of ignorance’, as Wheeler described it, where there are many others far more qualified than me.
 
I not-so-recently wrote a post where I challenged a specific scenario often cited by physicists, where two observers hypothetically ‘observe’ contradictory outcomes of an event on a distant astronomical body that is supposedly happening simultaneously with them.
 
As I said before, relativity is an observer-dependent theory, almost by definition, and we know it works just by using the GPS on our smart-phones. There are algorithms that make relativistic corrections to the signals coming from the satellites, otherwise the map on your phone would not match the reality of your actual location.
 
What I challenge is the application of relativity theory to an event that the observer can’t observe, even in principle. In fact, relativity theory rules out a physical observation of a purportedly simultaneous event. So I’m not surprised that we get contradictory results. The accepted view among physicists is that each observer ‘sees’ a different ontology (one in the future and one in the past), whereas I contend that there is an agreed ontology that becomes observable at a later time, when it’s in both observers’ past. (Brian Greene has another video demonstrating the ‘conventional’ view among physicists.)
 
Claudia de Rahm is Professor of Physics at Imperial College London, and earlier this year, she gave a talk titled, What We Don’t Know About Gravity, where she made the revelatory point
that Einstein’s GR (general theory of relativity) predicted its own limitations. Basically, if you apply QM probabilities to extreme curvature spacetime, you get answers over 100%, so nonsense. GR and QM are mathematically incompatible if we try to quantise gravity, though QFT (quantum field theory) ‘works fine on the manifold of spacetime’, according to expert, Viktor T Toth.
 
Given that relativity theory, as it is applied, is intrinsically observer dependent, I question if it can be (reliably) applied to events that have no causal relation to the observer (meaning outside the observer's light cone, both past and future). Which is why I challenge its application to events the observer can't observe (refer 2 paragraphs ago).

 

Addendum: I changed the title so it's more consistent with the contents of the post. The previous title was Ignorance and bliss; philosophy and science. Basically, the reason we have different interpretations of the same phenomenon is because physics can only tell us about what we observe, and what that means for reality is often debatable; superdeterminism being a case in point. Many philosophers and scientists talk about a ‘gap’ between theory and reality, whereas I claim the gap is between the observation and reality, a la Kant.