Paul P. Mealing

Check out my book, ELVENE. Available as e-book and as paperback (print on demand, POD). Also this promotional Q&A on-line.
Showing posts with label Science. Show all posts
Showing posts with label Science. Show all posts

Sunday 3 March 2024

Is randomness real or illusion?

 Let’s look at quantum mechanics (QM). I watched a YouTube video on Closer To Truth with Fred Alan Wolf, a theoretical physicist, whom I admit I’d never heard of. It’s worth watching the first 7 mins before he goes off on a speculative tangent that maybe dreams are a more fundamental level of reality, citing Australian Aboriginal ‘dreamtime’ mythology, of which I have some familiarity, though no scholarship.
 
In the first 7 mins he describes QM: its conceptual frustrations juxtaposed with its phenomenal successes. He gives a good synopsis, explaining how it describes a world we don’t actually experience, yet apparently underpins (my term, not his) the one we do. In particular, he explains:
 
There is a simple operation that takes you out of that space into (hits the table with his hand) this space. And that operation is simply multiplying what that stuff - that funny stuff – is, by itself (waves his hands in circles) in a time-reverse manner, called psi star psi (Ψ*Ψ) in the language of quantum physics.
 
What he’s describing is called the Born rule, which gives probabilities of finding that ‘stuff’ in the real world. By ‘real world’ I mean the one we are all familiar with and that he can hit his hand with. Ψ (pronounced sy) is of course the wave function in Schrodinger’s eponymous equation, and Schrodinger himself wrote a paper (in 1941) demonstrating that Born’s rule effectively multiplies the wave function by itself running backwards in time.
 
Now, some physicists argue that Ψ is just a convenient mathematical fiction and Carlo Rovelli went so far as to argue that it has led us astray (in one of his popular books). Personally, I think it describes the future, which explains why we never see it, or as soon as we try to, it disappears, and if we’re lucky, we get a particle or some other interaction, like a dot on a screen, all of which exist in our past. Note that everything we observe, including our own reflection in a mirror, exists in the past.
 
Wolf then goes on to speculate that the infinite possibilities we use for our calculations are perhaps the true reality. In his own words: What I’m interested in are the things we can’t see… And he makes an interesting point that most people don’t know: that if we don’t take into account the things we can’t see, ‘we get the wrong answers’.
 

And this is where it gets interesting, because he’s alluding to Feynman’s sum-over-histories methodology, which takes into account all the infinite paths that the particle (as wave function) can take. In fact, the more paths that are allowed for, the more accurate the calculation. Wolf doesn’t mention Feynman, but I’m sure that’s what he’s referring to.
 
Feynman’s key insight into QM was that it obeys the least-action principle, which is mathematically expressed as a Lagrangian. It’s the ‘least-action principle’ that determines where light goes through a change in medium (like glass), obeying Fermat’s law where it takes the path of ‘least time’. It also determines the path a ball follows if you throw it into the air by following the path of ‘maximum relativistic time’. I elaborate on this in another post.
 
There is something teleological about this principle, as if the ball, particle, light, ‘knows’ where it has to go. Freeman Dyson, who was a close collaborator with Feynman, argued that QM cannot describe the past, but only the future, and that only classical physics describes the past. So these infinitude of paths that are part of the calculation to determine the probability of where it will actually be ‘observed’ make more sense to me if they exist in the future. I don’t think we need a ‘dream state’ unless that’s a euphemism for the future.
 
Like Dyson, I don’t think we need consciousness to make a quantum phenomenon become real, but it does provide the reference point. In his own words:
 
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.
 
The thing about consciousness is that it exists in a ‘constant present’, as pointed out by Schrodinger himself (when he wasn’t talking about QM), so it logically correlates with 'a point of reference, to separate past from future', that Dyson refers to.
 
Schrodinger coined a term, ‘statistico-deterministic’, to describe quantum phenomena, because, at a statistical level, it can be very predictable, otherwise we wouldn’t be able to call it ‘successful’. He gives the example of radioactive decay (exploited in his eponymous cat thought experiment) whereby we can’t determine the decay of a single isotope, yet we can statistically determine the half-life of astronomical numbers of atoms very accurately, as everyone knows.
 
I contend that real randomness, that we all observe and are familiar with, is caused by chaos, but even this is a contentious idea. I like to give the example of tossing a coin, but a lot of physicists will tell you that tossing a coin is not random. In fact, I recently had a lengthy, but respectful, discourse with Mark John Fernee (physicist at Qld Uni) on Quora on this very topic. When I raised the specific issue of whether tossing a coin is ‘random’, he effectively argued that there are no random phenomena in physics. To quote him out of context:
 
Probability theory is built from statistical sampling. There is no assumed underlying physics.
 
The underlying physics can be deterministic, while a statistical distribution of events can indicate random behaviour. This is the assumption that is applied to every coin toss. Because this is just an assumption, you can cheat the system by using specific conditions that ensure deterministic outcomes.
 
What I am saying is that randomness is a statistical characterisation of outcomes that does not include any physical mechanism. As such, it is not a fundamental property of nature.
(Emphasis in original)
 
I get the impression from what I’ve read that mathematicians have a different take on chaos to physicists, because they point out that you need to calculate initial conditions to infinite decimal places to achieve a 100% predicted outcome. Physicist, Paul Davies, provided a worked example in his 1988 book, The Cosmic Blueprint. I quoted Davies to Fernee during our ‘written’ conversation:
 
It is actually possible to prove that the activity of the jumping particle is every bit as random as tossing a coin.
 
The ‘jumping particle’ Davies referred to was an algorithm using clock arithmetic, that when graphed produced chaotic results, and he demonstrated that it would take a calculation to infinity to get it ‘exactly right’. Fernee was dismissive of this and gave it as an example of a popular science book leading laypeople (like myself) astray, which I thought was a bit harsh, as Davies actually goes into the mathematics in some detail, and I possibly misled Fernee by quoting just one sentence.
 
Just to be clear, Fernee doesn’t disagree that chaotic phenomena are impossible to predict; just that they are fully deterministic and, in his words, only ‘indicate random behaviour’.
 
Sabine Hossenfelder, who argues very strongly for superdeterminism, has a video demonstrating how predicting chaotic phenomena (like the weather) has a horizon (my term, not hers) of predictability that can never be exceeded, even in principle (10 days in the case of the weather).
 
So Fernee and Hossenfelder distinguish between what we ‘cannot know’ and what physically transpires. But my point is that chaotic phenomena, if rerun, will always produce a different result – it’s built into the mathematics underlying the activity – and includes significant life-changing phenomena like evolutionary biology and the orbits of the planets, as well as weather and earthquakes. Even the creation of the moon is believed to be a consequence of a chaotic event, without which life on Earth would never have evolved.
 
Note that both QM and chaos have mathematical underpinnings, and whilst most see that as modelling or a very convenient method of making predictions, I see it as more fundamental. I contend that mathematics transcends the Universe, yet it’s also a code that allows us to plumb Nature’s deepest secrets and fathom the dynamics of the Universe on all scales.

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.
 

Thursday 31 August 2023

Can relativity theory be reconciled with common sense?

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

But SR didn’t take into account gravity, which unlike the fictitious aether, does permeate the whole universe, so Einstein developed GR. This was a mathematical theory, so not based on empirical observations, but it had to satisfy 3 criteria, established by Einstein at the outset.
 
1)    It had to satisfy the conservation laws of energy, momentum and angular momentum
2)    It had to allow for the equivalence of gravitational and inertial mass.
3)    It had to reduce mathematically to Newton’s formula when relativistic effects were negligible.
 
Many people overlook the last one, when they claim that Einstein’s theory made Newton’s theory obsolete, when in fact, it extended it into realms it couldn’t compute. Likewise, Einstein’s theory also has limitations, yet to be resolved. Observations that confirmed the theory followed its mathematical formulation, which was probably a first in physics.

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

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

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)
 

Wednesday 7 June 2023

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

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


 My diagram follows the convention in that the horizontal axis represents space (all 3 dimensions) and the vertical axis represents time. So the 4 dotted lines represent 4 observers who are ‘stationary’ but ‘travelling through time’ (vertically). As per convention, light and other signals are represented as diagonal lines of 45 degrees, as they are travelling through both space and time, and nothing can travel faster than them. So they also represent the ‘edge’ of their light cones.
 
So notice that observer A sees the birth of Albert when he sees the pulsar and observer B sees the death of Albert when he sees the pulsar, which is exactly the same as Sabine’s scenario, with no relativity theory required. Albert, by the way, for the sake of scalability, must have lived for thousands of years, so he might be a tree or a robot.
 
But I’ve also added 2 other observers, C and D, who see the pulsar before Albert is born and after Albert dies respectively. But, of course, there’s no contradiction, because it’s completely dependent on how far away they are from the sources of the signals (the pulsar and Earth).
 
This is Sabine’s perspective:
 
Once you agree that anything exists now elsewhere, even though you see it only later, you are forced to accept that everything in the universe exists now. (Her emphasis.)
 
I actually find this statement illogical. If you take it to its logical conclusion, then the Big Bang exists now and so does everything in the universe that’s yet to happen. If you look at the first quote I cited, she effectively argues that the past and future exist alongside the present.
 
One of the points she makes is that, for events with causal relationships, all observers see the events happening in the same sequence. The scenario where different observers see different sequences of events have no causal relationships. But this begs a question: what makes causal events exceptional? What’s more, this is fundamental, because the whole of physics is premised on the principle of causality. In addition, I fail to see how you can have causality without time. In fact, causality is governed by the constant speed of light – it’s literally what stops everything from happening at once.
 
Einstein also believed in the block universe, and like Sabine, he argued that, as a consequence, there is no free will. Sabine is adamant that both ‘now’ and ‘free will’ are illusions. She argues that the now we all experience is a consequence of memory. She quotes Carnap that our experience of ‘past, present and future can be described and explained by psychology’ – a point also made by Paul Davies. Basically, she argues that what separates our experience of now from the reality of no-now (my expression, not hers) is our memory.
 
Whereas, I think she has it back-to-front, because, as I’ve pointed out before, without memory, we wouldn’t know we are conscious. Our brains are effectively a storage device that allows us to have a continuity of self through time, otherwise we would not even be aware that we exist. Memory doesn’t create the sense of now; it records it just like a photograph does. The photograph is evidence that the present becomes the past as soon as it happens. And our thoughts become memories as soon as they happen, otherwise we wouldn’t know we think.
 
Sabine spends an entire chapter on free will, where she persistently iterates variations on the following mantra:
 
The future is fixed except for occasional quantum events that we cannot influence.

 
But she acknowledges that while the future is ‘fixed’, it’s not predictable. And this brings us to chaos theory. Sabine discusses chaos late in the book and not in relation to free will. She explicates what she calls the ‘real butterfly effect’.
 
The real butterfly effect… means that even arbitrarily precise initial data allow predictions for only a finite amount of time. A system with this behaviour would be deterministic and yet unpredictable.
 
Now, if deterministic means everything physically manifest has a causal relationship with something prior, then I agree with her. If she means that therefore ‘the future is fixed’, I’m not so sure, and I’ll explain why. By specifying ‘physically manifest’, I’m excluding thoughts and computer algorithms that can have an effect on something physical, whereas the cause is not so easily determined. For example, In the case of the algorithm, does it go back to the coder who wrote it?
 
My go-to example for chaos is tossing coins, because it’s so easy to demonstrate and it’s linked to probability theory, as well as being the very essence of a random event. One of the key, if not definitive, features of a chaotic phenomenon is that, if you were to rerun it, you’d get a different result, and that’s fundamental to probability theory – every coin toss is independent of any previous toss – they are causally independent. Unrepeatability is common among chaotic systems (like the weather). Even the Earth and Moon were created from a chaotic event.
 
I recently read another book called Quantum Physics Made Me Do It by Jeremie Harris, who argues that tossing a coin is not random – in fact, he’s very confident about it. He’s not alone. Mark John Fernee, a physicist with Qld Uni, in a personal exchange on Quora argued that, in principle, it should be possible to devise a robot to perform perfectly predictable tosses every time, like a tennis ball launcher. But, as another Quora contributor and physicist, Richard Muller, pointed out: it’s not dependent on the throw but the surface it lands on. Marcus du Sautoy makes the same point about throwing dice and provides evidence to support it.
 
Getting back to Sabine. She doesn’t discuss tossing coins, but she might think that the ‘imprecise initial data’ is the actual act of tossing, and after that the outcome is determined, even if can’t be predicted. However, the deterministic chain is broken as soon as it hits a surface.
 
Just before she gets to chaos theory, she talks about computability, with respect to Godel’s Theorem and a discussion she had with Roger Penrose (included in the book), where she says:
 
The current laws of nature are computable, except for that random element from quantum mechanics.
 
Now, I’m quoting this out of context, because she then argues that if they were uncomputable, they open the door to unpredictability.
 
My point is that the laws of nature are uncomputable because of chaos theory, and I cite Ian Stewart’s book, Does God Play Dice? In fact, Stewart even wonders if QM could be explained using chaos (I don’t think so). Chaos theory has mathematical roots, because not only are the ‘initial conditions’ of a chaotic event impossible to measure, they are impossible to compute – you have to calculate to infinite decimal places. And this is why I disagree with Sabine that the ‘future is fixed’.
 
It's impossible to discuss everything in a 223 page book on a blog post, but there is one other topic she raises where we disagree, and that’s the Mary’s Room thought experiment. As she explains it was proposed by philosopher, Frank Jackson, in 1982, but she also claims that he abandoned his own argument. After describing the experiment (refer this video, if you’re not familiar with it), she says:
 
The flaw in this argument is that it confuses knowledge about the perception of colour with the actual perception of it.
 
Whereas, I thought the scenario actually delineated the difference – that perception of colour is not the same as knowledge. A person who was severely colour-blind might never have experienced the colour red (the specified colour in the thought experiment) but they could be told what objects might be red. It’s well known that some animals are colour-blind compared to us and some animals specifically can’t discern red. Colour is totally a subjective experience. But I think the Mary’s room thought experiment distinguishes the difference between human perception and AI. An AI can be designed to delineate colours by wavelength, but it would not experience colour the way we do. I wrote a separate post on this.
 
Sabine gives the impression that she thinks consciousness is a non-issue. She talks about the brain like it’s a computer.
 
You feel you have free will, but… really, you’re running a sophisticated computation on your neural processor.
 
Now, many people, including most scientists, think that, because our brains are just like computers, then it’s only a matter of time before AI also shows signs of consciousness. Sabine doesn’t make this connection, even when she talks about AI. Nevertheless, she discusses one of the leading theories of neuroscience (IIT, Information Integration Theory), based on calculating the amount of information processed, which gives a number called phi (Φ). I came across this when I did an online course on consciousness through New Scientist, during COVID lockdown. According to the theory, this number provides a ‘measure of consciousness’, which suggests that it could also be used with AI, though Sabine doesn’t pursue that possibility.
 
Instead, Sabine cites an interview in New Scientist with Daniel Bor from the University of Cambridge: “Phi should decrease when you go to sleep or are sedated… but work in Bor’s laboratory has shown that it doesn’t.”
 
Sabine’s own view:
 
Personally, I am highly skeptical that any measure consisting of a single number will ever adequately represent something as complex as human consciousness.
 
Sabine discusses consciousness at length, especially following her interview with Penrose, and she gives one of the best arguments against panpsychism I’ve read. Her interview with Penrose, along with a discussion on Godel’s Theorem, which is another topic, discusses whether consciousness is computable or not. I don’t think it is and I don’t think it’s algorithmic.
 
She makes a very strong argument for reductionism: that the properties we observe of a system can be understood from studying the properties of its underlying parts. In other words, that emergent properties can be understood in terms of the properties that it emerges from. And this includes consciousness. I’m one of those who really thinks that consciousness is the exception. Thoughts can cause actions, which is known as ‘agency’.
 
I don’t claim to understand consciousness, but I’m not averse to the idea that it could exist outside the Universe – that it’s something we tap into. This is completely ascientific, to borrow from Sabine. As I said, our brains are storage devices and sometimes they let us down, and, without which, we wouldn’t even know we are conscious. I don’t believe in a soul. I think the continuity of the self is a function of memory – just read The Lost Mariner chapter in Oliver Sacks’ book, The Man Who Mistook His Wife For A Hat. It’s about a man suffering from retrograde amnesia, so his life is stuck in the past because he’s unable to create new memories.
 
At the end of her book, Sabine surprises us by talking about religion, and how she agrees with Stephen Jay Gould ‘that religion and science are two “nonoverlapping magisteria!”. She makes the point that a lot of scientists have religious beliefs but won’t discuss them in public because it’s taboo.
 
I don’t doubt that Sabine has answers to all my challenges.
 
There is one more thing: Sabine talks about an epiphany, following her introduction to physics in middle school, which started in frustration.
 
Wasn’t there some minimal set of equations, I wanted to know, from which all the rest could be derived?
 
When the principle of least action was introduced, it was a revelation: there was indeed a procedure to arrive at all these equations! Why hadn’t anybody told me?

 
The principle of least action is one concept common to both the general theory of relativity and quantum mechanics. It’s arguably the most fundamental principle in physics. And yes, I posted on that too.

 

Wednesday 31 May 2023

Immortality; from the Pharaohs to cryonics

 I thought the term was cryogenics, but a feature article in the Weekend Australian Magazine (27-28 May 2023) calls the facilities that perform this process, cryonics, and looking up my dictionary, there is a distinction. Cryogenics is about low temperature freezing in general, and cryonics deals with the deep-freezing of bodies specifically, with the intention of one day reviving them.
 
The article cites a few people, but the author, Ross Bilton, features an Australian, Peter Tsolakides, who is in my age group. From what the article tells me, he’s a software engineer who has seen many generations of computer code and has also been a ‘globe-trotting executive for ExxonMobil’.
 
He’s one of the drivers behind a cryonic facility in Australia – its first – located at Holbrook, which is roughly halfway between Melbourne and Sydney. In fact, I often stop at Holbrook for a break and meal on my interstate trips. According to my car’s odometer it is almost exactly half way between my home and my destination, which is a good hour short of Sydney, so it’s actually closer to Melbourne, but not by much.
 
I’m not sure when Tsolakides plans to enter the facility, but he’s forecasting his resurrection in around 250 years time, when he expects he may live for another thousand years. Yes, this is science fiction to most of us, but there are some science facts that provide some credence to this venture.
 
For a start, we already cryogenically freeze embryos and sperm, and we know it works for them. There is also the case of Ewa Wisnierska, 35, a German paraglider taking part in an international competition in Australia, when she was sucked into a storm and elevated to 9947 metres (jumbo jet territory, and higher than Everest). Needless to say, she lost consciousness and spent a frozen 45 mins before she came back to Earth. Quite a miracle and I’ve watched a doco on it. She made a full recovery and was back at her sport within a couple of weeks. And I know of other cases, where the brain of a living person has been frozen to keep them alive, as counter-intuitive as that may sound.
 
Believe it or not, scientists are divided on this, or at least cautious about dismissing it outright. Many take the position, ‘Never say never’. And I think that’s fair enough, because it really is impossible to predict the future when it comes to humanity. It’s not surprising that advocates, like Tsolakides, can see a future where this will become normal for most humans. People who decline immortality will be the exception and not the norm. And I can imagine, if this ‘procedure’ became successful and commonplace, who would say no?
 
Now, I write science fiction, and I have written a story where a group of people decided to create an immortal human race, who were part machine. It’s a reflection of my own prejudices that I portrayed this as a dystopia, but I could have done the opposite.
 
There may be an assumption that if you write science fiction then you are attempting to predict the future, but I make no such claim. My science fiction is complete fantasy, but, like all science fiction, it addresses issues relevant to the contemporary society in which it was created.
 
Getting back to the article in the Weekend Australian, there is an aspect of this that no one addressed – not directly, anyway. There’s no point in cheating death if you can’t cheat old age. In the case of old age, you are dealing with a fundamental law of the Universe, entropy, the second law of thermodynamics. No one asked the obvious question: how do you expect to live for 1,000 years without getting dementia?
 
I think some have thought about this, because, in the same article, they discuss the ultimate goal of downloading their memories and their thinking apparatus (for want of a better term) into a computer. I’ve written on this before, so I won’t go into details.
 
Curiously, I’m currently reading a book by Sabine Hossenfelder called Existential Physics; A Scientist’s Guide to Life’s Biggest Questions, which you would think could not possibly have anything to say on this topic. Nevertheless:
 
The information that makes you you can be encoded in many different physical forms. The possibility that you might one day upload yourself to a computer and continue living a virtual life is arguably beyond present-day technology. It might sound entirely crazy, but it’s compatible with all we currently know.
 
I promise to write another post on Sabine’s book, because she’s nothing if not thought-provoking.
 
So where do I stand? I don’t want immortality – I don’t even want a gravestone, and neither did my father. I have no dependents, so I won’t live on in anyone’s memory. The closest I’ll get to immortality are the words on this blog.

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.


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.