Does simultaneity have any meaning?

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

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

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

What would Kant say?

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

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

The role of prejudice in scientific progress

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

 

Can AI have free will?

This is a question I’ve never seen asked, let alone answered. I think there are good reasons for that, which I’ll come to later.
 
The latest issue of Philosophy Now (Issue 159, Dec 2023/Jan 2024), which I’ve already referred to in 2 previous posts, has as its theme (they always have a theme), Freewill Versus Determinism. I’ll concentrate on an article by the Editor, Grant Bartley, titled What Is Free Will? That’s partly because he and I have similar views on the topic, and partly because reading the article led me to ask the question at the head of this post (I should point out that he never mentions AI).
 
It's a lengthy article, meaning I won’t be able to fully do it justice, or even cover all aspects that he discusses. For instance, towards the end, he posits a personal ‘pet’ theory that there is a quantum aspect to the internal choice we make in our minds. And he even provides a link to videos he’s made on this topic. I mention this in passing, and will make 2 comments: one, I also have ‘pet’ theories, so I can’t dismiss him out-of-hand; and two, I haven’t watched the videos, so I can’t comment on its plausibility.
 
He starts with an attempt to define what we mean by free will, and what it doesn’t mean. For instance, he differentiates between subconscious choices, which he calls ‘impulses’ and free will, which requires a conscious choice. He also differentiates what he calls ‘making a decision’. I will quote him directly, as I still see this involving free will, if it’s based on making a ‘decision’ from alternative possibilities (as he explains).
 
…sometimes, our decision-making is a choice, that is, mentally deciding between alternative possibilities present to your awareness. But your mind doesn’t always explicitly present you with multiple choices from which to choose. Sometimes no distinct options are present in your awareness, and you must cause your next contents of your mind on the basis of the present content, through intuition and imagination. This is not choice so much as making a decision. (My emphasis)
 
This is worth a detour, because I see what he’s describing in this passage as the process I experience when writing fiction, which is ‘creating’. In this case, some of the content, if not all of it, is subconscious. When you write a story, it feels to you (but no one else) that the characters are real and the story you’re telling already exists. Nevertheless, I still think there’s an element of free will, because you make choices and judgements about what your imagination presents to your consciousness. As I said, this is a detour.
 
I don’t think this is what he’s referring to, and I’ll come back to it later when I introduce AI into the discussion. Meanwhile, I’ll discuss what I think is the nub of his thesis and my own perspective, which is the apparent dependency between consciousness and free will.
 
If conscious causation is not real, why did consciousness evolve at all? What would be the function of awareness if it can’t change behaviour? How could an impotent awareness evolve if it cannot change what the brain’s going to do to help the human body or its genes survive? (Italics in the original)
 
This is a point I’ve made myself, but Bartley goes further and argues “Since determinism can’t answer these questions, we can know determinism is false.” This is the opposite to Sabine Hossenfelder’s argument (declaration really) that ‘free will is an illusion [therefore false]’.
 
Note that Bartley coins the term, ‘conscious causation’, as a de facto synonym for free will. In fact, he says this explicitly in his conclusion: “If you say there is no free will, you’re basically saying there is no such thing as conscious causation.” I’d have to agree.
 
I made the point in another post that consciousness seems to act outside the causal chain of the Universe, and I feel that’s what Bartley is getting at. In fact, he explicitly cites Kant on this point, who (according to Bartley) “calls the will ‘transcendental’…” He talks at length about ‘soft (or weak) determinism’ and ‘strong determinism’, which I’ve also discussed. Now, the usual argument is that consciousness is ‘caused’ by neuron activity, therefore strong determinism is not broken.
 
To quote Hossenfelder: Your brain is running a calculation, and while it is going on you do not know the outcome of that calculation. So the impression of free will comes from our ‘awareness’ that we think about what we do, along with our inability to predict the result of what we are thinking. (Hossenfelder even uses the term ‘software’ to describe what does the ‘calculating’ in your brain.)
 
And this allows me to segue into AI, because what Hossenfelder describes is what we expect a computer to do. The thing is that while most scientists (and others) believe that AI will eventually become conscious (not sure what Hossenfelder thinks), I’ve never heard or seen anyone argue that AI will have free will. And this is why I don’t think the question at the head of this post has ever been asked. Many of the people who believe that AI will become conscious also don’t believe free will exists.
 
There is another component to this, which I’ve raised before and that’s imagination. I like to quote Raymond Tallis (neuroscientist and also a contributor to Philosophy Now).
 
Free agents, then, are free because they select between imagined possibilities, and use actualities to bring about one rather than another. (My emphasis)
 
Now, in another post, I argued that AI can’t have imagination in the way we experience it, yet I acknowledge that AI can look at numerous possibilities (like in a game of chess) and 'choose' what it ‘thinks’ is the optimum action. So, in this sense, AI would have ‘agency’, but that’s not free will, because it’s not ‘conscious causation’. And in this sense, I agree with Bartley that ‘making a decision’ does not constitute free will, if it’s what an AI does. So the difference is consciousness. To quote from that same post on this topic.
 
But the key here is imagination. It is because we can imagine a future that we attempt to bring it about - that's free will. And what we imagine is affected by our past, our emotions and our intellectual considerations, but that doesn't make it predetermined.
 
So, if imagination and consciousness are both faculties that separate us from AI, then I can’t see AI having free will, even though it will make ‘decisions’ based on data it receives (as inputs), and those decisions may not be predictable.
 
And this means that AI may not be deterministic either, in the ‘strong’ sense. One of the differences with humans, and other creatures that evolved consciousness, is that consciousness can apparently change the neural pathways of the brain, which I’d argue is the ‘strange loop’ posited by Douglas Hofstadter. (I have discussed free will and brain-plasticity in another post)
 
But there’s another way of looking at this, which differentiates humans from AI. Our decision-making is a combination of logical reasoning and emotion. AI only uses logic, and even then, it uses logic differently to us. It uses a database of samples and possibilities to come up with a ‘decision’ (or output), but without using the logic to arise at that decision the way we would. In other words, it doesn’t ‘understand’ the decision, like when it translates between languages, for example.
 
There is a subconscious and conscious component to our decision-making. Arguably, the subconscious component is analogous to what a computer does with algorithm-based software (as per Hossenfelder’s description). But there is no analogous conscious component in AI, which makes a choice or decision. In other words, there is no ‘conscious causation’, therefore no free will, as per Bartley’s definition.
 

How can we achieve world peace?

 Two posts ago, I published my submission to Philosophy Now's Question of the Month, from 2 months ago: What are the limit of knowledge? Which was published in Issue 159 (Dec 2023/Jan 2024). Logically, they inform readers of the next Question of the Month, which is the title of this post. I'm almost certain they never publish 2 submissions by the same author in a row, so I'm publishing this answer now. It's related to my last post, obviously, and one I wrote some time ago (Humanity's Achilles Heel).

There are many aspects to this question, not least whether one is an optimist or a pessimist. It’s well known that people underestimate the duration and cost of a project, even when it’s their profession, because people are optimists by default. Only realists are pessimistic, and I’m in the latter category, because I estimate the duration of projects professionally.
 
There are a number of factors that mitigate against world peace, the primary one being that humans are inherently tribal and are quick to form ingroup-outgroup mental-partitions, exemplified by politics the world over. In this situation, rational thought and reasoned argument take a back seat to confirmation bias and emotive rhetoric. Add to this dynamic, the historically observed and oft-repeated phenomena that we follow charismatic, cult-propagating leaders, and you have a recipe for self-destruction on a national scale. This is the biggest obstacle to world peace. These leaders thrive on and cultivate division with its kindred spirits of hatred and demonisation of the ‘other’: the rationale for all of society’s ills becomes an outgroup identified by nationality, race, skin-colour, culture or religion.
 
Wealth, or the lack of it, is a factor as well. Inequality provides a motive and a rationale for conflict. It often goes hand-in-hand with oppression, but even when it doesn’t, the anger and resentment can be exploited and politicised by populist leaders, whose agenda is more focused on their own sense of deluded historical significance than actually helping the people they purportedly serve.
 
If you have conflict - and it doesn’t have to be military – then as long as you have leaders who refuse to compromise, you’ll never find peace. Only moderates on both sides can broker peace.
 
So, while I’m a pessimist or realist, I do see a ‘how’. If we only elect leaders who seek and find consensus, and remove leaders who sow division, there is a chance. The best leaders, be they corporate, political or on a sporting field, are the ones who bring out the best in others and are not just feeding their own egos. But all this is easier said than done, as we are witnessing in certain parts of the world right now. For as long as we elect leaders who are narcissistic and cult-like, we will continue to sow the seeds of self-destruction.

Addendum: This was published in Issue 161. So it's the first time they've published 2 of my submissions in a row.

Bad things happen when good people do nothing

 At present there are 2 conflicts holding the world’s attention – they are different, yet similar. They both involve invasions, one arguably justified, involving a response to a cowardly attack, and the other based on the flimsiest of suppositions. But what they highlight is a double-standard in the policies of Western governments in how they respond to the humanitarian crises that inevitably result from such incursions.
 
I’m talking about the war in Ukraine, following Russia’s invasion 2 years ago next month, and Israel’s war in Gaza, following Hamas’s attack on 7 Oct. 2023, killing around 1200 people and taking an estimated 240 hostages; a reported 120 still in captivity (at the time of writing).
 
According to the UN, 'Gaza faces the "highest ever recorded" levels of food insecurity', as reported on the Guardian website (21 Dec 2023). And it was reported on the news today (6 Jan 2024) that ‘Gaza is uninhabitable’. Discussions within the UN have been going on for over a month, yet have been unable to unlock a stalemate concerning humanitarian aid that requires a cessation of hostilities, despite the obvious existential need.
 
Noelia Monge, the head of emergencies for Action Against Hunger, said: “Everything we are doing is insufficient to meet the needs of 2 million people. It is difficult to find flour and rice, and people have to wait hours to access latrines and wash themselves. We are experiencing an emergency like I have never seen before.” (Source: Guardian)
 
I don’t think it’s an exaggeration to say that this is a humanitarian crisis of unprecedented proportions in modern times. It’s one thing for Israel to invade a country that harbours a mortal enemy, but it is another to destroy all infrastructure, medical facilities and cut off supplies of food and essential services, without taking any responsibility. And this is the double-standard we are witnessing. Everyone in the West condemns Putin’s attack on Ukrainian civilians, their homes and infrastructure, and calls them out as ‘war crimes’. No one has the courage to level the same accusation at Benjamin Netanyahu, despite the growing, unprecedented humanitarian crisis created by his implacable declaration to ‘destroy Hamas’. Has anyone pointed out that it’s impossible to destroy Hamas without destroying Gaza? Because that’s what he’s demonstrating.
 
The UN’s hunger monitoring system, Integrated Food Security Phase Classification (IPC), issued a report saying the “most likely scenario” in Gaza is that by 7 February “the entire population in the Gaza Strip [about 2.2 million people] would be at “crisis or worse” levels of hunger. (Source: Guardian)
 
In America, you have the perverse situation where many in the Republican Party want to withdraw support from Volodymyr Zelensky while providing military aid to Israel. They are, in effect, supporting both invasions, though they wouldn’t couch it in those terms.
 
Israel has a special status in Western eyes, consequential to the unconscionable genocide that Jews faced under Nazi Germany. It has led to a tendency, albeit unspoken, that Israel has special privileges when it comes to defending their State. This current conflict is a test of the West’s conscience. How much of a moral bankruptcy are we willing to countenance, before we say enough is enough, and that humanity needs to win.