Space and time: still a mystery after all this (time?)

How’s that for a self-referential title, hence the question mark and parentheses. It highlights the fact that time is an everyday phenomenon that literally runs our lives and yet it remains one of the great mysteries of the Universe, still debated among philosophers and scientists. You may think that space is less of a mystery, yet it sparks debate as well, even without Einstein’s revelation that they are cosmologically entwined thanks to the constant speed of light, c.

The problem is with how do we categorise space and time. Are they entities, parameters, dimensions, metrics, mathematical constructions? Perhaps all of the above. I think we can safely say they are not physical objects, yet they determine the relationships between objects everywhere in the Universe, including those that we can’t perceive. In fact, some scientists would argue that time and space are all about relationships and nothing else, which I’ll return to later.

 

But let’s start with one obvious question, which was raised by Kant and still persists today, thanks to Donald Hoffman (refer my last post), and that is: are time and space simply constructs of the mind? To quote Kant from Critique of Pure Reason:

 

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.

 

The problem with this viewpoint is that it’s readily believed by almost everyone that space and time existed for billions of years before any ‘mind’ arose in the Universe.

 

Another contentious point is to whether space is an ‘entity’ that ‘expands’ and ‘stretches’ as the Universes itself expands (which is not disputed). Viktor T Toth, a renowned expert on physics on Quora, argues very strongly that it doesn’t and what we witness is the ‘distance’ actually increasing between objects. Proponents against space expanding (like Toth) argue that the space within atoms doesn’t expand. My response is that the size of atoms is determined almost solely by Planck’s constant (h), for which there is no evidence that it changes with the universe’s expansion.

 

However, space can travel faster than light, which suggests it is an entity. This is not disputable, and it’s why there is a horizon to the observable universe (refer my post on the End of the Universe). It’s also why we can incorporate ‘inflation’ into the birth of the Universe. It also has ramifications for black holes, which I’ll come to later. According to Einstein’s theories of relativity, both space and time can change according to the observer and these changes are measurable. In other words, space and time are not ‘fixed’ and they are affected by gravity. In fact, Einstein’s famous formula for his general theory has the curvature of spacetime on one side and the momentum-energy tensor on the other side. In other words, spacetime is curved by energy/matter. To quote John Wheeler: “Spacetime tells matter how to move; matter tells spacetime how to curve.”

 

During this discussion, I’ll cite people who know a lot more than me, like Viktor T Toth and John Wheeler (already cited), even if I disagree with them. But I’m going to attempt the impossible: I’m going to argue ideas that I consider obvious, though not incontrovertible, and I will probably fail, since they will include black holes, quantum mechanics and relativity, all of which I don’t have as much knowledge as I would like. But bear with me, because it’s mostly just logic.

 

I want to point out, right at the start, that I’m not one of those people who think Einstein got it wrong, quite the contrary, but I will point out the limitations of his theory based on what we can actually observe. And that’s a good place to start. A common diagram used to visualise Einstein’s formulation of spacetime is the light cone going both forwards and backwards in time. If you are an observer at the centre of this cone you can only be affected by events from the past within the past light cone, and you can only affect events in the future within the future light cone. Everything else outside these cones can’t be observed or have a causal relationship with you, and this is what I mean when I say relativity has limitations because they are real limitations. Sometimes people will tilt the cones over, indicating movement on your part and the horizontal plane, called the 'hypersurface present', also tilts over. However, there is no causal connection along that 'hypersurface' (through spacetime), according to what I’ve just described.

But this brings one to the subject of simultaneity, because Einstein showed with his famous train and platform thought experiment that 2 observers in different frames of reference could observe different sequences of the same event or perceive a difference in what occurs simultaneously.

 

This is a video that explains this better than I can, including the mathematics involved. Two things worth mentioning: the lecturer includes the spatial Lorenz contraction as well as the time dilation in his calculations; and the observer in the same frame of reference as the source of light sees zero difference and therefore observes a ‘true simultaneity’, though no one calls it that. I’ve long argued that the ‘other observer’ who doesn’t see the simultaneity, observes a difference in the Doppler effect caused by the ‘moving’ frame of reference with the moving light source, which should tell that observer that their observation is incorrect. The Doppler effect tells the observer if the light source is in their frame of reference or a frame of reference moving relative to them. It’s the Doppler effect that tells us that the Universe is expanding uniformly in all directions – it has no centre. It also tells us that we’re moving relative to the CMBR (cosmic microwave background radiation). In other words, we can measure our ‘velocity’ relative to the whole of spacetime, which, of course, is the Universe.

 

I’ve explained elsewhere how different observers in different parts of the Universe literally see different ‘now(s)’. They can literally see events occurring in opposite sequences, as a consequence of the finite speed of light, even without relativistic effects. However, if the events have a causal relationship, then all observers will see them in the same sequence. But this also means that my present will be seen in another observer’s past in their future, but it doesn’t mean the converse: that their future can be seen in my present. In fact, the relationship is reciprocal because I will see their past in my present. Observers can only see another observer’s past, no matter where they are. No observer can see another observer’s future. 

 

To give an example, a hypothetical observer in the Small Magellanic Cloud would see us 210,000 years ago when we were just emerging from Africa. Likewise, we would observe them 210,000 years ago (relative to us) if that was physically possible. Therefore, I don’t hold to the widely held view that we can theoretically see another observer’s future (due to the tilting 'hypersurface' plane in the light cone graphic), which infers that the future must already exist for everyone.

 

We know from the twin paradox thought experiment, as well as data from orbiting satellites, that clocks do literally run at different rates due to gravity as well as motion (your satnav depends on making corrections). Also, the famous muon observations arriving on the Earth’s surface. So both special and general theories of relativity change the rate of time, yet when the clocks are back in the same reference frame, they will show a different time duration while agreeing on where they are in the spacetime co-ordinates of the solar system. In other words, they don’t exist in different ‘now(s)’ just because they measured different durations to arrive at the same destination.

 

We know that different animals see time ‘flow’ at different rates. Many birds and insects see the world in slow-motion compared to us. This means they will see the hands of a clock literally moving slower while telling the same time. As Paul Davies has pointed out, if time was to slow down or speed up, you wouldn’t notice. But you can notice if you compare clocks in relativity. My point is that ‘now’ doesn’t change for these creatures even though they perceive time flowing at a different rate to us.

 

Well, I contend the same is true on a cosmic scale. If you were to go near the event horizon of a black hole, like in the movie, Interstellar, time would slow down for you compared to everyone back on Earth, even though you wouldn’t notice it. My argument is that this is no different, perceptually, to the bird observing time going slower. If you were to use the Doppler effect of receding galaxies as a clock, they would actually appear to be going faster (assuming you could take accurate enough measurements) compared to what Earthlings observed, and when you returned, you would agree on what ‘now’ is, compared to these distant cosmic clocks, though you would be considerably younger than your counterparts, if they were still alive, but more likely you would be meeting their subsequent generations.

 

And this is true even on Earth, where clocks run infinitesimally faster on mountaintops compared to sea level. But you don’t see an accumulated difference in ‘now’ over millions of years of the Earth’s rotation. All the while, the clocks are in the same ‘present’ while they are measuring different rates of time passing.

 

Carlo Rovelli gave a talk at the Royal Institute on ‘time’, where he argues that there is no ‘universal time’. But during the 15min question time (shown in another video), he contends that we arrive at a cosmic time for the Universe by taking an ‘average’. Brian Greene, in his book, The Fabric of the Universe, said something similar. However, if you lived on a planet orbiting near a black hole, surely the age of the Universe would be much less than what we observe, because any clock would be measuring time passing at a much slower rate than what we measure on Earth. Like the clocks on top of the mountains on Earth, I don’t believe hypothetical observers orbiting close to a black hole, perceive a ‘now’ that progressively gets out of step with the ‘now’ Earthlings observe over the course of their lives in the Universe, even if they measured a different age. In other words, I contend that you can have a universal now for the whole universe even if different clocks measure different rates of time dependent on where they are located.

 

Another video, which is an interview with loop quantum gravity theorist, Lee Smolin, describes time and space as being separate, which is both heretical and interesting. I think he has a point when you consider that, on a cosmic scale, time is finite and space is possibly infinite. Space could also be finite but perceptually infinite, like a hyperbolic universe, but, as Marcus du Sautoy pointed out in his book, What We Cannot Know, if the Universe is truly spatially infinite, we might never know. Smolin conjectures that space could be a consequence of ‘causal relationships’ between physical objects, which he doesn’t elaborate on, but which I find difficult to conceptualise. Causation is determined by the speed of light, otherwise everything would happen at once (Caspar Henderson, A New Map of Wonders). Smolin also contends that time might be an ‘emergent’ property (also without elaborating). The point is that causality requires time axiomatically. The thing about both space and time is that they are dimensions and if you add light (c) into the mix, you get a 4-dimensional universe that is fundamental for it to function in the way it does. With more than 3 spatial dimensions, planets would not have stable orbits, and if there was more than 1 dimension of time you would get time loops. If you have 2 spatial dimensions you would literally fall apart. Also, more than 3 spatial dimensions causes light waves to travel inconsistently. Our universe has the ideal time-space dimensional combination for its goldilocks existence.

 

In the same video, Smolin explains how the event horizon of a black hole breaks causality. This can be seen mathematically by Schwarzchild’s equation for a static black hole, which is described in this video. As the presenter explains, the +ve and -ve signs of the equation change when you cross the event horizon, which breaks causality. Causality is caused by the space dimension being less than the (negative) time dimension, and they are reversed on the other side of the event horizon (watch the video). It should be pointed out that Einstein was initially sceptical about the existence of black holes, even though Schwarzchild derived his equation from Einstein’s tensor.

 

There is a paradox inherent in a black hole (more than one, actually) but the most fundamental one is that time theoretically stops at the event horizon because time is related to light, and light can’t escape a black hole by definition. Viktor T Toth says that ‘the event horizon is always in an observer’s future’, so how can anyone (or anything) fall into a black hole? In a previous post, I speculated that maybe ‘space’ itself ‘falls’ into the black hole and that’s exactly what the guy in the video says. This is only possible because space can travel faster than light, as I described earlier.

 

This is already a lengthy post but I can’t talk about time without mentioning quantum mechanics. The same guy (who talks about black holes), gives a very good summary explanation of Richard Feynman’s path integral formulation of QED (quantum electrodynamics) in this video. It should be pointed out that Julian Schwinger’s ‘field’ interpretation called QFT (quantum field theory) is now more popular, if that’s the right word. In QFT, particles are seen as ‘excitations’ of a quantum field which is everywhere in the Universe. Someone on Quora even suggested that the word ‘particle’ should be erased from every physics text book, because they just don’t exist. Curiously, Feynman, in his book, QED, argued that everything is ‘particles’, but that was in the context of whether quantum phenomena are ‘waves’ or ‘particles’ in the Bohr tradition. I like Freeman Dyson’s view that it depends on whether an event is in an observer’s future or past, but I’m getting ahead of myself.

 

A good place to start with QM is Schrodinger’s equation. Carlo Rovelli, whom I cited earlier, in one of his books, is almost dismissive of Schrodinger’s equation and argues that the wave function (ψ) has misled us in our understanding of QM. But Schrodinger’s wave function is the basis of Feynman’s QED, so that’s where I’ll start.

 

Schrodinger’s equation encapsulates all the characteristics of QM which make it weird: superposition, entanglement and the uncertainty principle. The wave function also incorporates time-reversal symmetry, which is an inherent feature of QM. It doesn’t incorporate relativity, but I’ll come to that later.

 

The thing about Schrodinger’s equation, which is rarely mentioned, is that it describes the future – it makes predictions about where something will be in time. It was Dirac who derived the Lagrangian for QM, and Feynman adopted that for his ‘sum over histories’ or ‘path integral’ formulation, because it calculates the path of ‘least action’, which dictates what something does. (This also applies in a gravitational field, by the way, but I don’t want to confuse you.) Feynman used the proper time (τ) in place of t (that Schrodinger used) which automatically allows for special relativity (as explained in the video).

 

As someone on Quora once explained (David Moore, who is a Sydney based GP), a probability of ONE exists in the past, after the event. In the future, the probability is always less than one. This is what happens when the wave function ‘collapses’, for want of a better word, and neatly incorporates Freeman Dyson’s view that QM describes the future while classical physics describes the past. Feynman’s formulation has an infinity of possible future paths, that he integrates (hence the ‘integral’ in path integral) and also gives the path of least action. There is an element of teleology in this, but I don’t believe it makes the universe deterministic, though others disagree. On a large enough scale, as Schrodinger himself pointed out, you get a statistical deterministic effect, which he coined ‘statistico-deterministic’. But it can’t predict individual events, like when a radioactive isotope will decay, which is the crucial component in his eponymous cat thought experiment.

 

In regard to photons being the ‘particle’ nature of light, Mark John Fernee (physicist at Queensland University and regular Quora contributor) made the point in one of his posts, that if we didn’t observe light as photons, we would not be able to see many of the distant stars that we do. If light was purely a wave, then it would be so dispersed over the massive sphere of its influence it would be too faint to see. But, as a photon, it can arrive in just one point in space, where we happen to observe it.

 

I will leave the last word to Paul Davies. Even though he’s talking about QM in reference to black holes and Hawking radiation, the principle he describes is universal.

 

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.

Addendum: This video gives a more detailed and accurate explanation of black holes. It's more complex than my exposition would suggest.

Revisiting Donald Hoffman’s alternative theory of evolution

 Back in November 2016, so 5 years ago, I wrote a post in response to an academic paper by Donald Hoffman and Chetan Prakash called Objects of Consciousness, where I specifically critiqued their ideas on biological evolution. Despite co-authoring the paper, I believe this particular aspect of their paper is predominantly Hoffman’s, based on an article he wrote for New Scientist, where he expressed similar views. One of his key arguments was that natural selection favours ‘fitness’ over ‘truth’.

 

...we find that natural selection does not, in general, favor perceptions that are true reports of objective properties of the environment. Instead, it generally favors perceptual strategies that are tuned to fitness.

 

One way to use fewer calories is to see less truth, especially truth that is not informative about fitness. (My emphasis)

 

What made me revisit this was an interview in Philosophy Now (Issue 147, Dec 2021/Jan 2022) with Samuel Grove, who recently published Retrieving Darwin’s Revolutionary Idea: The Reluctant Radical. According to Grove, Darwin was reluctant to publish The Decent of Man, because applying natural selection to humans was controversial, despite the success of The Origin of Species by Means of Natural Selection (full title). The connection to Hoffman’s argument is that Darwin struggled with the idea that evolution could ‘select’ for ‘truth’. To quote Grove:

 

Natural selection is premised on three laws: the law of inheritance, the law of variation, and the law of superfecundity (where organisms produce more offspring than can possibly survive). Together, these laws produce selection, and over the course of time, evolution. Well, Darwin’s question was, how could evolution produce a subject capable of knowing these very laws? Or, why would evolution select for fidelity to truth or laws? Selection favours survival, not truth. (My emphasis again)

 

Darwin turned to arguments, that as Grove points out, were ‘the common garden variety racism of the time’ – specifically, ‘group selection’ that favoured Anglo Saxon groups. Apparently, Darwin was reluctant to consider ‘group selection’ (as opposed to ‘individual selection’), but did so because it led to a resolution that would have been politically acceptable in his day. I will return to this point later.

 

So, even according to Darwin, Hoffman may have a point, though I’m not sure that Darwin and Hoffman are even talking about the same idea of ‘truth’. More on that later.

 

For those unfamiliar with Hoffman, his entire argument centres on the fundamental idea that ‘nothing exists unperceived, including space and time’. For more details, read my previous post, or read his co-authored paper with Prakash. I need to say upfront that I find it hard to take Hoffman seriously. Every time I read or listen to him, I keep expecting him to say, ‘Ah, see, I fooled the lot of you.’ His ideas only make sense to me if he believes we live in a computer simulation, which he’s never claimed. In fact, that would be my first question to him, if I ever met him. It’s an idea that has some adherents. Just on that, I would like to point out that chaos is incomputable, and the Universe is chaotic on a number of levels, including evolution, as it turns out.

 

In a previous life, I sometimes became involved in contractual disputes on major engineering projects (in Australia and US), preparing evidence for lawyers, and having to address opponents’ arguments. What I found in a number of cases, was that people prepared simple arguments that were nevertheless compelling. In fact, they often delivered them as if they were a fait accompli. In most of these cases, I found that by digging a little deeper, they could be challenged successfully. I have to admit that I’m reminded of this when I examine Hoffman’s argument on natural selection favouring ‘fitness’ over ‘truth’.

 

Partly, this is because his arguments highlight contradictions in his own premise and partly because one of his key arguments is contradicted by evidence, which, I concede, he may not be aware of.

 

For a start, what does Hoffman mean by ‘fitness’?

 

He talks about fitness in terms of predators and prey:

 

But in the real world where predators are on the prowl and prey must be wary, the race is often to the swift. It is the slower gazelle that becomes lunch for the swifter cheetah. 

 

This quote is out of context, where he’s arguing that ‘swiftness’ in response, be it the gazelle or the cheetah, favours less information, therefore less time; over more information, therefore lost time. Leaving aside the fact that survival of either animal is dependent on the accuracy of their ‘modelling’ of their environment, if the animal being chased or doing the chasing ‘doesn’t exist unperceived’, then they might as well be in a dream. In fact, we often find ourselves being chased in a dream, which has no consequences to our ‘survival’ in real life. The argument contradicts the premise.

 

Hoffman and Prakash quote Steven Palmer from a ‘graduate-level textbook’ (1999):

 

Evolutionarily speaking, visual perception is useful only if it is reasonably accurate . . . Indeed, vision is useful precisely because it is so accurate. By and large, what you see is what you get. When this is true, we have what is called veridical perception . . . perception that is consistent with the actual state of affairs in the environment. This is almost always the case with vision . . .  (Authors’ emphasis)

 

Hoffman and Prakash then argue that ‘using Monte Carlo simulations of evolutionary games and genetic algorithms, we find that natural selection does not, in general, favor perceptions that are true reports of objective properties of the environment’. In other words, they effectively argue that Palmer’s emphasis on ‘veridical perception’ is wrong. I can’t argue with their Monte Carlo simulations, because they don’t provide the data. However, real world evidence would suggest that Palmer is correct.

 

I read a story on Quora by a wildlife ranger about eagles who have had one eye damaged, usually in intra-species mid-air fights. In nearly all cases (he described one exception), an eagle who is blind in one eye needs to be euthanised because they would invariably starve to death due to an inability to catch prey. So here you have ‘fitness’ dependent on vision being accurate.

 

Leaving aside all this nit-picking about natural selection favouring ‘fitness’ over ‘truth’, how does it support their fundamental thesis that reality only exists in the mind? According to them, their theory of evolution ‘proves’ that reality doesn’t exist unperceived. Can you even have evolution if reality doesn’t exist (except in the mind)?

 

And this brings me back to Darwin, because what he didn’t consider was that, in the case of humans, cultural evolution has overtaken biological evolution, and this is unique to humanity. I wrote another post where I argue that The search for ultimate truth is unattainable, but there are 'truths' we have found throughout the history of our cultural evolution and they are in mathematics. It’s true that evolution didn’t select for this; it’s an unexpected by-product, but it has led to the understanding of laws governing the very Universe that even Darwin would be amazed to know. 

Cancel culture – the scourge of our time

There are many things that cause me some anguish at the moment, not least that Donald Trump could easily be re-elected POTUS in 2024, despite deliberately undermining and damaging the very institution he wants to lead, which is American democracy. It’s not an exaggeration to say that he’s attacked it at its core.

This may seem a mile away from the topic I’ve alluded to in the title of my post, but they both seem to be symptoms of a divisiveness I haven’t seen since the Vietnam war. 

 

The word, ‘scourge’, is defined as ‘a whip used as an instrument of punishment’; and that’s exactly how cancel culture works, with social media the perfect platform from which to wield it.

 

In this weekend’s Good Weekend magazine (Fairfax Group), the feature article is on this very topic. But I would like to go back to the previous weekend, when another media outlet, Murdoch’s Weekend Australian Magazine published an article on well known atheist, Richard Dawkins. It turns out that at the ripe old age of 80, Dawkins has been cancelled. To be precise, he had his 1996 Humanist of the Year award withdrawn by the American Humanist Association (AHA) earlier this year, because, in 2015, he tweeted a defence of Rachel Doleza (a white chapter president of NAACP, the National Association for the Advancement of Coloured People) who had been vilified for identifying as Black.

 

Of course, I don’t know anything about Rachel Doleza or the context of that stoush, but I can identify with Dawkins, even though I’ve never suffered the same indignity. Dawkins and I are of a similar mould, though we live in different strata of society. In saying that, I don’t mean that I agree with all his arguments, because I obviously don’t, but we are both argumentative and are not shy in expressing our opinions. I really don’t possess the moral superiority to throw stones at Dawkins, even though I have.

 

I remember my father once telling me that if you admired an Australian fast bowler (he had someone in mind) then you also had to admire an English fast bowler (of the same generation), because they had the exact same temperament and wicket-taking abilities. Of course, that also applies to politicians. And it pretty much applies to me and Dawkins.

 

On the subject of identifying as ‘black’, I must tell a story related to me by a friend I knew when I worked in Princeton in 2001/2. She was a similar age to me and originally from Guyana. In fact, she was niece to West Indies champion cricketer, Lance Gibbs, and told me about attending his wedding when she was 8 years old (I promise no more cricketing references). But she told me how someone she knew (outside of work) told her that she ‘didn’t know what it was like to be black’. To which she replied, ‘Of course I know I’m black, I only have to look in the mirror every morning.’  Yes, it’s funny, but it goes to a deeper issue about identity. So a black person, who had lived their entire life in the USA, was telling another black person, who had come from outside of the US, that they didn’t know what it was like to be ‘black’. 

 

Dawkins said that, as a consequence, he’d started to self-censor, which is exactly what his detractors want. If Dawkins has started to self-censor, then none of us are safe or immune. What hurt him, of course, was being attacked by people on the Left, which he mostly identifies with. And, while this practice occurs on both sides, it’s on the Left where it has become most virulent. 

 

“I self-censor. More so in recent years. Why? It’s not a thing I’ve done throughout my life, I’ve always spoken my mind openly. But we’re now in a time when if you do speak your mind openly, you are at risk of being picked up and condemned.”

 

“Every time a lecturer is cancelled from an American university, that’s another God knows how many votes for Trump.”

 

And this is the thing: the Right loves nothing more than the Left turning on itself. It’s insidious, self-destructive and literally soul-destroying. In the Good Weekend article, they focus on a specific case, while also citing other cases, both in Australia and America. The specific case was actor, Hugh Sheridan, having a Sydney Festival show cancelled, which he’d really set his sights on, because he was playing a trans-gender person which created outrage in the LGBTQIA+ community. Like others cited in the article, he contemplated suicide which triggered close friends to monitor him. This is what it’s come to. It’s a very lengthy article, which I can’t do justice to on this post, but there is a perversion here: all the shows and people who are being targeted are actually bringing diversity of race and sexuality into the public arena and being crucified by the people they represent. The conservatives, wowsers and Bible-bashers must love it.

 

This is a phenomenon that is partly if not mostly, generational, and amplified by social media. People are being forced to grovel.

 

Emma Dawson, head of the Labor-aligned (Australian political party, for overseas readers) Per Capita think tank, told the Good Weekend, “[cancel culture is] more worrying to me than just about anything other than far-right extremism. It is pervasive among educated young people; very few are willing to question it.”

 

‘In 2019, Barack Obama warned a group of young people: “This idea of purity, and you’re never compromised and always politically woke... you should get over that quickly. The world is messy.”’

 

And this is the nub of the issue: cancel culture is all about silencing any debate, and, without debate, you have authoritarianism, even though it’s disguised as its opposite.

 

In the same article, the author, James Button, argues that the rise of Donald Trump is not a coincidence in the emergence of this phenomenon.

 

The election of Donald Trump horrified progressives. Here was a president – elected by ordinary Americans – who was racist, who winked at neo-Nazis and who told bare-faced lies in a brazen assertion of power while claiming that the liars were progressive media. His own strategy adviser, Stephen Bannon, said that the way to win the contest was to overwhelm the media with misinformation, to “flood the zone with shit”.

 

And they succeeded so well that America is more divided than it has been since its historical civil war.

To return to Hugh Sheridan, whom I think epitomises this situation, at least as it’s being played out in Australia, in that it’s the Arts that are coming under attack, and from the Left, it has to be said. Actors and writers (like myself) often portray characters who have different backgrounds to us. To give a recent example on ABC TV, which produces some outstanding free-to-air dramas with internationally renowned casts, when everything else is going into subscribed streaming services. Earlier this year, they produced and broadcast a series called The Newsreader, set in the 1980s when a lot of stuff was happening both locally and overseas. ‘At the 11th AACTA (Australian Academy of Cinema and Television Arts) awards, the show was nominated for more awards than any other program’ (Wikipedia).

 

A key plotline of the show was that the protagonist was gay but not openly so. The point is that I assume the actor was straight, although I don’t really know, but it’s what actors do. God knows, there have been enough gay actors who have played straight characters (Sir Ian McKellen, who played Gandalf, as well as Shakespearean roles). So why crucify someone who is part of the LGBTQIA+ community for playing a transgender role. He was even accused of being homophobic and transgenderphobic. He tweeted back, “you’re insane”, which only resulted in him being trolled for accusing his tormentors of being ‘insane’.

 

Someone recently asked me why I don’t publish what I write anymore. There is more than one reason, but one is fear of being cancelled. I doubt a publisher would publish what I write, anyway. But also, I suffer from impostor syndrome in that I genuinely feel like an impostor and I don’t need someone to tell me. The other thing is that I simply don’t care; I don’t feel the need to publish to validate my work.

To the End of the Universe

I like to remind myself and others how little I know. It’s one of the reasons I like Quora, where I get to occasionally interact with people who know considerably more than me. One such person is Mark John Fernee, a physicist at the University of Queensland. I’ve learned a lot of science from an approach based on scepticism. For example, I was sceptical about relativity theory: that clocks could really slowly down and why did they slow down for one observer but not another, as demonstrated in the famous twin paradox. In fact, it’s nature’s paradoxes that provide the incentive to try and understand it to the extent that one can. 

 

Another example is quantum mechanics. For a long time, I followed David Bohm’s approach, which was really an attempt to bring QM back down to Earth so-to-speak. I believe that both Schrodinger and Einstein also believed in a ‘hidden-variables’ approach.

 

I finally gave this up when I concluded that QM and classical physics obey different rules: superposition and entanglement are not part of classical physics, either experimentally or mathematically. And I found that special relativity only made sense in the context of general relativity (which I discuss in more detail below).

 

And then you have the combination of special relativity with QM, which, from a mathematical perspective, allows anti-particles to exist. As Fernee points out, because an anti-particle can be represented mathematically by a particle going backwards in time, it ensures that charge is conserved by time’s arrow. In other words, you can turn an electron into a positron, or vice versa, by reversing time, which is why it’s never observed.

 

One of the paradoxes I now struggle with is that, according to special relativity, you can have different ‘nows’ in different parts of the universe. This is why most, if not all physicists, argue that the universe is completely deterministic, if someone’s future can be hypothetically observed by someone else’s motion. I confess I’m very sceptical about this. What they're saying is that the ‘now’ in some other part of the Universe is changed by an observer’s motion locally. Fernee quotes Roger Penrose in response to a question: can we theoretically teleport to some other location in the Universe instantaneously, like we see in science-fiction movies? According to Fernee (quoting Penrose), if you could and then teleport back, you might arrive before you left, because a random movement by you could change the ‘now’ in that distant part of the universe into your past. I’m assuming this can be demonstrated mathematically; it’s a consequence of simultaneity changing depending on the observer, according to special relativity. 

 

I’ve discussed this in other posts. I like to point out that, where there’s a causal relationship, the sequence of events can’t be changed, dependent on an observer’s perspective. Which makes me wonder: does a sequence change, dependent on an observer’s perspective, when they’re not causal? Is it possible that there is a sequence of events independent of any observer?

 

And this leads to another paradox that is hardly ever addressed which is that, despite this proliferation of ‘nows’, dependent on observers’ perspectives, we have an ‘age of the Universe’. I actually raised this with Fernee in a dialogue I had with him, and he referenced a paper by Tamara M. Davis and Charles H. Lineweaver at the University of New South Wales, titled, Expanding Confusion: Common Misconceptions of Cosmological Horizons and the Superluminal Expansion of the Universe. I’ve lost the link, and I can no longer even find the post on Quora, but I downloaded the paper, which is 24 pages long, not including the references.

 

Of course, it’s an academic paper, yet I found it easier to follow and understand than I might have expected. Which is not to say I have a full grasp of it, but I feel I can relay some of its most pertinent points. The paper is dated 13 November 2013, so it seems apt I’m writing about it on 13 Nov, 2021. Firstly, the cosmological model of the Universe the authors discuss, is referred to as ΛCDM cosmology (Lambda-CDM cosmology), where CDM is an acronym for Cold Dark Matter. Lambda (Λ) is the cosmological constant that gives us ‘dark energy’, so the model includes both dark energy and dark matter.

 

As the title suggests, the authors discuss misconceptions found in the literature concerning the horizon problem, and at the end they provide a list of examples, including one by Richard Feynman (1995), 

 

“It makes no sense to worry about the possibility of galaxies receding from us faster than light, whatever that means, since they would never be observable by hypothesis.” 

 

And this one by Paul Davies (1978): 

 

“. . . galaxies several billion light years away seem to be increasing their separation from us at nearly the speed of light. As we probe still farther into space the redshift grows without limit, and the galaxies seem to fade out and become black. When the speed of recession reaches the speed of light we cannot see them at all, for no light can reach us from the region beyond which the expansion is faster than light itself. This limit is called our horizon in space, and separates the regions of the universe of which we can know from the regions beyond about which no information is available, however powerful the instruments we use.” 

 

What the authors expound upon in the main body of their text is that there are, in effect, a number of horizons, which makes these statements erroneous at best. To be fair to both Feynman and Davies, the ΛCDM model of the Universe wasn’t known at the time. Dark energy wasn’t officially ‘discovered’ until 1998. Davis and Lineweaver provide diagrams to show these various horizons, which I can’t duplicate here, and if I did, I’d have trouble explicating them. But basically, there is a particle horizon, which is the limit of the observable universe, the Hubble sphere, which is the boundary of the expanding universe (where it equals c) and the event horizon. (To quote the authors: Our event horizon is our past light cone at the end of time, t = ∞ in this case.) There is a logical tendency to think they should all be the same thing, but they’re not, as the authors spend a good portion of their 24 pages expounding upon. To quote again:

 

The particle horizon at any particular time is a sphere around us whose radius equals the distance to the most distant object we can see... Our effective particle horizon is the cosmic microwave background (CMB).

 

Whereas:

 

Hubble sphere is defined to be the distance beyond which the recession velocity exceeds the speed of light, DHS = c/H. As we will see, the Hubble sphere is not an horizon. Redshift does not go to infinity for objects on our Hubble sphere (in general) and for many cosmological models we can see beyond it... The ratio of ∼ 3/1 is the ratio between the radius of the observable universe and the age of the universe, 46 Glyr/13.5 Gyr.

 

What you have to get your head around is that the universe is dynamic, and given the time it takes for light to reach us from the edge of the Universe, both the edge and the objects (we’re observing) have moved on, quite literally. This means we can observe objects over the horizon so-to-speak. But it’s even more complex than that, because the Hubble sphere, which is expanding, can overtake photons that were emitted beyond the horizon but are travelling towards us. According to the authors, we can observe objects that are ‘now’ travelling at superluminal speeds relative to us. 

 

This is how the authors explain it:

 

Light that superluminally receding objects emit propagates towards us with a local peculiar velocity of c, but since the recession velocity at that distance is greater than c, the total velocity of the light is away from us. However, since the radius of the Hubble sphere increases with time, some photons that were initially in a superluminally receding region later find themselves in a subluminally receding region. They can therefore approach us and eventually reach us. The objects that emitted the photons however, have moved to larger distances and so are still receding superluminally. Thus we can observe objects that are receding faster than the speed of light. 

 

One of the most illuminating aspects of their dissertation, for me, was that one needs to use a general relativistic (GR) derivation of the Doppler redshift and not a special relativistic (SR) derivation, which is usually used. They show graphically that the SR and GR derivations diverge, especially for further distances. On the same graph, they show how a non-relativistic Doppler shift, which would be ‘tired light’ (authors’ term) is actually a horizonal line, so nowhere near. The graph, of course, shows these curves against observations of super novae. As they explain it:

 

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. 

 

What they are saying is that there is a distinction between the movement of the objects in space and the movement of space itself. For me, this ends the debate about whether ‘space’ is an entity or just the distance between objects. As much as I admire and respect Viktor T Toth, I’ve always had a problem with his argument that space ‘doesn’t expand’, but only the objects ‘move’ thus creating more space between them. The Hubble sphere, as I understand it, is where space equals c.

 

Later in their paper, Davis and Lineweaver describe how they derived their equation for the GR redshift.

 

For the observed time dilation of supernovae we have to take into account an extra time dilation factor that occurs because the distance to the emitter (and thus the distance light has to propagate to reach us) is increasing.

 

In other words, in calculating the redshift of a ‘comoving galaxy’, they also have to take into account the constant expansion of space in the photon’s journey to the observer. 

 

....the peculiar velocity of a photon, Rχ ̇, is c. Since the velocity of light through comoving coordinates is not constant (χ ̇ = c/R), to calculate comoving distance we cannot simply multiply the speed of light through comoving space by time. We have to integrate over this changing comoving speed of light for the duration of propagation. Thus, the comoving coordinate of a comoving object that emitted the light we now see at time t is attained by integrating.  (χ ̇is the time dependent expansion of space and R is the radial distance). 

 

Notice that in contrast to special relativity, the redshift does not indicate the velocity, it indicates the distance. That is, the redshift tells us not the velocity of the emitter, but where the emitter sits (at rest locally) in the coordinates of the universe. 

 

In other words, when we integrate χ ̇, we get χ, which is distance. The authors provide another equation for determining the velocity.

 

Now, one of the obvious aspects of this whole exercise is that they are calculating a redshift across space that changes over time, so what does time mean in this context?

 

This is how the authors explain it, just before their conclusion:

 

Throughout this paper we have used proper time, t, as the temporal measure. This is the time that appears in the RW metric and the Friedmann equations. This is a convenient time measure because it is the proper time of comoving observers. Moreover, the homogeneity of the universe is dependent on this choice of time coordinate — if any other time coordinate were chosen (that is not a trivial multiple of t) the density of the universe would be distance dependent. Time can be defined differently, for example to make the SR Doppler shift formula correctly calculate recession velocities from observed redshifts (Page, 1993). However, to do this we would have to sacrifice the homogeneity of the universe and the synchronous proper time of comoving objects.

 

I find it interesting that they adopt a ‘proper time’ for the whole universe. It makes one wonder what ‘now’ really means.

 

Footnote 1: I want to point out that in their acknowledgements, Davis and Lineweaver reference Brian Schmidt, who received a joint Nobel Prize for his work in empirically confirming dark energy, or the cosmological constant (Λ).

Footnote 2: You can download the paper here.

Addendum: This is a video by someone (who knows more than me) and doesn’t give his name. I posted a video by him before, regarding the question: Is gravity a force? His videos on Penrose tiling and the Feigenbaum constant are among the best.

 

In this video, he refutes my claim, arguing that space doesn’t expand. He makes one very compelling point that if space expanded so would atoms and so would we. Victor T Toth makes the exact same point, and I’d have to agree. The size of all atoms is determined by h (Planck's constant), which doesn't change with the expansion of the Universe. I might add that this presenter and Toth disagree on whether gravity is a force or not, so physicists don’t always agree, even in the same field, like cosmology.

 

In the video, he argues that there are 3 types of Doppler shift and contends that they are actually all the same. Most intriguing was the thought experiment that someone in ‘free fall’ wouldn’t see the Doppler shift that another observer would. In other words, it’s observer dependent.

 

But there is a spacetime metric or manifold, which forms the basis of general relativity theory (GR) and this can warp and curve (according to said theory). In fact, there is a phenomenon called ‘frame dragging’, where spacetime is dragged around by a spinning black hole. Light is always c in reference to this spacetime manifold. So when ‘space’ reaches the speed of light at the horizon relative to us, light is still c in that reference frame, even though it is expanding away from us at c or more. Space can travel faster than light, even though massive particles can’t, which is why ‘inflation’, proposed at the birth of the Universe, is possible.

 

Getting back to the Doppler shift the authors cite in their paper, they use a GR Doppler shift, which I believe isn’t covered in the video.

Reality and our perception of it

The latest issue of Philosophy Now (Issue 146, Oct/Nov 2021) has as its theme, ‘Reality’. The cover depicts Alice falling down the rabbit hole, with the notated question, What’s Really Real? I was motivated (inspired is the wrong word) to write a letter to the Editor, after reading an essay by Paul Griffiths, titled, Against Direct Realism. According to the footnote at the end of the article: Dr Paul H. Griffiths has a background in physics and engineering, and a longstanding interest in the philosophy and science of perception. I have a background in engineering and an interest in philosophy and science (physics in particular), but there the similarity ends.

 

Griffiths gives an historical account, mostly last century, concerning problems and points of view on ‘direct realism’ and ‘indirect realism’, using terms like ‘disjunctivism’ and ‘representationalism’, making me wonder if all of philosophy can be reduced to a collection of isms. To be fair to Griffiths, he’s referencing what others have written on this topic, and how it’s led to various schools of thought. I took the easy way out and didn’t address any of that directly, nor reference any of his many citations. Instead, I simply gave my interpretation of the subject based on what I’ve learned from the science, and then provided my own philosophical twist.

 

I’ve covered a lot of this before when I wrote an essay on Kant. Griffiths doesn’t mention Kant, but arguably that’s where this debate began, when he argued that we can never know the ‘thing-in-itself’, but only a perception of it. Just to address that point, I’ve argued that the thing-in-itself varies depending on the scale one observes it at. It also depends on things like what wavelength radiation you might use to probe it. 

 

But, in the context of direct realism or indirect realism, various creatures perceive reality in different ways, which I allude to in my 400 word response. If I was to try and put myself in one of Griffith’s categories, I expect I’m an ‘indirect realist’ because I believe in an independent reality and that my ‘perception’ of it is unique to my species, meaning other species would perceive it differently, either because they have different senses or the senses they have can perceive other parts of the spectrum to mine. For example, some insects and birds can see in the ultra-violet range, and we can see some colours that other primates can’t see.

 

However, I never mention those terms, or even Kant, in my missive to the Editor. I do, however, mention the significance of space and time, both to reality, and our perception of it. Here is my response:

 

 

Paul Griffith’s essay titled, Against Direct Realism (Issue 146, October/November 2021) discusses both the philosophy and science of ‘perception’, within the last century in particular. There are two parts to this topic: an objective reality and our ability to perceive it. One is obviously dependent on the other, and they need to be addressed in that order.

 

The first part is whether there is an objective reality at all. Donald Hoffman claims that ‘nothing exists unperceived, including space and time’, and that there are only ‘conscious agents’. This is similar to the argument that we live in a simulation. There is, of course, one situation where this happens, and that’s when we are dreaming. Our brains create a simulacrum of reality in our minds, which we can not only see but sometimes feel. We’re only aware that it’s not reality when we wake up.

 

There is a major difference between this dream state and ‘real life’ and that is that reality can be fatal – it can kill you. This is key to understanding both aspects of this question. It’s not contentious that our brains have evolved the remarkable ability to model this reality, and that is true in other creatures as well, yet we perceive different things, colour being the most obvious example, which only occurs in some creature’s mind. Birds can see in almost 300 degree vision, and bats and dolphins probably ‘see’ in echo-location, which we can’t even imagine. Not only that, but time passes at different rates for different creatures, which we can mimic with time-lapse or slow-motion cinematography. 

 

But here’s the thing: all these ‘means’ of perception are about keeping us and all these creatures alive. Therefore, the model in our minds must match the external reality with some degree of accuracy, yet it does even better than that, because the model even appears to be external to our heads. What’s more, the model predicts the future, otherwise you wouldn’t be able to catch a ball thrown to you. *

 

There is one core attribute of both reality and its perception that is rarely discussed, and that is space and time. We live in a universe with three spatial dimensions and one time dimension, so the models our brains create need to reflect that. The reason we can’t imagine a higher dimensional space, even though we can represent it mathematically, is because we don’t live in one.

 

 

·      * There is a 120 millisecond delay between the action and the perception, and your brain compensates for it.

Natural laws; a misnomer?

I’ve referenced Raymond Tallis before, and I have to say up front that I have a lot of respect for his obvious erudition and the breadth of his intellectual discourse. He is an author and regular columnist in Philosophy Now, with a background in neuroscience. I always read his column, because he’s erudite and provocative. In Issue 144 (June/July 2021) he wrote an essay titled, The Laws of Nature. He didn’t use the term ‘misnomer’ anywhere, but that was the gist of his argument.

Tallis and I have a fundamental disagreement concerning the philosophy of science; and physics, in particular. This will become obvious as I expound on his article. He starts by pointing out how the word ‘law’ has theological connotations, as well as cultural ones. It’s a word normally associated with humanmade rules or edicts, which are necessary just so we can live together. An obvious one is what side of the road to drive on, otherwise we would have carnage and road-rage would be the least of our worries.

 

Science evolved out of a religious epistemology (I know that’s an oxymoron), but the pioneers of physics, like Galileo, Kepler and Newton, were all religious people and, from their perspective, they were uncovering ‘God’s laws’. This even extended to Einstein, who often referred to ‘God’ in a metaphorical sense, and saw himself and his contemporary physicists as uncovering the ‘Old One’s Secrets’. Even Stephen Hawking, a self-declared atheist, coined the phrase, ‘The Mind of God’.

 

So I agree with Tallis on this point that the use of the word, law, in this context, is misleading and carries the baggage of an earlier time, going back to the ancient Greeks (and other cultures) that human affairs were contingent on the whims of the Gods.

 

So Tallis searched around for an alternative term, and came up with ‘habits’, whilst admitting that it’s not ideal and that ‘it will have to punch above its usual weight’. But I think Tallis chose the word because, in human terms, ‘habit’ means something we acquire out of familiarity, and may or may not be the best method, or approach, to a specific situation. The idea that nature follows ‘habits’ implies there is no rhyme or reason behind their efficacy or apparent success. Even the word, 'success', is loaded, yet I think it subverts his point, because they are ‘successful’ in the sense that they ultimately produced a lifeform that can cognise them (more on that below).

 

Tallis makes the point that in nature ‘things just happen’, and the ‘laws’ are our attempt to ‘explain’ them. But, extending this line of thought, he suggests that actually we invent laws to ‘describe’ what nature does, which is why ‘habits’ is a better term.

 

The expectation of finding an explanation of nature’s regularity is the result of extrapolating to the whole of things the belief that every individual thing happens for a reason – that nothing ‘just happens’.

 

The word ‘regularity’ is apt and is one that physicists often use, because that is what we have learned about nature on all scales, and it is why it is predictable to the degree that it is. There is, of course, a missing element in all this, and that is the role of mathematics. I’m not surprised that Tallis doesn’t mention the word (even once as best I can recall), because he believes that physicists have a tendency to ‘mistake the map for the territory’ when they invoke mathematics as having a pivotal role in our epistemology. In another essay, he once argued that the only reason mathematics has a place in physics is because we need to measure things, or quantify them, in order to make predictions that can be verified. However, the very laws (or habits) that are the subject of his essay, are completely dependent on mathematics to be comprehensible at all.

 

In closing, Tallis makes a very good argument: there is a gap between the ‘habits’ that nature follows and the humanmade ‘laws’ in our science that we use to describe these habits. He makes the point that we are forever trying to close this gap as we discover more about nature’s habits. And he’s right, because it appears that no matter how much we learn, there are always more of nature’s secrets to decipher. Every theory we’ve devised thus far has limits and we’ve even reached a point where our theory for the very large appears irreconcilable (mathematically) with our theory for the very small. But the point I’d make is that mathematics not only gives us our best description of reality, it also delineates the limitations of any particular theory. Consequently, I contend there will always be a gap.

 

Physicists say that the best we can do is provide a model and that model is always mathematical. Hawking made this point in his book, The Grand Design. So the model describes the laws, or habits, to the extent that we understand them at the time, and that it gets updated as we learn more.

 

Tallis mentions the well-known example of Newton’s ‘laws’ being surpassed by Einstein’s. But here’s the thing: the ‘inverse square law’ still applies and that’s not surprising, as it’s dependent on the Universe existing in 3 spatial dimensions. So we not only have a ‘law’ that carries over, but we have an explanation for it. But here’s another thing: the 3 spatial dimensions in combination with the single dimension of time is probably the only combination of dimensions that would allow for a universe to be habitable. Cosmologist and Fellow of the Royal Society, John D Barrow, expounds on this in some detail in his book, The Constants of Nature. (As a side note, planets can only remain in stable orbits over astronomical time periods in 3 dimensions of space.) So where I depart philosophically from Tallis is that there are fundamental parameters in the Universe’s very structure that determine the consequences of something existing that can understand that structure. 

 

Nevertheless, I agree with Tallis to the extent that I think the term, 'law', is a misnomer, and I think a better word is ‘principle’. If one goes back to Einstein’s theory of gravity replacing Newton’s, it introduces a fundamental principle called the 'principle of least action', which I think was pointed out by Emmy Noether, not Einstein. As it turns out, the principle of least action also ‘explains’ or ‘describes’ optical refraction, as well as forming the basis of Richard Feynman’s path integral method for QED (quantum electrodynamics). The principle of least action, naturally, has a mathematical formulation called the Lagrangian.

 

Speaking of Emmy Noether, she derived a famous mathematical theorem (called Noether’s theorem) that is a fundamental ‘principle’ in physics, describing the intrinsic relationship between symmetries and conservation laws. It’s hard to avoid the term, 'law', in this context because it appears to be truly fundamental based on everything we know.

 

So, is this a case of confusing the map with the terrain? Maybe. The Universe doesn’t exist in numbers – it exists as a process constrained by critical parameters, all of which can only be deciphered by mathematics. To give just one example: Planck’s constant, h, determines the size of atoms which form the basis of everything you see and touch.

Other relevant posts: the-lagrangian-possibly-most.html

                                   the-universes-natural-units_9.html