In Conversation about Karma and Rebirth

This post is to accompany an interview with me by Matthew O'Connell of the Imperfect Buddha Podcast. Most of what I said was first written in the web pages of this blog, so it shouldn't surprise anyone familiar with my writing, but it might interest readers, especially those who don't know me, to hear me in conversation. We covered a good deal of ground as one might imagine with such a large topic. My book on the subject currently stands at about 170,000 words over 500 pages. I'm editing it now, but can't say when it will be finished.

We talked a lot about my discovery that karma and rebirth can't work based on any of the traditional models. Matthew focussed particularly on my essay, There is No Life After Death, Sorry, which recapitulates Sean Carroll's arguments against any afterlife based on the equation he is now calling The Core Theory:

"It’s a good equation, representing the Feynman path-integral formulation of an amplitude for going from one field configuration to another one, in the effective field theory consisting of Einstein’s general theory of relativity plus the Standard Model of particle physics." (Now available as a tee-shirt in the USA).

What we need to understand about this equation is that at the mass, energy, and length scales relevant human experience, we can describe the behaviour of matter and energy very, very accurately. No extra force needs to be added to explain any observed behaviour of matter and energy on these scales. If there were other forces, of any kind, that could affect matter on this scale (and thus be part of our experience of the world), then we'd have seen some evidence of them in the millions of experiments carried out to date. If they cannot affect matter then they are of no interest as they cannot make a difference to us.

I also talked a little bit about how karma contradicts dependent arising, i.e. what I have called the problem of Action at a Temporal Distance, and how the several solutions to this problem do not stand up to scrutiny. These have been the subject of a number of recent essays that can be found under the heading Karma and Rebirth. In fact I've put a lot more more effort into this kind of argument than I have the science-based argument.

Karma and Rebirth Have Never Worked

Matthew, in an attempt to move the discussion along, begins to ask me, "So, if we get rid of karma and rebirth...". As you can hear, I interrupt at this point because something occurred to me that I had not thought of before. It's not that we "get rid" of anything. I don't advocate getting rid of karma and rebirth. At no stage in Buddhist history have we ever had a workable theory of either karma or rebirth. We cannot get rid of what we never had it to begin with. 

We never had a workable theory of karma. Our theories of karma always contradicted dependent arising. Even when Buddhist intellectuals tweaked dependent arising to come up with the Theravāda doctrine of momentariness or the bīja/ālayavijñāna theory of the Yogacārins (which currently dominate the Buddhist intellectual landscape), what I've shown is that even these more sophisticated versions of the karma doctrine do not work as explanations (See The Logic of Karma). Other explanations such as the sarva-asti-vāda or the pudgala-vāda, which were popular in North India for a time, did not work either though they were ingenious alternatives to the explanations that by accident of history are familiar to us today. The ingenuity doesn't become apparent until one realises what they were grappling with, i.e. action at a temporal distance. It is such a huge problem, and yet the Buddhist world suffered a collective case of amnesia about it. Once it was the driving force in the development of the most influential schools of Buddhist thought, with at least two schools taking their name from their solution to the problem. Without understanding the problem many of the major developments in Buddhist thought don't make any sense.

We never had a workable theory of rebirth either. Rebirth either destroyed the connection between action and consequence, thereby destroying the possibility of morality; or it proposed a definite and substantial continuity which allows for morality, but is eternalistic. If the person who experiences the consequences is not me, then I won't care (as much) about the consequences. If it is me, then I seem to be altogether too substantial in an impermanent universe. Early commentators and systematisers tried to get around this by arguing that it is neither me or not me (e.g. Milindapañha), but this simply fails to meet any reasonable criteria for a workable morality (See Unresolvable Plurality in Buddhist Metaphysics?). As far as morality is concerned, it has to be me. But according to Buddhist metaphysics, it certainly cannot be me. The result is an intellectual stalemate. Not that Buddhists ever admit this. No, they seamlessly segue between non-continuity when talking about metaphysics, and continuity when talking about ethics without anyone ever noticing what they are doing. I listened to and read Buddhists doing this for about 20 years before I realised that they were doing it. We can charitably chalk this up to pragmatism, but it does mean that dependent arising cannot explain rebirth or morality.

Dependent arising, the explanation for how mental states arise, cannot explain karma, rebirth, or ethics. This is already clear from Buddhist śāstras composed in the period ca 200-400 CE. Nāgārjuna says as much in his second-century work the Mūlamadhyamakakārikā (Chapter 17.1-6). Unfortunately for Nāgārjuna, his radical alternative of treating the whole shebang as like an illusion never caught on in the mainstream. I think his solution, while metaphysically more tenable, pragmatically could not be used as the basis of a system of morality. It required that awful Buddhist fudge: the Two Truths. The Two truths formalises the me/not-me hedge and makes it a feature rather than a bug. But any Buddhist theory couched in terms of existence or non-existence, let alone any absolutes, is faulty.

Modern science also shows us that dependent arising is not a good explanation of how matter and energy work either. I play down the role of science in critiquing karma and rebirth because in my experience Buddhists simply dismiss any inconvenient science as "Materialism" and stop paying attention. Such critiques are often seen as attacks on Buddhism itself, which Buddhists take rather personally. But the critique is there, it's quite comprehensive and compelling. The main problem for Buddhists who wish to deny it, is that they end up having to re-write the laws of physics. And I have yet to see any Buddhist even try to do this.

Sometimes, even within the same anti-science context, science can be seen as the saviour of Buddhism. Buddhists do this in two main ways. The first is through drawing false analogies, usually between Buddhism and quantum mechanics. I've dealt with this problem at some length before in two essays that try to debunk the kinds of claims that Buddhists make (see under Quantum Mechanics).

The second way is looking for confirmation of our beliefs in the empirical results of studies of the brain and behaviour under the influence of Buddhist practices. As far as I can tell this research is certainly worth pursuing. But the field is rife with confirmation bias and needs to find some rigour. We need to pay attention to study design (especially sample size), start doing pre-registration of studies, and publication of negative results before we can get too excited. The buzz word in this kind of work is reproducibility. We are not there yet. And even if we were the evidence is for a fairly mundane form of efficacy. Meditation causes measurable changes in the brain that probably affect how we perceive ourselves, other people, and the world in general. It has nothing to say about karma, or rebirth. 

Modernists Responses to the Crisis in Buddhist Doctrine

One of the ways that Buddhist Modernists negate some of the criticism of traditional Buddhism is to read inconvenient aspects of Buddhism as allegorical. They argue that we have to understand rebirth as an allegory, a symbol of some psychological process that plays out in our lives. A fine example of this is an essay by Alan Peto I stumbled on recently. In Is Buddhism Bewitched With Superstition? Peto puts forward exactly this kind of argument about superstition. However, in reading his argument I realised that while his central values were modernist, he none-the-less was endeavouring to justify his Modernist readings in traditional Buddhist terms.

There was the inevitable reference to the Pāḷi Canon, for example, in which the character of the Buddha is portrayed as reprimanding his followers for being superstitious (the word used is actually maṅgalika, but superstitious is not too bad a translation). This is read literally, rather than allegorically, as The Buddha telling his followers to abandon superstition. "Basically, the Buddha is saying that we should not fall into the trap of superstition, but instead pursue and gain wisdom." So if it fits our preconceptions, read it literally; if it does not, then take it as allegory.

Because there is a canonical injunction against it, the argument goes, there is no superstition in Buddhism, or at least in true Buddhism. In fact an injunction against something is evidence for the opposite, i.e. that it was widely practised. This leads us to the realisation that, in practice, Buddhists are really a very superstitious bunch. But how did pristine, rational Buddhism become infected with irrational elements? According to Peto, it is the creeping influence of "beliefs and traditions of society". Unfortunately there is simply no evidence for an originally rational Buddhism. That entity is a fiction of the modern imagination. As far as we know, Buddhism was never rational, did not decline over time. Indeed the opposite is evidence, major efforts went into making Buddhism more rational over time. Repeated attempts were made to solve the problems apparent in early formulations of Buddhism.

In another essay on rebirth, Peto tells us:

"While karma is referred to in popular culture as some sort of supernatural force (almost godlike) that determines your “fate”, but it is nothing like that at all."

Which is simply not true. Karma is the supernatural force that links willed actions and their consequences over time. It is supernatural because it cannot be accounted for by natural forces. In this case however, pre-modern Buddhists did see karma as a natural force. But mind you so were the miracles associated with the birth of the Buddha. So were the various spirits (benign and demonic) which abound in the pages of the Canon. Peto actually doesn't tell us what karma is, if it is not a supernatural force, but he hints that it is like "cause and effect" (which is not the traditional Buddhist view, but one clearly influenced by modernism). This particular allegory works because cause and effect is something that everyone intuitively understands and non-reflectively believes. Our understanding of cause and effect grows out of our experience of gaining control of our limbs as infants and learning how to use them to manipulate objects in the world. But karma is in fact nothing like this. Karma not only defies our modern understanding of cause and effect by separating the two ends of the relationship in time and space, but defies the traditional understanding for the same reasons! The consequence of the action is stored up until the end of your life, and then it manifests as the arising of vijñāna in another, embryonic, being either in the moment after death or after some time in a kind of limbo.

How this is achieved is unclear. For example, according to most schools of thought, the skandhas are definitely not transferred. So it is not personality, intelligence or experience, that are transferred, nor strictly speaking could it include memories (which are covered by the skandhas). And yet somehow the results of our actions are visited upon that embryo as it lives and dies. 

The approach falls well short of coherence. Modernism is applied unconsciously and inconsistently to patch the inconsistent tradition with inconsistent results. This is perhaps the biggest problem of Modernist Buddhism, i.e. the failure to fully embrace Modernism and apply it consistently.


Comments

Does the fact that so far no model of Karma and Rebirth works mean that there is no model that can possibly work? Probably. We've had 2000 years to think about it. The brightest minds of Buddhist history thought about it. And got nowhere. Now we are in a worse situation, because we must also consider science. Physics shows that there are strict limits on how matter and energy can behave and that these limits appear to be universal. At the mass, energy, and length scales relevant to human experience, this means that no afterlife is possible. So rebirth is ruled out, except as allegory and I side with those who find allegory distasteful. Of course it is always possible that someone will turn up with reliable evidence that the Core Theory is wrong. But anecdote is certainly not going to cut it as evidence in that argument. And any new evidence that would allow for an afterlife would require a whole new understanding of physics and chemistry. Again, this is possible, but nothing like this is on offer at present. What's on offer is philosophical (i.e. ontological) dualism, which states as an axiom that the mind is not to be understood through studying matter and energy. But dualism is also ruled out by the Core Theory. If the other stuff could affect our body and, in particular, our brain then it would be obvious to detectors other than the brain - there are only so many ways to influence matter;. Matter itself shows no signs of being nudged by forces other than the four so far identified (of which we can observe two unaided by machinery: gravity and electromagnetism). 

Many people get to this point in the discussion and the same question arises as Matthew asked me: "Now what?". I didn't answer that question very well in the interview I thought, so this is my attempt to do better.

So, "Now what?"

Now we need to take stock. It is only fair that we allow time to consolidate our arguments and for people to catch up if they wish. When you undermine someone's worldview to the point of collapse, a good deal of what they value suddenly must be reassessed. This is not easy and must take time. Many people will be so strongly committed to the traditionalist view are not interested in a major reassessment of their life and work, especially not on my say so. I expect virtually all people who've made life-long vows of celibacy, or those who make their living from traditionalist Buddhism, will be in this camp.

I think we have to take the psychology of belief seriously and not expect everyone to drop everything just because we have better facts. My case study for this has been the problem of communicating evolution, which in many respects has been disastrous. According to some surveys, only about half of Britons believe in evolution. Less Americans. Buddhists who agree with me about karma and rebirth ought to take evolution as a cautionary tale. We can easily screw this up, by failing to express enough kindness towards the people whose views we disagree with. My role in this is to establish new facts. I'm not a diplomat or a politician.

The problems we face are not yet well enough understood. My work, for example, only scratches the surface and my ability to persuade people is quite limited. People who are smarter and/or better connected need to be exposed to my conclusions and to test the logic of my argument. My book on this material might help with that, but I ought also to write something more pithy for an academic journal and see if I can get it through the editorial and review processes. At the very least I'd like to write something about the Problem of Action at a Temporal Distance for a journal. Other's need to take my ideas and see if they stand up to scrutiny. Not just in the sense of accusing me of Materialism (believe me this happens all too often), but by looking again at my primary sources, at the Kathavatthu, the Abhidharmakośabhāṣya, and the Mūlamadhyamakakārikā (which ideally involves being able to read Pāḷi, Chinese and Sanskrit; though all three are translated into English); and at my secondary sources (particularly David Bastow and Collett Cox). Someone needs to assess how well or how badly I've understood the sources, and either way to develop the ideas I'm proposing here. But the reality is that this is extremely unlikely to happen. That dynamic is almost entirely lacking in Buddhist scholarship even when the idea is put forward by a well know scholar with qualifications and a teaching post in a university. Most scholars are too busy pursuing their own avenues of research to spend time criticising the work of others. 80% of social science journal articles are never cited at all, so the problem goes beyond Buddhist Studies. Though I may say that David Drewes is a positive example of someone who does engage in this way. 

Interviews like the one for Imperfect Buddha Podcast are valuable in the sense that a friendly discussion of challenging material is possible, and the discussion reaches a new audience. Most of the time I don't go around trying to upset people, so I tend to pull my punches when talking to them if I think they are unlikely to agree with me. I have only one or two friends with whom I can be completely unguarded about what I say on these subjects. Some people I know have quite strong views themselves, often developed over decades. I tend not to insist on my own conclusions at the expense of another's. Something about the dynamic of the interview allowed me to state my conclusions without hedging. To put it out there in a more public way. And that felt good. Maybe there will be some response from IBP's audience that I could never get from my blog. Matthew says his own beliefs might have shifted as a result of talking to me. That's more than I could have hoped for.

Once the ideas have been more rigorously tested and refined, and once a lot more people with a stake in the game are on board, then would be the time to start exploring what to do next. I'd prefer to see us coming up with something cooperatively, than for Buddhists to continue atomising. If we get dozens or hundreds of competing models then it will take a very long time to sort out which is best. In my mind what Buddhism lacks is something like Sean Carroll's Core Theory. With a modern Buddhist Core Theory we could explain how our practices work to bring about positive change. The way that mental states arise and pass away will most likely be at the heart of our Core Theory. This is also extremely unlikely. 

The likelihood is that in 50 years time I'll be long dead and all this will be forgotten. And I will have changed nothing. Life is absurd, eh?  

~~oOo~~

My thanks to Matthew and Stuart of the Imperfect Buddha Podcast for their interest and the opportunity to talk to them and their audience about my ideas. 

Reality. Again.

There's a lot of talk about reality in Buddhism. Buddhists will often claim that our meditations will give a person direct access to reality, or knowledge of reality. I've come to see that these claims are bunk. Part of the problem is that our Iron Age predecessors introduced a term yathābhūta-ñāṇadassana which is taken to mean "knowledge and vision of things as they are". Now these Iron Age predecessors were not seeking knowledge of reality by any definition of that word that might be relevant to a modern reader. They sought knowledge of the origins and ending of suffering, where suffering was primarily experienced through repeated rebirth into the world. They claimed to have knowledge of how the rebirth process works and the conditions which lead to suffering. At no point do they claim knowledge of reality as we understand that term.

One of the problems we have in the philosophy of science is that classical mechanics is a description of reality as we experience it, but quantum mechanics is not a description of any reality we could experience. Of course we can experience the classical consequences of quantum phenomena - the scattering pattern of the two-slit experiment, for example, is a classical consequence of the quantum phenomenon. But we do not experience the phenomenon inferred by quantum mechanics (a photon passing through both slits simultaneously and interfering with itself). All the clever people do is work out mathematically how to make the same result appear in their calculations. Sure the calculations are accurate, but they have an entirely uncertain relationship to reality. Given that we have an equation that is accurate at predicting the classical consequences of quantum phenomenon, it is tempting to think we have a map of some hidden territory. But nothing could be less certain than this conclusion. No one understands the reality that quantum mechanics describes, however, good they are at fiddling with the parameters to create classical consequences. Reality at that level is a black box and likely to remain so forever. 

We have much the same problem with General Relativity. These days we wonder how stupid people must have been to think that the sun goes around the earth. But just by looking at the sun it is very difficult indeed to  see this. The ending of the geocentric worldview was not brought about by insights into the sun, but into the planets. It was understanding that the planets were not in orbit around the earth, but around the sun that made us question the geocentric model. General Relativity tells us that there really is no force of gravity. The reality is that masses cause spacetime to curve in around them. We know from Newton that masses travel in a straight line unless some force acts upon them (from the First Law of Motion). So when we see an object moving in a curved path we naturally conclude that some force is acting on it. If we throw a ball it travels in a curve (a specific kind of curve known as a parabola) and falls to the earth. As one of my Buddhist teachers once said at a public meeting "Gravity is a larger mass attracting a smaller one". That's completely wrong of course and attracted gasps of horror from the Cambridge audience (there was more than one physics PhD in the room!). But that does describe the experience. Two tennis balls don't attract each other the way that the earth and a tennis ball do. The fact that the earth moves an infinitesimal amount towards the tennis ball is obscure because the effect is too small for us to measure, let alone see. Experience suggests that objects are attracted to the earth in a way that they are not attracted to each other. 

That's just how it seems. But it is not the case at all. A very cleverly designed experiment in Cambridge's Cavendish laboratory showed that small masses do appear to attract each other gravitationally, but that the apparent force is very tiny because the masses involved are so small. Even so all this is incidental because Einstein's theory tells a different story. General Relativity tells us that the reason the ball follows a curved path is that spacetime is strongly curved near the surface of the earth. The ball is doing it's best to obey Newton's First Law of Motion and travel in a straight-line. What it "discovers" is that there are no straight lines near the earth. So the ball follows the curvature of spacetime which happens to be in the shape of a parabola. 

Try as we might we cannot see spacetime. We know it must exist precisely because of things like light propagating through space, and the path of light being bent near masses (light is itself massless so there is no possibility of a gravitational interaction). There is an enormous body of evidence which makes us quite certain that we have understood spacetime under normal circumstances. However, the theory itself must be incomplete because it breaks down at the Big Bang. The maths says that at the Big Bang, the dimensions of spacetime were all zero; implying infinite density. My many physics teachers over the years always emphasised that when your calculation produces an infinity, then you have done something wrong and must go back and check your working. Reality does not contain infinities, or if it did then everything would be incomprehensible different than it is. Either way we do not understand the Big Bang because it involves infinity. 

No amount of mediation and insight is going to directly help us with these problems. One can imagine that meditation and insight might help a physicist or mathematician in their work, but, on the whole, the two projects are completely unrelated. The experience of rarefied mental states does not shed light on reality. So what does it shed light on? Experience. It ought to come as no surprise that what we gain insight into when we examine our experience, is experience itself. I'm more and more convinced that specific types of meditative experiences are what the Buddhists were aiming at. They come under the broad heading of emptiness. Of course, there are many kinds of experience that one can have in meditation. Some of incidental or spurious and others profound. But in terms of the liberating insights said to end rebirth or being (bhava) I am beginning to focus my attention on those states in which there is no content: so sense experience and no normal mental experience, and yet still some kind of experience. I first noticed this in 2008 in an essay called Communicating the Dharma:

Further there are sensations associated with desire (chanda), thinking (vitakka) and with the perceptions (saññā). Sensations are present in all the combinations of presence or absence of these three. When they are all absent something new arises that is simply described as stretching out for (āyāmaṃ) the attainment of the as-yet unattained (appattassa pattiyā), and finally there are sensations associated with this.

It is in these states of emptiness that one has a kind of transformative experience that reorganises the psyche and the relationship with sensory experiences. From the same essay:

The Buddha here is saying something quite profound - that if one looks beyond mundane everyday experiences, if one can put aside desire, intellectual twisting and turning, if one reaches beyond the normal scope of consciousness - then one finds not annihilation, but something as yet unattained. 

And I think it is this kind of experience that is being described or discussed in the Perfection of Wisdom texts. Consider for example this abstruse discussion between Subhuti and Śāriputra from the first chapter of the Aṣṭasāhasrikā-prajñāpāramitā (Chp1, para 7, my translation.)

Then indeed, Elder Śāriputra said this to Elder Subhūti, “Still, Elder Subhūti, does that mind which is without mind, exist?” 

That said, Elder Subhūti said this to Elder Śāriputra, “With respect to a state of being without mind (acittatā) can existence (astitā) or non-existence (nāstitā) be found or obtained?”

Sāriputra said, “This is not [the case], Elder Subhūti!” 

Subhūti said, “If, Elder Śāriputra, existence or non-existence are not found or obtained there in the state of being without mind, is the question, 'Does that mind which is without mind, exist?' appropriate for you Elder Śāriputra?”

When that was said, Elder Śāriputra said this to Elder Subhūti, “So what is this state of being without mind, Elder Subhūti?” 

Subhūti said, “Śāriputra, the state of being without mind (acittatā) is immutable (avikāra), does not falsely distinguish (avikalpa)  [between real and unreal].

This is one of several passages in the Aṣṭa that are reminiscent of the Kaccānagotta Sutta (SN 12.15) in denying the applicability of the ideas of existence & non-existent or real & unreal in discussions about Buddhism. These concepts do not apply to the world of experience.

Following D T Suzuki and Edward Conze, we usually take this kind of self-negating language in the Perfection of Wisdom texts to be an attempt to confuse the rational mind in accordance with Romantic anti-intellectualism. Romantics believe that ultimate truth comes rather from the inner spirit than from the intellect. The idea here is that by tying the rational mind up in riddles, the spirit can assert itself. Apart from the fact that Romantics interpretations are all dualistic and eternalistic, and thus grossly false by most Buddhist standards, this procedure is akin to banging one's head against a brick wall in pursuit of wisdom. Treating the entire Prajñāpāramitā literature as a gigantic koan is simply a mistake. Just because Suzuki and Conze were confused does not mean that confusion is the only possible response to these texts. 

On the other hand, if we assume that the context of the dialogue is two master meditators trying to articulate the experience of emptiness, in the sense of contentless meditative states, then we can stop banging our head against the wall. I don't claim to have unlocked the language of the text, but I am hopeful that abandoning Conze's awful translation and re-reading the text as though it makes sense will be fruitful. Compare this to my comments on Paul Harrison's work on the comprehensibility of the Vajracchedikā-prajñāpāramitā. Part of my optimism stems from several essays written about emptiness by my colleagues in the Triratna Order, one of which is available for public consumption (the others are embargoed as they are part of an in-house discussion in the Order, I am trying to encourage my colleagues to make their work more widely available). Satyadhana's essay The Shorter Discourse on Emptiness (Cūḷasuññatasutta, Majjhima-nikāya 121): Translation and Commentary, in the Western Buddhist Review, gives us a flavour of the discussion. It seems to me that there are important continuities that have yet to be explored, but which promise to shed a great deal of light on the intentions of the Prajñāpāramitā authors.

Buddhists often assume that because Quantum Mechanics and Emptiness are both confusing and reputedly profound, that one must shed light on the other. I've done my best to debunk this fallacy in two previous essays (Erwin Schrödinger Didn't Have a Cat and Buddhism and the Observer Effect in Quantum Mechanics). The reality that we struggle to understand through the abstruse mathematics is not the same as the reality that we seek to understand through religious exercises. The mistake seems to rest on a misunderstanding of what the word "reality" means. Scientists and meditators use the word in ways that are almost entirely unrelated.

~~oOo~~

This essay is partly inspired by a series of essays on the blog a filosofer's thots, starting here: Bohr’s reply to EPR (Part I) spotted in the Twitter feed of @seancarroll.

Why Artificial Intelligences Will Never Be Like Us and Aliens Will Be Just Like Us.

"Yet across the gulf of space, minds that are to our minds as ours are to those of the beasts that perish, intellects vast and cool and unsym-pathetic, regarded this earth with envious eyes, and slowly and surely drew their plans against us."

cosmicorigins.com

Artificial Intelligence (AI) is one of the great memes of science fiction and as our lives come to resemble scifi stories ever more, we can't help by speculate what an AI will be like. Hollywood aside seem to imagine that AIs will be more or less like us because we aim to make them like us. And as part of that we will make them with affection for, or at least obedience to us. Asimov's Laws of Robotics are the most well known expression of this. And even if they end up turning against us, it will be for understandable reasons. 

Extra-terrestrial aliens on the other hand will be incomprehensible. "It's like Jim, but not at we know it." We're not even sure that we'll recognise alien life when we see it. Not even sure that we have a definition of life that will cover aliens. It goes without saying that aliens will behave in unpredictable ways and will almost certainly be hostile to humanity. We won't understand them minds or bodies and we will survive only by accident (War of the Worlds, Alien) or through Promethean cunning (Footfall, Independence Day). Aliens will surprise us, baffle us, and confuse us (though hidden in this narrative is a projection of fears both rational and irrational). 

In this essay I will argue that we have this backwards: in fact AI will be incomprehensible to us, while aliens will be hauntingly familiar. This essay started off as a thought experiment I was conducting about aliens and a comment on a newspaper story on AI. Since then it's become a bit more topical as a computer program known as a chatbot was trumpeted as having "passed the Turing Test for the first time". This turned out to be a rather inflated version of events. In reality a chatbot largely failed to convince the majority of people that it was a person despite a minor cheat that lowered the bar. The chatbot was presented as a foreigner with poor English and was still mostly unconvincing. 

But here's the thing. Why do we expect AI to be able to imitate a human being? What points of reference would a computer program ever have to enable it to do so?

Robots Will Never Be Like Us.

There are some fundamental errors in the way that AI people think about intelligence that will begin to put limits on their progress if they haven't already. The main one being that they don't see that human consciousness is embodied. Current AI models tacitly subscribe to a strong form of Cartesian mind/body dualism: they believe that they can create a mind without a body. There's now a good deal of research to show that our minds are not separable from our bodies. I've probably cited four names more than any other when considering consciousness: George Lakoff, Mark Johnson, Antonio Damasio, and Thomas Metzinger. What these thinkers collectively show is that our minds are very much tied to our bodies. Our abstract thoughts are voiced using on metaphors drawn from how we physically interact with the world. Their way of understanding consciousness posits the modelling of our physical states as the basis for simple consciousness. How does a disembodied mind do that? We can only suppose that it cannot.

One may argue that a robot body is like a human body. And that an embodied robot might be able to build a mind that is like ours through it's robot body. But the robot is not using it's brain primarily to sustain homoeostasis mainly because it does not rely on homoeostasis for continued existence. But even other mammals don't have minds like ours. Because of shared evolutionary history we might share some basic physiological responses to gross stimuli that are good adaptations for survival, but their thoughts are very different because their bodies and particularly their sensory apparatus are different. An arboreal creature is just not going to structure their world the way a plains dweller or an aquatic animal does. Is there any reason to suppose that a dolphin constructs the same kind of world as we do? And if not then what about a mind with no body at all? Maybe we could communicate with dolphin with difficulty and a great deal of imagination on out part. But with a machine? It will be "Shaka, when the walls fell." For the uninitiated this is a reference to a classic of first-contact scifi story. The aliens in question communicate in metaphors drawn exclusively from their own mythology, making them incomprehensible to outsiders, except Picard and his crew of course (there is a long, very nerdy article about this on The Atlantic Website). Compare Dan Everett's story of learning to communicate with the Pirahã people of Amazonia in his book Don't Sleep There Are Snakes.

Although Alan Turing was a mathematical genius he was not a genius of psychology. And he made a fundamental error in his Turing Test in my opinion. Our Theory of Mind is tuned to assume that other minds are like ours. If we can conceive any kind of mind independent of us, then we assume that it is like us. This has survival value, but it also means we invent anthropomorphic gods, for example. A machine mind is not going to be at all like us, but that doesn't stop us unconsciously projecting human qualities onto it. Hypersensitive Agency Detection (as described by Justin L Barrett) is likely to mean that even if a machine does pass the Turing Test then we will have over estimated the extent to which it is an agent.

The Turing Test is thus a flawed model for evaluating another mind because of limitations in our equipment for assessing other minds. The Turing Test assumes that all humans are good judges of intelligence, but we aren't. We are the beings who see faces everywhere, and can get caught up in the lives of soap opera characters and treat rain clouds as intentional agents. We are the people who already suspect that GIGO computers have minds of their own because they breakdown in incomprehensible ways at inconvenient times and that looks like agency to us! (Is there a good time for a computer to break?). The fact that any inanimate object can seem like an intentional agent to us, disqualifies us as judges of the Turing Test. 

AI's, even those with robot bodies, will sense themselves and the world in ways that will always fundamentally different to us. We learn about cause and effect from the experience of bringing our limbs under conscious control, by grabbing and pushing objects. We learn about the physical parameters of our universe the same way. Will a robot really understand in the same way? Even if we set them up to learn heuristically through electronic senses and a computer simulation of a brain, they will learn about the world in a way that is entirely different to the way we learned about it. They will never experience the world as we do. AIs will always be alien to us. 

All life on the planet is the product of 3.5 billion years of evolution. Good luck simulating that in a way that is not detectable as a simulation. At present we can't even convincingly simulate a single celled organism. Life is incredibly complex as this 1:1 million scale model of a synapse (right) demonstrates. 

Aliens Will Be Just Like Us.

Scifi stories like to make aliens as alien as possible, usually by making them irrational and unpredictable (though this is usually underlain by a more comprehensible premise - see below).

In fact we live in a universe with limitations: 96 naturally occurring elements, with predictable chemistry; four fundamental forces; and so on. Yes, there might we weird quantum stuff going on, but in bodies made of septillions (10²³) of atoms we'd never know about it without incredibly sophisticated technology. On the human scale we live in a more or less Newtonian universe.

Life as we know it involves exploiting energy gradients and using chemical reactions to move stuff where it wouldn't go on its own. While the gaps in our knowledge still technically allow for vitalistic readings of nature, it does remove the limitations imposed on life by chemistry: elements have strictly limited behaviour the basics of which can be studied and understood in a few years. It takes a few more years to understand all the ways that chemistry can be exploited, and we'll never exhausted all of the possibilities of combining atoms in novel ways. But the possibilities are comprehensible and new combinations have predictable behaviour. Many new drugs are now modelled on computers as a first step.

So the materials and tools available to solve problems, and in fact most of the problems themselves, are the same everywhere in the universe. A spaceship is likely to be made of metals. Ceramics is another option, but they require even higher temperatures to produced and tend to be brittle. Ceramics sophisticated enough to do the job suggest a sophisticated metal-working culture in the background. Metal technology is so much easier to develop. Iron is one of the most versatile and abundant metals: other mid-periodic table metallic elements (aluminium, titanium, vanadium, chromium, cobalt, nickel, copper, zinc, etc) make a huge variety of chemical combinations, but for pure metal and useful alloys, iron is king. Iron alloys give the combination of chemical stability, strength to weight ratio, ductility, and melting point to make a space ship. So our aliens are most likely going to come from a planet with abundant metals, probably iron, and their space ship is going to make extensive use of metals. The metals aliens use will be completely pervious to our analytical techniques. 

Now in the early stages of working iron one needs a fairly robust body: one has to work a bellows, wield tongs and hammer, and generally be pretty strong. That puts a lower limit on the kind of body that an alien will have, though strength of gravity on the alien planet will vary this parameter. Very gracile or very small aliens probably wouldn't make it into space because they could not have got through the blacksmithing phase to more sophisticated metal working techniques. A metal working culture also means an ability to work together over long periods of time for quite abstract goals like the creation of alloys composed of metals extracted from ores buried in the ground. Thus our aliens will be social animals by necessity. Simple herd animals lack the kind of initiative that it takes to develop tools, so they won't be as social as cows or horses. Too little social organisation and the complex tasks of mining and smelting enough metal would be impossible. So no solitary predators in space either. 

The big problem with any budding space program is getting off the ground. Gravity and the possibilities of converting energy put more practical limitations on the possibilities. Since chemical reactions are going to be the main source of energy and these are fixed, gravity will be the limiting factor. The mass of the payload has to be not too large to be to costly or just too heavy, and it must be large enough to fit a being in (a being at least the size of a blacksmith). If the gravity of a n alien planet was much higher than ours it would make getting into space impractical - advanced technology might theoretically overcome this, but with technology one usually works through stages. No early stage means no later stages. If the gravity of a planet was much lower than ours then the density would make large concentrations of metals unlikely. It would be easier to get into space, but without the materials available to make it possible and sustainable. Also the planet would struggle to hold enough atmosphere to make it long-term liveable (like Mars). So alien visitors are going to come from a planet similar to ours and will have solved similar engineering problems with similar materials. 

Scifi writers and enthusiasts have imagined all kinds of other possibilities. Silicon creatures were a favourite for a while. Silicon (Si) sits immediately below carbon in the periodic table and has similar chemistry: it forms molecules with a similar fourfold symmetry. I've made the silicon analogue (SiH₄) of methane (CH₄) in a lab: it's highly unstable and burns quickly in the presence of oxygen or any other moderately strong oxidising agent (and such agents are pretty common). The potential for life using chemical reactions in a silicon substrate is many orders of magnitude less flexible than that based on carbon and would of necessity require the absolute elimination of oxygen and other oxidising agents from the chemical environment. Silicon tends to oxidise to silicon-dioxide SiO₂ and then become extremely inert. Breaking down silicon-dioxide requires heating to melting point (2,300°C) in the presence of a powerful reducing agent, like pure carbon. In fact silicon-dioxide, or silica, is one of the most common substances on earth partly because silicon and oxygen themselves are so common. The ratio of these two is related to the fusion processes that precede a supernova and again are dictated by physics. Where there is silicon, there will be oxygen in large amounts and they will form sand, not bugs. CO₂ is also quite inert, but does undergo chemical reactions, which is lucky for us as plants rely on this to create sugars and oxygen.

One of the other main memes is beings of "pure energy", which are of course beings of pure fantasy. Again we have the Cartesian idea of disembodied consciousness at play. Just because we can imagine it, does not make it possible. But even if we accept that the term "pure energy" is meaningful, the problem is entropy. It is the large scale chemical structures of living organisms that prevent the energy held in the system from dissipating out into the universe. The structures of living things, particularly cells, hold matter and energy together against the demands of the laws of thermodynamics. That's partly what makes life interesting. "Pure energy" is free to dissipate and thus could not form the structures that make life interesting.

When NASA scientists were trying to design experiments to detect life on Mars for the Viking mission, they invited James Lovelock to advise them. He realised that one didn't even need to leave home. All one needed to so was measure the composition of gases in a planet's atmosphere, which one could do with a telescope and a spectrometer. If life is going to be recognisable, then it will do what it does here on earth: shift the composition of gases away from the thermodynamic and chemical equilibrium. In our case the levels of atmospheric oxygen require constant replenishment to stay so high. It's a dead give away! And the atmosphere of Mars is at thermal and chemical equilibrium. Nothing is perturbing it from below. Of course NASA went to Mars anyway, and went back, hoping to find vestigial life or fossilised signs of life that had died out. But the atmosphere tells us everything we need to know. 

The Nerdist

So where are all the aliens visitors? (This question is known as the Fermi Paradox after the Enrico Fermi who first asked it). Recall that as far as we know the limit of the speed of light invariably applies to macro objects like spacecraft - yes, theoretically, tachyons are possible, but you can't build a spacecraft out of them! Recently some physicists have been exploring an idea that would allow us to warp space and travel faster than light, but it involves "exotic" matter than no one has ever seen and is unlikely to exist. Aliens are going to have to travel at sub-light speeds. And this would take subjective decades. And because of Relativity time passes slower on a fast moving object, centuries would pass on their home planet. Physics is a harsh mistress.

These are some of the limitations that have occurred to me. There are others. What this points to are a very limited set of circumstances in which an alien species could take to space and come to visit us. The more likely an alien is to get into space, the more like us they are likely to be. The universality of physics and the similarity of the problems that need solving would inevitably lead to parallelism in evolution, just as it has done on earth.

Who is More Like Us?

Unlike scifi, the technology that allows us to meet aliens will be strictly limited by physics. There will be no magic action at a distance on the macro scale (though, yes, individual subatomic particles can subvert this); there will be no time travel, no faster than light travel; no materials impervious to analysis; no cloaking devices, no matter transporters, and no handheld disintegrators. Getting into space involves a set of problems that are common to any being on any planet that will support life, and there are a limited set of solutions to those problems. Any being that evolves to be capable of solving those problems will be somewhat familiar to us. Aliens will mostly be comprehensible and recognisable, and do things on more or less the same scale that we do. As boring as that sounds, or perhaps as frightening depending on your view of humanity.

And AI will forever be a simulation that might seem like us superficially, but won't be anything like us fundamentally. When we imagine that machine intelligences will be like us, we are telling the Pinocchio story (and believing it). This tells us more about our own minds, than it does about the minds of our creations. If only we would realise that we're looking in a mirror and not through a window. All these budding creators of disembodied consciousness ought to read Frankenstein; or, The Modern Prometheus by Mary Shelly. Of course many other dystopic or even apocalyptic stories have been created around this theme, some of my favourite science fiction movies revolve around what goes wrong when machines become sentient. But Shelly set the standard before computers were even conceived of; even before Charles Babbage invented his Difference Engine. She grasped many of the essential problems involved in creating life and in dealing with otherness (she was arguably a lot more insightful than her ne'er-do-well husband). 

Lurking in the background of the story of AI is always some version of Vitalism: the idea that matter is animated by some élan vital which exists apart from it; mind apart from body; spirit as opposed to matter. This is the dualism that haunts virtually everyone I know. And we seem to believe that if we manage to inject this vital spirit into a machine that the substrate will be inconsequential, that matter itself is of no consequence (which is why silicon might look viable despite it's extremely limited chemistry; or a computer might seem a viable place for consciousness to exist). It is the spirit that makes all the difference. AI researchers are effectively saying that they can simulate the presence of spirit in matter with no reference to the body's role in our living being. And this is bunk. It's not simply a matter of animating dead matter, because matter is not dead in the way that Vitalists think it is; and nor is life consistent with spirit in the way they think it is.

The fact that such Vitalist myths and Cartesian Duality still haunt modern attempts at knowledge gathering (and AI is nothing if not modern) let alone modern religions, suggests that the need for an ongoing critique. And it means there is still a role for philosophers in society despite what Stephen Hawking and some scientists say (see also Sean Carroll's essay "Physicists Should Stop Saying Silly Things about Philosophy"). If we can fall into such elementary fallacies at the high-end of science then scientists ought to be employing philosophers on their teams to dig out their unspoken assumptions and expose their fallacious thinking.

~~oOo~~

Erwin Schrödinger Didn't Have a Cat

image: Erwin Schrödinger

"Science is the belief in the ignorance of experts."
Richard Feynman. "What is Science?"
The Physics Teacher Vol. 7, issue 6 (1969)

"I think I can safely say that
nobody understands quantum mechanics."
Richard Feynman. The Character of Physical Law (1965)

~~~~

SCHRÖDINGER'S CAT is one of the most famous thought experiments in the history of science. Erwin Schrödinger (left) used it to try to argue against adopting one approach Quantum Mechanics. Most people seem unaware that he was trying to highlight a problem with what was, in 1935, a controversial theory, but which has become the orthodoxy: namely the Copenhagen Interpretation of Quantum Mechanics . These days when we say Quantum Mechanics we usually mean the Copenhagen Interpretation of Quantum Mechanics (hereafter QM). Many people who know next to nothing about science, or about Schrödinger, have tried to co-opt Schrödinger's cat to show how there is a relationship between physics and Buddhism. Let me say at the beginning that I don't believe that there is any significant cross-over between physics and Buddhism, and that I hope to explain why in the rest of this post. Granted my degree is in chemistry and it was a long time ago; but I also studied physics, and I'm an ordained Buddhist, so I feel at least not-overly-unqualified to comment.

To begin with we need to be clear on scale. An atom is between 32 picometres and 225 picometres in diameter. A picometer is 1×10⁻¹² m, i.e. a trillionth of a metre, or 0.000000000001 m. By contrast a human hair is around 50 µm or 0.000005 m. So a single hair is about about 1.5 million helium atoms in diameter. Basically this scale is unimaginable, so let's put it another way: if the diameter an atom was the thickness of a single sheet of copier paper (0.08mm) then a human hair would be 120 metres in diameter. Amedeo Avogadro showed that 12g of carbon contains approximately 6 x 10²³ atoms of carbon. That is 600,000,000,000,000,000,000,000 (600 sextillion) atoms. If each carbon atom was 1 mm³ then the 12g of carbon would fill the Western Mediterranean Ocean (from Gibraltar to Sicily), with plenty to spare. In fact 12g of carbon (in the form of powdered soot) is about 2 teaspoons. In QM we're dealing with the subatomic world, with the protons, neutrons and elections, and the weirder particles which make up atoms. A proton is about 1/50th of the diameter of the smallest atom; while an electron is thought to be in the region of 10⁻²²m, which is one 10-billionth the diameter of a proton. Don't be fooled by our ability to write these properties down in numbers: they are highly abstract, unimaginable, incomprehensible, and none of us can draw on experience to get a sense of them. If you are still confident that any of this is relevant to human existence then read on.

Those with an interest in this subject will know that QM conceives of subatomic particles as waves (which can behave like particles under some conditions) that are described not in terms of physical properties, but in mathematical formulas. QM is the first theory of science to not be based on observations of physical properties, but to emerge from abstract mathematical speculation. [ 1 ] Though of course QM makes testable predictions about the behaviour of matter on the picometer scale. This description of sub-atomic particles as waves has some interesting consequences. One is that the particle is not a point in space, but is smeared out over space. Another is that all we can know about the particles in atoms are the odds of the particle being in any one place in space at any given time. What's more, as Heisenberg showed, if we know precisely where a particle is, then we can't simultaneously know how fast it is going - this is called the Uncertainty Principle.

Schrödinger's thought experiment related to a curious prediction arising out of the mathematics of waves (subsequently experimentally confirmed). Under certain circumstances two wavy particles can become 'entangled' which means that their waves combine into a single system, though they retain their identities. (Don't worry if you don't quite understand how this works - Feynman was not being ironic when he said that no one understands QM.) Schrödinger's problem was that this meant that observing some of the properties of one of the particles, meant having certain knowledge about the other particle because the two must be in opposition. The main property we are concerned with is called 'spin' - which relates to the magnetic properties of charged particles.

The two entangled particles can be in one of two spin states, but cannot both occupy the same state. With regard to the spin state of any single particle we can only talk about the probability that they will be in a given state at any time until we observe it. However, observing the spin of one entangled particle, determines which state the other will be in with 100% certainty without observing it, no matter where it is in the universe. This appears to contradict the limit introduced by Einstein's Special Theory of Relativity (1905) that nothing, not even information, can travel faster than the speed of light. But also, and even more weirdly, before an observation we can only think about spin states in terms of probabilities and the the maths tells us that the combined probabilities of the two particles being in any given state always equals one. The Copenhagen Interpretation says that this effectively means that the two entangled particles are both in both states simultaneously - the two states are superimposed as the jargon goes.

This is quite counter-intuitive, but it has been a boon for science-fiction because the spin states of the entangled particles are linked no matter how far apart they are - "spooky action at a distance" as Einstein facetiously referred to it - which if you aren't too fussy about details gives you an excellent medium for instantaneous communications across the vastness of space.

However, it begs the question: how can something be in two states at once until observed? It was in order to highlight these paradoxical aspects of QM that Schrödinger put his imaginary cat in the imaginary box. With it he placed a mechanism which would release cyanide gas, with a switch triggered by the decay of an atom of Uranium, the timing of which we cannot predict from theory. Close the lid of the box, prime the switch and think: is the cat alive at this moment, or is it dead? If the atom has not decayed the cat will be alive, and if it has decayed the cat will be dead. We can't know until we open the box and observe. Schrödinger invited us to think of the cat as a metaphor for the infinitesimal sub-atomic particle, whose wave was metaphorically entangled with the Uranium atom. If the cat truly was like a sub-atomic particle, then it was both alive and dead until the box was opened, and it was observed to be one or the other. He was trying to show that this is a ridiculous conclusion, and that therefore the Copenhagen Interpretation must be flawed. He lost that particular argument.

A lot of people jump from the picometre scale to the metre scale without any thought for the consequences of a trillion-fold change in scale - even though we know, for example, that our bath water doesn't really behave like an ocean! Or though we know that those pre-CGI movie special effects with models are totally unconvincing. The problem is that in a real cat there are several thousand sextillions of atoms, made up of many particles. Although each infinitesimal particle is a wave and subject to QM effects, these are averaged out over some tens or hundreds of thousands of sextillions of particles. The behaviour of any one particle, or even any million or billion particles, is not going to change the average properties of the cat. Unlike sub-atomic particles, cats simply do not wink in and out of existence; they are not smeared out over space (except perhaps when run over); and we can in fact know quite precisely (compared to the size of the cat) where a cat is and how fast it is moving at the same time. The Uncertainty Principle doesn't apply on the macro level. QM has almost no relevance to the macro world, to a world where objects are made up of septillions of atoms because of the averaging effect of so many particles - if weird stuff was happening we'd never know because a human hair is millions of atoms in diameter. And this is partly why Schrödinger was unable to undermine the Copenhagen Interpretation with this thought experiment, and why it has been co-opted by the targets of his critique, not to mention Buddhists! Actually sub-atomic particles are not alive and it is not ridiculous to argue that they can be in two superimposed states at once, even though it is ridiculous to argue it for a cat. In effect, Schrödinger's Cat proved nothing.

One of the unfinished tasks of modern physics is finding some way to marry QM with Relativity (E=mc² yadda yadda again we don't really understand this). This has proved elusive, though work is going on at both the empirical and the theoretical ends of the problem. So far no one has unequivocal evidence for, say, quantum gravity; and no one has been able to make the maths add up. It may in fact turn out that the two theories are not adequate to the task and that both will be subsumed into some larger construct (some people claim that String Theory will do it, if anyone can ever solve the equations; Stephen Hawking barracks for M-Theory if anyone can both figure out what equations are and how to solve them). Certainly dark matter and dark energy are causing a scramble to rework the Standard Model of Cosmology to account for the observations that gave rise to those terms. Often theories don't survive being scaled up by a dozen orders of magnitude, and this is the case for QM (so far).

It's pretty clear that QM, a mathematical abstraction, doesn't apply to our macro world. However it does have indirect consequences for us as QM issues have to be taken into account in designing new micro-processors which pack millions of transistors into square millimetres; and in nascent nano-technology. But in terms of our daily lives none of the observations of sub-atomic particles apply. None. The similarity of vocabulary is superficial and coincidental, just as the similarity of ethical jargon in various religions is largely superficial and coincidental! well, perhaps not entirely coincidental because like Schopenhauer, both Schrödinger and Niels Bohr were interested in so-called 'Eastern philosophy' and built some of it into the narrative.

Some weeks ago now, in the comments to my post on Rebirth and the Scientific Method Elisa and Krishna were asking: "why do Buddhists feel the need to justify their beliefs by appealing to science?" Part of my answer related to the way the scientific paradigm has dominated our lives for roughly 150 years. Science is incredibly successful in describing the physical world, and predicting new observations and properties of matter. Just look at the recent crop of Nobel Prizes to see the contribution that science makes. In a way it's obvious that we'd want to participate in that. It is a bit ironic that so few Buddhists are educated in the sciences, and tend to approach science with a mixture of abhorrence for perceived materialism, and credulous wonder at its success and authoritativeness.

I don't see much advantage in invoking the talisman of science in defence of religion, especially when on the whole we religieux are so ignorant of science (one of my teachers recently mentioned the way "larger bodies attract smaller ones" in a public talk. He's not an idiot, nor spiritually shallow, but he is clearly, painfully ignorant of science!). It so happens that Buddhists avoid some of the pitfalls of the modern world view (we don't have creation stories for instance), but though monotheism more obviously runs foul of science, I don't think we can sustain our traditional eschatologies, nor claims of ESP powers, nor to know the nature of 'reality', if we are working in a scientific paradigm. It's a minefield.

I don't think Buddhism on its own terms needs any scientific apologetic. Buddhism is originally the product of Iron Age India, and has adapted to many different cultural environments and world-views because, in my opinion, it is not so concerned with the realm of physics, it is concerned with the realm of the mind. Physics provides us with a far superior description of the physical world; but equally in the domain of the mind, and especially the problem of suffering, that Buddhism is far superior descriptively and practically (in terms of practices for working on the mind). This superiority in its own field is not a consequence of levels of technology or an understanding of physics. It's to do with observing our own minds. We don't need a Large Hadron Collider for this. We just need to sit quietly and observe our minds. It is a kind of empiricism, but we don't need to get caught up in making a 'science' out of it.

~~ oOo ~~

Notes

1. This feature of QM not deriving from observations of physical properties was recently the subject of an article in the New Scientist: Webb, Richard. 'Reality Gap' 21 August 2010, p.32-6. NS apparently subscribes to another uncertainty principle as the article title is quite changeable:
   • on the cover - The Ultimate Quantum Paradox
   • contents page - The Ultimate Paradox
   • printed article - Reality Gap
   • online article - Is quantum theory weird enough for the real world? [login required]
   • ScienceDirect article database - Quantum Mechanics: The Reality Gap [login required].
   (return to article)

(Note: Though I gather that Schrödinger loved women and a good party, I confess I'm not really sure whether he owned a cat. Some people claim that Schrödinger was a cat lover, and some that he was a cat hater, but I thought my title was catchy and ran with it. I hope my readers will allow me some poetic licence.)

image: Erwin Schrödinger (internet endemic, i.e. copied so many times that there is no longer a discernible source).

Feynman quotes from Wikiquote.

If you want to learn about Quantum Theory from one of the men who helped to develop it, then I can recommend these three lectures by Hans Bethe: Quantum Physics Made Relatively Simple. As the site says, the Prof is 93 years old and lecturing to the other residents at his retirement home.


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