some readings from the eBook
A six-year old platypus lives in her burrow beside a tiny creek in Tasmania. It is a world that she knows well. In some ways she knows her world more completely than we do ours, since, in addition to the senses we have, she has electroreceptors, so sensitive that they can detect the weak electric fields generated by muscle contractions. She uses those to locate her prey. But her world does not include oceans or deserts or volcanoes, or even the people who live not ten kilometres away, and the road that leads to their houses. The world of the platypus is small but intense. She knows what she needs to know, and no more.
I think an individual human brain/mind like yours or mine, is like an individual platypus. You, like me and like that platypus, are one particular outcome of an immensely long evolution. We too have individual worlds, though those worlds, your actuality and my actuality, are arguably larger than the actuality of the platypus. We know much more than we need to know. We know about oceans and deserts and volcanoes and roads and houses and people. In our different ways, we are familiar with music and mathematics and Paris and the Olympic Games. The shared Mind of our species, in which we individually participate, is very big. But it is hubris, simply hubris, to imagine that we know theTruth about theWorld or even that we know a lot of what might be knowable.
The radical empiricism, advocated in this book, enjoins humility. Our worlds and our truths are less than we think. They have mainly been made by our species, and there is no reason to think that we have escaped the kinds of constraints that limit the world of the platypus. Or that we will ever escape them.
In a game of 5-card draw poker you may discard one card from your hand of QD, QS, 7S, 6S, 5S. You have paid an initial stake to stay in the game, and now you need to decide whether to hold the two queens or to discard the diamond queen and hope for a flush in spades. You think that the pair may not be good enough to win, but you also realise that the chance of drawing another spade is not great. On the other hand, a flush would be rather likely to win. You infer what you can about their hands from the behaviours of the other players. Even if you draw but fail to get the flush, a bold bluff might succeed. What goes on in your quantum brain?
Maybe it is like this. A quantum coherent process is established, a superposition of just two possible actions: discard the queen or pass. The weights of these alternatives change as you bring to mind some of the many considerations that might have a bearing on the outcome. That quantum coherent processing itself is not experienced, but the thoughts that you do experience feed into it and out of it. At some stage you bring this to an end by deciding what to do, and doing it. This is the experienced moment of reduction.
[If this exact situation could be repeated many times, then probabilities would be observed (as the frequencies of the two alternatives). But of course, it cannot be repeated. That is a fundamental reason that mindful physics must be different from the familiar physics of mindless objects.]
Here, an answer is proposed to Penrose's question: they do. To see this, we only need to open our eyes.
Think about two phenomena, one familiar to everyone and not viewed as mysterious, the other familiar to physicists and viewed as very mysterious:
• Frank and Ernest, both Shakespeare fans, have been given copies of Palgrave's Golden Treasury of English Verse. Frank opens her book at some page she chooses and asks the question: is there a Shakespeare poem on this page? Her answer may be “YES” or “NO”; but repeated trials of this experiment yield “YES” with frequency about 0.05. It is the same for Ernest. However, when it happens that Frank and Ernest both choose the same page, they invariably get the same answer.
• Frank and Ernest have received twin electrons — two electrons that share their spin. Frank chooses some direction and asks a question about her electron: is the spin up in this direction? . . . . .
Despite those scare quotes, Brian Greene overlooks the obvious fact that there actually is something that knows about both slits: the experimenter. This is an oversight of the kind induced by blind faith in an objective classical theWorld (or, for that matter, by blind faith in an objective classical universe or multiverse). It is a faith that Professor Greene is prepared to honestly profess:
I believe that a physical system is fully determined by the arrangement of its particles. Tell me how the particles making up the earth, the sun, the galaxy and everything else are arranged and you have fully articulated reality. This reductionist view is common among physicists.
Brian Greene, The Hidden Reality, p.33.
The double-slit experiment leads us inescapably to a conclusion that is hard to fathom. Regardless of which slit it passes through, each individual electron somehow “knows" about both.
Brian Greene, The Hidden Reality, 2011. p.194.
The algebraic way of thinking that Descartes initiated was essential for the miracle of Newton's new physics to become possible. It transformed our grasp of phenomena by opening up new ways of bringing measurement — especially measurements of time — into our descriptions of what happens. This was a crucial step in the emergence of the experimental method of modern physics. The method of coordinates opened up a new way for human minds/brains to observe and to act. It opened the way to physics and to engineering.
In schools, the geometry of Euclid was eventually replaced by Cartesian geometry, though that process took a long time. I learned geometry, not so very long ago, from Hall and Stephens, a school text that was a straight but simplified transcription of Euclid's Elements, published about 2,300 years ago. And I also learned some coordinate geometry.
I greatly preferred Euclid’s geometry to Descartes’. My reason, I now see, was that Euclidean geometry has a mind-independent character that Cartesian geometry lacks. Proofs in an axiomatic system are not open to doubt, but the assignment of coordinates introduces choices of the assigner. I would say now that the former has to do with a mind/brain looking inside, while the latter has to do with minds/brains looking outside.
A Euclidean proof of the theorem of Pythagoras is arguably more objective than a Cartesian proof, because the latter assumes that however the observer chooses his origin and axes the result is independent of that choice. And that is a big assumption about the nature of whatever is out there. What I seem to be suggesting here is that Cartesian geometry, when it applies, makes an assumption about the homogeneity of physical space that Euclidean geometry does not. Indeed, it has been known for a long time that neither of these fits the non-local structure of physical space. We do not know if there is a geometry that fits globally, but, until we do, a sceptic must doubt it.
The distinction between coordinate-free and objective persists, and indeed has played a big role in modern physics, whose theorists seek stories that are what they call diffeomorphism invariant (or also, rather oddly, covariant). Those invariant stories have a very tight grip upon those who write them, physicists who tend to think they are seeing theTruth. But what they see are truths of mathematics. What happens is not bound by mathematics. Nature is free to do as it likes, and it does. This is not to deny that some parts of mathematics are amazingly powerful as predictors of what happens. But they are not theTruth of what happens.
What just happens
The fundamental revelation of quantum-scale experiments is that there are things that just happen. Of course, we already knew this, but it runs counter to deterministic beliefs of which echoes persist, even now.
Empiricism is the view that experience is the source of knowledge. Your knowledge is what you make of your experience; I call that your actuality. Your actuality, of course, is not the same as mine. Our actualities are different, though they have a great deal in common.
In your actuality (and mine), there are objects and events. Despite the fact that we may say that this table is the same as that, each object is unique. Sameness is only similarity. That goes for events, too. Events are unique. Everything that happens, happens just once. Science is based upon the (empirical!) fact that there are similarities between objects (one table and another) and between events (one sunrise and another).
The experimental method is to create artificial isolated worlds in which similar events can repeatedly be initiated and observed. Patterns are observed and theories are invented that match those patterns. Those theories have useful predictive power. Although we do not think of it this way, the production line for, say, automobiles of a particular model is an exercise of the experimental method with very predictable results.
Nevertheless, most of what happens is unpredictable. We see this in social theories, like economics, that aspire to be sciences. We should see clearly by now that the failure of those theories to predict is not down to lack of data. It is down to the dependence of what happens upon minds being exercised freely (and hence unpredictably). Just as the trajectory of a particular electron in a simple experiment is not predictable, so the trajectory of a particular financial crisis is not predictable. I have come to think that the unpredictability in both cases must be attributed to irreducible chance. [A classical thinker’s complementary view would be that the unpredictability we see in economics is down to complexity. If only we had the complete data!]
For both that particular electron and that particular financial crisis, the notion of empirical becomes fuzzy. No-one sees that electron and no-one sees that financial crisis. But someone observes the click of a Geiger counter, someone observes that bond yields have sharply declined. What we see as happening is brought into being by minds exercising rationality.
Some may find that "brought into being" hard to swallow. My response is this: what would be the significance of that click if no-one paid attention to it; what would that crisis matter if no-one was aware of it? And where are they now, that click and that crisis, other than in the minds of those who experience them? If you answer "in the mind of God", I have no response. For me, there are minds of others and there is no mind of God. If you answer "in the real world", then my response is that your words have no explanatory or practical value. It is a faith that you have, and that I do not even comprehend. To see this particular financial crisis and this particular experiment as belonging to minds of people has both explanatory value and practical value.
Another feature of what just happens is that it is all that happens. In an odd, almost mystical, sense, what happens is determined. Just one thing happens. It might have been different, but is not. It is only in minds, with language, that alternatives are conceived.
Those are just a few of the five hundred pages of the eBook Mindful Physics. The underlined terms are links to the book's very useful interactive Glossary.
The book is written for educated people of the 21st century who would like to better understand what happens. Though the book is not a text book, it occasionally assumes some familiarity with physics to about BSc level. Serious readers without a physics background will not lose too much if they skip those bits.
Mindful Physics accepts current physics but shows that current physics alone is not enough. One of the many reasons is the failure of physics to account for minds or take account of them. Consequently neither time nor entanglement has been well understood.
Since, according to quantum mechanics, entanglement is such a ubiquitous phenomenon — and we recall that the stupendous majority of quantum states are actually entangled ones — why is it something that we barely notice in our direct experience of the world? Why do these ubiquitous effects of entanglement not confront us at every turn?
Roger Penrose, The Road to Reality, 20o4. p.591.