Physics and Poetry

Yes, it's another Nonbelieving Literati post [Edit: This one's about Cosmicomics by Italo Calvino. How could I forget to say that?] . I'm late again, but, as I posted on the Exterminator's contribution, this one did sort of look like one that I should make the effort on. John Evo, responding to the comment, was kind enough to characterise me as a poet, specifically by saying "I'd definitely like to hear what a poet has to say about this". But did I read this book as a poet?

I started out reading as a physicist. What can I say? When I was younger I used to love the slide and switch of reference frames, the pure and perfect mechanics of Galileo, Newton, Einstein. The characters' names in this book even sort of look like arcane mathematical expressions with symbols incomprehensibly juxtaposed: Qfwfq, (k)yK, Mrs. Ph(i)Nk_o. So when I read Qfwfq babbling away like an old man about how the Moon used to be closer to the Earth in those days, I started mentally checking the details. "She rolled around the sky like an umbrella chased by the wind". Well, the Moon would have to go fast. To be in orbit is to cross the horizon before you can fall to the ground. If the ground is closer, the Moon must reach the horizon more quickly! Indeed, the necessary speed bothered me a little.

This is how we did the job: in the boat we had a ladder: one of us held it, another climbed to the top, and a third, at the oars, rowed until we were right under the Moon . . .

What's wrong with this picture? I kept finding myself imagining the Moon falling until I realised that, at the distance I was imagining it, the Moon would probably have to be travelling a lot faster than the average rowboat. Ah, but isn't it fun to imagine that you could climb to the Moon on a ladder? Poetic license. Never mind.

Yes, the Moon was so strong that she pulled you up; you realised this the moment you passed from one to the other: you had to swing up abruptly, with a kind of somersault, grabbing the scales, throwin your legs over your head, until your feet were on the Moon's surface. Seen from the Earth, you looked as if you were hanging there with your head down, but for you, it was the normal position, and the only odd thing was that when you raised your eyes you saw the sea above you, glistening, with the boat and the others upside down, hanging like a bunch of grapes from the vine.

I was skeptical of this one at first. It is, however, true that the closer you get to the Moon, the stronger the Moon's pull. The question is, how close do you have to be? If the Moon is that close to the Earth, might not the point at which the Moon's attraction becomes stronger actually be inside the Moon?

A quick calculation informs me that I was wrong, however. As the distance between the Earth and the Moon increases, the point of equal gravitational pull becomes outside the Moon before the distance becomes greater than the Earth's radius! So that's all good.

"Cling together! Idiots! Cling together!" the Captain yelled. At this command, the sailors tried to form a group, a mass, to push all together until they reached the zone of the Earth's attraction: all of a sudden a cascade of bodies plunged into the sea with a loud splash.

Okay, this is not poetic licence. It's not my fault for being picky either. This isn't something I could fail to notice. It's blatantly wrong. In fact, there's a nice thought experiment due to Galileo that tries to disprove the above using basically that example. You see, bigger things do not fall faster than smaller ones. Not unless the smaller one is a feather, in which case the key phrase is air resistance. Without air resistance, all objects would fall at the same speed. With air resistance, well, the air resistance does not have to be as big in order to affect the fall of a small thing as it would need to be in order to affect the fall of a large thing. This is what creates the disparity. However, I can assure you that tying the lace of one shoe to the lace of the other will not make your shoes fall faster; it affects neither the air resistance nor the gravitational pull on each shoe. Similarly, coming together in a group will not make each person fall faster. Gravity does not check whether you are holding hands before deciding how hard to pull each of you!

Thus began an uneasy balance between science and poetry. The delight of these stories is in the way that they take a snippet of science and build around it an absurd flight of fancy, an almost narcissistic reflection of human foibles created around a simple detached fact. Moreover, although the science may sometimes be bent or broken, the humanity never is. Who cannot sympathise with the narrator of 'The Light Years', suddenly realising that the inhabitants of other galaxies have been watching him and worrying desperately about what they must think of him, but knowing that they are so distant that they will not see any improvement he makes to his behaviour for millions of years?

As with all stories that have an allegorical component, there is always a temptation to try to find the more commonplace 'meaning' behind the fantastical description. I suspect that, having begun my reading thinking like a scientist, I was slightly more prone to this than I might otherwise have been, and spent a certain amount of time reminding myself not to try to decode. The stories are sympathetic in their own right, and their meaning is in their sympathy. A reader should not need more.

Ah, but I loved the final story! I had settled down into poetry far enough that I could dispense with the science by means of a mere 'of course evolution couldn't really have this sort of purpose' and enjoy the pretty story of how we create beauty -- the beauty of a spiral, no less! How very mathematical. This book is not all true, but it is clearly truthful.

Objectivity

I think it was sometime last year that I had a Christian, in the course of a friendly but challenging conversation, pull the 'everything is subjective' argument on me. I gather the argument is basically "All of our experience is subjective to some extent, framed by our human minds, and none of our experience is absolutely certain, so I can believe whatever I want." It's an inventive defence; I shall not accuse it of being borrowed from postmodernists (atheist or otherwise), for postmodernists owe something to Soren Kierkegaard, and Kierkegaard was a devout Christian who did use this argument in a fashion at least vaguely similar, albeit with much more depth and the insertion of several other fascinating ideas that I don't quite agree with but which expand my mind nevertheless. At the time, I simply conceded that arguing against that idea might take a little more thought than being able to simply point to the evidence. But I've thought further on the subject, and by now I think I can offer a defence.

Let me start by conceding outright that of course we are trapped in our own minds; we do filter what we see through a subjective lens. Yet objectivity makes its way in, nevertheless. Suppose we're wandering along in our subjective experience, dum de dum, subjective subjective subjective, and we notice categories, yes? For example, some of the things we experience are experienced as being 'black' (whatever that means), some are 'white', some are 'coloured'. The edges of those categories might be blurred, but we can generally say that some things definitely fall more into one category than another. The boundaries between categories can also shift depending on time and place. Some things feel cold to the touch, some things feel hot, but which way such things are felt depends heavily on what we have been touching previously.

Now, as we're wandering along in our subjective experience, we might notice a category of perceptions which do not tend to shift depending on time and place and the experiencer and the method of experiencing. For example, temperature as measured by a column of mercury doesn't shift in the same way that subjective perception of heat does. To take a more interesting example, we can measure the structure of a crystal with X-ray diffraction, and we can measure it with an electron microscope, and when we do, we find a strong overlap between the two different methods of perception -- things which don't shift depending on the method of measurement. Or, yet another example, working from the hypothesis that all animals have a common ancestry, we might guess their relationships by looking at them, and we might guess their relationships from similar structures in their DNA. If the guesses tend to agree, well that's an indication that this 'distance of relationships' property really is measuring something that belongs somewhat to the category of perceptions which do not depend heavily on the method of perception.

So tell me, what name do we give to this category of things which remain constant depending on the method of perception? Why, 'objective', of course! The word 'objective', like most words, has some variations in meaning, but this is at least one definition which seems to me to be well thought out, and worth keeping. The observation that there is some subjectivity in all of our experience does not negate the usefulness of this category. Moreover, if we wish to know what things we can rely on to remain constant and predictable, it is in the category of objective perceptions that we should be looking.

Science is an attempt to identify members of this 'objective' category. Given this fact, I am inclined to consider the notion of consilience as being science's central point. Consilience refers precisely to the sort of situation I have described above -- to situations where several different types of measuring, of guessing, of perceiving all come to the same conclusion. If my characterisation of objectivity is allowed to stand, consilience is by definition objectivity's hallmark. As such, any idea which wishes to attain the status of 'objective' must pass a scientific test -- a test which varies the conditions and/or the method of perception, and still gets the result which our earlier generalisations would have predicted. The bigger the variation in circumstances of the test, the stronger an indication of objectivity it is.

Ideas that do not show this sort of consilience cannot be said to be 'objective' in this sense. People's ideas of God, for instance, depend heavily on the culture in which they were brought up. If there is any consilience to be found here, it will certainly not be found in the extraneous trappings and extra details which vary from place to place. Yet the variations are so large, encompassing even differing ideas about how many gods there are, that it is difficult to see how any objectivity in this matter may be found. Perhaps someday somebody will show an idea of God which does stand up to scientific tests, which does display consilience. Until then, though, I remain an atheist.

Laughing at Luskin

At Pharyngula, PZ Myers reports on this review by Casey Luskin of a book I haven't read but that looks mighty interesting: The Making of the Fittest: DNA and the Ultimate Forensic Record of Evolution, by Sean Carroll. Casey Luskin is a major figure from the Discovery Institute, which, in case you didn't know, houses all those Intelligent Design people who go around attempting to discredit evolution.

PZ found it excruciating:

I skimmed it in short sessions punctuated with bouts of whimpering, eye drops, and obsessive hand-washing; you'll have to forgive me if I don't attempt a thorough dissection.

Fear not, PZ! To the intelligent non-biologist reader who has not had to suffer this sort of garbage before, the report is a scream. I've been giggling all over the place. See, I've been learning all manner of stuff that contradicts Luskin's claims just by reading the parts of the book that he quotes. Like this bit, quoted on page 9 of the review:

The possibilities for building species trees based upon DNA, RNA, and protein sequences were quickly recognized by scientists (such as Francis Crick, Emile Zuckerlandl, and Linus Pauling), as soon as protein sequencing began to reveal the similarities and differences in proteins shared among groups of species. … Darwin described the geneology of species as trees, with speciation producing ramifying branches. But in the world of microbes, unknown to Darwin, some events happen that violate the pattern of treelike evolution. Microbes exchange genes, and some microbes live within the host species in a process called endosymbiosis. These processes enable the transfer of genes between very distant relatives, and thus confuse the family tree. - Sean Carroll, TMoTF, page 85 if Luskin's credentials as a lawyer have given him the ability to at least quote the page number correctly.

Get this: here's a biological way for the genes of a species to change in a new way. But Luskin quotes it as evidence against evolution. Specifically, against the idea that we can sort species into evolutionary trees. Because, obviously, if natural, random, non-designed changes happen that don't fit the tree format, then, er... there must have been a designer?

Luskin seems to think that any evidence that contradicts even a tiny part of the picture can somehow bring down the whole - even if it's just a small alteration in one corner that can be fitted in to the rest of the picture with perfectly consistent changes. He's mad. But then, he is trying to say that "neo-Darwinism" is a religion. Perhaps he thinks he has finally found the scientific equivalent of that bit in 1 Kings chapter 7 that implies that pi = 3. The trouble is, of course, that every scientific theory is subject to change; we keep them because (or, if...) they accurately describe the stuff we know.

On the other hand, that book by Carroll sounds really interesting. Maybe I should read it.