I’d always thought that “what should you bring to a desert island?” was a party game, not a serious scientific question, but this Boston Globe article suggests otherwise:
In the event that life as we know it is truly upended, the survivors will have to rebuild our civilization. Given everything humanity has learned over the past hundred thousand years, what information should we leave them? And how do we store it so they can actually make use of it?
In recent years, these questions have jumped from the pages of science fiction novels and onto the research agendas of a range of thinkers, from physicists to philosophers to agricultural engineers to librarians…..
Some of the approaches the article discusses are intriguing, but most won’t do for a true catastrophe; what good will an open source blueprint library do anyone when the Simpletons burn it down? We need to think smaller; we need to think of things that can be remembered. Perhaps someone should write a didactic poem with instructions on how to recreate indoor plumbing and allergy medicine. Until that time, we’re left with however much civilization-building knowledge we have buried in our memories.
So who remembers how to prove that the earth is round? Or at least suggest some easily observable facts that would lead us to think that it might be?
It’s not so difficult. Here’s a few: The horizon limits how far we can see on the earth’s surface; the shadow of the earth on the moon during a lunar eclipse is round; the angle of the sun and stars over the horizon changes when we move significant distances north and south. The third of these facts can even be used to calculate the earth’s circumference within a reasonable degree of accuracy, if you know how far north you are of a place where at noon the sun casts no shadow–you just measure the angle of the shadow the sun casts where you are, and do some geometry.
How about showing that the earth revolves around the sun? Now you can, with Geocentrism Debunked! There’s something terrifying about the fact that this website is…. necessary.
But proving the earth revolves around the sun is harder than you think; it’s worth reading The Great Ptolemaic Smackdown to get a sense for the complexities of the science as it was developing at the turn of the 17th century. Suffice it to say that there’s not really anything visible to the naked eye that would indicate such revolution, and quite a number of arguments that, prima facie, are quite convincing. For example, take the fact that that there’s no stellar parallax visible to the naked eye. If the earth were moving, such parallax would be visible unless the stars were insanely far away; but if they were that far away, they would be too small to see, unless they were massive (as in, many thousands of times larger than the sun); and that’s a very strange (not to mention false) idea.
The proper response to this objection is that there is stellar parallax, it’s just invisible to the naked eye; and the stars would, in fact, appear much smaller than they do, if it were not for the distorting effect of the atmosphere, which is the cause of their twinkling. Galileo, incidentally, never made this argument.
These are just a few examples of science being hard. It’s easy to imagine the universe a certain way when we’ve been told to imagine it that way; it’s a lot harder to actually justify counter-intuitive theories in the face of the most commonsensical explanation of the immediate evidence. Part of the problem is that scientific theories have gotten to the point where they’re pretty much impossible to understand intuitively. Read this NYT article about visualizing the interior of a cell. The first video is quite comforting; it makes the cell seem a bit like a factory. The second (more accurate, but still idealized) video shows something else: a world where apparent intentionality not only coexists alongside, but asserts itself through, utter randomness.
Or take the recent proof of the Erdős discrepancy problem for n=2. The proof is valid… probably… but it was generated by a computer, and is too long for any human to verify. Clearly the problem here isn’t physical; it’s not as if better telescopes or microscopes would make verifying the proof by hand any more possible. Our minds themselves are limited. We can only think so many things at once (which is why we use paper, abacus, computer, etc. to help us along). It’s not any particular limitation that’s the issue. If our minds were larger we could delve deeper and rise to a higher plane of abstraction, but soon enough we’d run back up against a wall.
And yet minds are the most complex thing we know. How complex? As this post from a few years ago points out, it’s nonsense to say that it can’t be any more complex than the human genome:
The genome is not the program; it’s the data. The program is the ontogeny of the organism, which is an emergent property of interactions between the regulatory components of the genome and the environment, which uses that data to build species-specific properties of the organism. He doesn’t even comprehend the nature of the problem, and here he is pontificating on magic solutions completely free of facts and reason.
The thought that form (i.e. genome) corresponds to data, and matter (i.e. laws-of-physics) to program, seems to me a potentially powerful metaphysical approach. It suggests, among other things, that translating a form into new matter. e.g. modeling the human brain on a computer, really consists in refactoring the relevant physical laws, e.g. biochemistry, into a new set of laws that has the same effect on the form, e.g. code that a computer could actually execute.
Now, a computer could never model the laws of physics in anything like a reasonable amount of time–the complexity of the differential equations grows exponentially in proportion to the number of particles being simulated. But perhaps there’s a more efficient program that would produce (at least approximately) the same results for the phenomena in question. Somehow I doubt it.