And a new place to look for them?
George Dyson is the author of Turing’s Cathedral. This book was newly released when we saw copies at Princeton’s celebration of the Alan Turing Centennial last May. It covers John von Neumann and his wife Klára von Neumann even more than Alan Turing in a multifaceted canvas of the emerging digital age. He also wrote Darwin Among the Machines: The Evolution of Global Intelligence. His works show both the lyricism and the futurism of his renowned physicist father, Freeman Dyson.
Today we discuss evolution and technology as we close the Turing centennial year, and consider how Nature provides scientific gifts.
We are thinking of gifts in the Christmas season, of course. Often you receive a gift you wished for, maybe even after circulating the idea to loved ones or putting it on a public wish list. There are gifts of things you need that aren’t exciting. Some gifts alas you’d like to return. But then there are gifts that are unexpected and yet deeply appropriate, which bring the “aha” of discovery and are relished most afterward. We like to think of gifts from science as being this kind.
Dyson’s two books make a complicated argument and prediction about communications technology and the near future of humanity, not all of which we follow. It accords with Ray Kurzweil’s famous assertions that a “Technological Singularity” is at hand, but argues that humanity will not be able to control natural processes of evolution and selection at work in it. We have a few simpler points to offer.
Darwin Drawn Inward
“…[I]t appears to us that we are ourselves creating our own successors … we are daily giving them greater power and supplying by all sorts of ingenious contrivances that self-regulating, self-acting power which will be to them what intellect has been to the human race. In the course of ages we shall find ourselves the inferior race…
Day by day, however, the machines are gaining ground upon us; day by day we are becoming more subservient to them; more [people] devoting the energies of their whole lives to the development of mechanical life. The upshot is simply a question of time, but that the time will come when the machines will hold the real supremacy over the world and its inhabitants is what no person of a truly philosophic mind can for a moment question.”
Did we fool you, or did you notice our use of quotes—which are not the style for book titles? These words were penned not recently but almost 150 years ago, in an anonymous letter published under that title in 1863, and later acknowledged as his by the essayist and polymath Samuel Butler. Dyson named his book after that letter.
Butler was already extending the argument of Charles Darwin’s Origin of Species, which was published in 1859 just four years before, to intimate aspects of human societal development. Dyson brings this up to date. Well, even in 2013 we think people “of philosophic mind” can question the supremacy of computers as an inevitable evolutionary outcome.
What we observe is simply that much of today’s technology comes from scientific facts that seem to be separate from both the long-term process of evolution by natural selection, and the civilizing process of the last 10,000 or so years. Hence we think of them as “gifts.” This already has consequences.
What Makes a Scientific Gift?
Here are some things we don’t mean: That carbon is wonderful for biology, and that we breathe oxygen and expel carbon dioxide, while flora largely does the opposite, are vital facts—but life as we know it is already predicated on them. We are enjoying a humanly long interval of temperate climate over most of the Earth’s surface after a series of ice ages, but civilization needed this to flourish. To have complex materials at all may require supernovas, and to have matter at all may require physical constants to be just-so, but precisely because of their necessity for life we exclude all such anthropic coincidences from our notion of “gift.”
Muons provide a boundary case. In response to the discovery of the muon particle, when it seemed to have no larger purpose in physical theory, Isidor Rabi famously exclaimed, “Who ordered that?” Now we know that muons—aided by a relativistic phenomenon that we explain as lengthening their lifetimes so they can reach the Earth’s surface from cosmic-ray bursts high in the atmosphere—are a significant source of mutations. [Update: see note.] Hence we could class them as necessity not gift. On the other hand, evolution was already well established without a preconceived need for the muons’ agency, so they were a freely-made discovery.
So does the mass-energy conversion represented by Albert Einstein’s . That we get so much from so little was unexpected, and has been a driver of technology for good and ill. But this is fundamental to how the world works to begin with. Other facts of quantum mechanics are transparently basic to life processes. Also at issue is how far beauty in mathematics is concomitant with these facts, and how far beauty in Nature is at the behest of natural selection.
A gift is a fact where we could still expect the world as we know it if it were false, but can hope for a better life tomorrow because it is true. Many facts underlying technology covered in Dyson’s book strike us here.
For example, it is remarkable that radio waves broadcast from New York City and Chicago can both reach my basic car radio driving on the NY Thruway upstate, going through my body without damage. We did not evolve with radio receivers, and although one can note living beings’ imperviousness to ambient waves, this doesn’t automatically give carte blanche to powerful human-pumped radiation. A still-controversial related matter is radiation exposure from cellphones. As described by Dana Mackenzie in his book The Universe in Zero Words, this theoretically avoids being a cancer risk owing to a fundamental equation governing rates of absorption after emission.
Gifts From Complexity?
There are also technological bummers: desirable applications that might need a slight rewrite of natural laws. Hot fusion—not to mention cold fusion—may prove no better as an energy source than lumps of coal in our stockings. Just talking on cellphones makes us wish light could be a little faster. Whether quantum computers will scale or fail has been our running subject this year.
This draws into computational complexity as a bearer and arbiter of gifts. One of the central questions of our times, broadly stated, concerns the computational complexity of natural processes needed to build complex structures. We don’t expect a simple answer, but need ask only whether we can put a simple upper bound on it. Perhaps , or going higher to or lower to ?
Whatever the particular level C bounding the great mass of life-building processes, functions f above C meet our main stated qualification for being gifts. Of course f must still be realizable in Nature, but need artifice to harness.
A new development we caught at the end of the last post illustrates our intent. Scott Aaronson and his student Alexander Arkhipov showed how to rig n-many interacting bosons to reflect properties of the permanent function that may not be feasibly simulable by non-quantum means. Scott announced a week ago that several teams of researchers have built and verified his mechanism for n = 3.
The previously-known facts this rests on are simple. Bosons are characterized by having integer spins, so that interchanging two of them cycles components of the overall quantum state a whole number of times around the unit circle, and so leaves them unchanged. Fermions have half-integer spins, which causes a sign flip from rotating 180 degrees upon interchange. For n-by-n matrices whose rows correspond to the n particles, the property of flipping sign upon interchanging two rows or columns characterizes the determinant function, which is in . Whereas, complete invariance under interchange is characteristic of the permanent function, which is -hard.
The facts themselves give rise to the Pauli exclusion principle and the periodic table, and hence are basic to life. The involvement of the permanent, allowing computations that are otherwise hard, is the gift. As Scott commented in further detail here, there are still obstacles to scaling up the mechanism, and it is doubtful to help with -hard problems themselves, but it can aspire no less than full universal quantum computers to provide real benefits beyond what is classically feasible.
What other gifts may come in complexity wrapping paper? Maybe our points are innocuous, but at least they differ from philosophical presentations we have seen: Many features of the natural world that support life are philosophically contingent, but we are passing them over as conditional necessities of life. While truths of mathematics are classed as necessary and a-priori, we are thinking as if they are contingent. At least this reflects discovery the way we as mathematical theorists experience it.
Do you find our notion of “scientific gift” worthwhile? Can you add examples for discussion, also of possible “bummers”?
[qualified remarks about muons]