2006 |
Contrast the present — think how different was a meeting in the 2020s of the National Joint Council, which has been retained for form's sake. On the one side sit the I.Q.s of 140, on the other the I.Q.s of 99. On the one side the intellectual magnates of our day, on the other honest, horny-handed workmen more at home with dusters than documents. On the one side the solid confidence born of hard-won achievement; on the other the consciousness of a just inferiority.Seriously, anybody who doesn't see the satire in this must be none too Swift. Although the book is cast as a retrospective from 2038, and there passing references to atomic stations, home entertainment centres, school trips to the Moon and the like, technologically the world seems very much like that of 1950s. There is one truly frightening innovation, however. On p. 110, discussing the shrinking job market for shop attendants, we're told, “The large shop with its more economical use of staff had supplanted many smaller ones, the speedy spread of self-service in something like its modern form had reduced the number of assistants needed, and piped distribution of milk, tea, and beer was extending rapidly.” To anybody with personal experience with British plumbing and English beer, the mere thought of the latter being delivered through the former is enough to induce dystopic shivers of 1984 magnitude. Looking backward from almost fifty years on, this book can be read as an alternative history of the last half-century. In the eyes of many with a libertarian or conservative inclination, just when the centuries-long battle against privilege and prejudice was finally being won: in the 1950s and early 60s when Young's book appeared, the dream of equal opportunity so eloquently embodied in Dr. Martin Luther King's “I Have a Dream” speech began to evaporate in favour of equality of results (by forced levelling and dumbing down if that's what it took), group identity and entitlements, and the creation of a permanently dependent underclass from which escape was virtually impossible. The best works of alternative history are those which change just one thing in the past and then let the ripples spread outward over the years. You can read this story as a possible future in which equal opportunity really did completely triumph over egalitarianism in the sixties. For those who assume that would have been an unqualifiedly good thing, here is a cautionary tale well worth some serious reflexion.
Paging Friar Ockham! If unnecessarily multiplying hypotheses are stubble indicating a fuzzy theory, it's pretty clear which of these is in need of the razor! Further, while one can imagine scientific investigation discovering evidence for Theory 1, almost all of the mechanisms which underlie Theory 2 remain, barring some conceptual breakthrough equivalent to looking inside a black hole, forever hidden from science by an impenetrable horizon through which no causal influence can propagate. So severe is this problem that chapter 9 of the book is devoted to the question of how far theoretical physics can go in the total absence of experimental evidence. What's more, unlike virtually every theory in the history of science, which attempted to describe the world we observe as accurately and uniquely as possible, Theory 2 predicts every conceivable universe and says, hey, since we do, after all, inhabit a conceivable universe, it's consistent with the theory. To one accustomed to the crystalline inevitability of Newtonian gravitation, general relativity, quantum electrodynamics, or the laws of thermodynamics, this seems by comparison like a California blonde saying “whatever”—the cosmology of despair. Scientists will, of course, immediately rush to attack Theory 1, arguing that a being such as that it posits would necessarily be “indistinguishable from magic”, capable of explaining anything, and hence unfalsifiable and beyond the purview of science. (Although note that on pp. 192–197 Susskind argues that Popperian falsifiability should not be a rigid requirement for a theory to be deemed scientific. See Lee Smolin's Scientific Alternatives to the Anthropic Principle for the argument against the string landscape theory on the grounds of falsifiability, and the 2004 Smolin/Susskind debate for a more detailed discussion of this question.) But let us look more deeply at the attributes of what might be called the First Cause of Theory 2. It not only permeates all of our universe, potentially spawning a bubble which may destroy it and replace it with something different, it pervades the abstract landscape of all possible universes, populating them with an infinity of independent and diverse universes over an eternity of time: omnipresent in spacetime. When a universe is created, all the parameters which ultimately govern its ultimate evolution (under the probabilistic laws of quantum mechanics, to be sure) are fixed at the moment of creation: omnipotent to create any possibility, perhaps even varying the mathematical structures underlying the laws of physics. As a budded off universe evolves, whether a sterile formless void or teeming with intelligent life, no information is ever lost in its quantum evolution, not even down a black hole or across a cosmic horizon, and every quantum event splits the universe and preserves all possible outcomes. The ensemble of universes is thus omniscient of all its contents. Throw in intelligent and benevolent, and you've got the typical deity, and since you can't observe the parallel universes where the action takes place, you pretty much have to take it on faith. Where have we heard that before? Lest I be accused of taking a cheap shot at string theory, or advocating a deistic view of the universe, consider the following creation story which, after John A. Wheeler, I shall call “Creation without the Creator”. Many extrapolations of continued exponential growth in computing power envision a technological singularity in which super-intelligent computers designing their own successors rapidly approach the ultimate physical limits on computation. Such computers would be sufficiently powerful to run highly faithful simulations of complex worlds, including intelligent beings living within them which need not be aware they were inhabiting a simulation, but thought they were living at the “top level”, who eventually passed through their own technological singularity, created their own simulated universes, populated them with intelligent beings who, in turn,…world without end. Of course, each level of simulation imposes a speed penalty (though, perhaps not much in the case of quantum computation), but it's not apparent to the inhabitants of the simulation since their own perceived time scale is in units of the “clock rate” of the simulation. If an intelligent civilisation develops to the point where it can build these simulated universes, will it do so? Of course it will—just look at the fascination crude video game simulations have for people today. Now imagine a simulation as rich as reality and unpredictable as tomorrow, actually creating an inhabited universe—who could resist? As unlimited computing power becomes commonplace, kids will create innovative universes and evolve them for billions of simulated years for science fair projects. Call the mean number of simulated universes created by intelligent civilisations in a given universe (whether top-level or itself simulated) the branching factor. If this is greater than one, and there is a single top-level non-simulated universe, then it will be outnumbered by simulated universes which grow exponentially in numbers with the depth of the simulation. Hence, by the Copernican principle, or principle of mediocrity, we should expect to find ourselves in a simulated universe, since they vastly outnumber the single top-level one, which would be an exceptional place in the ensemble of real and simulated universes. Now here's the point: if, as we should expect from this argument, we do live in a simulated universe, then our universe is the product of intelligent design and Theory 1 is an absolutely correct description of its origin. Suppose this is the case: we're inside a simulation designed by a freckle-faced superkid for extra credit in her fifth grade science class. Is this something we could discover, or must it, like so many aspects of Theory 2, be forever hidden from our scientific investigation? Surprisingly, this variety of Theory 1 is quite amenable to experiment: neither revelation nor faith is required. What would we expect to see if we inhabited a simulation? Well, there would probably be a discrete time step and granularity in position fixed by the time and position resolution of the simulation—check, and check: the Planck time and distance appear to behave this way in our universe. There would probably be an absolute speed limit to constrain the extent we could directly explore and impose a locality constraint on propagating updates throughout the simulation—check: speed of light. There would be a limit on the extent of the universe we could observe—check: the Hubble radius is an absolute horizon we cannot penetrate, and the last scattering surface of the cosmic background radiation limits electromagnetic observation to a still smaller radius. There would be a limit on the accuracy of physical measurements due to the finite precision of the computation in the simulation—check: Heisenberg uncertainty principle—and, as in games, randomness would be used as a fudge when precision limits were hit—check: quantum mechanics.Theory 1: Intelligent Design. An intelligent being created the universe and chose the initial conditions and physical laws so as to permit the existence of beings like ourselves.
Theory 2: String Landscape. The laws of physics and initial conditions of the universe are chosen at random from among 10500 possibilities, only a vanishingly small fraction of which (probably no more than one in 10120) can support life. The universe we observe, which is infinite in extent and may contain regions where the laws of physics differ, is one of an infinite number of causally disconnected “pocket universes“ which spontaneously form from quantum fluctuations in the vacuum of parent universes, a process which has been occurring for an infinite time in the past and will continue in the future, time without end. Each of these pocket universes which, together, make up the “megaverse”, has its own randomly selected laws of physics, and hence the overwhelming majority are sterile. We find ourselves in one of the tiny fraction of hospitable universes because if we weren't in such an exceptionally rare universe, we wouldn't exist to make the observation. Since there are an infinite number of universes, however, every possibility not only occurs, but occurs an infinite number of times, so not only are there an infinite number of inhabited universes, there are an infinite number identical to ours, including an infinity of identical copies of yourself wondering if this paragraph will ever end. Not only does the megaverse spawn an infinity of universes, each universe itself splits into two copies every time a quantum measurement occurs. Our own universe will eventually spawn a bubble which will destroy all life within it, probably not for a long, long time, but you never know. Evidence for all of the other universes is hidden behind a cosmic horizon and may remain forever inaccessible to observation.
Might we expect surprises as we subject our simulated universe to ever more precise scrutiny, perhaps even astonishing the being which programmed it with our cunning and deviousness (as the author of any software package has experienced at the hands of real-world users)? Who knows, we might run into round-off errors which “hit us like a ton of bricks”! Suppose there were some quantity, say, that was supposed to be exactly zero but, if you went and actually measured the geometry way out there near the edge and crunched the numbers, you found out it differed from zero in the 120th decimal place. Why, you might be as shocked as the naïve Perl programmer who ran the program “printf("%.18f", 0.2)” and was aghast when it printed “0.200000000000000011” until somebody explained that with about 56 bits of mantissa in IEEE double precision floating point, you only get about 17 decimal digits (log10 256) of precision. So, what does a round-off in the 120th digit imply? Not Theory 2, with its infinite number of infinitely reproducing infinite universes, but simply that our Theory 1 intelligent designer used 400 bit numbers (log2 10120) in the simulation and didn't count on our noticing—remember you heard it here first, and if pointing this out causes the simulation to be turned off, sorry about that, folks! Surprises from future experiments which would be suggestive (though not probative) that we're in a simulated universe would include failure to find any experimental signature of quantum gravity (general relativity could be classical in the simulation, since potential conflicts with quantum mechanics would be hidden behind event horizons in the present-day universe, and extrapolating backward to the big bang would be meaningless if the simulation were started at a later stage, say at the time of big bang nucleosynthesis), and discovery of limits on the ability to superpose wave functions for quantum computation which could result from limited precision in the simulation as opposed to the continuous complex values assumed by quantum mechanics. An interesting theoretical program would be to investigate feasible experiments which, by magnifying physical effects similar to proposed searches for quantum gravity signals, would detect round-off errors of magnitude comparable to the cosmological constant.
But seriously, this is an excellent book and anybody who's interested in the strange direction in which the string theorists are veering these days ought to read it; it's well-written, authoritative, reasonably fair to opposing viewpoints (although I'm surprised the author didn't address the background spacetime criticism of string theory raised so eloquently by Lee Smolin), and provides a roadmap of how string theory may develop in the coming years. The only nagging question you're left with after finishing the book is whether after thirty years of theorising which comes to the conclusion that everything is predicted and nothing can be observed, it's about science any more.So prolific was Jules Verne that more than a century and a half after he began his writing career, new manuscripts keep turning up among his voluminous papers. In the last two decades, Paris au XXe siècle, the original un-mangled version of La chasse au météore (October 2002), and the present volume have finally made their way into print. Verne transformed the account of his own trip into a fictionalised travel narrative of a kind quite common in the 19th century but rarely encountered today. The fictional form gave him freedom to add humour, accentuate detail, and highlight aspects of the country and culture he was visiting without crossing the line into that other venerable literary genre, the travel tall tale. One suspects that the pub brawl in chapter 16 is an example of such embroidery, along with the remarkable steam powered contraption on p. 159 which prefigured Mrs. Tweedy's infernal machine in Chicken Run. The description of the weather, however, seems entirely authentic. Verne offered the manuscript to Hetzel, who published most of his work, but it was rejected and remained forgotten until it was discovered in a cache of Verne papers acquired by the city of Nantes in 1981. This 1989 edition is its first appearance in print, and includes six pages of notes on the history of the work and its significance in Verne's œuvre, notes on changes in the manuscript made by Verne, and a facsimile manuscript page.
What is remarkable in reading this novel is the extent to which it is a fully-developed “template” for Verne's subsequent Voyages extraordinaires: here we have an excitable and naïve voyager (think Michel Ardan or Passepartout) paired with a more stolid and knowledgeable companion (Barbicane or Phileas Fogg), the encyclopedist's exultation in enumeration, fascination with all forms of locomotion, and fun with language and dialect (particularly poor Jacques who beats the Dickens out of the language of Shakespeare). Often, when reading the early works of writers, you sense them “finding their voice”—not here. Verne is in full form, the master of his language and the art of story-telling, and fully ready, a few years later, with just a change of topic, to invent science fiction. This is not “major Verne”, and you certainly wouldn't want to start with this work, but if you've read most of Verne and are interested in how it all began, this is genuine treat.
This book is out of print. If you can't locate a used copy at a reasonable price at the Amazon link above, try abebooks.com. For comparison with copies offered for sale, the cover price in 1989 was FRF 95, which is about €14.50 at the final fixed rate.
He was born Graf Heinrich Karl Wilhelm Otto Friedrich von Übersetzenseehafenstadt, but changed his name to Nigel St. John Gloamthorpby, a.k.a. Lord Woadmire, in 1914. In his photograph, he looks every inch a von Übersetzenseehafenstadt, and he is free of the cranial geometry problem so evident in the older portraits. Lord Woadmire is not related to the original ducal line of Qwghlm, the Moore family (Anglicized from the Qwghlmian clan name Mnyhrrgh) which had been terminated in 1888 by a spectacularly improbable combination of schistosomiasis, suicide, long-festering Crimean war wounds, ball lightning, flawed cannon, falls from horses, improperly canned oysters, and rogue waves.On p. 352 we find one of the most lucid and concise explanations I've ever read of why it far more difficult to escape the grasp of now-obsolete technologies than most technologists may wish.
(This is simply because the old technology is universally understood by those who need to understand it, and it works well, and all kinds of electronic and software technology has been built and tested to work within that framework, and why mess with success, especially when your profit margins are so small that they can only be detected by using techniques from quantum mechanics, and any glitches vis-à-vis compatibility with old stuff will send your company straight into the toilet.)In two sentences on p. 564, he lays out the essentials of the original concept for Autodesk, which I failed to convey (providentially, in retrospect) to almost every venture capitalist in Silicon Valley in thousands more words and endless, tedious meetings.
“ … But whenever a business plan first makes contact with the actual market—the real world—suddenly all kinds of stuff becomes clear. You may have envisioned half a dozen potential markets for your product, but as soon as you open your doors, one just explodes from the pack and becomes so instantly important that good business sense dictates that you abandon the others and concentrate all your efforts.”And how many New York Times Best-Sellers contain working source code (p, 480) for a Perl program? A 1168 page mass market paperback edition is now available, but given the unwieldiness of such an edition, how much you're likely to thumb through it to refresh your memory on little details as you read it, the likelihood you'll end up reading it more than once, and the relatively small difference in price, the trade paperback cited at the top may be the better buy. Readers interested in the cryptographic technology and culture which figure in the book will find additional information in the author's Cryptonomicon cypher-FAQ.
…I think all this superstring stuff is crazy and it is in the wrong direction. … I don't like that they're not calculating anything. I don't like that they don't check their ideas. I don't like that for anything that disagrees with an experiment, they cook up an explanation—a fix-up to say “Well, it still might be true.”Feynman was careful to hedge his remark as being that of an elder statesman of science, who collectively have a history of foolishly considering the speculations of younger researchers to be nonsense, and he would have almost certainly have opposed any effort to cut off funding for superstring research, as it might be right, after all, and should be pursued in parallel with other promising avenues until they make predictions which can be tested by experiment, falsifying and leading to the exclusion of those candidate theories whose predictions are incorrect. One wonders, however, what Feynman's reaction would have been had he lived to contemplate the contemporary scene in high energy theoretical physics almost twenty years later. String theory and its progeny still have yet to make a single, falsifiable prediction which can be tested by a physically plausible experiment. This isn't surprising, because after decades of work and tens of thousands of scientific publications, nobody really knows, precisely, what superstring (or M, or whatever) theory really is; there is no equation, or set of equations from which one can draw physical predictions. Leonard Susskind, a co-founder of string theory, observes ironically in his book The Cosmic Landscape (March 2006), “On this score, one might facetiously say that String Theory is the ultimate epitome of elegance. With all the years that String Theory has been studied, no one has ever found a single defining equation! The number at present count is zero. We know neither what the fundamental equations of the theory are or even if it has any.” (p. 204). String theory might best be described as the belief that a physically correct theory exists and may eventually be discovered by the research programme conducted under that name.
From the time Feynman spoke through the 1990s, the goal toward which string theorists were working was well-defined: to find a fundamental theory which reproduces at the low energy limit the successful results of the standard model of particle physics, and explains, from first principles, the values of the many (there are various ways to count them, slightly different—the author gives the number as 18 in this work) free parameters of that theory, whose values are not predicted by any theory and must be filled in by experiment. Disturbingly, theoretical work in the early years of this century has convinced an increasing number of string theorists (but not all) that the theory (whatever it may turn out to be), will not predict a unique low energy limit (or “vacuum state”), but rather an immense “landscape” of possible universes, with estimates like 10100 and 10500 and even more bandied around (by comparison, there are only about 1080 elementary particles in the entire observable universe—a minuscule number compared to such as these). Most of these possible universes would be hideously inhospitable to intelligent life as we know and can imagine it (but our imagination may be limited), and hence it is said that the reason we find ourselves in one of the rare universes which contain galaxies, chemistry, biology, and the National Science Foundation is due to the anthropic principle: a statement, bordering on tautology, that we can only observe conditions in the universe which permit our own existence, and that perhaps either in a “multiverse” of causally disjoint or parallel realities, all the other possibilities exist as well, most devoid of observers, at least those like ourselves (triune glorgs, feeding on bare colour in universes dominated by quark-gluon plasma would doubtless deem our universe unthinkably cold, rarefied, and dead).
But adopting the “landscape” view means abandoning the quest for a theory of everything and settling for what amounts to a “theory of anything”. For even if string theorists do manage to find one of those 10100 or whatever solutions in the landscape which perfectly reproduces all the experimental results of the standard model (and note that this is something nobody has ever done and appears far out of reach, with legitimate reasons to doubt it is possible at all), then there will almost certainly be a bewildering number of virtually identical solutions with slightly different results, so that any plausible experiment which measures a quantity to more precision or discovers a previously unknown phenomenon can be accommodated within the theory simply by tuning one of its multitudinous dials and choosing a different solution which agrees with the experimental results. This is not what many of the generation who built the great intellectual edifice of the standard model of particle physics would have considered doing science.
Now if string theory were simply a chimæra being pursued by a small band of double-domed eccentrics, one wouldn't pay it much attention. Science advances by exploring lots of ideas which may seem crazy at the outset and discarding the vast majority which remain crazy after they are worked out in more detail. Whatever remains, however apparently crazy, stays in the box as long as its predictions are not falsified by experiment. It would be folly of the greatest magnitude, comparable to attempting to centrally plan the economy of a complex modern society, to try to guess in advance, by some kind of metaphysical reasoning, which ideas were worthy of exploration. The history of the S-matrix or “bootstrap” theory of the strong interactions recounted in chapter 11 is an excellent example of how science is supposed to work. A beautiful theory, accepted by a large majority of researchers in the field, which was well in accord with experiment and philosophically attractive, was almost universally abandoned in a few years after the success of the quark model in predicting new particles and the stunning deep inelastic scattering results at SLAC in the 1970s. String theory, however, despite not having made a single testable prediction after more than thirty years of investigation, now seems to risk becoming a self-perpetuating intellectual monoculture in theoretical particle physics. Among the 22 tenured professors of theoretical physics in the leading six faculties in the United States who received their PhDs after 1981, fully twenty specialise in string theory (although a couple now work on the related brane-world models). These professors employ graduate students and postdocs who work in their area of expertise, and when a faculty position opens up, may be expected to support candidates working in fields which complement their own research. This environment creates a great incentive for talented and ambitious students aiming for one the rare permanent academic appointments in theoretical physics to themselves choose string theory, as that's where the jobs are. After a generation, this process runs the risk of operating on its own momentum, with nobody in a position to step back and admit that the entire string theory enterprise, judged by the standards of genuine science, has failed, and does not merit the huge human investment by the extraordinarily talented and dedicated people who are pursuing it, nor the public funding it presently receives. If Edward Witten believes there's something still worth pursuing, fine: his self-evident genius and massive contributions to mathematical physics more than justify supporting his work. But this enterprise which is cranking out hundreds of PhDs and postdocs who are spending their most intellectually productive years learning a fantastically complicated intellectual structure with no grounding whatsoever in experiment, most of whom will have no hope of finding permanent employment in the field they have invested so much to aspire toward, is much more difficult to justify or condone. The problem, to state it in a manner more inflammatory than the measured tone of the author, and in a word of my choosing which I do not believe appears at all in his book, is that contemporary academic research in high energy particle theory is corrupt. As is usually the case with such corruption, the root cause is socialism, although the look-only-left blinders almost universally worn in academia today hides this from most observers there. Dwight D. Eisenhower, however, twigged to it quite early. In his farewell address of January 17th, 1961, which academic collectivists endlessly cite for its (prescient) warning about the “military-industrial complex”, he went on to say, although this is rarely quoted,In this revolution, research has become central; it also becomes more formalized, complex, and costly. A steadily increasing share is conducted for, by, or at the direction of, the Federal government. Today, the solitary inventor, tinkering in his shop, has been over shadowed by task forces of scientists in laboratories and testing fields. In the same fashion, the free university, historically the fountainhead of free ideas and scientific discovery, has experienced a revolution in the conduct of research. Partly because of the huge costs involved, a government contract becomes virtually a substitute for intellectual curiosity. For every old blackboard there are now hundreds of new electronic computers. The prospect of domination of the nation's scholars by Federal employment, project allocations, and the power of money is ever present and is gravely to be regarded.And there, of course, is precisely the source of the corruption. This enterprise of theoretical elaboration is funded by taxpayers, who have no say in how their money, taken under threat of coercion, is spent. Which researchers receive funds for what work is largely decided by the researchers themselves, acting as peer review panels. While peer review may work to vet scientific publications, as soon as money becomes involved, the disposition of which can make or break careers, all the venality and naked self- and group-interest which has undone every well-intentioned experiment in collectivism since Robert Owen comes into play, with the completely predictable and tediously repeated results. What began as an altruistic quest driven by intellectual curiosity to discover answers to the deepest questions posed by nature ends up, after a generation of grey collectivism, as a jobs program. In a sense, string theory can be thought of like that other taxpayer-funded and highly hyped program, the space shuttle, which is hideously expensive, dangerous to the careers of those involved with it (albeit in a more direct manner), supported by a standing army composed of some exceptional people and a mass of the mediocre, difficult to close down because it has carefully cultivated a constituency whose own self-interest is invested in continuation of the program, and almost completely unproductive of genuine science. One of the author's concerns is that the increasingly apparent impending collapse of the string theory edifice may result in the de-funding of other promising areas of fundamental physics research. I suspect he may under-estimate how difficult it is to get rid of a government program, however absurd, unjustified, and wasteful it has become: consider the space shuttle, or mohair subsidies. But perhaps de-funding is precisely what is needed to eliminate the corruption. Why should U.S. taxpayers be spending on the order of thirty million dollars a year on theoretical physics not only devoid of any near- or even distant-term applications, but also mostly disconnected from experiment? Perhaps if theoretical physics returned to being funded by universities from their endowments and operating funds, and by money raised from patrons and voluntarily contributed by the public interested in the field, it would be, albeit a much smaller enterprise, a more creative and productive one. Certainly it would be more honest. Sure, there may be some theoretical breakthrough we might not find for fifty years instead of twenty with massive subsidies. But so what? The truth is out there, somewhere in spacetime, and why does it matter (since it's unlikely in the extreme to have any immediate practical consequences) how soon we find it, anyway? And who knows, it's just possible a research programme composed of the very, very best, whose work is of such obvious merit and creativity that it attracts freely-contributed funds, exploring areas chosen solely on their merit by those doing the work, and driven by curiosity instead of committee group-think, might just get there first. That's the way I'd bet. For a book addressed to a popular audience which contains not a single equation, many readers will find it quite difficult. If you don't follow these matters in some detail, you may find some of the more technical chapters rather bewildering. (The author, to be fair, acknowledges this at the outset.) For example, if you don't know what the hierarchy problem is, or why it is important, you probably won't be able to figure it out from the discussion here. On the other hand, policy-oriented readers will have little difficulty grasping the problems with the string theory programme and its probable causes even if they skip the gnarly physics and mathematics. An entertaining discussion of some of the problems of string theory, in particular the question of “background independence”, in which the string theorists universally assume the existence of a background spacetime which general relativity seems to indicate doesn't exist, may be found in Carlo Rovelli's "A Dialog on Quantum Gravity". For more technical details, see Lee Smolin's Three Roads to Quantum Gravity. There are some remarkable factoids in this book, one of the most stunning being that the proposed TeV class muon colliders of the future will produce neutrino (yes, neutrino) radiation which is dangerous to humans off-site. I didn't believe it either, but look here—imagine the sign: “DANGER: Neutrino Beam”! A U.S. edition is scheduled for publication at the end of September 2006. The author has operated the Not Even Wrong Web log since 2004; it is an excellent source for news and gossip on these issues. The unnamed “excitable … Harvard faculty member” mentioned on p. 227 and elsewhere is Luboš Motl (who is, however, named in the acknowledgements), and whose own Web log is always worth checking out.
A nuclear isomer is an atomic nucleus which, due to having a greater spin, different shape, or differing alignment of the spin orientation and axis of symmetry, has more internal energy than the ground state nucleus with the same number of protons and neutrons. Nuclear isomers are usually produced in nuclear fusion reactions when the the addition of protons and/or neutrons to a nucleus in a high-energy collision leaves it in an excited state. Hundreds of nuclear isomers are known, but the overwhelming majority decay with gamma ray emission in about 10−14 seconds. In a few species, however, this almost instantaneous decay is suppressed for various reasons, and metastable isomers exist with half-lives ranging from 10−9 seconds (one nanosecond), to the isomer Tantalum-180m, which has a half-life of at least 1015 years and may be entirely stable; it is the only nuclear isomer found in nature and accounts for about one atom of 8300 in tantalum metal.
Some metastable isomers with intermediate half-lives have a remarkably large energy compared to the ground state and emit correspondingly energetic gamma ray photons when they decay. The Hafnium-178m2 (the “m2” denotes the second lowest energy isomeric state) nucleus has a half-life of 31 years and decays (through the m1 state) with the emission of 2.45 MeV in gamma rays. Now the fact that there's a lot of energy packed into a radioactive nucleus is nothing new—people were calculating the energy of disintegrating radium and uranium nuclei at the end of the 19th century, but all that energy can't be used for much unless you can figure out some way to release it on demand—as long as it just dribbles out at random, you can use it for some physics experiments and medical applications, but not to make loud bangs or turn turbines. It was only the discovery of the fission chain reaction, where the fission of certain nuclei liberates neutrons which trigger the disintegration of others in an exponential process, which made nuclear energy, for better or for worse, accessible.
So, as long as there is no way to trigger the release of the energy stored in a nuclear isomer, it is nothing more than an odd kind of radioactive element, the subject of a reasonably well-understood and somewhat boring topic in nuclear physics. If, however, there were some way to externally trigger the decay of the isomer to the ground state, then the way would be open to releasing the energy in the isomer at will. It is possible to trigger the decay of the Tantalum-180 isomer by 2.8 MeV photons, but the energy required to trigger the decay is vastly greater than the 0.075 MeV it releases, so the process is simply an extremely complicated and expensive way to waste energy.
Researchers in the small community interested in nuclear isomers were stunned when, in the January 25, 1999 issue of Physical Review Letters, a paper by Carl Collins and his colleagues at the University of Texas at Dallas reported they had triggered the release of 2.45 MeV in gamma rays from a sample of Hafnium-178m2 by irradiating it with a second-hand dental X-ray machine with the sample of the isomer sitting on a styrofoam cup. Their report implied, even with the crude apparatus, an energy gain of sixty times break-even, which was more than a million times the rate predicted by nuclear theory, if triggering were possible at all. The result, if real, could have substantial technological consequences: the isomer could be used as a nuclear battery, which could store energy and release it on demand with a density which dwarfed that of any chemical battery and was only a couple of orders of magnitude less than a fission bomb. And, speaking of bombs, if you could manage to trigger a mass of hafnium all at once or arrange for it to self-trigger in a chain reaction, you could make a variety of nifty weapons out of it, including a nuclear hand grenade with a yield of two kilotons. You could also build a fission-free trigger for a thermonuclear bomb which would evade all of the existing nonproliferation safeguards which are aimed at controlling access to fissile material. These are the kind of things that get the attention of folks in that big five-sided building in Arlington, Virginia.
And so it came to pass, in a Pentagon bent on “transformational technologies” and concerned with emerging threats from potential adversaries, that in May of 2003 a Hafnium Isomer Production Panel (HIPP) was assembled to draw up plans for bulk production of the substance, with visions of nuclear hand grenades, clean bunker-busting fusion bombs, and even hafnium-powered bombers floating before the eyes of the out of the box thinkers at DARPA, who envisioned a two-year budget of USD30 million for the project—military science marches into the future. What's wrong with this picture? Well, actually rather a lot of things.
But bad science, absurd economics, a nonexistent phenomenon, damning evaluations by panels of authorities, lack of applications, and ridiculous radiation risk in the extremely improbable event of success pose no insurmountable barriers to a government project once it gets up to speed, especially one in which the relationships between those providing the funding and its recipients are complicated and unseemingly cozy. It took an exposé in the Washington Post Magazine by the author and subsequent examination in Congress to finally drive a stake through this madness—maybe. As of the end of 2005, although DARPA was out of the hafnium business (at least publicly), there were rumours of continued funding thanks to a Congressional earmark in the Department of Energy budget.
This book is a well-researched and fascinating look inside the defence underworld where fringe science feeds on federal funds, and starkly demonstrates how weird and wasteful things can get when Pentagon bureaucrats disregard their own science advisors and substitute instinct and wishful thinking for the tedious, but ultimately reliable, scientific method. Many aspects of the story are also quite funny, although U.S. taxpayers who footed the bill for this madness may be less amused. The author has set up a Web site for the book, and Carl Collins, who conducted the original experiment with the dental X-ray and styrofoam cup which incited the mania has responded with his own, almost identical in appearance, riposte. If you're interested in more technical detail on the controversy than appears in Weinberg's book, the Physics Today article from May 2004 is an excellent place to start. The book contains a number of typographical and factual errors, none of which are significant to the story, but when the first line of the Author's Note uses “sited” when “cited” is intended, and in the next paragraph “wondered” instead of “wandered”, you have to—wonder.
It is sobering to realise that this folly took place entirely in the public view: in the open scientific literature, university labs, unclassified defence funding subject to Congressional oversight, and ultimately in the press, and yet over a period of years millions in taxpayer funds were squandered on nonsense. Just imagine what is going on in highly-classified “black” programs.
Adult mantis shrimp (Stomatapoda) live in burrows. The five anterior thoracic appendages are subchelate maxillipeds, and the abdomen bears pleopods and uropods. Some hatch as antizoeas: planktonic larvae that swim with five pairs of biramous thoracic appendages. These larvae gradually change into pseudozoeas, with subchelate maxillipeds and with four or five pairs of natatory pleopods. Other stomatopods hatch as pseudozoeas. There are no uropods in the larval stages. The lack of uropods and the form of the other appendages contrasts with the condition in decapod larvae. It seems improbable that stomatopod larvae could have evolved from ancestral forms corresponding to zoeas and megalopas, and I suggest that the Decapoda and the Stomatopoda acquired their larvae from different foreign sources.In addition to the zoö-jargon, another deterrent to reading this book is the cost: a list price of USD 109, quoted at Amazon.com at this writing at USD 85, which is a lot of money for a 260 page monograph, however superbly produced and notwithstanding its small potential audience; so fascinating and potentially significant is the content that one would happily part with USD 15 to read a PDF, but at prices like this one's curiosity becomes constrained by the countervailing virtue of parsimony. Still, if Williamson is right, some of the fundamental assumptions underlying our understanding of life on Earth for the last century and a half may be dead wrong, and if his conjecture stands the test of experiment, we may have at hand an understanding of mysteries such as the Cambrian explosion of animal body forms and the apparent “punctuated equilibria” in the fossil record. There is a Nobel Prize here for somebody who confirms that this supposition is correct. Lynn Margulis, whose own theory of the origin of eukaryotic cells by the incorporation of previously free-living organisms as endosymbionts, which is now becoming the consensus view, co-authors a foreword which endorses Williamson's somewhat similar view of larvae.
In this book, he presents these concepts to a popular audience, beginning by explaining the fundamentals of quantum mechanics and the principles of quantum computation, before moving on to the argument that the universe as a whole is a universal quantum computer whose future cannot be predicted by any simulation less complicated than the universe as a whole, nor any faster than the future actually evolves (a concept reminiscent of Stephen Wolfram's argument in A New Kind of Science [August 2002], but phrased in quantum mechanical rather than classical terms). He argues that all of the complexity we observe in the universe is the result of the universe performing a computation whose input is the random fluctuations created by quantum mechanics. But, unlike the proverbial monkeys banging on typewriters, the quantum mechanical primate fingers are, in effect, typing on the keys of a quantum computer which, like the cellular automata of Wolfram's book, has the capacity to generate extremely complex structures from very simple inputs. Why was the universe so simple shortly after the big bang? Because it hadn't had the time to compute very much structure. Why is the universe so complicated today? Because it's had sufficient time to perform 10122 logical operations up to the present.
I found this book, on the whole, a disappointment. Having read the technical papers cited above before opening it, I didn't expect to learn any additional details from a popularisation, but I did hope the author would provide a sense for how the field evolved and get a sense of where he saw this research programme going in the future and how it might (or might not) fit with other approaches to the unification of quantum mechanics and gravitation. There are some interesting anecdotes about the discovery of the links between quantum mechanics, thermodynamics, statistical mechanics, and information theory, and the personalities involved in that work, but one leaves the book without any sense for where future research might be going, nor how these theories might be tested by experiment in the near or even distant future. The level of the intended audience is difficult to discern. Unlike some popularisers of science, Lloyd does not shrink from using equations where they clarify physical relationships and even introduces and uses Dirac's “bra-ket” notation (for example, <φ|ψ>), yet almost everywhere he writes a number in scientific notation, he also gives it in the utterly meaningless form of (p. 165) “100 billion billion billion billion billion billion billion billion billion billion” (OK, I've done that myself, on one occasion, but I was having fun at the expense of a competitor). And finally, I find it dismaying that a popular science book by a prominent researcher published by a house as respectable as Knopf at a cover price of USD26 lacks an index—this is a fundamental added value that the reader deserves when parting with this much money (especially for a book of only 220 pages). If you know nothing about these topics, this volume will probably leave you only more confused, and possibly over-optimistic about the state of quantum computation. If you've followed the field reasonably closely, the author's professional publications (most available on-line), which are lucidly written and accessible to the non-specialist, may be more rewarding.
I remain dubious about grandiose claims for quantum computation, and nothing in this book dispelled my scepticism. From Democritus all the way to the present day, every single scientific theory which assumed the existence of a continuum has been proved wrong when experiments looked more closely at what was really going on. Yet quantum mechanics, albeit a statistical theory at the level of measurement, is completely deterministic and linear in the evolution of the wave function, with amplitudes given by continuous complex values which embody, theoretically, an infinite amount of information. Where is all this information stored? The Bekenstein bound gives an upper limit on the amount of information which can be represented in a given volume of spacetime, and that implies that even if the quantum state were stored nonlocally in the entire causally connected universe, the amount of information would be (albeit enormous), still finite. Extreme claims for quantum computation assume you can linearly superpose any number of wave functions and thus encode as much information as you like in a single computation. The entire history of science, and of quantum mechanics itself makes me doubt that this is so—I'll bet that we eventually find some inherent granularity in the precision of the wave function (perhaps round-off errors in the simulation we're living within, but let's not revisit that). This is not to say, nor do I mean to imply, that quantum computation will not work; indeed, it has already been demonstrated in proof of concept laboratory experiments, and it may well hold the potential of extending the growth of computational power after the pure scaling of classical computers runs into physical limits. But just as shrinking semiconductor devices is fundamentally constrained by the size of atoms, quantum computation may be limited by the ultimate precision of the discrete computational substrate of the universe which behaves, on the large scale, like a continuous wave function.
The failure of the Occupation could not, perhaps, have been averted in the very nature of the case. But it might have been mitigated. Its mitigation would have required the conquerors to do something they had never had to do in their history. They would have had to stop doing what they were doing and ask themselves some questions, hard questions, like, What is the German character? How did it get that way? What is wrong with its being that way? What way would be better, and what, if anything, could anybody do about it?Wise questions, indeed, for any conqueror of any country. The writing is so superb that you may find yourself re-reading paragraphs just to savour how they're constructed. It is also thought-provoking to ponder how many things, from the perspective of half a century later, the author got wrong. In his view the occupation of West Germany would fail to permanently implant democracy, that German re-militarisation and eventual aggression was almost certain unless blocked by force, and that the project of European unification was a pipe dream of idealists and doomed to failure. And yet, today, things seem to have turned out pretty well for Germany, the Germans, and their neighbours. The lesson of this may be that national character can be changed, but changing it is the work of generations, not a few years of military occupation. That is also something modern-day conquerors, especially Western societies with a short attention span, might want to bear in mind.
So long as spirituality was an idea, such as believing in God, it fell under religious control. However, if doctors redefined spirituality to mean a sensual phenomenon—a feeling—then doctors would control it, since feelings had long since passed into the medical profession's hands, the best example being unhappiness. Turning spirituality into a feeling would also help doctors square the phenomenon with their own ideology. If spirituality were redefined to mean a feeling rather than an idea, then doctors could group spirituality with all the other feelings, including unhappiness, thereby preserving their ideology's integrity. Spirituality, like unhappiness, would become a problem of neurotransmitters and a subclause of their ideology. (Page 226.)A reader opening this book is confronted with 293 pages of this. This paragraph appears in chapter nine, “The Last Battle”, which describes the Manichean struggle between doctors and organised religion in the 1990s for the custody of the souls of Americans, ending in a total rout of religion. Oh, you missed that? Me too. Mass medication with psychotropic drugs is a topic which cries out for a statistical examination of its public health dimensions, but Dworkin relates only anecdotes of individuals he has known personally, all of whose minds he seems to be able to read, diagnosing their true motivations which even they don't perceive, and discerning their true destiny in life, which he believes they are failing to follow due to medication for unhappiness. And if things weren't muddled enough, he drags in “alternative medicine” (the modern, polite term for what used to be called “quackery”) and ”obsessive exercise” as other sources of Artificial Happiness (which he capitalises everywhere), which is rather odd since he doesn't believe either works except through the placebo effect. Isn't it just a little bit possible that some of those people working out at the gym are doing so because it makes them feel better and likely to live longer? Dworkin tries to envision the future for the Happy American, decoupled from the traditional trajectory through life by the ability to experience chemically induced happiness at any stage. Here, he seems to simultaneously admire and ridicule the culture of the 1950s, of which his knowledge seems to be drawn from re-runs of “Leave it to Beaver”. In the conclusion, he modestly proposes a solution to the problem which requires completely restructuring medical education for general practitioners and redefining the mission of all organised religions. At least he doesn't seem to have a problem with self-esteem!
Now, this may seem mind-boggling enough, but from these premises, which it must be understood are accepted by most experts who study the origin of the universe, one can deduce some disturbing consequences which seem to be logically unavoidable.
- At the largest scale, the geometry of the universe is indistinguishable from Euclidean (flat), and the distribution of matter and energy within it is homogeneous and isotropic.
- The universe evolved from an extremely hot, dense, phase starting about 13.7 billion years ago from our point of observation, which resulted in the abundances of light elements observed today.
- The evidence of this event is imprinted on the cosmic background radiation which can presently be observed in the microwave frequency band. All large-scale structures in the universe grew from gravitational amplification of scale-independent quantum fluctuations in density.
- The flatness, homogeneity, and isotropy of the universe is best explained by a period of inflation shortly after the origin of the universe, which expanded a tiny region of space, smaller than a subatomic particle, to a volume much greater than the presently observable universe.
- Consequently, the universe we can observe today is bounded by a horizon, about forty billion light years away in every direction (greater than the 13.7 billion light years you might expect since the universe has been expanding since its origin), but the universe is much, much larger than what we can see; every year another light year comes into view in every direction.
Let me walk you through it here. We assume the universe is infinite and unbounded, which is the best estimate from precision cosmology. Then, within that universe, there will be an infinite number of observable regions, which we'll call O-regions, each defined by the volume from which an observer at the centre can have received light since the origin of the universe. Now, each O-region has a finite volume, and quantum mechanics tells us that within a finite volume there are a finite number of possible quantum states. This number, although huge (on the order of 1010123 for a region the size of the one we presently inhabit), is not infinite, so consequently, with an infinite number of O-regions, even if quantum mechanics specifies the initial conditions of every O-region completely at random and they evolve randomly with every quantum event thereafter, there are only a finite number of histories they can experience (around 1010150). Which means that, at this moment, in this universe (albeit not within our current observational horizon), invoking nothing as fuzzy, weird, or speculative as the multiple world interpretation of quantum mechanics, there are an infinite number of you reading these words scribbled by an infinite number of me. In the vast majority of our shared universes things continue much the same, but from time to time they d1v3r93 r4ndtx#e~—….
Reset . . . Snap back to universe of origin . . . Reloading initial vacuum parameters . . . Restoring simulation . . . Resuming from checkpoint.What was that? Nothing, I guess. Still, odd, that blip you feel occasionally. Anyway, here is a completely fascinating book by a physicist and cosmologist who is pioneering the ragged edge of what the hard evidence from the cosmos seems to be telling us about the apparently boundless universe we inhabit. What is remarkable about this model is how generic it is. If you accept the best currently available evidence for the geometry and composition of the universe in the large, and agree with the majority of scientists who study such matters how it came to be that way, then an infinite cosmos filled with observable regions of finite size and consequently limited diversity more or less follows inevitably, however weird it may seem to think of an infinity of yourself experiencing every possible history somewhere. Further, in an infinite universe, there are an infinite number of O-regions which contain every possible history consistent with the laws of quantum mechanics and the symmetries of our spacetime including those in which, as the author noted, perhaps using the phrase for the first time in the august pages of the Physical Review, “Elvis is still alive”. So generic is the prediction, there's no need to assume the correctness of speculative ideas in physics. The author provides a lukewarm endorsement of string theory and the “anthropic landscape” model, but is clear to distinguish its “multiverse” of distinct vacua with different moduli from our infinite universe with (as far as we know) a single, possibly evolving, vacuum state. But string theory could be completely wrong and the deductions from observational cosmology would still stand. For that matter, they are independent of the “eternal inflation” model the book describes in detail, since they rely only upon observables within the horizon of our single “pocket universe”. Although the evolution of the universe from shortly after the end of inflation (the moment we call the “big bang”) seems to be well understood, there are still deep mysteries associated with the moment of origin, and the ultimate fate of the universe remains an enigma. These questions are discussed in detail, and the author makes clear how speculative and tentative any discussion of such matters must be given our present state of knowledge. But we are uniquely fortunate to be living in the first time in all of history when these profound questions upon which humans have mused since antiquity have become topics of observational and experimental science, and a number of experiments now underway and expected in the next few years which bear upon them are described.
Curiously, the author consistently uses the word “google” for the number 10100. The correct name for this quantity, coined in 1938 by nine-year-old Milton Sirotta, is “googol”. Edward Kasner, young Milton's uncle, then defined “googolplex” as 1010100. “Google™” is an Internet search engine created by megalomaniac collectivists bent on monetising, without compensation, content created by others. The text is complemented by a number of delightful cartoons reminiscent of those penned by George Gamow, a physicist the author (and this reader) much admires.
WITHIN THIS VALE |
OF TOIL |
AND SIN |
YOUR HEAD GROWS BALD |
BUT NOT YOUR CHIN—USE |
THIRTY DAYS |
HATH SEPTEMBER |
APRIL |
JUNE AND THE |
SPEED OFFENDER |
Jacqueline Wexler was such an administrator. Gracious and charming in public, accommodating and willing to compromise at meetings, she nevertheless had the steel-hard will and sharp intellect to drive the ICU's ramshackle collection of egos toward goals that she herself selected. Widely known as ‘Attila the Honey,’ Wexler was all sweetness and smiles on the outside, and ruthless determination within.After spending a third of page 70 on this paragraph, which makes my teeth ache just to re-read, the formidable Ms. Wexler walks off stage before the end of p. 71, never to re-appear. But fear not (or fear), there are many, many more such paragraphs in subsequent pages. An Earth-based space elevator, a science fiction staple, is central to the plot, and here Bova bungles the elementary science of such a structure in a laugh-out-loud chapter in which the three principal characters ride the elevator to a platform located at the low Earth orbit altitude of 500 kilometres. Upon arrival there, they find themselves weightless, while in reality the force of gravity would be imperceptibly less than on the surface of the Earth! Objects in orbit are weightless because their horizontal velocity cancels Earth's gravity, but a station at 500 kilometres is travelling only at the speed of the Earth's rotation, which is less than 1/16 of orbital velocity. The only place on a space elevator where weightlessness would be experienced is the portion where orbital velocity equals Earth's rotation rate, and that is at the anchor point at geosynchronous altitude. This is not a small detail; it is central to the physics, engineering, and economics of space elevators, and it figured prominently in Arthur C. Clarke's 1979 novel The Fountains of Paradise which is alluded to here on p. 140. Nor does Bova restrain himself from what is becoming a science fiction cliché of the first magnitude: “nano-magic”. This is my term for using the “nano” prefix the way bad fantasy authors use “magic”. For example, Lord Hacksalot draws his sword and cuts down a mighty oak tree with a single blow, smashing the wall of the evil prince's castle. The editor says, “Look, you can't cut down an oak tree with a single swing of a sword.” Author: “But it's a magic sword.” On p. 258 the principal character is traversing a tether between two parts of a ship in the asteroid belt which, for some reason, the author believes is filled with deadly radiation. “With nothing protecting him except the flimsy…suit, Bracknell felt like a turkey wrapped in a plastic bag inside a microwave oven. He knew that high-energy radiation was sleeting down on him from the pale, distant Sun and still-more-distant stars. He hoped that suit's radiation protection was as good as the manufacturer claimed.” Imaginary editor (who clearly never read this manuscript): “But the only thing which can shield you from heavy primary cosmic rays is mass, and lots of it. No ‘flimsy suit’ however it's made, can protect you against iron nuclei incoming near the speed of light.” Author: “But it's a nano suit!” Not only is the science wrong, the fiction is equally lame. Characters simply don't behave as people do in the real world, nor are events and their consequences plausible. We are expected to believe that the causes of and blame for a technological catastrophe which killed millions would be left to be decided by a criminal trial of a single individual in Ecuador without any independent investigation. Or that a conspiracy to cause said disaster involving a Japanese mega-corporation, two mass religious movements, rogue nanotechnologists, and numerous others could be organised, executed, and subsequently kept secret for a decade. The dénouement hinges on a coincidence so fantastically improbable that the plausibility of the plot would be improved were the direct intervention of God Almighty posited instead. Whatever became of Ben Bova, whose science was scientific and whose fiction was fun to read? It would be uncharitable to attribute this waste of ink and paper to age, as many science fictioneers with far more years on the clock have penned genuine classics. But look at this! Researching the author's biography, I discovered that in 1996, at the age of 64, he received a doctorate in education from California Coast University, a “distance learning” institution. Now, remember back when you were in engineering school struggling with thermogoddamics and fluid mechanics how you regarded the student body of the Ed school? Well, I always assumed it was a selection effect—those who can do, and those who can't…anyway, it never occurred to me that somewhere in that dark, lowering building they had a nano brain mushifier which turned the earnest students who wished to dedicate their careers to educating the next generation into the cognitively challenged classes they graduated. I used to look forward to reading anything by Ben Bova; I shall, however, forgo further works by the present Doctor of Education.
Finally, demand for fab labs as a research project, as a collection of capabilities, as a network of facilities, and even as a technological empowerment movement is growing beyond what can be handled by the initial collection of people and institutional partners that were involved in launching them. I/we welcome your thoughts on, and participation in, shaping their future operational, organizational, and technological form.Well, I am but a humble programmer, but here's how I'd go about it. First of all, I'd create a “Fabrication Trailer“ which could visit every community in the United States, Canada, and Mexico; I'd send it out on the road in every MIT vacation season to preach the evangel of “make” to every community it visited. In, say, one of eighty of such communities, one would find a person who dreamed of this happening in his or her lifetime who was empowered by seeing it happen; provide them a template which, by writing a cheque, can replicate the fab and watch it spread. And as it spreads, and creates wealth, it will spawn other Fab Labs. Then, after it's perfected in a couple of hundred North American copies, design a Fab Lab that fits into an ocean cargo container and can be shipped anywhere. If there isn't electricity and Internet connectivity, also deliver the diesel generator or solar panels and satellite dish. Drop these into places where they're most needed, along with a wonk who can bootstrap the locals into doing things with these tools which astound even those who created them. Humans are clever, tool-making primates; give us the tools to realise what we imagine and then stand back and watch what happens! The legacy media bombard us with conflict, murder, and mayhem. But the future is about creation and construction. What does An Army of Davids do when they turn their creativity and ingenuity toward creating solutions to problems perceived and addressed by individuals? Why, they'll call it a renaissance! And that's exactly what it will be. For more information, visit the Web site of The Center for Bits and Atoms at MIT, which the author directs. Fab Central provides links to Fab Labs around the world, the machines they use, and the open source software tools you can download and start using today.