Posted on October 1st, 2013 No comments
An article about fusion just appeared on the Livescience website promisingly entitled “Fusion Experiments Inch Closer to Break-Even Goal” that is unexceptionable hype except for one little detail; the goalpost for fusion ignition has been moved. It hasn’t been nudged. It hasn’t been tweaked. It has been torn up by the roots, carried down the road a few miles, and planted in an entirely new place that bears no resemblance to the original goal. The article in question is about fusion experiments at Lawrence Livermore National Laboratory’s (LLNL’s ) National Ignition Facility, usually referred to by its acronym, as the NIF. The goalpost is that which applies to inertial confinement fusion (ICF), which is the flavor being pursued at LLNL. The other mainstream approach is magnetic fusion, which will be implemented at the ITER facility currently under construction in France. Here’s the money quote from the article:
That got the NIF closer to the “scientific break-even point,” where the amount of energy that comes out of the fusion reaction is equal to that which was put in by the kinetic energy from the implosion. (The energy from the laser isn’t counted in the calculation). Right now, the amount of energy coming out of the NIF setup is about 80 percent of what is put in.
“NIF is built to ignite a fusion pellet,” said Stewart Prager, director of the Princeton Plasma Physics Laboratory. “They didn’t get it by the time they originally stated, but they are making progress.” The NIF was built in 2008; its original mandate was to achieve ignition — the break-even point — in 2012.
What’s wrong with this picture? LLNL explicitly agreed that “ignition” would occur at the point where fusion energy out equals laser energy in. They did so before a committee of prestigious scientists appointed by the National Academy of Sciences’ National Research Council to review the nation’s ICF program. It was entirely fitting and proper that they should do so, because that definition puts them on a level playing field with magnetic fusion. It’s not as if this is a minor point. After all, the very name of the facility in question is the National Ignition Facility. Now, suddenly, “ignition” is being redefined as “fusion energy out equals kinetic energy of the implosion put in!”
Why is this happening? Because, in spite of recent encouraging progress, the NIF is still a long way from achieving real ignition. Politicians are griping because the ignition they were promised hasn’t happened, and there have been dark mutterings about defunding the project. In other words, the NIF’s survival is at stake. I can see the problem. What I can’t see is that gross scientific dishonesty is the answer to the problem. For that strategy to succeed, it is necessary for virtually all the members of Congress to be fools. Although that is certainly a common assumption, it is not necessarily true. There are actually a few scientists in Congress, and I doubt that all of them can be hoodwinked into swallowing this latest redefinition of ignition.
What to do? Try telling it like it is. The NIF hasn’t achieved ignition, and maybe it never will. In spite of that, it remains the finest facility of its kind in the world for accomplishing the mission it was actually funded for; insuring the safety and reliability of our nuclear arsenal. No facility outside the United States can approach so closely the physical conditions that occur in nuclear explosions. No other facility is so precise, or has such a fine suite of diagnostics. The NIF gives us a huge leg up in maintaining our arsenal and avoiding technological surprise as long as nuclear testing is not resumed. As long as we have such facilities and the rest of the world doesn’t, it would be dumb for us to even think about resuming testing. It would be throwing away a massive advantage. Think none of our weaponeers wants to resume testing? Think again! The NIF and facilities like it are the best argument against them. Try pointing that out to Congress. I suspect it would work better than these ham-handed attempts to move the goalposts.
Posted on September 8th, 2013 3 comments
While a question such as “Can issues of morality be answered by scientific experiments?” may be important, introducing the term “scientism” with all its baggage distracts from addressing the question in a rational manner.
He certainly has a point, but what about the question itself? Can issues of morality be answered by scientific experiments? One answer to the question, as absurd as it is famous, was given by Steven Jay Gould. He claimed that science can’t answer moral questions because science and religion belong to “non-overlapping magisteria,” and issues of morality belong in the magisterium of religion. This “solution” relies on two separate fallacies of objectification; that there is a “science” object, and that separate, independent objects known as “issues of morality” also exist. In the first place, there is no such thing as a science “thing,” and in the second, good and evil have no independent existence as things-in-themselves.
In fact, issues of morality can’t be answered by scientific experiments because there are no such entities as issues of morality. Experiments can’t examine things that don’t exist. No one has ever invented a butterfly net good enough to capture so much as a single “good” or “evil” as it floats about through the ether. It turns out that they are more elusive by far than magnetic monopoles, for the very good reason that they don’t exist. It’s amazing how few evolutionary psychologists and others who appear to accept the evolutionary origin of moral emotions fail to grasp this fundamental fact. Moral emotions are part of the behavioral repertoire of several species of animals, including human beings. As such they cannot somehow transcend their fundamental nature as emotions in the minds of individual animals and acquire some sort of independent legitimacy. It is a testament to the power of these emotions that these seemingly obvious implications of their evolutionary origins are so often simply overlooked. It is not uncommon to find people who should know better alluding to a transcendental morality complete with “good” and “evil” objects in the very context of discussions of those origins.
A typical example appears in an essay by Michael Price on the This View of Life website of group selection proponent David Sloan Wilson. In an essay entitled “Why Evolutionary Science Is The Key To Moral Progress” he writes,
We’d be better able to move on from these disputes in productive ways—and thus to make moral progress—if we could better understand our own moral beliefs. But how can we do this when our beliefs seem so opaque to introspection? It’s easy to feel passionate about our beliefs, but how can we see behind our emotions, to find out where our beliefs came from and whether they are leading us to where we want to go? Evolutionary science provides the key to such moral progress.
When I say that evolutionary science is the key to moral progress, there’s at least one thing I don’t mean and two things I do mean.
What I don’t mean is that the evolutionary process itself can provide guidance about right or wrong. If something increased or increases reproductive fitness, does that mean we should judge it as morally good? Of course not; I agree with philosophers who identify such thinking as a flawed ‘appeal to nature’ or ‘naturalistic fallacy’. Consider behavioral outputs of what are probably evolved psychological adaptations: many of these (e.g. xenophobia) could usually be considered bad, whereas many others (e.g. parental investment) could usually be considered good. By the same token, many behaviors that are probably by-products of evolved adaptations (e.g. reading and mathematics) could be judged as good, whereas many others (e.g. crippling drug addiction) could be judged as bad. Suffice it to say: whether or not a behavior is adaptive, or whether it is the product or by-product of an evolved adaptation, implies nothing about its moral value.
Here, in the very context of a discussion of “evolved psychological adaptations,” we have an explicit statement of faith in the objective existence of such mystical entities as “good,” “bad,” “moral progress,” and “moral value.”
Obviously, Price does not consider it in the least necessary to explain his bald assumption that such objects actually exist independently of his own subjective perceptions. However, he can get away with this rational disconnect, because he can safely assume that his readers experience similar subjective perceptions. They, too, perceive “good,” “bad,” etc., as things. They do so, not because they really are objects and things-in-themselves, but because their perception as such has enhanced the probability that the individuals who experience them in that way will survive and reproduce. As far as evolution by natural selection is concerned, that’s all that matters. Evolution is a process, not a thing, and as such is not equipped to appreciate the rational inconsistency of “seeing” things that don’t exist.
Which brings us back to the title of this essay. Is science relevant to morality? Assuming we are not too finicky about the meaning of the word “science,” we can say that it is relevant to understanding the nature of moral emotions, and the reasons for their existence. However, when it comes to understanding “good” and “evil” as things, science is, indeed, useless. It is not possible to investigate objects that don’t exist using the scientific or any other method.
Posted on August 17th, 2013 No comments
In an article that appeared recently in The New Republic entitled, “Science is not Your Enemy,” Steven Pinker is ostensibly defending science, going so far as to embrace “scientism.” As he points out, “The term “scientism” is anything but clear, more of a boo-word than a label for any coherent doctrine.” That’s quite true, which is reason enough to be somewhat circumspect about self-identifying (if I may coin a term) as a “scientismist.” Nothing daunted, Pinker does just that, defending scientism in “the good sense.” He informs us that “good scientism” is distinguished by “an explicit commitment to two ideals,” namely, the propositions that the world is intelligible, and that the acquisition of knowledge is hard.
Let me say up front that I am on Pinker’s side when it comes to the defense of what he calls “science,” just as I am on his side in rejecting the ideology of the Blank Slate. Certainly he’s worthy of a certain respect, if only in view of the sort of people who have been coming out of the woodwork to attack him for his latest. Anyone with enemies like that can’t be all bad. It’s just that, whenever I read his stuff, I find myself rolling my eyes before long. Consider, for example, his tome about the Blank Slate. My paperback version runs to 500 pages give or take, and in all that prose, I find only a single mention of Robert Ardrey, and then only accompanied by the claim that he was “totally and utterly wrong.” Now, by the account of the Blank Slaters themselves (see, in particular, the essays by Geoffrey Gorer in Man and Aggression, edited by Ashley Montagu), Robert Ardrey was their most effective and influential opponent. In other words, Pinker wrote a thick tome, purporting to be an account of the Blank Slate, in which he practically ignored the contributions of the most important player in the whole affair, only mentioning him at all in order to declare him wrong, when in fact he was on the same side of the issue as Pinker.
Similar problems turn up in Pinker’s latest. For example, he writes,
Just as common, and as historically illiterate, is the blaming of science for political movements with a pseudoscientific patina, particularly Social Darwinism and eugenics. Social Darwinism was the misnamed laissez-faire philosophy of Herbert Spencer. It was inspired not by Darwin’s theory of natural selection, but by Spencer’s Victorian-era conception of a mysterious natural force for progress, which was best left unimpeded.
Here, as in numerous similar cases, it is clear Pinker has never bothered to read Spencer. The claim that he was a “Social Darwinist” was a red herring tossed out by his enemies after he was dead. Based on a minimal fair reading of his work, the claim is nonsense. If actually reading Spencer is too tedious, just Google something like “Spencer Social Darwinism.” Check a few of the hits, and you will find that a good number of modern scholars have been fair-minded enough to actively dispute the claim. Other than that, you will find no reference to specific writings of Spencer in which he promotes Social Darwinism as it is generally understood. The same could be said of the laissez faire claim. Spencer supported a small state, but hardly rejected stated intervention in all cases. He was a supporter of labor unions, and even was of the opinion that land should be held in common in his earlier writings. As for “Victorian-era” conceptions, if memory serves, Darwin wrote during that era as well, and while Spencer embraced Lamarckism and had a less than up-to-date notion of how evolution works, I find no reference in any of his work to a “mysterious natural force for progress.”
Pinker’s comments about morality are similarly clouded. He writes,
In other words, the worldview that guides the moral and spiritual values of an educated person today is the worldview given to us by science… The facts of science, by exposing the absence of purpose in the laws governing the universe, force us to take responsibility for the welfare of ourselves, our species, and our planet. For the same reason, they undercut any moral or political system based on mystical forces, quests, destinies, dialectics, struggles, or messianic ages. And in combination with a few unexceptionable convictions – that all of us value our own welfare and that we are social beings who impinge on each other and can negotiate codes of conduct – the scientific facts militate toward a defensible morality, namely, adhering to principles that maximize the flourishing of humans and other sentient beings.
In other words, Pinker has bought in to the Sam Harris “human flourishing” mumbo-jumbo, and thinks that the “facts of science” can somehow become material objects with the power to dictate that which is “good” and that which is “evil.” Here Pinker, in company with Harris, has taken leave of his senses. Based on what he wrote earlier in the essay, we know that he is aware that what we understand as morality is the expression of evolved behavioral traits. Those traits are their ultimate cause, and without them morality would literally cease to exist as we know it. They exist in the brains of individuals, solely by virtue of the fact that, at some point in the distant past utterly unlike the present, they promoted our survival. And yet, in spite of the fact that Pinker must understand, at least at some level, that these things are true, he agrees with Harris that the emotional responses, or, as Hume, whom Pinker also claims to have read, puts it, sentiments, can jump out of our heads, become objects, or things in themselves, independent of the minds of individuals, and, as such, can be manipulated and specified by the “facts of science.” Presumably, once the “educated” and the “scientists” have agreed on what the “facts of science” tell us is a “defensible morality,” at that point the rest of us become bound to agree with them on the meanings of “good” and “evil” that they pass down to us, must subordinate our own emotions and inherent predispositions regarding such matters to “science,” and presumably be justifiably (by “science”) punished if we do not. What nonsense!
“Science” is not an object, any more than “good” and “evil.” “Science” cannot independently “say” anything, nor can it create values. In reality, “science” is a rather vague set of principles and prescriptions for approaching the truth, applied willy-nilly if at all by most “scientists.” By even embracing the use of the term “science” in that way, Pinker is playing into the hands of his enemies. He is validating their claim that “science” is actually a thing, but in their case, a bête noire, transcending its real nature as a set of rules, more or less vaguely understood and applied, to become an object in itself. Once the existence of such a “science” object is accepted, it becomes a mere bagatelle to fix on it the responsibility for all the evils of the world, or, in the case of the Pinkers of the world, all the good.
In reality, the issue here is not whether this imaginary “science” object exists and, assuming it does, whether it is “good” or “evil.” It is about whether we should be empowered to learn things about the universe in which we live or not. The opponents of “scientism” typically rail against such things as eugenics, Social Darwinism, and the atomic bomb. These are supposedly the creations of the “science” object. But, in fact, they are no such thing. In the case of eugenics and Social Darwinism, they represent the moral choices of individuals. In the case of the atomic bomb, we have a thing which became possible as a result of the knowledge of the physical world acquired in the preceding half a century, give or take. What would the opponents of “scientism” have us change? The decision to build the atomic bomb? Fine, but in that case they are not opposing “science,” but rather a choice made by individuals. Opposition to “science” itself can only reasonably be construed as opposition to the acquisition of the knowledge that made the bomb possible to begin with. If that is what the opponents of “scientism” really mean, let them put their cards on the table. Let them explain to us in just what ways those things which the rest of us are to be allowed to know will be limited, and just why it is they think they have the right to dictate to the rest of us what we can know and what we can’t.
It seems to me this whole “science” thing is getting out of hand. If we must have an object, it would be much better for us to go back to the Enlightenment and use the term “reason.” It seems to me that would make it a great deal more clear what we are talking about. It would reveal the true nature of the debate. It is not about the “science” object, and whether it is “good” or “evil,” but about whether we should actually try to use our rational minds, or instead relegate our brains to the less ambitious task of serving as a convenient stuffing for our skulls.
Posted on March 3rd, 2013 No comments
Back in 2002, Robert Kurzban, who writes a blog for the journal Evolutionary Psychology, wrote a review of Alas, Poor Darwin: Arguments Against Evolutionary Psychology, by Steven and Hilary Rose. The Roses, ideological zealots and leftover Blank Slaters who have devoted their careers to scientific obscurantism, had regurgitated all the usual specious arguments against human nature, which had already become hackneyed by that time. Anyone with a passing interest in human behavior likely knows most of them by heart. They include the claim that the hypotheses of EP are unfalsifiable, that evolutionary explanations of human behavior serve evil political ends rather than science, etc. etc., usually topped off with that most ancient and threadbare red herring of them all, that anyone who dares to say anything nice about EP is a “genetic determinist.” In his review, entitled, “Alas Poor Evolutionary Psychology: Unfairly Accused, Unjustly Condemned,” Kurzban demolishes them all in turn, writing in his conclusion,
There are now a collection of dialogues in the popular press between evolutionary psychologists and their critics. The discussions all seem to have the same form: Critics assert that evolutionary psychologists are wrong in believing behavior is genetically determined, that every aspect of the organism is an adaptation, and that discovering what is informs what ought be. Evolutionary psychologists reply that they never made any of these claims, and document places where they claim precisely the reverse. The critics then reply that evolutionary psychologists are wrong in believing behavior is genetically determined, that every aspect of the organism is an adaptation, and that discovering what is informs what should be.
The contradictions between what evolutionary psychologists have said and what their critics have said they said are as clear as they are infuriating. All of the correctives that I have presented here have been discussed before, and all of them are in the pieces cited by the critics of evolutionary psychology. It is unfathomable how the Roses and the other contributors to Alas Poor Darwin could have come away from the primary literature with their impressions of genetic determinism, panglossian adaptationism, and so on.
I suspect that Kurzban fathomed the reasons well enough, even then. Such attacks on EP are not scientific refutations, but propaganda, designed to prop up pseudo-religious ideological shibboleths that happen to be badly out of step with reality. Even then, they already had all the familiar trappings of propaganda, including the “Big Lie”; endless repetition while studiously ignoring counter-arguments. Nothing has changed in the ensuing decade. “Genetic determinism” is still as much a fixture in the screeds of left-over Blank Slaters as ever. Pointing out the absurdity of the charge is as futile as trying to refute the charge of “fascism” by carefully explaining the theory of the corporate state. Razib Khan, who writes the Gene Expression blog for Discover magazine, notes that he was just denounced as a “genetic determinist” for daring to even question the scientific credentials of cultural anthropologists, in a couple of posts that didn’t so much as take up the question of the connection between genes and behavior.
All this points up a fact that is as true now as it was in the days of Galileo. “Science,” understood as a disinterested and cautious search for truth inspired by a spirit of skepticism, can still be as easily derailed by secular religious zealots as it was by the more traditional “spiritual” variety who intimidated Galileo and still fume against Darwin. The puerile myths of the Blank Slate represented the prevailing orthodoxy in the behavioral “sciences” for decades, propped up, not by a tolerant and open spirit of academic freedom, but by vilification and intimidation of anyone who dared to step out of line. Evolutionary psychologists are hardly the only victims, but they are probably the most prominent. They have the misfortune of representing an idea that happens to tread on far more ideological toes than most. Blank Slate orthodoxy is hardly unique in that regard.
For example, one of the common hypotheses of evolutionary psychology that there may be an innate component of human morality immediately elicits a “territorial defense” response from the legions of those who spend their time devising new moral systems for the edification of mankind. Most of them spend their time cobbling elaborate proofs of the existence of the Good just as their intellectual forebears once concocted proofs of the existence of God. Consider, for example, the case of the author of the Atheist Ethicist blog, who has demonstrated that, because a equals b and b equals c, it therefore follows that anyone who dares to claim that there is “an evolutionary basis for morality” is immoral. To make a long story short, the “ethicist” believes that those insidious evolutionary psychologists are not limiting themselves to studying the “is” of human moral behavior, but have a disquieting tendency to lap over into the “ought,” a territory which he has reserved for himself and his revolutionary moral system of “desire utilitarianism.” He does not actually name any specific examples of the most egregious of these evildoers, but no doubt we can trust him given his unique moral qualifications.
It isn’t difficult to find similar examples illustrating why the ideologically inspired find EP such a tempting target. However, the fact that it is is a stroke of very bad luck for our species. After all, EP is a field devoted to expanding our understanding of our selves, and there is no more critical knowledge than self-knowledge. For example, what if the greed of evil corporations, or the imperialist pretentions of certain uniquely evil races, or “frustration” don’t turn out to be completely adequate and all-encompassing explanations of human warfare after all? Is it really possible to know with absolute certainty that innate behavioral traits play no role whatsoever? If they do, the failure to discover and understand them may threaten our very survival. I happen to prefer survival to the alternative. For that reason, it seems to me that the time for refuting such charges as “genetic determinism” with patient, reasoned arguments is past. It is high time to begin fighting back against the ideological zealots with the same weapons they have long been using against their victims.
Posted on January 21st, 2013 No comments
The 155 intellectuals chosen by Edge.org to answer their annual question, (What *Should” we be Worried About?), were worried about a number of other interesting things besides Geoffrey Miller’s Chinese eugenics, discussed in my last post. One of these, which turned up in the contribution of philosopher Helena Cronin was the continuing rejection of evolved human nature, a subject I’ve also often discussed. Her worry is not overblown. The Blank Slaters may be in retreat, but they have hardly disappeared. One still often finds them grumbling on the sidelines of evolutionary psychology. Cronin refers to the phenomenon as a scientific “asymmetry,” which she describes as, “the discrepancy between the objective status of the science and its denigration by a clamorous crowd of latter-day Blakes.” (Painter and printmaker William Blake was a furious opponent of the Enlightenment whose famous print of Newton, shown below, depicts him as the embodiment of “desiccated rationality and soulless materialism.”) Her “worry” is worth quoting at length:
Generally, the public reception of a scientific theory concurs by and large with the judgement of the objective world of ideas. Not, however, in the case of the scientific understanding of our evolved human nature and, above all, male and female natures. If the arguments against the evolutionary science of human nature were conducted in the world of the objective content of ideas, there would be no contest; evolutionary theory would win hands down. But, as a sociological fact, in the public market-place it loses disastrously against its vociferous critics.
How? Because, in a complete reversal of the objective relationship between the science and these critics, all the asymmetries are reversed.
First, the burden of ‘proof’, the burden of argument, is transferred from the criticisms onto the science; it is Darwinism that’s on trial. Meanwhile, anti-Darwinian attitudes don’t have to defend themselves—they are accepted uncritically; the standards for judgement of these views involve all-too-ready credibility and suspensions of disbelief.
Second, adding insult to injury, a plethora of home-made alternatives is conjured up to fill the gap where the real science should be. This DIY-science includes: pseudo-methodological denunciations, where mere name-callings suffice—essentialist, reductivist, teleological, Panglossian (all very bad) and politically incorrect (very bad indeed); the immutable ‘entanglement’ of nature and nurture, which renders nature impenetrable—thereby freeing ‘pure nurture’ to be discussed at length; a cavalier disregard for hard-won empirical evidence—though with a penchant for bits of brains lighting up (no; I don’t know either); the magical potency of ‘stereotyping’ (bad) and ‘role models’ (good); a logic-defying power to work miracles on tabula-rasa psychologies, as in ‘socialisation’ (bad) and ‘empowerment’ (good); made-up mechanisms, even though discredited—multi-tasking, self-esteem, stereotype threat; complaints of ‘controversial’ and ‘tendentious’ – which are true sociologically but false scientifically (a case of raising the dust and then complaining they cannot see). The science-free policy that this generates is epitomised by the ‘women into science’ lobby, which is posited on a ‘bias and barriers’ assumption and an a priori rejection of—yes, the science of sex differences.
This mish-mash is low on scientific merit. But it is not treated as opinion versus science. On the contrary, psychologically and sociologically, it has a voice far more influential and persuasive than its objective status warrants.
This double standard applied to evolutionary psychology, or “asymmetry,” as Cronin puts it, is hardly a figment of her imagination. It’s obvious to anyone not wearing blinkers. See, for example, evolutionary psychologist Robert Kurzban’s blog, where he is constantly fending off just such “asymmetrical” attacks as Cronin describes. The obscurantist “not in our genes” orthodoxy the Blank Slaters managed to prop up for so many decades in the behavioral sciences may have been broken, but they are still around. I suspect we will continue to detect their stench from the sidelines for some time, along with that of the old Marxists who spawned them.
There were some related comments in the bit submitted by anthropologist John Tooby. Tooby is described by Edge, without batting an eye, as “the founder of the field of evolutionary psychology.” Apparently the ever-fluid “history” of the field has been revised again, and I didn’t even notice. One can only speculate that the last “founder of the field of evolutionary psychology,” E. O. Wilson, has been deposed because of his embrace of group selection. Be that as it may, in his contribution, embellished with the catchy title, “Unfriendly Physics, Monsters From The Id, And Self-Organizing Collective Delusions,” Tooby cites a number of existential threats to the survival of mankind, and suggests that we may be ill-equipped to deal with them because of the way we do science. As he puts it, scientists are no more immune than anyone else to “the self-organizing collective delusions that we all participate in, and mistake for reality.” Elaborating on this theme, he writes,
Because intellectuals are densely networked in self-selecting groups whose members’ prestige is linked (for example, in disciplines, departments, theoretical schools, universities, foundations, media, political/moral movements, and other guilds), we incubate endless, self-serving elite superstitions, with baleful effects: Biofuel initiatives starve millions of the planet’s poorest. Economies around the world still apply epically costly Keynesian remedies despite the decisive falsification of Keynesian theory by the post-war boom (government spending was cut by 2/3, 10 million veterans dumped into the labor force, while Samuelson predicted “the greatest period of unemployment and industrial dislocation which any economy has ever faced”). I personally have been astonished over the last four decades by the fierce resistance of the social sciences to abandoning the blank slate model in the face of overwhelming evidence that it is false. As Feynman pithily put it, “Science is the belief in the ignorance of experts.”
I heartily concur. Behavioral scientists, in particular, would do well to turn their gaze inward for a change, and explain to the rest of us how they could have been so wrong about something so critical to us all for so long as human nature.
Posted on December 3rd, 2012 No comments
According to the frontispiece of his The Evolution of Man, published in 1924, Grafton Elliot Smith held the titles of M.A., M.D., Litt. D., D.Sc., F.R.C.P., F.R.S., and Professor of Anatomy at the University of London. If titles and academic honors are any guide, he must have been a very intelligent man. He was well aware of the limitations of human intelligence, and wary of the influence of the emotions on judgments of fact. For example, in the book referred to above, from which all the following quotes are taken as well, he wrote,
The range of true judgment is in fact extremely limited in the vast majority of human beings. Emotions and the unconscious influence of the environment in which an individual has grown up play an enormous part in all his decisions, even though he may give a rational explanation of the motives for many of his actions without realizing that they were inspired by causes utterly alien to those which he has given – and given without any intention of dishonesty – in explanation of them. It is the exception rather than the rule for men to accept new theories on evidence that appeals to reason alone. The emotional factor usually expresses itself in an egotistical form. The ‘will to believe’ can often be induced by persuading a man that he discovered the new theory of his own initiative.
No one could have written a better post mortem for Smith’s career. When it came to questions that really mattered about the evolution of man, he had a positive penchant for getting it wrong. Regarding the issue of whether erect posture or a large brain came first in the transition from ape to man, he noted in passing,
The case for the erect attitude was ably put by Dr. Munro (Neil Gordon Munro, better known for his studies of the Japanese Ainu, ed.) in 1893. He argued that the liberation of the hands and the cultivation of their skill lay at the root of Man’s mental supremacy.
Smith would have done well to listen to Munro, not to mention Charles Darwin and Ernst Haeckel, both of whom proposed similar, “bipedalism before large brain” theories. However, he would have none of it, writing,
It was not the adoption of the erect attitude that made Man from an Ape, but the gradual perfecting of the brain and the slow upbuilding of the mental structure, of which erectness of carriage is one of the incidental manifestations.
Noting that the above quote was included in the substance of an address to the British Association delivered in the autumn of 1912, he rejoiced in a latter chapter that his conjecture had been followed almost immediately by a “dramatic confirmation”:
Within the month after its delivery a dramatic confirmation was provided of the argument that in the evolution of Man the brain led the way. For the late Mr. Charles Dawson (in association with Dr. – now Sir Arthur – Smith Woodward) brought to light in Sussex the remains of a hirtherto unknown type of Primate with a brain that, so far as size is concerned, came within the range of human variation, being more than 200 c.cm. larger than that of the more ancient and primitive member of the Human Family (Pithecanthropus), in association with a jaw so like that of a Chimpanzee that many of the leading palaeontologists believed it to be actually the remains of that Ape.
This, of course, was the famous Piltdown Man, probably the most damaging scientific forgery of all times, proved in 1953 to be a composite of a medieval human skull and the jaw of an orangutan. It was probably fabricated by Dawson himself, who had a knack for making similar “sensational” finds, and whose antiquarian collection was found to include at least 38 specimens that were “clear fakes” after his death. Ironically, its discovery induced just such a “will to believe” in Smith as he had warned his readers about earlier in the book. He rationalized the “genuineness” of Piltdown Man with arguments that were formidably “scientific” and astoundingly intricate. For example,
When the skull is restored in this way (according to an intricate reconstruction process described earlier, ed.) its conformation is quite distinctive, and differs profoundly from all other human skulls, recent or fossil. The parietal bone exhibits a peculiar depression between the diverging temporal lines, and the lower margin of the bone, below the depression, is everted. This creates a peculiarity in the form of the cranium that is found in the Gorilla and Chimpanzee. But the simian resemblances are revealed most strikingly in a transverse section of the reconstructed Piltdown Skull, when compared with corresponding sections of those of a Chimpanzee, a Gorilla, and a modern European. It will then be realized how much more nearly the Piltdown skull approaches the simian type. The general form of the cranium in transverse section is greatly expanded like that of an Ape. This applies particularly to the contour of the parietal bones. But the construction of the temporal bone is even more strikingly Ape-like in character.
…and so on. One can but feel a painful and vicarious sense of shame for the worthy professor, who had so thoroughly succeeded in hoodwinking himself. Unfortunately, his weighty testimony hoodwinked many others as well, eventually including even Sir Arthur Keith, who had immediately smelled a rat and publicly cast doubt on the discovery, only to later accept the forgery as real against his better judgment with the help of Smith’s “coaching.”
Piltdown Man wasn’t the only sensational discovery of the day. Raymond Dart had also discovered the first specimen of Australopithecus Africanus in the same year as Smith’s book was published. Dart had immediately noticed evidence of the creature’s upright posture, but Smith would have none of it:
But there is no evidence to suggest that its posture differed from that of the Chimpanzee. The peculiarity in the position of the foramen magnum – which Professor Dart assumed to afford further corroboration of its human affinity – is merely an infantile trait that is found equally in other young Anthropoids.
Poor old Dart. He was always being “debunked” for being right. He was similarly “set straight” by his peers for suggesting that early man engaged in anything so unsavory and politically incorrect as hunting live game. Next it was the turn of Neanderthal Man. To add insult to the injury of his recent extinction, Smith’s unflattering description spawned a myriad museum displays of a stooped, bestial creature, seemingly unattractive as a sex partner except to the most desperate:
His short, thick-set, and coarsely built body was carried in a half-stooping slouch upon short, powerful, and half-flexed legs of peculiarly ungraceful form. His thick neck sloped forward from the broad shoulders to support the massive flattened head, which protruded forward, so as to form an unbroken curve of neck and back, in place of the alternation of curves which is one of the graces of the truly erect Homo sapiens.
In a word, Professor Smith left us with a wealth of disinformation that it took decades of careful research to correct. His example should teach us humility. His book and a few others like it should be required reading for nascent Ph.D.’s. Many of them will find little time for such ephemera later on in their struggles to stay up to speed with all the latest in the collection of learned journals that pertain to their specialty. Still, they might find it amusing and even informative to occasionally step back from the information maelstrom, dust off some of the old books and journals in forgotten stacks, and recall the foibles as well as the triumphs of their compatriots gone before. In ambling through the old source material, they’re likely to find that the history they find on the Internet isn’t always served straight up. As is regrettably the case with Prof. Smith, it often happens that some of the more egregious warts and blemishes have been charitably removed. They are likely to find the unexpurgated versions more helpful, especially if they happen to specialize in fields that are long on unfalsifiable theories and short on repeatable experiments.
Posted on October 22nd, 2012 2 comments
We have passed the end of the fiscal year, and the National Ignition Facility, or NIF, at Lawrence Livermore National Laboratory (LLNL) failed to achieve its goal of ignition (more fusion energy out than laser energy in). As I noted in earlier post about the NIF more than three years ago, this doesn’t surprise me. Ignition using the current indirect drive approach (most of the jargon and buzzwords are explained in the Wiki article on the NIF) requires conversion of the laser energy into an almost perfectly symmetric bath of x-rays. These must implode the target, preserving its spherical shape in the process in spite of a very high convergence ratio (initial radius divided by final radius), and launching a train of four shocks in the process, which must all converge in a tiny volume at the center of the target, heating it to fusion conditions. That will release energetic alpha particles (helium nuclei) which must then dump their energy in the surrounding, cold fuel material, causing a “burn wave” to propagate out from the center, consuming the remaining fuel. It would have been a spectacular achievement if LLNL had pulled it off. Unfortunately, they didn’t, for reasons that are explained in an excellent article that recently appeared in the journal Science. (Unfortunately, it’s behind a subscriber wall, and I haven’t found anything as good on the web at the moment. You can get the gist from this article at Huffpo.) The potential political implications of the failure were addressed in a recent article in the New York Times.
All of which begs the question, “What now?” My opinion, in short, is that the facility should remain operational, at full capacity (not on half shifts, which, for various reasons, would reduce the experimental value of the facility by significantly more than half).
I certainly don’t base that opinion on the potential of inertial confinement fusion (ICF), the technology implemented on the NIF, for supplying our future energy needs. While many scientists would disagree with me, I feel it has virtually none. Although they may well be scientifically feasible, ICF reactors would be engineering nightmares, and far too expensive to compete with alternative energy sources. It would be necessary to fabricate many thousands of delicate, precisely built targets every day and fill them with highly radioactive tritium. Tritium is not a naturally occurring isotope of hydrogen, and its half-life (the time it takes for half of a given quantity to undergo radioactive decay) is just over 12 years, so it can’t be stored indefinitely. It would be necessary to breed and extract the stuff from the reactor on the fly without releasing any into the environment (hydrogen is notoriously slippery stuff, that can easily leak right through several types of metal barriers), load it into the targets, and then cool them to cryogenic temperatures. There is not a reactor design study out there that doesn’t claim that this can be done cheaply enough to make ICF fusion energy cost-competitive. They are all poppycock. The usual procedure in such studies is to pick the cost number you need, and then apply “science” to make it seem plausible.
However, despite all the LLNL hype, the NIF was never funded as an energy project, but as an experimental tool to help maintain the safety and reliability of our nuclear stockpile in the absence of nuclear testing. The idea that it will be useless for that purpose, whether it achieves ignition or not, is nonsense. The facility has met and in some cases exceeded its design goals in terms of energy and precision. Few if any other facilities in the world, whether existing or planned, will be able to rival its ability to explore equations of state, opacities, and other weapons-relevant physics information about materials at conditions approaching those that exist in nuclear detonations. As long as the ban on nuclear testing remains in effect, the NIF will give us a significant advantage over other nuclear states. It seems to me that maintaining the ban is a good thing.
It also seems to me that it would behoove us to maintain a robust nuclear stockpile. Nuclear disarmament sounds nice on paper. In reality it would invite nuclear attack. The fact that nuclear weapons have not been used since 1945 is a tremendous stroke of luck. However, it has also seduced us into assuming they will never be used again. They will. The question is not if, but when. We could continue to be very lucky. We could also suffer a nuclear attack tomorrow, whether by miscalculation, or the actions of terrorists or rogue states. If we continue to have a stockpile, it must be maintained. Highly trained scientists must be available to maintain it. Unfortunately, babysitting a pile of nuclear bombs while they gather dust is not an attractive career path. Access to facilities like the NIF is a powerful incentive to those who would not otherwise consider such a career.
One of the reasons this is true is the “dual use” capability of the NIF. It can be used to study many aspects of high energy density physics that may not be relevant to nuclear weapons, but are of great interest to scientists in academia and elsewhere who are interested in fusion energy, the basic science of matter at extreme conditions, astrophysics, etc. Some of the available time on the facility will be reserved for these outside users.
As for the elusive goal of ignition itself, we know that it is scientifically feasible, just as we know that its magnetic fusion equivalent is scientifically feasible. The only question remaining is how big the lasers have to be to reach it. It may eventually turn out that the ones available on the NIF are not big enough. However, the idea that because we didn’t get ignition in the first attempts somehow proves that ignition is impossible and out of the question is ridiculous. It has not even been “proven” that the current indirect drive approach won’t work. If it doesn’t, there are several alternatives. The NIF is capable of being reconfigured for direct drive, in which the lasers are aimed directly at the fusion target. For various reasons, the beams are currently being frequency-tripled from the original “red” light of the glass lasers to “blue.” Much more energy, up to around four megajoules instead of the current 1.8, would be available if the beams were only frequency-doubled to “green”. It may be that the advantage of the extra energy will outweigh the physics-related disadvantages of green light. An interesting dark horse candidate is the “fast ignitor” scenario, in which the target would be imploded as before, but a separate beam or beams would then be used to heat a small spot on the outer surface to ignition conditions. An alpha particle “burn wave” would then propagate out, igniting the rest of the fuel, just as originally envisioned for the central hot spot approach.
Some of the comments following the Internet posts about NIF’s failure to reach ignition are amusing. For example, following an article on the Physics Today website we learn to our dismay:
With all due respect to the NIF and its team of well-meaning and enthusiastic researchers here, I am sorry to state hereby that sustainable nuclear fusion is predestined to fail, whether it be in the NIC, the Tokamak or anywhere else in solar space, for fundamentally two simple reasons paramount for fusion: ((1) vibrational synchronism (high-amplitude resonance) of reacting particles; and (2) the overall isotropy of their ambient field.
Obviously the commenter hadn’t heard that the scientific feasibility of both inertial and magnetic fusion has already been established. He reminds me of a learned doctor who predicted that Zadig, the hero of Voltaire’s novel of that name, must inevitably die of an injury. When Zadig promptly recovered, he wrote a thick tome insisting that Zadig must inevitably have died. Voltaire informs us that Zadig did not read the book. In an article on the IEEE Spectrum website, suggestively entitled National Ignition Facility: Mother of All Boondoggles?, another commenter chimes in:
How about we spend the billions on real research that actually has a chance of producing something useful? There are a gazillion ideas out there for research that has a much higher probability of producing useful results. Must be nice to work for LLNL where your ideas don’t need vetting.
In fact, the NIF was “vetted” by a full scale Federal Advisory Committee. Known as the Inertial Confinement Fusion Advisory Committee, or ICFAC, its members included Conrad Longmire, Marshall Rosenbluth, and several other experts in plasma physics and technology of world renown who had nothing whatsoever to gain by serving as shills for LLNL. It heard extensive testimony on plans to build the NIF, both pro and con, in the mid-90’s. Prominent among those who opposed the project was Steve Bodner, head of the ICF Program at the Naval Research Laboratory (NRL) at the time. Steve cited a number of excellent reasons for delaying major new starts like the NIF until some of the outstanding physics issues could be better understood. The Committee certainly didn’t ignore what he and other critics had to say. However, only one of the 15 or so members dissented from the final decision to recommend proceeding with the NIF. I suspect that LLNL’s possession of the biggest, baddest ICF computer code at the time had something to do with it. No one is better at bamboozling himself and others than a computational physicist with a big code. The one dissenter, BTW, was Tim Coffey, Director of NRL at the time, who was convinced that Bodner was right.
There are, of course, the predictable comments by those in the habit of imagining themselves geniuses after the fact, such as,
I am convinced. Garbage research.
Don’t these people feel ashamed telling so many lies?
after the IEEE Spectrum article, and,
It’s amazing to think that you can spout lies to the government to receive $6 billion for a machine that doesn’t come close to performing to spec and there are no consequences for your actions.
Following a post on the NIF at the LLNL – The True Story blog. Fortunately, most of the comments I’ve seen recently have been at a rather more thoughtful level. In any event, I hope Congress doesn’t decide to cut and run on the NIF. Pulling the plug at this point would be penny-wise and pound-foolish.
Posted on July 24th, 2012 No comments
According to a recent press release from Lawrence Livermore National Laboratory (LLNL) in California, the 192-beam National Ignition Facility (NIF) fired a 500 terawatt shot on July 5. The world record power followed a world record energy shot of 1.89 Megajoules on July 3. As news, this doesn’t rise above the “meh” category. A shot at the NIF’s design energy of 1.8 Megajoules was already recorded back in March. It’s quite true that, as NIF Director Ed Moses puts it, “NIF is becoming everything scientists planned when it was conceived over two decades ago.” The NIF is a remarkable achievement in its own right, capable of achieving energies 50 times greater than any other laboratory facility, with pulses shaped and timed to pinpoint precision. The NIF team in general and Ed Moses in particular deserve great credit, and the nation’s gratitude, for that achievement after turning things around following a very shaky start.
The problem is that, while the facility works as well, and even better than planned, the goal it was built to achieve continues to elude us. As its name implies, the news everyone is actually waiting for is the announcement that ignition (defined as fusion energy out greater than laser energy in) has been achieved. As noted in the article, Moses said back in March that “We have all the capability to make it happen in fiscal year 2012.” At this point, he probably wishes his tone had been a mite less optimistic. To reach their goal in the two months remaining, the NIF team will need to pull a rabbit out of their collective hat. A slim chance remains. Apparently the NIF’s 192 laser beams were aimed at a real ignition target with a depleted uranium capsule and deuterium-tritium fuel on July 5, and not a surrogate. The data from that shot may prove to be a great deal more interesting than the 500 terawatt power announcement.
Meanwhile, the Russians are apparently forging ahead with plans for their own superlaser, to be capable of a whopping 2.8 Megajoules, and the Chinese are planning another about half that size, to be operational at about the same time (around 2020). That, in itself, speaks volumes about the real significance of ignition. It may be huge for the fusion energy community, but not that great as far as the weaponeers who actually fund these projects are concerned. Many weapons designers at LLNL and Los Alamos were notably unenthusiastic about ignition when NIF was still in the planning stages. What attracted them more was the extreme conditions, approaching those in an exploding nuke, that could be achieved by the lasers without ignition. They thought, not without reason, that it would be much easier to collect useful information from such experiments than from chaotic ignition plasmas. Apparently the Russian bomb designers agree. They announced their laser project back in February even though LLNL’s difficulties in achieving ignition were well known at the time.
The same can be said of some of the academic types in the NIF “user community.” It’s noteworthy that two of them, Rick Petrasso of MIT and Ray Jeanloz of UC Berkeley, whose enthusiastic comments about the 500 terawatt shot where quoted in the latest press release, are both key players in the field of high energy density physics. Ignition isn’t a sine qua non for them either. They will be able to harvest scores of papers from the NIF whether it achieves ignition or not.
The greatest liability of not achieving early ignition may be the evaporation of political support for the NIF. The natives are already becoming restless. As noted in the Livermore Independent,
In early May, sounding as if it were discussing an engineering project rather than advanced research, the House Appropriations Committee worried that NIF’s “considerable costs will not have been warranted” if it does not achieve ignition by September 30, the end of the federal fiscal year.
Later that month, in a tone that seemed to demand that research breakthroughs take place according to schedule, the House Armed Services Committee recommended that NIF’s ignition research budget for next year be cut by $30 million from the requested $84 million budget unless NIF achieves ignition by September 30.
Funding cuts at this point, after we have come so far, and are so close to the goal, would be short-sighted indeed. One must hope that a Congress capable of squandering billions on white elephants like the International Space Station will not become penny-wise and pound-foolish about funding a project that really matters.
Posted on July 9th, 2012 2 comments
I know, I’ve been a mite heavy on the group selection stuff lately, but I can’t help it. Recent developments touched off by the publication of E. O. Wilson’s The Social Conquest of Earth are, to coin a term, “fascinating,” if you know the history of the theory and the controversy surrounding it. The latest plot twist is the appearance of an article by group selection proponent Martin Nowak entitled “Why We Help,” as the cover story in the latest edition of Scientific American. Nowak was co-author with Wilson and Corina Tarnita of a hard-core group selection paper entitled The Evolution of Eusociality that appeared in Nature in August 2010. I say “hard-core” because the paper included a section announcing the “fall of inclusive fitness theory,” a claim alluded to by Wilson in his book as if it were an accomplished fact. This drew immediate counter-blasts from inclusive fitness theorists such as Richard Dawkins, Steven Pinker and Jerry Coyne. Now, perhaps all unbeknownst to themselves, the group selectionists have played the “virtue” card.
Scientific American, as it happens, should have been renamed Politically Correct American long ago. Its editors are relentless promoters of the “progressive” version of the Good. Enter Martin Nowak, with an article about the evolution of cooperation, a progressive Good if ever there was one. To make sure its readers get the point, SA added the following blurb on the cover: “The Evolution of Cooperation; Competition is not the only force that shaped life on earth.” Competition is, of course, anathema to all right thinkers on the left. The Dawkins/Pinker faction, on the other hand, has stressed the notion of the “selfish” gene, which they associate with innate “selfish” human behaviors. If history is any guide, they are treading on thin ice. In the past, Scientific American has responded to such deviations from the “correct” line with thinly veiled hints that their authors are “conservative,” or even, heaven forefend, fascist!
Group selectionists have long had the virtue card up their sleeves. For example, Mark Borrello cites saintly anarchist godfather Peter Kropotkin (fondly referred to by Lenin as “that old fool Kropotkin”) as an early advocate of the idea in his book, Evolutionary Restraints:
Kropotkin argued (in a series of articles published between 1905 and 1919, ed.) that in the course of the struggle against the environment, species were more apt to practice mutual aid, and that cooperative species would increase in numbers and outlast their individualistic rivals. In this scenario, natural selection ceases to be “a selection of haphazard variations, but becomes a physiological selection of those individuals, societies and groups which are best capable of meeting the new requirements by new adaptations of their tissues, organs and habits. It operates largely as a selection of groups of individuals, modified all at once, more or less, in a given direction.
Of course, Kropotkin was a political ideologue, and political ideologues have a habit of construing “reality” to favor whatever flavor of utopia they happen to prefer. I’m not aware of the political proclivities of Nowak, and have no evidence that his theories are tainted by ideology. However, there are some hints in the article, perhaps reflecting the context (Scientific American) in which he is writing. For example,
As the human population expands and the climate changes, we will need to harness that adaptability and figure out ways to work together to save the planet and its inhabitants.
Policy makers should take note of indirect reciprocity and the importance of information and reputation in keeping defectors in check. And they should exploit the capacity of these factors to make better cooperators of us all in the mother of all public goods games: the seven-billion-person mission to conserve the rapidly dwindling resources of planet Earth.
It is interesting that Nowak is very reserved about his advocacy of group selection in the paper. Instead, he cites his background in the mathematics of game theory. Group theory is only mentioned in passing as the last of five mechanisms that may have contributed to the evolution of cooperation. As Nowak puts it,
Last, individuals may perform selfless acts for the greater good, as opposed to abetting a single peer. This fifth means by which cooperation may take root is known as group selection.
No matter, at this point, “Nowak” and “group selection” are virtually synonymous among evolutionary biologists, so they’ll get the drift, although most of them would probably dispute the fact that the acts involved are really “selfless.” Still, “selfless acts for the greater good” hits the right tone for an article in Scientific American.
And so continues the melodramatic career of the theory of group selection. Used by Steven Pinker as a pretext to dismiss the life work of the most effective and influential debunker of the Blank Slate, Robert Ardrey, in a single paragraph as “totally and utterly wrong” in his comical “history” of the Blank Slate, it would seem the theory has now risen from the grave. Pinker had better step lively, or he may soon find himself on the wrong side of the “virtue” line. There may be poetic justice in science after all.
Posted on July 7th, 2012 No comments
It’s been over a century since Max Planck came up with the idea that electromagnetic energy could only be emitted in fixed units called quanta as a means of explaining the observed spectrum of light from incandescent light bulbs. Starting from this point, great physicists such as Bohr, de Broglie, Schrödinger, and Dirac developed the field of quantum mechanics, revolutionizing our understanding of the physical universe. By the 1930’s it was known that matter, as well as electromagnetic energy, could be described by wave equations. In other words, at the level of the atom, particles do not behave at all as if they were billiard balls on a table, or, in general, in the way that our senses portray physical objects to us at a much larger scale. For example, electrons don’t act like hard little balls flying around outside the nuclei of atoms. Rather, it is necessary to describe where they are in terms of probability distributions, and how they act in terms of wave functions. It is impossible to tell at any moment exactly where they are, a fact formalized mathematically in Heisenberg’s famous Uncertainty Principle. All this has profound implications for the very nature of reality, most of which, even after the passage of many decades, are still unknown to the average lay person. Among other things, it follows from all this that there are two basic types of elementary particles; fermions and bosons. It turns out that they behave in profoundly different ways, and that the idiosyncrasies of neither of them can be understood in terms of classical physics.
Sometimes the correspondence between mathematics and physical reality seems almost magical. So it is with the math that predicts the existence of fermions and bosons. When it was discovered that particles at the atomic level actually behave as waves, a brilliant Austrian scientist named Erwin Schrödinger came up with a now-famous wave equation to describe the phenomenon. Derived from a few elementary assumptions based on some postulates derived by Einstein and others relating the wavelength and frequency of matter waves to physical quantities such as momentum and energy, and the behavior of waves in general, the Schrödinger equation could be solved to find wave functions. It was found that these wave functions were complex numbers, that is, they had a real component, and an “imaginary” component that was a multiple of i, the square root of minus one. For example, such a number might be written down mathematically as x + iy. Each such number has a complex conjugate, found by changing the sign of the complex term. The complex conjugate of the above number is, therefore, x – iy. Max born found that the probability of finding a physical particle at any given point in space and time could be derived from the product of a solution to Schrödinger’s equation and its complex conjugate.
So far, so good, but eventually it was realized that there was a problem with describing particles in this way that didn’t arise in classical physics; you couldn’t tell them apart! Elementary particles are, after all, indistinguishable. One electron, for example, resembles every other electron like so many peas in a pod. Suppose you could put two electrons in a glass box, and set them in motion bouncing off the walls. Assuming you had very good eyes, you wouldn’t have any trouble telling the two of them apart if they behaved like classical billiard balls. You would simply have to watch their trajectories as they bounced around in the box. However, they don’t behave like billiard balls. Their motion must be described by wave functions, and wave functions can overlap, making it impossible to tell which wave function belongs to which electron! Trying to measure where they are won’t help, because the wave functions are changed by the very act of measurement.
All this was problematic, because if elementary particles really were indistinguishable in that way, they also had to be indistinguishable in the mathematical equations that described their behavior. As noted above, it had been discovered that the physical attributes of a particle could be determined in terms of the product of a solution to Schrödinger’s equation and its complex conjugate. Assuming for the moment that the two electrons in the box didn’t collide or otherwise interact with each other, that implies that the solution for the two particle system would depend on the product of the solution for both particles and their complex conjugates. Unfortunately, the simple product didn’t work. If the particles were labeled and the labels switched around in the solution, the answer came out different. The particles were distinguishable! What to do?
Well, Schrödinger’s equation has a very useful mathematical property. It is linear. What that means in practical terms is that if the products of the wave functions for the two particle system is a solution, then any combination of the products will also be a solution. It was found that if the overall solution was expressed as the product of the two wave functions plus their product with the labels of the two particles interchanged, or of the product of the two wave functions minus their product with the labels interchanged, the resulting probability density function was not changed by changing around the labels. The particles remained indistinguishable!
The solution to the Schrödinger equation, referred to mathematically as an eigenfunction, is called symmetric in the plus case, and antisymmetric in the minus case. It turns out, however, that if you do the math, particles act in very different ways depending on whether the plus sign or the minus sign is used. And here’s where the magic comes in. So far with just been doing math, right? We’ve just been manipulating symbols to get the math to come out right. Well, as the great physicist, Richard Feynman, once put it, “To those who do not know mathematics it is difficult to get across a real feeling as to the beauty, the deepest beauty, of nature.” So it is in this case. The real particles act just as the math predicts, and in ways that are completely unexplainable in terms of classical physics! Particles that can be described by an antisymmetric eigenfunction are called fermions, and particles that can be described by an symmetric eigenfunction are called bosons.
How do they actually differ? Well, for reasons I won’t go into here, the so-called exclusion principle applies to fermions. There can never be more than one of them in exactly the same quantum state. Electrons are fermions, and that’s why they are arranged in different levels as they orbit the nucleus of an atom. Bosons behave differently, and in ways that can be quite spectacular. Assuming a collection of bosons can be cooled to a low enough temperature they will tend to all condense into the same low energy quantum state. As it happens, the helium atom is a boson. When it is cooled below a temperature of 2.18 degrees above absolute zero, it shows some very remarkable large scale quantum effects. Perhaps the weirdest of these is superfluidity. In this state, it behaves as if it had no viscosity at all, and can climb up the sides of a container and siphon itself out over the top!
No one really knows what matter is at a fundamental level, or why it exists at all. However, we do know enough about it to realize that our senses only tell us how it acts at the large scales that matter to most living creatures. They don’t tell us anything about its essence. It’s unfortunate that now, nearly a century after some of these wonderful discoveries about the quantum world were made, so few people know anything about them. It seems to me that knowing about them and the great scientist who made them adds a certain interest and richness to life. If nothing else, when physicists talk about the Higgs boson, it’s nice to have some clue what they’re talking about.