Dinesh D'Souza, in the Dark about Dark Matter and about Science

Of all the attacks leveled against science by the religious faithful, the most insidious are the ones that cast religion and science as comparable approaches to understanding natural the world.  In a debate with Christopher Hitchens at Notre Dame this past January conservative author and speaker Dinesh D'Souza showcased a variation of this kind of "we're just two peas in a pod" claim and, in doing so, succeeded in demonstrating a genuine failure to understand how science really works.  In the process, he does no great service to religion, either.

In making his case for a faith-based approach to science, D'Souza proposes that the existence of God can be employed as a working hypothesis much like any other.  And, as with any provisional hypothesis, he says it should be embraced when it helps account for phenomena which have otherwise resisted explantion.  Seeking confirmation of this God of the gaps argument - familiar to us from the Intelligent Design controversy - D'Souza turns to astrophysics for an illustration of how science relies on the same kind of speculative thinking that religion does.  Here is the background on the example he finds there to exploit.

Galaxy cluster ACO 3341, located
almost 500 million years away
(European Southern Observatory)

The Mystery of the Missing Mass
In the 1920s, not long after galaxies outside our own Milky Way were first identified, they were seen to arrange themselves into clusters, orbiting about one another, presumably, under the influence of their mutual gravitational attraction.  Indeed, the working of gravity in these far, far away places was not unexpected.  Contrary to popular conception, Isaac Newton's stroke of genius had not been in observing a falling apple - he was hardly the first to notice that things fall - but in his bold conjecture that the force responsible for causing his proverbial knock on the head was the very same force responsible for the motion of the planets about the Sun.  Newton's theory proposed that gravity was universal, applying uniformly to everything, everywhere; to the objects of our everyday experience; to the planets and moons of our solar system; and, presumably, to galaxies, each consisting of hundreds of billions of stars, located millions of light-years away.

What took astronomers of the 1930s by surprise was that, when the amount of stuff in these galactic clusters was finally tallied, gravitational accounts did not balance.  A census of the visible matter contained within them - stars and dust clouds and other such "luminous" things - resulted in a total mass insufficient to bind them in their mutual orbits.  According to calculations the galaxies in these clusters should be flying apart at breakneck speed.  The physicists faced a quandary: either Newton had got it wrong, and the force of gravity he proposed was, in fact, not universal, or their exhaustive attempts to catalog the constituents of these galactic clusters had left a significant amount of matter unaccounted for.

Bullet Cluster, best evidence
to date for the existence of
dark matter.

At first this astrophysical mystery went by the name "missing mass" and it was presumed to be an artifact of limitations of the observational techniques available at the time.  Perhaps, for example, large numbers of dead or dormant stars had gone unobserved and, therefore, uncounted in the celestial tally.  But even when astronomers refined their efforts at detection, their gravitational bookkeeping kept coming up short.  To make matters worse, after a few decades passed, new astrophysical puzzles were encountered that also hinted at the existence of missing matter in other astrophysical contexts.  Finally, and reluctantly, a working hypothesis came to be accepted.  The vexing missing mass was assumed to be bound up in a heretofore undetected kind of "dark matter" which was characterized solely by its heft and its failure to shine. Of what it was actually composed, no one had a clue.

Next generation detector,
Xenon Dark Matter Project

Desperately Seeking Dark Matter
Now, according to D'Souza, in the same way that physicists have proposed the existence of dark matter as an explanation for an enigmatic phenomenon, the stability of galactic clusters in spite of an apparent insufficiency of mass, so too can we rely on the hypothesis of God to explain other mysteries of the physical world.  He contends that such "presuppositions" are valid elements in the construction of scientific theories because they yield immense explanatory payoff; disconnected pieces of a puzzle fall into place and suddenly everything makes sense.

Is D'Souza right?  Are "materialist" scientists and those who defer to faith-based hypotheses playing by the same rules?  To see how the their approaches differ, consider this observation from a recent physics arXiv blog post - First Evidence That Mirror Matter May Fill the Universe? - regarding ongoing efforts to solve this problem.

Astronomers call this hidden mass 'dark matter' and physicists around the world are engaged in an increasingly desperate race to find evidence of it here on Earth. [emphasis added]

Now imagine, for a moment, an analogous report on the state of current investigations into some phenomenon or other "explained" by D'Souza's God presupposition:

Scientists call this hidden cause 'God' and researchers around the world are engaged in an increasingly desperate race to confirm His existence.

This comparison, of course, strikes us as ridiculous on its face; no one has ever embarked upon a search for God in order to confirm or refute a physical theory.  Good Lord, how could such a search even be conducted?  Perhaps more significantly, no teams of researchers have ever engaged in a desperate race to reveal God's existence.

What D'Souza fails to appreciate in his casting dark matter as just another presupposition is how unpalatable resorting to such a hypothesis is to physicists, one which they entertain reluctantly because the alternative, a rejection of Newton's theory of universal gravitation, would be even more distasteful.  They tolerate "dark matter" as a convenient fiction, but won't rest easy until the composition of this mysterious substance is revealed, or until a more acceptable explanation steps up to replace it.

History confirms how earnest physicists have been in wrestling similar "presuppositions" to the mat.  Interestingly enough, three examples involve a search for missing mass of one variety or another.

Neptune from the Voyager 2
flyby (1989).

A Missing Planet Found
The first hidden matter search came about with the discovery of Uranus by Sir William Herschel in 1781.  With Newton's theory in hand, astronomers were able to calculate the orbit of the newly discovered planet, but by the early 19th century it had become clear that discrepancies existed between the predicted trajectory of Uranus and that which had been meticulously observed.  These scientists were presented with a dilemma not unlike the one that their counterparts would face a century later: either Sir Isaac had gotten things wrong with his theory of gravity or a very significant mass had gone missing.  Perhaps it took the form of a yet undetected outlying planet which was perturbing the motion of Uranus in its path around the Sun?

As disagreement between theoretical calculations and observational evidence became more and more convincing, a desperate race ensued.  The hidden culprit, the planet Neptune, was revealed by Urbain LeVerrier in 1846.

First neutrino detection
in a bubble chamber (1970).

A Missing Particle Detected
In a second example of a missing mass mystery, by 1930 the radioactive decay of atomic nuclei into constituents components had been long-observed and carefully measured, yet, as a result, a vexing question arose.  When the energies of all the particles emerging from the site of such a decay were added up there was an unexpected energy shortfall.  Either a new kind of particle had fled the scene undetected, carrying with it just the right amount of energy (and, according to Einstein, mass) or the long-cherished principle of conservation of energy - far more fundamental for physics than even Newton's universal gravitation - would have to be abandoned.

This fugitive particle, dubbed the neutrino by Enrico Fermi in 1934, eluded capture for more than two decades; science did not breathe a sigh of relief until Clyde Cowan and Frederick Reines detected it directly in 1956.

Schematic of Earth moving
through the hypothetical aether.

The Aether goes Missing - with a Payoff
As a final example of the search for a missing substance - and an illustration that presuppositions demand verification - consider the state of the physics of electromagnetic radiation - i.e. light - in the late 19th century.  About the time of the American Civil War James Clerk Maxwell, in what has become to be regarded as the first unified field theory of physics, demonstrated mathematically that light traveled as a wave, not unlike the way waves spread across the surface of a body of a water.  In much the same way that other wave phenomena required a supporting medium - for example, some gas or mixture of gases for sound - it was presupposed that a medium was necessary for the propagation of light, something that pervaded every nook and cranny of space.  Confident in this hypothesis, physicists even gave the conjectured substance a name; it was called the luminiferous (light-bearing) aether.

An ingenious experiment to detect the existence of this mysterious stuff was undertaken by Albert Michelson and Edward Morley in 1887.  It failed utterly, but with that failure was planted the seed of Einstein's theory of special relativity which would blossom less than 20 years later.

As these examples illustrate, what Dinesh D'Souza does not understand is that for scientists a presupposition, better characterized as a working hypothesis, is not the end of an investigation, but a starting point.  Presupposing the existence of God as an explanation, as D'Souza suggests, offers no avenue for further research, it is nothing more than prescription for investigative complacency;  one might as well hang a "gone fishin'" sign on the laboratory door.  Regardless of the spiritual rewards that some derive from a belief in God, as a scientific hypothesis it is worse than a blind alley; positing God as an explanation discourages further research, sometimes benignly, by declaring, falsely, that a difficult problem has been solved, and at other times malignly, by intimidating those who dare to seek honest answers based in physical law.

It is important to point out that D'Souza's attempt to exploit the dark matter hypothesis as evidence of the comparability of scientific and religious reasoning about the world is just the latest round in the assault on science by those who, like him, feel that a purely materialist view of nature is incompatible with their deeply held religious beliefs.  In the late 1980s they took aim at the theory of evolution with their Intelligent Design hypothesis and were, in short order, discredited.  Probing for vulnerabilities elsewhere they have recently turned their sights on astrophysics and neuroscience, hoping for more favorable battlefields.

But, as Ken Miller, professor of biology at Brown University and a practicing Roman Catholic, noted in his essay, The Flagellum Unspun, which convincingly refutes claims of "irreducible complexity", the cornerstone of Intelligent Design theory,

... the struggles of the intelligent design movement are best understood as clamorous and disappointing double failures – rejected by science because they do not fit the facts, and having failed religion because they think too little of God.

Sadly, Dinesh D'Souza seems compelled to repeat this same mistake, looking for confirmation of his belief in God in the wrong places, misrepresenting the enterprise of science and futilely struggling to insert the Deity in the forever-narrowing gaps in our understanding of the natural world.


Dinesh D'Souza, in the Dark about Dark Matter and about Science by Marc Merlin is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at thoughtsarise.blogspot.com.

Why We Fight - For Science

A couple of nights ago, on the edge of the meadow at Piedmont Park, over a convivial dinner that included an appropriate amount of beer and wine, the conversation turned to science - more precisely to how to promote interest in science to the public at large. What, in conventional circles, would have been an unusual dinner-time topic, was an unexceptional one with this group, since we were members of the Atlanta Science Tavern, and we are given to talk about science every chance we get.

Enamored with science. but, somewhat blinded by our adoration, we are sometimes puzzled that others don't share our enthusiasm for the object of our affection. So, when we get together, we often wonder, "how can we encourage our friends to better support and appreciate science?"

A common answer to this question begins with a recitation of the connections between important developments in the history of science and the benefits that have accrued to modern society as a result: the double helix of DNA and cancer-fighting medical diagnosis; quantum physics and high-performance computer chips; genetic engineering and increases in agricultural productivity; Maxwell's theory of electromagnetic waves and near-instantaneous global communications; Newton's orbital mechanics and hurricane tracking. The list goes on and on. It is extraordinarily convincing.

[So as not to whitewash the matter, I readily acknowledge that science has been implicated in its share of failures and catastrophes. On balance, I believe that science comes out ahead in the cost-benefit tally, but some, notably Theodore Kaczynski - better known as the Unabomber - have constructed serious arguments to the contrary. Should, for example, the most dire predictions for global warming be borne out, Ted may well be proven right for his skepticism about technology being an unequivocal force for good, although he should never be excused for the psychotic tactics he used in trying to disrupt its advance.]

Although this kind of utilitarian argument for science is persuasive, I find it, in some respects, disingenuous and, in others, incomplete. It is less than forthright in that it fosters a misconception about why people undertake scientific careers. No doubt there are those who do so motivated primarily by their interest in benefiting mankind, but, in my experience, scientists are, more often than not, driven by an unabashedly self-centered desire to better understand the world in which they live. Public service, although a welcome side effect, is not preeminent among their personal goals. In addition, although arguing for science based on its practical applications may be the strongest hand we have to play in general, the fact of the matter is that many significant fields of scientific research have no chance of bearing technological fruit.



On the morning of the day of the informal Science Tavern dinner the New York Times had published a front-page article announcing the successful reconstruction of a skeleton nicknamed Ardi, the fossil remains of 4.4 million-year-old hominid, and a member of a likely bipedal species which may turn out to be a direct ancestor of our own. To say the least, it would be quite a stretch to come up with a justification for supporting such a masterwork in paleoanthropology based on its potential contribution to our practical technological progress.



I am no stranger, personally, to the rather quixotic pursuits that are part and parcel of basic research. As a graduate student in the late 1970s I worked with a group at the Fermi National Accelerator Laboratory (Fermilab) studying neutrino interactions. Neutrinos are subatomic particles notorious for having little or nothing to do with the real world. Cruising at near the speed of light, they would hardly notice planets placed in their path; the Greta Garbo of elementary particles, after all is said and done, they want to be alone. Consequently, they are seldom considered to be of much practical use, although a once-secret patent was issued for the far-fetched scheme of employing neutrinos to communicate with deep-ocean submarines. Why would anyone pay to study them?

Likewise, what is true about neutrino research in particular is true about the enterprise of elementary particle physics more generally; outside the realm of speculative science-fiction, it is hard to imagine how the knowledge revealed in the course of these investigations into the fundamental structure of matter could lead to anything of practical value. But the value, practical or not, of such basic research is a question we cannot avoid. CERN's Large Hadron Collider (LHC), a Europe-based successor to the accelerator at Fermilab, and the most ambitious instrument yet devised to advance our understanding of the submicroscopic workings of the universe, is scheduled to begin full-fledged operation within a year, at a cost of almost $6 billion. How do we begin to justify such an extravagant expense, given that there is no reasonable prospect of deriving practical benefits from the results that the experiments that will be performed there will produce?

A very similar question had been posed to post-war American researchers, during an era when that country, which had placed a high-stakes wager on the success of the Manhattan Project and had won, was eager to fund the research efforts of the generation of scientists who had participated in the development of the atomic bomb. Robert R. Wilson was not only one of the best of that wartime cohort of physicists, he was also a sculptor, an architect, and the driving force behind the development and construction of Fermilab, as well as its director for a number years, including the brief period that I worked there.

In 1969 Wilson was called before a joint congressional committee on atomic energy to give an accounting as to why the public should continue funding the building of his giant proton accelerator, which, when completed, would measure almost 4 miles in circumference and cost over $250 million, at a time, it should be recalled, when $250 million was a significant line-item in the federal budget.

It was the height of the cold war, and any relationship to military purposes could have been offered by Wilson as an explanation and would have been accepted on the spot. But Wilson, who had been deeply affected by the regret he felt for his work on the atomic bomb and had distanced himself from the defense establishment as a result, did not take this easy way out. Instead, declining to use "national security" as a justification, he said this of his Fermilab project:

It has only to do with the respect with which we regard one another, the dignity of men, our love of culture. It has to do with: Are we good painters, good sculptors, great poets? I mean all the things we really venerate in our country and are patriotic about. It has nothing to do directly with defending our country except to make it worth defending.

Promoting public appreciation of science in this way is much more challenging than appealing to concrete interests based on the expectations of advances, for example, in nutrition or healthcare or transportation or power production or consumer electronics or, in Wilson's case, national defense. But the fact of the matter is that it is the only honest way to argue for public support for many areas of basic research, and often more accurately reflects the motives of those engaged in scientific endeavors. In addition, it serves to reframe the debate about what genuinely constitutes the public interest and expands the conventional definition beyond concrete practical concerns. Ultimately the triumph of our civilization is not only the elevation of our comfort and our security, but also of our culture.

The Physics of Unwelcome Surprises

"Who ordered that?" This was the flustered response of physicist Isidor Isaac Rabi when he was told that a new elementary particle, one that would eventually be named the muon, had just been observed.

The year was 1936, and the world of 20th century physics, rocked by three decades of disorienting discoveries, was in need of a breather, a bit of time to take stock, to consolidate the mind-bending theories that had been cobbled together at an unprecedented pace.

This roller coaster ride of surprises was set in motion in 1900 with Max Planck's quantum hypothesis. It turned out, to Planck's despair, that the the elegant mathematical models of the physical world, painstakingly developed over the preceding three centuries, failed abjectly when scrutinized at extreme microscopic levels. Graceful, continuously-varying classical arcs gave way to jagged, stair-stepped quantum diagrams when atoms were the object of investigation. It was as though a mischief-maker had stolen into the Louvre one night and had replaced Leonardo's "Mona Lisa" with Braque's "Woman with a Guitar". Planck, crestfallen, soldiered on.

Only five years later Albert Einstein, exploiting Planck's conjecture about the particle nature of light to solve, virtually en passant, the problem of the photoelectric effect, proposed his theory of special relativity, demolishing the heretofore unquestioned notion that measurements of space and time were absolute. Astonishingly, distances shortened and clocks ticked more slowly as observers moved relative to one another - the closer their difference in speed to the unassailable speed of light, the more dramatic the distortion. Ever the iconoclast, Einstein forged ahead with his assault on Newton's theory of gravitation while the rest of the world was still reeling from his recent revelations.

Ironically, the troubled time after the Great War and the early years of the decade of the roaring twenties provided physicists an opportunity to recover their bearings. The early quantum musings of Planck and Einstein, followed soon by those of Niels Bohr, found rigorous mathematical expression with the so-called matrix mechanics of Werner Heisenberg and in Erwin Schrödinger's eponymous wave equation. The structure of the hydrogen atom could now be calculated to impressive precision. A tentative understanding of the universe - at least one consisting of protons, electrons and photons (quanta of light) - appeared to be within reach.

Forging ahead, in 1928, Paul Dirac advanced a formulation of quantum mechanics, which explicitly took into account Einstein's special relativity, and, in doing so, predicted the existence of antimatter. According to Dirac, every elementary particle possessed a negative-image twin of sorts. For the neutral photon, this turned out to be the photon itself. But, for the electron and the proton, Dirac's equations demanded the existence of, yet-unobserved, particles of identical mass and opposite charge. Dirac was serenely confident in the implications of his mathematically elegant theory. Other physicists, though, awaiting experimental confirmation, were skeptical. Four years later, the discovery of the positron, the electron's antimatter doppelgänger laid their doubts to rest.

At about the time of the positron's debut, the existence of another, apparently fundamental, particle was being established. The neutron, a sister particle to the proton - a little heavier but possessing no electrical charge - was, in many ways, a welcome addition to the particle family. Its discovery led to the understanding that the atomic nucleus was composed of an unimaginably compact knot of protons and neutrons, bound together by a hypothetical "strong" force.

The behavior of the electrons orbiting this nuclear droplet, in accordance with now established quantum theory, explained the chemical activity of the elements, while the numbers of protons and neutrons within their nuclei accounted for their atomic weights. At long last an explanation for the organization and the particulars of the periodic table of elements, devised by Dmitri Mendeleev in 1867, had been provided, and with it came the first comprehensive understanding of ordinary matter in the history of the world.

But, to everyone's surprise, the neutron itself proved to be anything but ordinary. Unlike the other elementary particles, neutrons were not immortal. Within an atomic nucleus their lifetimes varied widely, but left to fend for themselves they survived, on average, a little less than 15 minutes, decaying spontaneously into a proton and electron.

To make matters worse, when the momenta of the proton and the electron resulting from the neutron's decay were tallied, it turned out that energy accounts did not balance. Either the supposedly inviolable law of the conservation of energy had to be jettisoned, or a new particle had to be called into existence, one that fled the neutron's self-destruction unobserved, stealing away with the unaccounted for missing energy. This placeholder, promissory note of a particle, conjured into being by Wolfgang Pauli and christened the neutrino by Enrico Fermi escaped detection for another quarter century, owing to the fact that it felt the push and pull of only the aptly-named "weak" interaction. In the meantime, the hypothesis of the neutrino, a ghost of a particle bullet, allowed physics to dodge another, much more potentially damaging, one.

By the mid-1930s a family portrait of elementary particles looked like it was coming into focus. There were the "adults", the neutron and the proton: the heavy-set neutral momma and positive poppa particles, bound in enduring strong-force matrimony, comfortably ensconced in their nuclear home. Then there were the "kids": the bantam-weight, negatively-charged electron, a mercurial and rambunctious boy-child, hovering close by when mindful of his father's tugs, but venturing beyond the atomic neighborhood when overly stimulated, and the neutrino, an alienated and asthenic teenage daughter, resembling her brother in outline, but drained entirely of charge and heft, a Garbo manqué, withdrawn and in perpetual flight.

Of course, there was Planck's voluble particle of light, around from the beginning, less a full-fledged blood relation than a domesticated sprite, a restless go-between, bounding from electrical lap to electrical lap. There were rumors circulating, though, that the photon had relatives of her own, answerable to the commands of the strong force and weak force, the way she obeyed the beck and call of electricity and magnetism. Physicists were on the lookout for them.

That's about the time that, to Rabi's feigned consternation, the muon showed up, unsummoned. At first it appeared that it might be the strong-force cousin of the photon forecast by Hideki Yukawa only a year before. That turned out not to be the case. Instead, the muon was the harbinger of a wave of particle discoveries to come.

By the time the "unwelcome" muon arrived on the scene, the enterprise of physics had been transformed in a fundamental way by the philosophical buffeting of the preceding 30 years. Grudgingly, physicists had come to appreciate that the universe was such a strange and marvelous place, that their understanding of it was, in a profound way, destined to be forever provisional, and that any charter for their investigations required that they not only seek answers to long-standing questions, but also be prepared to wrestle with unexpected - even confounding - surprises.

This intellectual no man's land, bounded on one side by time-tested facts and theories and on the other by ever-restless skepticism and doubt, was both a precarious and a wondrous territory. Nevertheless, it was, and remains, the quintessential realm of all scientific discovery.