Explaining the Undetectable: Science or Faith?
Scientists routinely portray themselves superior to religious people who (in their estimation) accept things on faith. This ignores the fact that many theories in science walk by faith, too. Theories frequently posit entities that cannot be detected by any means – and may not exist at all, except as props for the consensus. When a potentially falsifying observation is made, the theory is often modified to accommodate the difficulty, but is rarely abandoned. Some recent examples might show how scientists respond by faith when evidence is lacking. These examples are from astronomy, but the problem is not restricted to that branch of science.
- Dark matter: Several expensive projects are underway to detect dark matter. Every once in awhile, a scientist or team publicizes a finding that might suggest an elusive dark matter particle has passed by. The discovery of these particles is routinely put in future tense, and is sometimes justified on the grounds that the neutrino was discovered long after its existence was deemed necessary for theory. One successful theoretical prediction, though, cannot justify reckless positing of unobserved entities to keep a theory going.
Today’s popular cosmologies require more matter than is detected – thus the search for dark matter. Last month, for instance, PhysOrg reported on a dark matter conference at UCLA. The substance was all about the detectors, not detections. Dr. David Cline, a UCLA physics professor, put a positive spin on how to describe unknowns by promising future treats: “Once we know what it really is, we will break through into a new realm of nature. It’s going to be an entirely new era for science, it’s going to pose fascinating new questions, it’s going to be exciting.” All excitement aside, how can he say we will know what it really is without begging the question that it really, indeed, is?
This week in Science,1 Rafael F. Lang tantalized the reader with the line, “After analysis of a year-long detection experiment, resolution of the dark matter mystery may be near.” Yet the same issue of Science said of the actual report,2 “Details of possible, but unlikely, detection events produced by dark matter are reported.” The paper said that analysis of two candidate detection events is “not statistically significant evidence” for dark matter. Lang remarked, “It is a sobering fact that of all the matter in the universe, only 17% is made of particles we know.” How can a fact be 83% unknown? Doesn’t a fact become a fact when it is known, based on some evidence? Dark matter may turn up some day, but until it does, how does the offering of tantalizing press releases differ from a cult that endlessly promises, sans evidence, that the deliverer will arrive any day now?
- The Venus that never was: Modern Venus is much, much different than the Venus of the 1960s. Before space probes landed and mapped it in radar, it seemed a twin to the earth that may have sported a lush, tropical environment. Those ideas are laughable now. Venus is so hot, life is unthinkable under its acidic clouds. But another surprise was the lack of plate tectonics and active geology we observe on Earth. The surface appears to have been catastrophically reworked all at once. Everything appears young – craters, volcanoes, lava flows. To explain this, planetary scientists have suggested that 90% of the planet’s history was erased by recent resurfacing events. An article on PhysOrg brings this idea up to date. Peter James (MIT) expected to find mass concentrations (mascons) that are detected for Earth, the moon and Mars, but was surprised to find none at Venus, the article said. “He believes that the absence of mascons is consistent with the idea that the Venus surface experienced some sort of ‘catastrophic overturning’ at least 500 million years ago.” Thus the anti-uniformitarian enigma remains. What caused it? James rightly noted that “that would require a mechanism that more thoroughly reworks the crust.” But what “sort of mechanism – perhaps large-scale volcanic activity – periodically creates a new surface on Venus”? Why would such a mechanism kick in 90% of the way down the planet’s timeline? Did the pre-catastrophic timeline even exist? Whatever evidence might exist for it is buried under lava.
- Missing light: What would you think of a theory that missed 90% of the data? Science Daily said that “Many Surveys of Distant Galaxies Miss 90 Percent of Their Targets.” Assumptions about spectra from distant targets have apparently only accounted for 1 in 10 objects that are out there. New methods with different assumptions about a particular spectral signature of hydrogen have concluded that “The number of missed galaxies is substantial.”
But it’s not as if this finding seals the deal and makes sky surveys more accurate. The article included a warning about interpreting observations that can be applied more generally: the answer you get may depend on the methods you choose. “Different observational methods, targeting the light emitted at different wavelengths, will always lead to a view of the Universe that is only partially complete,” the press release from the European Space Agency noted. “The results of this survey issue a stark warning for cosmologists, as the strong Lyman-alpha signature becomes increasingly relied upon in examining the very first galaxies to form in the history of the Universe.” This stark warning was followed up by a quote that assumed progress is being made: “Now that we know how much light we’ve been missing,” said co-author Miguel Mas-Hesse, “we can start to create far more accurate representations of the cosmos, understanding better how quickly stars have formed at different times in the life of the Universe.” But can we be so sure, when up till now, their numbers were off by 90%? What other unknowns remain unknown?
- Dynamo revisions: Students learn that magnetic fields are generated by convection currents inside the spinning liquid cores of planets. That presumes a massive enough body exists to support a molten core. What happens when you find magnetic fields in bodies thought too small? That’s exactly what PhysOrg reported, and the response of scientists is instructive. The article starts confidently with claims stated factually: “The Earth’s global magnetic field is generated in its metallic core, located nearly 3,000 kilometers beneath the planet’s surface. The field has existed on Earth for at least 3.5 billion years and offers clues about how other planets, stars and celestial bodies may have formed.” After some elaboration about dynamo theory, the article descends into problems:
But scientists’ understanding of dynamo theory has been complicated by recent discoveries of magnetized rocks from the moon and ancient meteorites, as well as an active dynamo field on Mercury – places that were thought to have perhaps cooled too quickly or be too small to generate a self-sustaining magnetic field. It had been thought that smaller bodies couldn’t have dynamos because they cool more rapidly and are therefore more likely to have metallic cores that do not stay in liquid form for very long.
Bring on the theory-rescue devices: it’s as if scientists respond, “Well, what do you know: small bodies can form a dynamo after all.” Isn’t that exactly what this sentence says? Notice the word somehow: “According to Weiss, the finding suggests that sustaining a magnetic field like the one on Earth might not require a large, cooling core that constantly moves liquid and creates currents, but could also be somehow generated by the cores of smaller bodies like planetesimals – some of which are only 160 kilometers wide.” The theory requires it; therefore it exists.
- Yucking it up over a weird supernova: Type Ia supernovae are standard candles for measuring cosmic distances – except when they’re not. A story in PhysOrg is at once heartwarming and heartburning. The casual reader will enjoy the narrative as scientists show their human side when trying to understand an anomalous supernova observation:
[Peter] Nugent [Berkeley Nearby Supernova Factory] laughs when he recalls the Caltech response. “Caltech got right back to us with their opinions, all expert and all different: ‘It’s a variable star’; ‘It’s an active galaxy’; ‘It’s a core-collapse supernova’; ‘It’s a funky nova outburst.’”
But later Avishay Gal-Yam at Caltech (now with Israel’s Weizmann Institute of Science) obtained spectra from Palomar after classical supernova features had emerged. He told Nugent he thought it was a Type Ia after all. “And we’re supposed to be the Ia experts,” says Nugent.
Nugent and team were able to save the phenomena by proposing that two white dwarfs had collided to cause the unusually bright supernova outburst. Otherwise, theorists would have been faced with explaining a star more massive than the Chandrasekhar Limit, a theoretical natural barrier to growth. Their elegant explanation might have saved the phenomena, but every solution breeds new problems. Several tweaks were necessary to get the idea to work – especially how to overcome another natural barrier about age. Notice the confidence in the ending line, “We know better now” –
“The last time I remember anybody trying to blow up a system like that I was in graduate school, and nobody believed it,” Nugent says, referring to modeling such a merger. “Back then, everybody thought it would take more than the age of the universe for two orbiting white dwarfs to get close enough together. We know better now.”
But how do they know better? Only because it happened – or if it did happen, there must have been some way for these white dwarfs to get into orbit in less time than expected, because theory demands it.
The explanation bred another problem. Type Ia supernova are widely used as standard candles in cosmic measurement. The assumption is that since the Chandrasekhar Limit cannot be breached, the white dwarfs that accrete matter and then blow up do so with a predictable luminosity. If some Type Ia’s can result from mergers, it casts doubt on the assumption of uniform brightness. Astronomers could exclude the superbright supernovae as a procedural matter, but that answer seems to make any conclusions tainted with human arbitrariness. How bright is too bright? What other factors could be altering the expected light output? What other observations are deemed anomalous, on what grounds? Type Ia supernovae were supposed to be a check against arbitrariness. They were supposed to be standard candles. The end of the article discussed various ways that astronomers have to pick and choose data based on theoretical considerations – a worrisome aspect made even more worrisome by the cavalier attitude expressed by Richard Scalzo of Yale in the concluding paragraph:
“If we are successful in differentiating between the subclasses of Type Ia’s, and can find spectral and physical features that will allow us to tag even less-obvious examples in a clear-cut way, that’s progress. If not, it could cause trouble. Whatever is not known should make people nervous – but excited!
Demolition derbies are exciting, too.
- Living galaxy dinosaur: “Imagine finding a living dinosaur in your backyard.” That’s how a story in Science Daily began last month, but it wasn’t about dinosaurs. It was about an apparent galaxy merger that was too recent for theory. “Astronomers have found the astronomical equivalent of prehistoric life in our intergalactic backyard: a group of small, ancient galaxies that has waited 10 billion years to come together,” the preface claimed. “These ‘late bloomers’ are on their way to building a large elliptical galaxy.”
According to their scenario, a collision in the Hickson Compact Group 31 is very improbable. Why? Because they are dated as far along their evolutionary path. “It is an extremely rare local example of what we think was a quite common event in the distant universe,” one astronomer explained. So why did these galaxies wait so long to interact? In science, hearing a folksy analogy does not always inspire confidence: “Perhaps… because the system resides in a lower-density region of the universe, the equivalent of a rural village,” Sarah Gallagher [U of Western Ontario] said. “Getting together took billions of years longer than it did for galaxies in denser areas.”
- Multiverse tugs: The most egregious example in recent memory of scientists appealing to unobservable entities is the multiverse hypothesis – that universes forever outside our observational horizon may exist ad infinitum. National Geographic News tried to sanctify the notion with a bit of empiricism by claiming proof exists: “New Proof Unknown ‘Structures’ Tug at Our Universe.” What is the proof? Actually, the only observation concerns some peculiar motions of galaxies that appear to be streaming in the same direction. Since “This mysterious motion can’t be explained by current models for distribution of mass in the universe,” the “controversial suggestion” has been made by some researchers “that the clusters are being tugged on by the gravity of matter outside the known universe.”
Not content to stop with that dramatic assertion, National Geographic sauntered into an even bigger unobservable notion: “The find adds to the case that chunks of matter got pushed outside the known universe shortly after the big bang—which in turn hints that our universe is part of something larger: a multiverse.”
“Seeing is believing” was the headline of a story in PhysOrg this week. It was about the detection of a gamma ray burst that may be the most distant object in the universe. Based on the stories above, however, it could be argued that for some scientists, believing is seeing. Having a strong enough faith in one’s favorite theory is enough to generate visions in the mind’s eye – by faith alone.
1. Rafael F. Lang, “Fishing for the Universe,” Science, 26 March 2010: Vol. 327. no. 5973, pp. 1582 – 1583, DOI: 10.1126/science.1187972.
2. CDMS II Collaboration, “Dark Matter Search Results from the CDMS II Experiment,” Science, 26 March 2010: Vol. 327. no. 5973, pp. 1619-1621, DOI: 10.1126/science.1186112.
These issues are important. Science has taken on the role of a priestly caste in our culture. We trust their pronouncements as much as ancient Romans trusted their oracles, on the basis of the assumption that they use methods guaranteed to generate true knowledge. The assumption is bolstered by the practical benefits science has brought us. We tend without adequate warrant to extend that assumption to all scientists and everything they say. We look to them for enlightenment about matters beyond our experience, assuming that they are trustworthy.
Many scientists are trustworthy. Many, hopefully most, have a deep regard for empirical facts, and maintain their epistemic modesty. But strict empiricists are rare these days. It is too restrictive on their imaginations. The trust we place in scientists is based on their presumed empiricism – that they walk by sight, not by faith. As these articles have shown, however (and they are not rare exceptions), much of what we call science today has become reckless in its propensity to trade in unobservable reality (if that oxymoron makes any sense).
The popular philosophy of science today is scientific realism – the assumption that scientists have the right to appeal to unobservable reality to explain observable reality. To a certain extent, this is reasonable. We all commonly infer unseen entities to explain observations – like an unobserved rainstorm when we see the car and the pavement wet. That kind of common-sense reasoning, though, usually refers to things that have been observed – like previous rainstorms that produced the same wet pavement and car. We could be wrong, though: a movie company’s rainmaking machine might have passed by. We wouldn’t usually say that a water asteroid from the Oort Cloud did it.
Despite the popularity of scientific realism, many philosophers strongly question the propriety of scientists to deal in unobservable realities. One of the values of David Berlinski’s book The Deniable Darwin (see Resource of the Week for 03/13/2010) is his deft expose of the pretensions of scientists. He said of multiverse theory,
A scientific crisis has historically been the excuse to which scientists have appealed for the exculpation of damaged doctrines…. What we are discovering is that many areas of the universe are apparently protected from our scrutiny, like sensitive files sealed from view by powerful encryption codes. However painful, the discovery should hardly be unexpected. Beyond every act of understanding, there is an abyss. Like Darwin’s theory of evolution, Big Bang cosmology has undergone that curious social process in which a scientific theory is promoted to secular myth. The two theories serve as points of certainty in an intellectual culture that is otherwise disposed to give the benefit of the doubt to doubt itself. It is within the mirror of these myths that we have come to see ourselves. But if the promotion of theory into myth satisfies one human agenda, it violates another. Myths are quite typically false, and science is concerned with truth. Human beings, it would seem, may make scientific theories or they may make myths, but with respect to the same aspects of experience, they cannot quite do both. (from “Was There a Big Bang?” in The Deniable Darwin, p. 232)
As we have seen some scientists have become so reckless in their mythmaking, they need to be shamed back to their empirical roots. They are turning science into a cult. They need to cultivate empiricism, not the occult. What is the occult, if not appeals to mysterious unseen entities and forces – the very things science was invented to avoid?
No fallible human being deserves your trust just because he or she claims to be a knower (scientist). If you would not join a cult, don’t follow any scientist blindly. Isn’t it ironic that the Good Book is sounding once again more empirical than modern science? The apostle Paul warned his readers about what is “falsely called knowledge” (science; I Timothy 6:20) and admonished them to not be “children tossed to and fro by every wind of doctrine” (Ephesians 4:14) but to “test all things; hold fast that which is good” (I Thessalonians 5:21). That’s solid scientific advice.