|
Some scientific theories that are in the way of religious, political, and corporate interests have been getting a bad rap. These theories are claimed to be false by their foes. So for example, creationist claim that evolution is false, climate change deniers claim that global warming is false, and so on. In fact, many people seem to imply that theories are ephemeral, and to buttress their claim they offer a list of theories that have been proven “false”. Why should we rely on a scientific theory to affect public policy today if it can be shown to be false tomorrow? In addressing this issue there are several things we have to consider. Before we begin, we need to make the clarification that the word “theory” in the popular parlance can be a synonym for a guess or a very preliminary explanation. In science, a theory is a vastly more stable form of knowledge. In fact, if the theory is sufficiently developed, it in itself can become a fact. So what are the characteristics of a sufficiently developed theory? They are: 1) It explains the existing observations and experimental results. 2) It has generated predictions that have been found to be true. 3) It has generated practical applications that work. 4) Results from other scientific disciplines corroborate the theory and the theory corroborates results in other scientific disciplines. Please read the list above again carefully. Don’t you think that when a theory fulfils these characteristics we can say with confidence that it has clearly grasped important aspects of the realities it’s trying to explain? But, you may ask, what if a genius like an Einstein comes along and thinks up a new interpretation for everything the theory explains and predicts, and expands it into a different theory to explain new things? Can’t we say then the theory was proven false?  Well, let’s consider what Einstein did. He reinterpreted Newton’s laws of gravitation and motion, and came up with explanations for phenomena the Newtonian interpretations could not explain. Einstein thus relegated Newton’s laws to particular cases where velocities are much lower than that of the speed of light or when very strong gravitational fields are not involved. But here is the thing: the speeds at which planets, rockets, space probes, and objects in everyday life move, and their behavior in the gravitational fields that they encounter most of the time, can be described with a satisfactory level of accuracy by Newton’s laws. The existence of a planet (Neptune) and the return of a comet (Halley’s Comet) were predicted using Newton’s laws. The life of astronauts and the integrity of multimillion dollar space probes depend on the veracity of the calculations employing Newton’s Laws. Is it fair to say that Einstein proved Newton’s theories were false?
Of course not! Einstein showed Newton’s theories were incomplete, and this is what the public has to understand when discussing scientific theories. Sufficiently developed scientific theories cannot be false, they can only be incomplete. When assessing scientific theories, it is counterproductive to talk in terms of true or false. What has to be discussed is whether a theory has been formulated at a high enough level of detail, in other words, whether the theory is complete enough. We don’t need theories to be 100% true. They can’t be (nothing can), and they don’t have to be. We only need the theory to be complete enough to be useful for society. Finally, it must be pointed out that the vast majority of scientific theories are not “big name” theories such as the theory of evolution or global warming. There are hundreds of scientific fields and subfields that have given rise to thousands of theories most of which are boring, highly technical, and devoid of importance to the “culture wars”. Therefore they do not make the news, and non-scientists are not even aware of them. Most of these theories have never been overturned, and in fact form the basis of modern science leading to tens of thousands of practical applications and policies. If these theories were not sufficiently complete representations of reality, modern life would not be possible! So next time you are pondering the worthiness of a scientific theory, remember, it's all in the completeness. The figure is a collage of a copy of a painting of Isaac Newton by Sir Godfrey Kneller (1689), which is in the public domain, and a photograph of Albert Einstein by Orren Jack Turner obtained from the Library of Congress, which is also in the public domain because it was published in the United States between 1923 and 1963 and the copyright was not renewed.
0 Comments
 Many snippets of wisdom that have permeated our culture are routinely quoted in social media such as the one from the Irish playwright George Bernard Shaw featured in the image above that states that all progress depends on the unreasonable man.
Everyone seems to have an affinity with this particular trope. After all, who doesn’t love the story of the little guy fighting against the establishment? It seems that most of us, within reason, are programed to root for the underdog. The mavericks, the misfits, the fringe-thinkers, the outcasts: why do these characters have a place in our hearts? Is it perhaps because in the daily tedium of our lives, as we persevere overburdened by challenges at work, in our homes, and in society, we sometimes wish we could upturn the established order and restart anew? Perhaps we have considered going against the current, challenging the system, rocking the boat, but then deemed the risks of doing so too dire and just bowed our heads and kept on going. So maybe when one of these colorful characters that actually dares to challenge the powers that be comes along, we live vicariously through their plight a fantasy that we ourselves are too cowardly to bring to reality. Be that as it may, in the field of science many of these characters have captivated the public’s imagination. Take the case of Dr. Barry Marshall who proposed the hypothesis that stomach ulcers are not caused by excessive acid secretion due to stress, as was thought by most experts, but by infections with a type of bacteria called Helicobacter pylori. Dr. Marshall failed to convince the scientific establishment. He was not able to develop an animal model of the disease, and could not obtain funds to perform a human experiment. So what did he do? He experimented on himself! He drank a broth infected with the H. pylori isolated from a patient who had developed severe gastritis. Within days he developed the same symptoms the patient had, and he was able to cure himself using antibiotics. It took another decade of struggles, but gastroenterologists were eventually convinced of the truth of his claim, and Dr. Marshall won a Nobel Prize in 2005. Isn’t that a great story? And like this story, there are many other such stories of the unreasonable man battling the system and prevailing in the end. However, the popularization of these stories has generated several notions in the public consciousness that are not accurate. The first is the notion that the only way science makes progress is when one of these characters upends conventional wisdom and triggers a revolution. This is not true. Most of the time progress in science occurs incrementally as thousands of scientists perform vital work within the system developing new knowledge, methodologies, procedures, and applications. The backgrounds and expertise of these scientists are fundamental to driving any new or old area of science forward. Without these individuals working within the system there would be no science. The notion that ALL progress, at least in science, depends on the unreasonable individual is simply false. The second notion is that just because you are one of the unreasonable individuals you must be right, and the scientific establishment must be wrong. It must be understood that for every individual who has challenged the established order successfully, there have been dozens to hundreds of other individuals who have challenged the established order and were proven to be wrong. The stories of these individuals are normally not of interest except, if at all, to those whose write historical descriptions of the development of a given scientific field, and they are barely mentioned in the popular press. Finally, the last (and probably most troublesome) notion is that when the scientific establishment lashes out at one of these unreasonable individuals, this is taken as proof that there is a bias within the scientific community motivated at best by intellectual conformity and closed-mindedness, or at worse by corrupt influences tied to granting agencies or corporate interests. However, what the public may interpret as an unfair treatment of a scientist by the scientific community is more often than not due to the fact that science is a very conservative enterprise, and the bar to overturn or reinterpret established science is set pretty high. Science is biased towards established knowledge; as it should be! When you go against established science, you’d better have some exceptional evidence and arguments or else you are going to be given a very hard time! Even scientists with Ph.Ds. can propose things that are wrong, misguided, or just plain stupid. Not all ideas deserve to be treated equally, not all evidence is sound, and not all interpretations of the data are correct. What most individuals seeking to change the prevailing scientific paradigm do is address the criticism made by their peers, generate more evidence, and reformulate their ideas or their presentation. Convincing other scientists that you are right is the warp and woof of science. However, a disturbing phenomenon has emerged. Today those individuals who have been rebuffed by the scientific community can take their case to “the people” arguing that they are victims of a corrupt scientific establishment that is hell bent on silencing them and discrediting their ideas. Such is the case of Dr. Andrew Wakefield who, when his views that vaccination was linked to autism were rejected by the medical community, took his case directly to the public. He actually succeeded in convincing many parents to avoid vaccinating their children leading to a spike in infant deaths from some diseases that are preventable nowadays. Established science is called that for a reason. Scientific theories are constructs that have grasped important aspects of the realties they seek to explain, and they cannot be overturned on a whim. The quixotic quest of the unreasonable man must not be romanticized. These individuals are wrong most of the time, and established science must be protected from them. If you want to upend established science, the burden of proof is on you! The image of George Bernard Shaw was modified from a photograph in the George Grantham Bain collection at the Library of Congress and has no known copyright restrictions. 2/7/2018 Is the Earth round? Avoiding The Absolute Truth to Find the Practical Truth: the Devil is in the Level of DetailRead NowMost people hold a “binary” notion of the truth. For them things can either be true or false, because that which is false cannot be true, and that which is true cannot be false. We will call this notion the “absolute truth”. I want to argue that this absolute truth notion is unsatisfactory and impractical at addressing the worthiness of scientific theories. For this purpose I will use an example. Consider the idea that the Earth is flat. For people in antiquity living in a flat place like the plains or a desert it probably made sense to think this, but eventually the ancients figured out that the Earth was not flat. The Earth is round and we know that for a fact nowadays. So, the Earth is flat: false, the Earth is round: true; right? Actually, the Earth is not round! As Isaac Newton proposed and was later found to be correct, the Earth, due to its rotation, is an “oblate spheroid”, which means it is flater at the poles and bulging at the equator (the distance from the Earth’s center to sea level is 13 miles longer at the equator). OK, so, the Earth is round: false, the Earth is an oblate spheroid: true, right? Well, not quite. The Earth is an oblate spheroid, but the southern hemisphere is wider than the northern hemisphere giving the Earth a bit of a pear shape. Fine, so the Earth is an oblate spheroid: false, the Earth is a pear-shaped, oblate spheroid: true, right? Actually, even this is false! The Earth’s mass is not distributed evenly across the planet, and the greater the mass, the greater the gravitational force, which leads to the creations of bumps in the Earth’s crust. Additionally these bumps change overtime due to the movement of continental plates, the changing weight of the oceans, lakes, ice masses, and atmosphere, and the gravitational pull of the sun and the moon. All of these processes can deform the Earth’s crust by the order of millimeters to a few dozen centimeters daily and by much larger amounts over geologic times. So the Earth is a bumpy, shapeshifting, pear-shaped, oblate spheroid? Yes. Wahoo, we did it! At last we have the absolute truth! The Earth is an pear-shaped, oblate spheroid: false, the Earth is a bumpy, shapeshifting, pear-shaped, oblate spheroid: true, right? At this point you are probably thinking: seriously, are you kidding?  This is the problem with the absolute truth notion: it ignores the level of detail that is required for adequately describing physical phenomena. The level of detail that is required from a description of the shape of the Earth will vary depending on what you are intending to use it for. For surveyors determining distances in small patches of the Earth’s surface, a flat Earth model is perfectly suitable, as the error in the measurements is negligible. For people dealing with time zones, the round Earth description is perfectly adequate. On the other hand, satellite orbits can be affected by small deviations of the Earth’s crust from a perfect sphere, so people following satellites must take into account the oblate spheroid and pear deformities of the Earth. Similarly, people running particle accelerators must understand that the Earth is constantly shifting its shape so they can keep track of very small deformities in the Earth’s crust that arise daily and may mess up their measurements.
The vast majority of people would accept that the claim that the Earth is flat is false (low level of detail). On the other hand, most people would consider further refinements to the round Earth claim such as the oblate spheroid; pear-shaped, oblate spheroid; or bumpy, shapeshifting, per-shaped, oblate spheroid to be a needless amount of precision (too high a level of detail), and rightly so. The type of deviations from a spherical shape that these highly detailed models of the Earth deal with is at most about a dozen miles. If you take into account that the Earth’s radius is 3,959 miles, we are talking about a difference of 0.3%. By this token the Earth’s crust, despite its mountains and sea trenches, is very smooth. So for the use that most of us make of the information regarding the shape of the Earth, a round Earth model is an acceptable level of detail. Depending on what you are trying to explain or achieve, trying to find the absolute truth may be not only impossible or unnecessary, but also cumbersome. So we come to the paradoxical realization that seeking the absolute truth may actually hinder or prevent our discovery of the practical truth! When scientists seek the truth regarding physical phenomena, what they have in mind is the practical truth which is a truth defined at a sufficiently high level of detail to explain the phenomena they are studying and derive predictions and useful applications. Later on other scientists may seek to explain things at a higher level of detail to address more complex questions that a lower detailed truth can’t answer satisfactorily, and so on. What the public has to understand is that a scientific theory does not have to explain everything to be considered “true”. It just has to explain the relevant phenomena at a sufficiently high level of detail to generate accurate predictions and useful applications. The debate should not be about whether a given theory is true or false, but rather about whether a theory has been formulated at a sufficiently high level of detail for society to benefit from it. The image from NASA is in the public domain. |
Categories
All
Archives
December 2023
|
RSS Feed