Quantum Diaries

Byron Jennings | TRIUMF | Canada

Read Bio

Science and Engineering: vive la Différence

Friday, May 11th, 2012

This essay was motivated by a question from an engineering colleague. It would be presumptuous to say “friend,” as scientist and engineers are in a state of “friendly” rivalry, however, not to the extent as with arts. I once saw a sign in an engineering department hallway that read: Friends do not let friends study arts. Be that as it may, my colleague’s question was why scientists do not show the same order in all their work as they show in writing papers. That question I will attempt to answer in this essay.

Engineering is far older than science, being perhaps the second oldest profession, dating back at least to the building of the pyramids (Imhotep from the 27^th century BCE is the oldest named engineer) and Stonehenge and probably back to when the first club was engineered. Stonehenge is amazing as it was probably built without the documentation that is the hallmark of modern engineering practice. Unfortunately, that means we do not know what the initial requirements[1] were and this has led to much futile speculation as to its purpose.

Science and engineering are sibling disciplines, frequently mentioned together and have much in common. The main similarity is that they both deal with the observable universe and are judged by their ability to make correct predictions regarding its behaviour. For example, that the Higgs boson will be found at the Large Hadron Collider (LHC) or that the building will not collapse in an earthquake. Secondarily they use similar techniques, placing high importance on analytic reasoning, to the extent that Asperger’s syndrome is sometimes called the engineer’s disease. The relation between Asperger’s syndrome and engineers or scientists may be an urban myth but it does indicate the relation of extreme analytic thought to both science and engineering. The solution to problems in both relies on the same problem solving skills, analytic thinking and mathematics. Do not let anyone tell you that either does not require a high degree of intellectual activity.

Science and engineering rely on each other. Behind every engineering project is a great deal of science, from the basic understanding of Newtonian mechanics in the building of a bridge to the advanced materials science in the construction of a cell phone. Actually, the cell phone is a good example of all the science needed: it depends on Newtonian mechanics (the construction of the cell phone towers), quantum mechanics (the operation of the transistors), classical electromagnetism i.e. Maxwell’s equations (the propagation of the signal from the tower to the cell phone), materials science (almost all the cell phone itself), and general and special relativity (the GPS timing that is necessary in some cell phone technologies).

Equally, science is beholden to engineering. From simple things like the buildings that house scientific equipment to complicated things like the ATLAS detector at the Large Hadron Collider (LHC). Making a building may seem simple but, as I see with the new ARIEL building at TRIUMF, nothing is simple and even something as basic as a laboratory building relies on engineering expertise. The ATLAS detector is another story. Its size and complexity are a marvel of engineering virtuosity. Back to TRIUMF, the IEEE has recognized the TRIUMF cyclotron, commissioned in 1974 and the main driver for much of TRIUMF’s science program, as an Engineering Milestone. Even the slide rule I used back in ancient history as an undergraduate[2] was an engineering achievement.

Despite the close relationship between science and engineering the two are different. The difference can be summarized in this statement: “In engineering you do not start a project unless you know the answer while in science you do not start a project if you know the answer.” Engineering is based on everything being predictable; you do not start building a bridge unless you know you can complete it. In science, the purpose of a project is to answer a question to which the answer is currently unknown. For example, if the properties of the Higgs boson were known, it would not have been necessary to build the LHC. Good engineering practice is based on order but at the center of science is chaos. We are exploring the unknown; great discoveries can come from serendipity. In science, something not working as expected can lead to the next big breakthrough. In engineering, something not working as expected can lead to the bridge collapsing. Advances in science are frequently due to creativity, not following rules.

This difference in perspective leads to very different cultures in the two disciplines. The engineer is much more concerned with process and following procedure. The scientist with following up his most recent hunch—after all, it could lead to a Nobel Prize. Engineering versus science: order versus creative chaos. This is clearly an oversimplification as there is no clean separation between engineering and science, but it is a good indication of the divergence between the two mindsets. Thus, although engineering and science are closely related and indeed intertwined, the two, in their heart of hearts, are very different; engineering uses science in order to build and science uses engineering in order to explore.

Additional posts in this series will appear most Friday afternoons at 3:30 pm Vancouver time. To receive a reminder follow me on Twitter: @musquod.

[1] Project management jargon alert: requirements used in technical project management sense.

[2] HP produced the first pocket calculator when I was an undergraduate student.

Tags: Engineering, Order versus creative chaos, Philosophy of science
Posted in Latest Posts | 12 Comments »

In Defense of Jargon

Friday, May 4th, 2012

Jargon, even the name has a harsh ring to it. Can anyone but an author love a title like[1]: Walking near a Conformal Fixed Point: the 2-d O(3) Model at theta near pi as a Test Case? “How can anyone take science seriously when it uses so much jargon?” said the teamster[2] as he told his helper to fasten the traces to the whiffletree and check the tugs and hames straps. Jargon is everywhere and not unique to science. While you may not understand what the teamster is talking about, my father would have understood instantly and then gone to get a jag of wood.

But back to jargon. To the uninitiated the above title, like the teamsters words, seems like so much gobbledygook. But to the initiated, those working in the field, it is a precise statement and easily understood. Trying to put the title, or the teamster’s words, in a form understandable to the layperson would have been a fool’s errand. In making it understandable to a more general audience, the precision would have been lost and we would probably never have gotten that jag of wood. That would have been unfortunate as Nova Scotian winters can be cold.

One of the principles of all good writing is to tailor the communication to the intended audience. When I am helping put together a report for TRIUMF, the instructions to the authors always includes a statement about the intended audience. Even then, the good authors frequently ask me to make the description of the intended audience more precise. Life gets more complicated when a document has more than one intended audience. Then it is necessary to have a layered document where introductory sections are understandable by an intelligent layperson while the later sections are directed at the specialist. One is reminded of the old joke about the structure of good seminar: The speaker starts at a low level understandable by anyone and then as the seminar progresses he becomes more technical and less understandable so that by the end, even the speaker does not know what he is talking about. Well, perhaps that is getting a little too carried away, but one can error on either side, by making the writing too technical for the audience or not technical enough.

Similarly, the reader has to realize that the writing may not be directed at him or her. We, as people with technical expertise, have to be careful not to judge non-technical writing too harshly because it does not capture all the subtle nuances we are aware of. Including them would lose the layperson. It is a fine line between not confusing the layman and misleading him. When I am reading an article directed at a general audience, on a topic I am an expert in, I find I have to translate the layman’s language back to the technical language before I can understand it. That is as it should be.

Conversely, in fields we are not experts in, we should not criticize technical writing as being too filled with jargon. This latter mistake is made frequently by politicians and commentators who criticize technical writing due to ignorance. Few have the wisdom of the former Canadian Prime Minister, Pierre Elliot Trudeau, who said on opening TRIUMF, “I do not know what a cyclotron is, but I am glad Canada has one.” It is a rare politician who has the confidence to admit ignorance. As an undergraduate student, I picked up a copy of Rose’s book: Elementary Theory of Angular Momentum. That is when I learned one should be leery of books with elementary in the title[3]. If that is an elementary book, I would hate to have to read an advanced one. It is a good book but I, at that stage in my career, was not the intended audience.

Words only have meaning within the context they are used. When used with a person possessing a similar background, the context does not have to be spelled out. Thus, in conversation with a colleague I have worked with for some time a lot is understood without being stated explicitly. Jargon speeds up communication and makes it less prone to misunderstanding. On the other hand, with people who are not acquainted with the field, we have to spell out the background assumptions and suppress the details that are only of interest to the expert.

In the end, it is quite unfortunate that jargon has been abused and hence has received a bad name. In technical writing, jargon or technical terms are not only acceptable but necessary. So press on and employ jargon—but only where appropriate.

Additional posts in this series will appear most Friday afternoons at 3:30 pm Vancouver time. To receive a reminder follow me on Twitter: @musquod.

[1] First title on the lattice archive the day I checked to get an example.

[2] The kind that drives horses.

[3] Books with elementary in the title are usually advanced while those with advanced in the tile are usually elementary.

Tags: Jargon, Philosophy of science, Wiffletree
Posted in Latest Posts | 6 Comments »

Is Science Consistent with Evolution?

Friday, April 27th, 2012

The evolutionary argument against naturalism

Alvin Plantinga (1932), professor emeritus of philosophy at the University of Notre Dame, is a leading theistic philosopher and opponent of evolution. He has proposed an intriguing, and specious—yet non-the-less intriguing—argument against evolution. It is intriguing for several reasons: First, because on the face of it, it is plausible. Second because it is typical of a whole class of specious arguments. Finally, because it highlights the difference between how scientists and philosophers approach a problem.

The argument runs as follows: The naturalist can be reasonably sure that the neurophysiology underlying belief formation is adaptive, but nothing follows about the truth of the beliefs depending on that neurophysiology. In fact, he’d have to hold that it is unlikely, given unguided evolution, that our cognitive faculties are reliable. It’s as likely, given unguided evolution, that we live in a sort of dream world as that we actually know something about ourselves and our world (original emphasis). In other words, if people in fact evolved, they could not trust their cognitive faculties to give them the truth and hence, do science. He goes on to argue that it is only possible to trust our cognitive faculties if people are created in God’s image.

It is amusing that unbelievers argue the opposite; namely that the existence of a God means science is impossible since he/she/it could override the rules of nature at will and there would be no reason to assume constant laws. Both are correct to this extent: Absolute knowledge is impossible,[1] independent of God’s existence. But back to Plantinga’s argument; it hinges on the concept of truth, or equivalently, reliability. But what is truth? A profound question—or a meaningless one. The difference between profound and meaningless is often vanishingly small.

At one level, the idea of truth is simple: Does the testimony of the person on the witness stand agree with what happened? Or perhaps the simpler question: Does the testimony agree with what the person thinks happened? The second is a less stringent requirement. But from this simple concept, the grand metaphysics concept of TRUTH ™ is generated. Whatever this grand metaphysical concept is, science is not concerned with it. Is it TRUTH ™ that colds are caused by viruses? The reductionist, at least if he believes in string theory, would say no. Colds, like all other phenomena, are caused by how strings vibrate in eleven dimensions. Viruses are just a wimpy low-energy approximation to the real TRUTH ™.

In science, we build models for how the universe works, which usually have a limited range of validity. Think of classical mechanics which is only valid for velocities much less than the speed of light. Is classical mechanics the TRUTH ™? No, certainly no, it fails in various places. But it is certainly useful. Science is a natural extension of the model building the unconscious mind does all the time, which is necessary for us to survive in a hostile world. The surprising thing is not that beings who evolved created science, but rather, that they did not do it sooner. Plantinga’s problem is that he does not understand what science is or how it works—seeking effective models rather than the TRUTH ™, whatever that may be. He should have known better, since by the Duhem-Quine thesis, no model can be falsified. Arguing that the current models have deficiencies is never enough. You have to provide better ones with more predicative power.

In the same manner that Plantinga’s argument relies on the grand metaphysics concept of TRUTH ™, many arguments in philosophy rely on similar word definitions. A prime example is the ontological agreement for God’s existence. First proposed by Anselm of Canterbury (1033 – 1109), the argument goes as follows: Define God as the greatest possible being we can conceive. If the greatest possible being exists in the mind, it must also exist in reality. If it only exists in the mind, a greater being is possible—one which exists in the mind and in reality. Note that his argument hinges on the definition of greatest. My daughter believes that anything, no matter how great, can be made greater by being pink. Thus the greatest being is pink. If I define non-existence as being greater than existence,[2] the ontological argument becomes an argument for God’s nonexistence. Evil is another word that is frequently made into a grand metaphysical concept, EVIL™, and used to justify various philosophical positions. The concept of actions I do not like is then taken a step further and personified in the concept of the devil.

While our concepts and word definitions may reflect reality, they do not constrain it. In the end, models founded on observation take precedence over philosophical arguments based on word definitions and phenomenologically unconstrained speculations. If such philosophical arguments disagree with scientific models, so much the worse for them. Thor showing up for Thursday afternoon tea at the Empress Hotel would make all arguments regarding his existence moot[3]. One observation is worth a thousand philosophical arguments.

Additional posts in this series will appear most Friday afternoons at 3:30 pm Vancouver time. To receive a reminder follow me on Twitter: @musquod.

[1] See The Limits of Science.

[2] See Ecclesiastes chapter 4 for why this definition may be reasonable.

[3] You can tell it is Thor because he would be carrying a large hammer and one of the goats pulling his chariot would be limping.

Tags: Duhem-Quine, evolution, Philosophy of science, Plantinga, truth
Posted in Latest Posts | 12 Comments »

The Role of Mathematics and Rational Arguments in Science

Friday, April 20th, 2012

Mathematics is a tool used by scientists to help them construct models of how the universe works and make precise predictions that can be tested against observation. That is really all there is to it, but I had better add some more or this will be a really short essay.

For an activity to be science, it is neither necessary, nor sufficient, for it to involve math. Astrology uses very precise mathematics to calculate the planetary positions, but that does not make it science any more than using a hammer makes one a carpenter (Ouch, my finger!). Similarly, not using math does not necessarily mean one is not doing science any more than not using a hammer means one is not a carpenter. Carl Linnaeus’s (1707 – 1778) classification of living things and Charles Darwin’s (1809 – 1882) work on evolution are prime examples of science being done with minimal mathematics (and yes, they are science). The ancient Greek philosophers, either Plato or Aristotle, would have considered the use of math in describing observations as strange and perhaps even pathological. Following their lead, Galileo was criticized for using math to describe motion. Yet since his time, the development of physics, in particular, has been joined at the hip to mathematics.

The foundation of mathematics itself is a whole different can of worms. Is it simply a tautology, with symbols manipulated according to well defined rules? Or is it synthetic a priori information? Is 2+2=4 a profound statement about the universe or simply the definition of 4? Bertrand Russell (1872 – 1970) argued the latter and then showed 3+1=4. Are the mathematical theorems invented or discovered? There are ongoing arguments on the topic, but who knows? I certainly don’t. Fortunately, it does not matter for our purposes. All we need to know about mathematics, from the point of view of science, is that it helps us make more precise predictions. It works, so we use it. That’s all.

I could end this essay here, but it is still quite short. Luckily, there is more. Mathematics is so entwined with parts of science that is has become its de facto language. That is certainly true of physics where the mathematics is an integral part of our thinking. When two physicists discuss, the equations fly. This is still using mathematics as a tool, but a tool that is fully integrated in to the process of science. This has a serious downside. People who do not have a strong background in mathematics are to some extent alienated from science. They can have, at best, a superficial understanding of it from studying the translation of the mathematics into common language. Something is always lost in a translation. In translating topics like quantum mechanics—or indeed most of modern particle physics—that loss is large; hence nonsense like the “God Particle”. There is no “God Particle” in the mathematics, only some elegant equations and, really, considering their importance, quite simple equations. One hears question like: How do you really understand quantum mechanics? The answer is clear, study the mathematics. That is where the real meat of the topic and where the understanding is—not in some dreamed up metaphysics-like the many worlds interpretation.

Closely related to mathematics are logical and rational arguments. Logic may or may not give rise to mathematics, but for science, all we require from logic is that it be useful. Rational arguments are a different story. Like mathematics, they are useful only to the extent they help us make better predictions. But that is where the resemblance stops. Rational arguments masquerade as logic, but often become rationalizations: seductive, but specious. Unlike mathematics, rational arguments are not sufficiently constrained by their rules to be 100% reliable. Indeed, one can say that the prime problem with much of philosophy is the unreliability of seemingly rational arguments. Philosophers using supposedly rational arguments come to wildly different conclusions: compare Plato, Descartes, Hume, and Kant. This is perhaps the main difference between science and philosophy: philosophers trust rational arguments, while scientists insist they be very tightly constrained by observation; hence the success of science.

In science, we start with an idea and develop it using rational arguments and mathematics. We check it with our colleagues and convince ourselves using entirely rational arguments that it must be correct, absolutely, 100%. Then the experiment is performed. Damn—another beautiful theory slain by an ugly fact. Philosophy is like science, but without the experiment[1]. Perhaps the real definition of a rational argument, as compared to a rationalization, is one that produces results that agree with observations. Mathematics, logic, and rational arguments are just a means to an end, producing models that allow us to make precise predictions. And in the end, it is only the success of the predictions that count.

Additional posts in this series will appear most Friday afternoons at 3:30 pm Vancouver time. To receive a reminder follow me on Twitter: @musquod.

[1] I believe this observation comes from one of the Huxelys but I cannot find the reference.

Tags: mathematics, Philosophy of science
Posted in Latest Posts | 11 Comments »

The Argument from Design

Friday, April 13th, 2012

Central to the scientific method is a process for deciding between conflicting models of how the universe operates. It is very instructive to apply this process to the argument from design for the existence of a higher intelligence in the universe. The argument from design is commonly associated with William Paley (1743 – 1805) and for those who like big words, is also called as the teleological argument for God’s existence. A counter argument is given in Richard Dawkins’ book: The Blind Watch Maker. The basic argument from design is, however, much older than Paley; it goes back to the ancient Greeks. Needless to say, Dawkins’ book has failed to lay the argument to rest. If one checks the current state of the arguments on the topic[1], they typically are of the form: Anyone who does not recognize design in the universe is in denial, and the counter argument is: Those who see design in the universe are delusional. Needless to say, neither argument is particularly convincing. So what can the scientific method add to resolving the impasse? Quite a bit actually.

Let’s begin by looking at the actual form of the argument. It was stated succinctly by Cicero (106BCE – 43 BCE): When you see a sundial or a water-clock, you see that it tells the time by design and not by chance. How then can you imagine that the universe as a whole is devoid of purpose and intelligence, when it embraces everything, including these artifacts themselves and their artificers? This analogy was expanded upon, most famously, by Paley (quoted from the Wikipedia):

[S]uppose I found a watch upon the ground, and it should be inquired how the watch happened to be in that place, I should hardly think … that, for anything I knew, the watch might have always been there. Yet why should not this answer serve for the watch as well as for [a] stone [that happened to be lying on the ground]?… For this reason, and for no other; namely, that, if the different parts had been differently shaped from what they are, if a different size from what they are, or placed after any other manner, or in any order than that in which they are placed, either no motion at all would have been carried on in the machine, or none which would have answered the use that is now served by it.

So what about the watch and how do we know that it was designed? We begin with one of the mantras of this series of essays: The meaning is in the model. To understand the watch and its creation, our mind, either consciously or unconsciously, develops a model for its origin. The watch is deduced to have to been made by humans, not by non-human agencies, and humans do things by design. Thus, by a two-step process we arrive at design. Now, the watch is fairly obvious, but what about that pointed rock on the ground? Is it due to design or natural causes? Is it simply a broken rock or is it an arrow head? Here the question of design is strictly one of if it was made by humans or not. If the indications on the rock show signs of human manufacture it is considered due to design, and if not, then accident.

The typical theist would claim that the universe and everything in it is designed. Thus, we cannot do the comparison of something designed to something that was not designed; a technique that was useful in deciding if the watch was humanly designed or not. So how do we tell if something is designed or not? Use the methodology from science, of course.

In science, there are two distinct steps with any model: first the model must be constructed, and then it must be tested. Model construction is a creative activity and does rely on analogy and pattern recognition. Thus, in the initial stage, the argument from design is on good grounds. Now for the crux of the matter: the crucial test is neither how good the analogy is, nor how striking the apparent pattern, but rather if the argument from design passes the tests of parsimony and also makes successful predictions for observations. The scientific method defines three criteria for judging models: the successful description of past observations, the ability to make correct predictions for future observations, and simplicity. Being able to describe past observations is just the price to play the game, and with sufficient ingenuity, can usually be done. The definitive test of a scientific model is the ability to make predictions for novel phenomena. By predictions, I mean definite predictions that can be falsified. Not the kind of predictions made by Nostradamus that after the fact can be claimed to have been fulfilled, but rather definite predictions that can be tested, like it will rain tomorrow at TRIUMF between 3:00 and 4:00 pm.

Finally, there is simplicity. Yes, there is always simplicity or parsimony. By simplicity, I mean the elimination of assumptions that do not help the model make predictions. Today, common descent for living things is pretty much established and is mainly challenged by gross violations of the simplicity principle. A prime example is the omphalos hypothesis of Phillip Gosse (1810 – 1888). He stated that the world was created six thousand years ago, but in a manner that cannot be distinguished from one that is much older. As pointed out in a previous essay, that hypothesis can only be eliminated by an appeal to parsimony. As for design, natural selection is one way of generating the design of living things without the need for external intelligence and, at least at the small scale, natural selection is observed to be happening. So, can an external intelligence as suggested by the argument from design, or the idea of intelligent design, add anything useful to this? Or can they both be eliminated, like the omphalos hypothesis, by the appeal to parsimony? The challenge to the proponents of the argument from design (and similarly for intelligent design) is to make precise testable predictions, not postdictions, that distinguish it from natural selection.

Additional posts in this series will appear most Friday afternoons at 3:30 pm Vancouver time. To receive a reminder follow me on Twitter: @musquod.

[1] This post was partly motivated by such an exchange on Huffington Post.

Tags: intelligent design, Paley, Philosophy of science, The argument from design
Posted in Latest Posts | 9 Comments »

The Role of the Crucial Experiment

Friday, April 6th, 2012

The idea of a crucial experiment that decisively confirms a model goes back at least to Francis Bacon (1561 – 1626) who used the term instantia cruci. Later, the term experimentum crucis was coined by Robert Hooke (1635 – 1703) and used by Isaac Newton (1642 – 1727), in particular with regard to his theory of light. Alternatively, Pierre Duhem (1861 – 1916) strongly disagreed with the possibility of crucial experiments. Somewhat in anticipation of Thomas Kuhn’s (1922–1996) paradigms, Duhem realized that scientific theories or models do not stand alone, but rather come coupled with auxiliary assumptions. Was what Galileo saw through the telescope features of the heavens, or only of his telescope, as some of his detractors claimed? One has to consider the combined heavens-telescope system to decide. When the detector is as complex as the ATLAS detector at CERN the question is even more apropos.

Karl Popper (1902 – 1994) refined the idea of the crucial experiment to one that falsifies a given model. But the Duhem-Quine hypothesis, a variation of Duhem’s idea, makes the point that falsification, at least in its naïve form, falls victim to same holistic argument: we can never test a single model in isolation. So is the idea of a crucial experiment just a will-o-the-wisp that vanishes on more careful evaluation?

We can think of many examples: Sir Arthur Eddington`s measurement of the bending of star light by the sun, the discovery of high-temperature superconductors, the measurement of the three degree microwave background, the Michelson–Morley experiment, and so on. Did none of these play a critical role in the history of science? I would suggest they did, but not in the simple manner suggested by Bacon or Popper.

Consider the Michelson–Morley experiment in 1887. Scientists did not do a Chicken Little impersonation and run around claiming the sky was falling or, in this case, that Newton (Newton`s laws of motion) and Maxwell (electromagnetism) were wrong. Rather, they started trying to understand what the explanation could be. This led to ideas like ether drag (the earth entraining the ether) or Lorentz-Fitzgerald contraction (the idea that objects shorten in the direction of motion). The latter idea was developed and expanded upon by Lorentz and Poincaré who developed the math for special relativity. Einstein claimed he was unaware of the Michelson–Morley experiment, but he was certainly aware of Lorentz`s early attempts to understand that experiment. Thus, the Michelson–Morley experiment started a chain of events that inexorably lead to special relativity, not in one easy step, but eventually and inevitably. If special relativity had been proposed thirty years sooner, it would have been treated as a curiosity like the Copernicus model when it was first proposed.

As another example, consider the measurement of the bending of light by the sun. The general theory of relativity and classical mechanics differ by a factor of two. Eddington`s 1919 experiment gave a result closer to general relativity and hence contributed to the early acceptance of general relativity (not that people are not still trying to test it; that is as it should be). A more striking example was the discovery of the three-degree kelvin cosmic microwave background. Before then, there were two models, both with strong support: the steady-state model and the big bang model. While the microwave background was a big boost for the big bang model, the solid state model did not give up without a struggle. There were various attempts to describe the microwave background in the solid state model but they were too little too late. Like the Michelson–Morley experiment, the discovery of the microwave background started a chain reaction that led to the acceptance of one model and the rejection of another.

Perhaps the best way of thinking of crucial experiments is not that they prove (that ugly word) one model better than another, but that they serve as a catalyst. Or perhaps, one can think of a super-cooled fluid that when slightly disturbed, suddenly solidifies. The same phenomenon is seen with people. A group are sitting at lunch and when one gets up to go and they all go, but only if the circumstances are right. Consider the discovery of the J/Ψ particle. The time was right and the background had been prepared so that when it was discovered, the particle physics community solidified around the quark model. Similarly, you can consider Galileo turning his telescope on the heavens as providing the catalyst for the acceptance of the heliocentric model.

Like models, experimental results do not exist in isolation. Rather, they build on each other and are given meaning by the prevailing models. The role of crucial experiments should be seen in relation to that milieu. They do not single handedly overturn or confirm the status quo, but rather, start chains of events that lead to or act as tipping points for the establishment of new paradigms. Thus, crucial experiments do exist but not in the naïve manner envisioned by Bacon, Hooke, or Popper.

Additional posts in this series will appear most Friday afternoons at 3:30 pm Vancouver time. To receive a reminder follow me on Twitter: @musquod.

The idea of a crucial experiment that decisively confirms a model goes back at least to Francis Bacon (1561 – 1626) who used the term instantia cruci. Later, the term experimentum crucis was coined by Robert Hooke (1635 – 1703) and used by Isaac Newton (1642 – 1727), in particular with regard to his theory of light. Alternatively, Pierre Duhem (1861 – 1916) strongly disagreed with the possibility of crucial experiments. Somewhat in anticipation of Thomas Kuhn’s (1922–1996) paradigms, Duhem realized that scientific theories or models do not stand alone, but rather come coupled with auxiliary assumptions. Was what Galileo saw through the telescope features of the heavens, or only of his telescope, as some of his detractors claimed? One has to consider the combined heavens-telescope system to decide. When the detector is as complex as the ATLAS detector at CERN the question is even more apropos.

Consider the Michelson–Morley experiment[W1] in 1887. Scientists did not do a Chicken Little impersonation and run around claiming the sky was falling or, in this case, that Newton (Newton`s laws of motion) and Maxwell (electromagnetism) were wrong. Rather, they started trying to understand what the explanation could be. This led to ideas like ether drag (the earth entraining the ether) or Lorentz-Fitzgerald contraction (the idea that objects shorten in the direction of motion). The latter idea was developed and expanded upon by Lorentz and Poincaré who developed the math for special relativity. Einstein claimed he was unaware of the Michelson–Morley experiment, but he was certainly aware of Lorentz`s early attempts to understand that experiment. Thus, the Michelson–Morley experiment started a chain of events that inexorably lead to special relativity, not in one easy step, but eventually and inevitably. If special relativity had been proposed thirty years sooner, it would have been treated as a curiosity like the Copernicus model when it was first proposed.

Perhaps the best way of thinking of crucial experiments is not that they prove (that ugly word) one model better than another, but that they serve as a catalyst. Or perhaps, one can think of a super-cooled fluid that when slightly disturbed, suddenly solidifies[W2] . The same phenomenon is seen with people. A group are sitting at lunch and when one gets up to go and they all go, but only if the circumstances are right. Consider the discovery of the J/Ψ particle. The time was right and the background had been prepared so that when it was discovered, the particle physics community solidified around the quark model. Similarly, you can consider Galileo turning his telescope on the heavens a��s��

Tags: crucial experiment, Hooke, Philosophy of science, Pierre Duhem, Popper
Posted in Latest Posts | Comments Off on The Role of the Crucial Experiment

The Agrostic Principle

Friday, March 30th, 2012

In honour of the season.

As I drive to and from work in Vancouver, I notice that even in winter, the grass is green. In the spring, people are out fertilizing their lawns and in summer watering them (even when they are not allowed to)—mollycoddled grass! They are now even putting grass on the top of buildings. You would almost think that Vancouver exists for the benefit of grass. But it is not just Vancouver; we have wide areas of the world devoted to grass, from bamboo to grain. You would think the world was created for the benefit of grass. After all, the earth is just the right distance from the sun to allow grass to flourish. Farther from the sun, it would be cold and arid like Mars. Closer to the sun it would be hot and sterile like Venus. Thus, we have what is known in the trade as the acrostic[1] principle: the philosophical argument that observations of the physical universe must be compatible with the preferred status of grass.

As just mentioned, the earth is just at the right distance from the sun for grass to flourish. But it goes beyond that. Carbon is a major component of grass. However, the creation of carbon in stars depends critically on the existence of an excited state in carbon, known as the Hoyle state, with exactly the right energy. If that state were not there, there would be no carbon and hence no grass. The horror of it! Just think, no grass. And it all depends on having the nuclear state at just the right energy.

The Hoyle state is not the only coincidence necessary for the existence of grass. If the fundamental constants of nature, things like the fine structure constant or the gravitational constant (big G) were slightly different, the universe would not support the existence of grass. There are two solutions to this problem. One is to assume that there is an intelligent designer with an inordinate fondness for grass who fine-tuned the universe so grass could exist. Now, there is a minority opinion that it is not grass that he is fond of, but rather beetles (coleoptera) and that he only created grass as a source of feed for beetles. After all, there are the order of a million species of beetles. But as I just said, the coleopteric principle is distinctly a minority position, but we should be open minded.

The other explanation of the fine tuning of the universe is based on the idea of the multiverse. This is the idea that many different universes exist with all possible values of the physical constants and that we are in the one in which grass is possible. Again, note the preferred role of grass. The evidence for this scenario, at the present time, is no stronger than that for the existence of the coleopterophillic intelligent designer.

Now one might ask what role consciousness and intelligence have in all this. The answer to that is fairly self-evident. The main role of consciousness and intelligence is the development of civilization, and the main role of civilization is the development of agriculture. It should be obvious to even the most obtuse reader that the main purpose of agriculture is to permit grass to more effectively compete with trees. Just think of the extent to which farmers have replaced forests with grassland. The bringing of European “civilization” to North America had as its main effect, the replacement of forest with grassland. It had some unfortunate side effects, like the creation of the United States of America, but what is more important—people or grass?

As further evidence of the agrostic principle, I note that it provides the only possible explanation for the existence of golf courses and cricket pitches. The very idea of grown men or women hitting a ball with a club to prove their virility is silly. Now artificial turf may be considered as evidence against the agrostic principle, but artificial turf seems to be a passing fad. In just 13 years, between 1992 and 2005, the National Baseball League went from having half of its teams (6 of 12) using artificial turf to all of them – now up to 16 – playing on natural grass. As for football (soccer), artificial turf is widely banned. Enough said.

The agrostic principle also highlights flaws in ancient Greek philosophy. Plato believed that the “good” was contemplating his ideals or ideas. That is incorrect; the greatest good is cultivating and contemplating grass. Like Euclid’s postulates, that should be self-evident. That the smoking of grass is the greatest good is a corruption of Epicurus’s teaching. Rather, he was the first of the new atheists. The Sophists, on the other hand, where the first post-modernists and believed that it was impossible to decide if contemplating or smoking grass was the greatest good. After smoking a few joints, the latter is probably true. Socrates believed that nothing could be learned from nature. Perhaps if he had spent more time cultivating and contemplating grass, he would not have been compelled to drink hemlock. However, Aristotle may have been onto something with his final cause or teleology. Evolution shows its bareness by failing to recognize that consciousness and intelligence arose due to the teleological purpose (final cause) of helping grass compete with trees. This is probably the best example of the need for Aristotle’s final cause that can be found in nature. Unfortunately, Aristotle starting worrying about essences rather than cultivating and contemplating grass. Thus, the Greek civilization decayed. And my wife wants me to replace the lawn with a garden. The end of western civilization is in sight.

The agrostic principle has some naysayers. Douglas Adams gives the example in his Hitch-hikers Guide to the Galaxy of the puddle which observed how well it fitted the hole it was in and concluded that the hole and the universe where created expressly for its benefit. It was consequently quite surprised and distressed when it evaporated. Imagine; the gall of Adams using satire to attack the agrostic principle. Now, of course, the properties of the hole can be deduced from the properties of the puddle, but this should not be used to infer the universe was not created for the sole benefit of the puddle. Some people have followed the example of Adams’s puddle and claimed that since humans nicely fit a hole in the universe, the universe was created for their benefit (this is sometimes call the anthropic principle). These people will probably be surprised when humans go extinct. The superiority of the agrostic principle to the anthropic principle is shown by the observation that while homo spaiens have existed for about 200,000 years, grass tickled the feet of dinosaurs over sixty million years ago. And grass will probably still exist after humans have, through sheer stupidly, destroyed themselves and have been replaced by a group with less intelligence and more wisdom, perhaps the coleoptera.

Additional posts in this series will appear most Friday afternoons at 3:30 pm Vancouver time. To receive a reminder follow me on Twitter: @musquod.

[1] From the Greek word ἄγρωστις for grass.

Posted in Latest Posts | 5 Comments »

Higgs vs Popper: Falsification Falsified.

Friday, March 23rd, 2012

Finding the Higgs boson will have no epistemic value whatsoever. A provocative statement. However, if you believe that science is defined by falsification, it is a true one. Can it really be true, or is the flaw in the idea of falsification? Should we thumb our noses at Karl Popper (1902 – 1994), the philosopher who introduced the idea of falsification?

The Higgs boson, the last remaining piece of the standard model, is the object of an enormous search involving scientists from around the world. The ATLAS collaboration alone has 3000 participants from 174 institutions in 38 different countries. Can only the failure of this search be significant? Should we send out condolence letters if the Higgs boson is found? Were the Nobel prizes for the W and Z bosons a mistake?

Imre Lakatos (1922 – 1974), a neo-falsificationist and follower of Popper, states it very cleanly and emphatically:

But, as many skeptics pointed out, rival theories are always indefinitely many and therefore the proving power of experiment vanishes. One cannot learn from experience about the truth of any scientific theory, only at best about it falsehood: confirming instances have no epistemic value whatsoever (emphasis in the original).

Yipes! What is going on? Can this actually be true? No! To see the flaw in Lakatos’s argument, let’s consider an avian metaphor—this time Cygnus not Corvus. Consider the statement: All swans are white. (Here we go again.) Before 1492, Europeans would have considered this a valid statement. All the swans they had seen were white. Then Europeans started exploring North America. Again, the swans were white. Then they went on to South America and found swans with black necks (Cygnus melancoryphus) and finally to Australia where the swans are black (Cygnus atratus). By the standards of the falsificationist, nothing was learned when white swans were found, but only when the black swans or partially black swans were found. With all due respect, or lack of same, that is nonsense. It is the same old problem: you ask a stupid question you get a stupid answer. Did we learn anything when white swans were found in North America? Yes. We learned that there were swans in North America and that they were white. Based on having white swans in Europe, we could not deduce the colour of swans in North America or even that they existed. In Australia, we learned that swans existed there and were black. Thus, we learned a similar amount of information in both cases—really nothing more or nothing less. The useful question is not, ‘Are all swans white?’ Rather, ‘On which continents do swans exist and what color are they on each continent?’

Moving on from birds to model cars (after all, the standard model of particle physics is a model). What can we learn about a model car? Certainly, not if it is correct. Models are never an exact reproduction of reality. But, we can ask, ‘Which part the car is correctly described by the model? Is it the color? Is it the shape of the head lights or bumper?’ The same type of question applies to models in science. The question is not, ‘Is the standard model of particle physics correct?’ We knew from its inception that it is not the answer to the ultimate question about life, the universe and everything. The answer to that is 42 (Deep Thought, from The Hitchhiker’s Guide to the Galaxy by Douglas Adams). We also know that the standard model is incomplete because it does not include gravity. Thus, the question never was, ‘Is this model correct?’ Rather, ‘What range of phenomena does it usefully describe?’ It has long history of successful predictions and collates a lot of data. So, like the model car, it captures some aspect of reality, but not all.

Finding the Higgs boson helps define what part of reality the standard model describes. It tells us that the standard model still describes reality at the energy scale corresponding to the mass of the Higgs boson. But, it also tells us more: It tells us that the mechanism for electroweak symmetry break –a fundamental part of the model—is adequately described by the mechanism that Peter Higgs (and others) proposed and not some more complex and exotic mechanism.

The quote from Lakatos, given above, misses a very important aspect of science–parsimony. The ambiguity noted there is eliminated by the appeal to simplicity. The standard model of particle physics describes a wide range of experimental observations. Philosophers call this phenomenological adequacy. But a lot of other models are phenomenologically adequate. The literature is filled with extensions to the standard model that agree with the standard model where the standard model has been experimentally tested. They disagree elsewhere, usually at higher energy. Why do we prefer the standard model to these pretenders? Simplicity and only simplicity. And the standard model will reign supreme until one of the more complicated pretenders is demonstrated to be more phenomenolgically adequate. In the meantime, I will be a heretic and proclaim that finding the Higgs boson would indeed confirm the standard model. Popper, Lakatos, and the falsificationists be damned.

Additional posts in this series will appear most Friday afternoons at 3:30 pm Vancouver time. To receive a reminder follow me on Twitter: @musquod.

Tags: falsification, Higgs boson, Lakatos, philosphy of science
Posted in Latest Posts | 17 Comments »

The Raven Paradox and the Flaw in Verification

Friday, March 16th, 2012

One of the more interesting little conundrums in understanding science is the raven paradox. It was proposed by Carl Hempel (1905 –1997) in the 1940s. Consider the statement: All ravens are black. In strict logical terms, this statement is equivalent to: Everything that is not black is not a raven. To verify the first we look for ravens that are black. To verify the latter we look for coloured objects that are not ravens. Thus finding a red (not black) apple (not raven) confirms that: Everything that is not black is not a raven, and hence that: all ravens are black. Seems strange: to learn about the colour of birds, we study a basket of fruit.

While the two statements may be equivalent for ravens, they are not equivalent for snarks. The statement: Everything that is not black is not a snark, is trivially true since snarks do not exist, except in Lewis Carroll’s imagination. However, the statement: All snarks are black, is rather meaningless since snarks of any colour do not exist (boojums are another matter). Hence, the equivalence of the two statements in the first paragraph relies on the hypothesis that ravens do exist.

One resolution of the paradox is referred to as the Bayesian solution. The ratio of ravens to non-black objects is as near to zero as makes no difference. Thus finding 20 black ravens is more significant than find 20 non-black, non-ravens. You have sampled a much larger fraction of the objects of interest. While it is not possible to check a significant fraction of non-black objects in the universe, it may be possible to check a significant faction of ravens, at least those which are currently alive.

But the real solution to the problem seems to me to lie in different direction. Finding a red apple confirms not only that all ravens are black but also that all ravens are green, or chartreuse, or even my daughter’s favorite colour, pink. The problem is that a given observation can confirm or support many different, and possibly contradictory, models. What we do in science is compare models and see which is better. We grade on a relative, not absolute scale. To quote Sir Carl Popper:

And we have learnt not to be disappointed any longer if our scientific theories are overthrown; for we can, in most cases, determine with great confidence which of any two theories is the better one. We can therefore know that we are making progress; and it is this knowledge that to most of us atones for the loss of the illusion of finality and certainty.

We do not want to know if: All ravens are black is true but rather if the statement all ravens are black is more accurate than the statement all ravens are green. A red apple confirms both statements, while a green apple confirms one and is neutral about the other. Thus the relative validity of the two statements cannot be checked by studying apples, but only by studying ravens to see what colour they are. Thus, the idea of comparing models leads to the intuitive result. Whereas, thinking in terms of absolute validity, leads to nonsense: Here, check this stone to see if ravens are black. Crack, tinkle (sound of broken glass as stone misses raven and goes through neighbor’s window)

We can go farther. Consider the two statements: All ravens are black, and Some ravens are not black. The relative validity of these two statements cannot be checked by studying apples or even black ravens. Rather what is needed is a non-black raven. This is just the idea of falsification. Hence, falsification is just a special case of comparing models: A is correct, A is not correct.

In practice, all ravens are not black. There are purported instances of white ravens. Google says so and Google is never wrong. Right? Thus, we have the statement: Most ravens are black. This statement does not imply anything about non-black objects; they may or may not be ravens. Curious… this whole raven paradox was based on a false statement and as with: All ravens are black, most absolute statements are false, or at least, not known for certain.

Even non-absolute statements can lead to trouble. Consider: Most ravens are black, and: Most raven are green. So we merrily check ravens to see which is correct. But is it not possible that the green ravens blend in so well with the green foliage that we are not aware that they are there? Rather like the elephants in the kid’s joke that paint their toe nails red so they can hide in cherry trees. Works like charm. Who has seen an elephant in a cherry tree? We are back to the Duhem-Quine thesis that no idea can be checked in isolation. Ugh. So, why do we dismiss the idea of perfectly camouflaged green ravens and red-nailed elephants? Like any good conspiracy theory, they can only be eliminated by an appeal to simplicity. We eliminate the perfectly camouflaged green raven by parsimony, and as for the red apple, I ate it for lunch.

Additional posts in this series will appear most Friday afternoons at 3:30 pm Vancouver time. To receive a reminder follow me on Twitter: @musquod.

Tags: falsification, philosphy of science, the raven paradox, verification
Posted in Latest Posts | 4 Comments »

The Accumulative Nature of Science

Friday, March 9th, 2012

Is science accumulative? Is the Pope a Catholic? Some things are truly self-evident. The accumulative nature of science is one of them. But the different ways science is accumulative does hold some surprises. Consider home improvement. We can add onto the top, build out from the side, fix the broken window, or build down from the foundations. Science is accumulative in all these directions. Think of classical mechanics and planetary motion. After Isaac Newton (1642 – 1727) introduced his three law of motion, various people, most notably Joseph-Louis Lagrange (1736 – 1813) and William Hamilton (1805 – 1865), developed more mathematically sophisticated treatments of classical motion. They used Newton’s work as a starting point and built new stories onto the superstructure. Pierre-Simon Laplace (1749 – 1827) added onto Newton’s work in other ways. He found an error in Newton’s calculation of planetary stability and added the nebular hypothesis to describe the origin of the solar system. The first of these corrected the structure Newton had built—replaced the broken window if you like—while the second, the nebular hypothesis, added a new room on the side. It extended Newton’s ideas beyond where they were originally applied. The discovery of Uranus by William Herschel (1738 – 1822) can also be considered a sidewise extension to planetary system; the discovery left the original work intact but extended it outward.

These advances all left the paradigm of classical mechanics intact but built on the foundation Newton had laid. But quantum mechanics was a whole different story. It left the superstructure intact but changed the foundation; like the magician’s trick of pulling the table cloth off the table while leaving the dishes in place. The advent of quantum mechanics did not require the recalculation of planetary orbits. The work of Newton, Laplace, Lagrange, and Hamilton could still be applied as before but only to a fixed range of phenomena. Quantum mechanics kept all the successes of classical mechanics, but put it on a new foundation.

Now, quantum mechanics frequently is seen as a complete overthrow of classical mechanics and if you are looking at the metaphysics, that is true. However, no one should take metaphysics seriously anyway. From the point of view of the person calculating planetary orbits, nothing changed when Schrodinger introduced his eponymous equation. Schrodinger built on the work of Hamilton just as much as Hamilton built on the work of Newton. (Quantum mechanics is built on Hamilton’s formulation of classical mechanics.) Whereas Hamilton added to the superstructure, Schrodinger helped replace the foundation. Both added to the existing structure rather than demolishing it, and the smoke went up the chimney just the same[1]. Or rather, the planets went round the sun just the same.

Replacing the foundation is largely synonymous with Thomas Kuhn’s idea of paradigm change. This is the reductionists dream and the foundations in various fields of science are indeed frequently replaced: quantum gravity will replace quantum field theory, which replaced quantum mechanics, which in turn replaced classical mechanics. But only the foundation was replaced, the superstructure was left intact. A similar process happened with this sequence: indivisible atoms, atom structure, nuclear structure, nucleon structure, and the standard model.

Thus, we see how science advances: fixing errors (Laplace), refining formalisms (Hamilton, Lagrange), extending to new areas (Laplace, Herschel), and replacing the foundations (Schrodinger). But these are all extensions to the existing knowledge. When we forget this, mistakes are made. When quantum chromodynamics was introduced, it changed the foundation of nuclear physics, but left most of the previous understanding of nuclear physics intact. The overzealous proponents of the quantum chromodynamics did not understand this and claimed that nuclear physics would have to be largely redone. But that was nonsense; we made a few minor changes and carried on. Science is amazing in that it can easily change the foundation without major damage to the superstructure. Try doing that with a sky scraper or even a two story house.

The reason this all works is that science is modular, with fairly well defined interfaces between the models. Consider chemistry. At one side, quantum chemistry is closely related to physics and share a common formalism: quantum mechanics. In the middle, chemistry developed independently of physics and did not depend on the quantum chemistry foundation. But then, parts of biology and applied science use chemistry as a foundation to build on; interlinked but each progressing separately.

So science oozes onwards in all directions: upward, downward, sideways, and inward. It discards what is no longer useful—yet, for the most part, the older models provide the scaffolding to support the new, and the more recent insights are obtained without destroying the older ones. And science unfolds as it should, building knowledge one room at a time.

Additional posts in this series will appear most Friday afternoons at 3:30 pm Vancouver time. To receive a reminder follow me on Twitter: @musquod.

[1] From a children’s song by Fred Chandler, 1901.

Tags: Philosophy of science
Posted in Latest Posts | 3 Comments »

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Latest Posts

Byron Jennings | TRIUMF | Canada

Search:

Blogs

People

Laboratories

Latest Posts

Follow

A project of the Interaction Collaboration

Blogroll