Thursday, February 28, 2008

Control Over Experiments - Analysis

Another hint about the defects of physics can be found in its reliance on the reasoning technique called "analysis." Analysis means that you solve problems by breaking them into pieces, and then handle the pieces one by one, or perhaps even break the pieces into smaller pieces, and so on. This approach is a key reasoning skill: any time you make a list you are probably performing analysis, and any time you count a group of things you have probably already done some analysis. What is strange is that physics relies so heavily, almost exclusively, on analysis. When trying to understand an object, material, phenomenon, etc., we start by trying to figure out what are its pieces and the rules governing their movements, and then based on the pieces we begin to reason about the behavior of the whole. For example, the solar system is conveniently broken into planets, asteroids, and the sun. Ceramics and metals may be understood as crystals packed against each other, or as large collections of atoms. Animals can be broken into collections of muscles, bones, and organs, or alternatively into cells, or alternatively into the building blocks of cells including the nucleus, DNA, cell wall, cell skeleton, etc. And any material as well as any force can be understood as "particles" - electrons, photons, gluons, quarks, etc. This sort of breaking things down - analysis - is always the starting point for physics. We will see later in this blog that matter and forces are not the only things physicists like to analyze - we also want to take apart time, space, and anything else we can think of. This attitude carries over into all of modern society; for instance analysis is at the root of how our workplace is organized, with many different specialties and degrees and professions and experts, so that one person knows how to solve one sort of problem and another person knows another sort of problem, and the general hope is that if we have enough specialists and if we train and pay them well enough then everything will come together into a great society.

Of course analysis has its limits. It's only one tool in the human toolbox. Almost every human activity, intellectual or not, involves breathtaking leaps far beyond the reaches of analysis. Following a path through the woods, writing a paragraph, figuring out whether a stranger is a friend or an enemy, tying your shoe, judging the beauty of a landscape, finding a concord with others, learning new ways of thinking - these may involve some element of analysis, some thinking about pieces and lists - but they go far beyond what analysis can do by itself. For instance, we are able to perceive a whole object, and make judgements about it, without consciously thinking about its pieces, and often enough we don't even know its parts. And organizations and societies based purely on specialization wouldn't get very far either - we all know where that would go: a lot of passing the buck when a problem doesn't fit into any particular specialist's competency, or when a new problem comes up, a lot of stereotyping, lack of humanity and compassion, bureaucrats not leaders, people falling through the cracks, and both big and small crimes against human dignity. The only way that our society functions is because a lot of people step outside of narrowly defined roles and let the buck stop with them: most importantly parents all of whom are jacks-of-all-trades for their children and and spouses, but also people in the workplace who do what it takes to make things work, secretaries who fill in wherever the specialists don't, those who truly innovate, those in politics who are truly not satisfied with the status quo.

What I'm saying is that analysis, by itself, gives a very incomplete vision of life and a very limited ability to understand or adapt to it. While physics doesn't rely exclusively on analysis, it is so focused on a component-wise view of the world that its vision is skewed substantially, and many things are just outside of physics' possibilities - for instance questions like communication between persons, beauty, ethics, etc. Consider the knowledge you might get by smashing a vase on the ground and looking at the fragments. That's a whole different ball game than what you will learn from looking at the vase's beauty, or its symbolism, or the functional experience of using the vase, or considering its place in artistic history, or in the culture, or as an expression of the particular artist. Not to mention just looking at the vase, touching it, smelling it. The knowlege physics gives us is often a lot more like the knowledge obtained by smashing the vase than like any of the others.

Analyzing something implies that you have a lot of power over it. You are taking it apart, either mentally, or in real life. Something that you can take apart is very much at your mercy. Moreover it is not your equal; it is subject to to you, and does not receive your full respect. You probably feel free to manipulate, modify, use, and discard it as you wish. For instance, if have an egg, you may wish to separate the yolk from the egg white and perhaps throw one away, or scramble them together, or leave them as is. Similarly, if you take an analytic approach to the earth then you may wish to dig up certain "valuable" parts of it, often destroying much more in the process. Even with human beings an analytic approach - whether in terms of organs and arteries and hormones, or in terms of psychological drives and hangups and instincts - is always accompanied by temptations to disrespect, toward forgetting that the person in front of you is far more than you could ever begin to discover by these analytical approaches. You may begin to think that you know more about the person you're analyzing than they do themselves, or that you should "fix" them, or find yourself reluctant to take to heart their opinions about yourself or others, their recommendations to you, and their wishes even about their own lives.

In other words, analysis is an inherently aggressive kind of reasoning, that runs hand in hand with power and control. Even the words that define analysis are telling: dividing something up, pieces, parts, taking something apart, breaking it apart, etc. All of these phrases have connotations of control, power, division, even destruction. If analysis is actually carried out physically then the object being analyzed ceases to exist for the duration of the analytic procedure. If we do not or can not put it back together then the analysis was the same as destruction. The sort of knowledge that can only be bought at the price destroying the thing known is very strange indeed. Have we really learned anything about the object that was destroyed?

As a matter of fact physics experiments often do destroy the things being measured. We need only think of the accelerators and colliders used to study high energy particle physics - the whole point of these experimental devices is to destroy atomic nuclei by hitting them with various things, and then see what fragments come out of the collision. This is physics' main way of finding out about atomic nuclei, and it involves the total destruction of the nuclei concerned.

While the collision experiments of particle physics are the natural end point of the analytic method, there are many other experimental techniques that cause permanent alterations to the thing being studied. Many observation techniques are based on throwing things at the object under study (this is called bombardment, another aggressive word) and seeing what happens. In some experiments the typical outcome is only that what is thrown just bounces off and you learn from how it bounces - this is what happens when you look through a microscope: you are seeing light that has bounced off of the thing you're studying. However in quite a few other experiments the bombardment process breaks things off of the thing under study, or makes cracks and other defects in it, etc, and then you learn from the debris and defects. Still other experiments take apart methodically the object under study rather than colliding it. Or perhaps a piece is removed (added, substituted) from the studied object, and then you observe changes in its behavior. In all these cases knowledge is obtained only at the cost of substantially changing or even destroying the object of study.

The physicist's theoretical understanding of nature always involves an analysis of things into their components, and physics experiments often are also analytical, even destroying the thing under study. While analysis is an important tool for solving problems and understanding things, it is particularly aggressive, based on our power to manipulate, and often ending in the destruction of the thing being analyzed. Analysis dovetails very well with physics' passion for experimental control, for being able to get nature to do the same thing, over and over again, on demand. Like magicians we are interested in power over nature, but unlike them we want only the power that works on demand for anyone who does the right manipulations. This focus on total control and power means that we who drink from the well of natural philosophy drink tainted water. We really need the water from that well, but unless we carefully watch and control its side effects, we should not be surprised by when we fall sick. The seeds of the abuses and horrors of this age, especially of destruction of the environment and manipulation of human beings, are part and parcel of natural philosophy.

Control Over Experiments - Alchemy

Just to be clear about where we are right now (!), we are still in the introductory phase of this blog, discussing the second of three ways that "natural philosophy" - physics and by extension the other hard sciences - differ decisively from its progenitor, philosophy. The first difference was an emphasis on experimental verification. The second difference, which we are discussing now, is restriction of our attention to experiments which are repeatable at will (under our control), accompanied by standards for "scientific truth." The third difference we will discuss later is physics' emphasis on numbers. But before we get there we will spend some more time on difference number two, experimental control.

A few blogs ago I listed a number of deficiencies in arguments that have been used to wash physics' hands entirely of all responsibility for the abuses of power over people and nature which have arisen in modern times. On the other hand, physics and indeed all the sciences have an inherent value and must not be abandoned even though they contain certain built-in defects. The only way forward therefore is to get to know physics' defects better, which in my opinion have a lot to do with experimental control, and its close connection with power.

I will give some examples of what is suspicious about physics, with the goal of providing an intuition rather than providing a water tight argument. It is noteworthy that some of the first natural philosophers were alchemists, a type of magician dedicated to changing ordinary materials to gold. They were just like pirates except that they wanted even more power than pirates do - they wanted to shape reality itself, remake nature in their own image. They had no respect for nature, claiming that certain substances were "base" and others "noble." Perhaps the only thing different today is that we (secretly or not so secretly) feel that all atoms are "base", now completely in our power to understand, predict, isolate, mix, move, tweak, and rip apart, and therefore simply mere atoms.

The Defects of Physics

I submit to you my reader that physics and indeed all the sciences contain certain built-in defects which are at the source of the abuses of power over people and nature which have arisen in modern times. Shortly we'll start trying to get to know physics' defects better, which in my opinion have a lot to do with experimental control, and its close connection with power. But first I want to clarify the big picture; here I go: Physics is good, but it has certain defects. Physics can do and already has done tremendous good for us, but if its thinking and results are embraced with naive enthusiasm, without discernment, then our own thinking and heart and actions can be distorted by physics' defects. Perhaps it would be fairer to say that there can be a vicious cycle where the shadows in the human heart and the defects of physics amplify each other. At each stage in the vicious cycle we become both crazier and more dangerous. The results have already been catastrophic for both the human race and the environment.

A few analogies may be helpful to understand my point on a more visceral level. The first is from nutrition: starchy foods are very good for us, the staple food of the human race. But if I eat only starch then I will get very sick and perhaps die. The starch must be eaten discerningly, mixed with other things. Another analogy is that of a tainted well: the water is absolutely necessary for life, but if you don't filter it you will eventually sicken. If the impurity is lead, then the tainted water will actually taste sweeter than the healthy water. Physics is like that.

I don't think that the filtering, discernment, or nutritional supplements can come from physics itself. Physics' weaknesses come from a sort of tunnel vision associated with its starting goals, passion, and identity. You have to be able to see outside the tunnel, take a step away from physics' focus, find a balance, and let physics find its correct place instead of taking over.

Control Over Experiments - Reaffirming the Value of Physics

I think it is clear that natural philosophy, physics, experiments, and science in general have their value. It is good to learn about nature, to understand it, even just to admire it - and we certain see nature with more detail and precision, and understand it better, than we did four centuries ago. Experiments and emphasis on reproducible scientific knowledge have made important contributions to the human race. Our possibilities individually and as a race have been considerably altered through the mass production of various technological devices, and natural philosophy is certainly one of the springs feeding the technological river.

Control Over Experiments - Is Physics Innocent?

There are several deficiencies in the arguments which have been used to wash physics' hands entirely of all responsibility for the abuses of power over people and nature which have arisen in modern times. Those arguing for the innocence of the scientific method emphasize science's search for knowledge, and make a sharp distinction between those searching for knowledge (scientists) and those using it (everyone else.) There are other very significant deficiencies: (a) A lot more time and excitement is given to knowledge per se than to nature, almost as if nature itself were less interesting than our ideas about it. (b) Faith in Progress (advances of science, discovery, technology, paradigm shifts, frontiers) - faith that progress is happening, that science is (the) key for carrying it forward, that progress is a good in and of itself, and that progress is sure (the provisos vary) to help the human race ("quality of life".) (c) A tendency to take full credit for the glory of the modern age while downplaying the broken-ness and horrors. (d) Underemphasis, lip service to, or neglect of the liberal arts, humanistic, religious, and social values, as if science were the cornerstone of all learning and intellectual pursuits. (e) A very simplified and even neutered perception of nature. (I remember an intelligent colleague arguing at length that animated movies are steadily looking more and more like real life, and that pretty soon it will be impossible to tell the difference between an animated movie and a filmed one! One glance out my window at the snow melting off winter trees is enough to disprove that thesis.) There can also be a tendency to accuse anyone with a less black and white attitude of being anti-science.

Control Over Experiments - Respect For Nature?

Physicists are saying to nature "Surprise me, tell me something more about yourself, but do it while following these rules." (If you were asked for the same question, how much would you tell?) And the surprise that nature gives us, the gift of new knowledge - it then becomes "ours," and gives us new power over nature. At least one writer compares scientific experiment to "putting nature on the rack" to force her to divulge her secrets. It is possible to pursue the scientific endeavour in a way that really respects and treasures the nature that is being studied, but for many researchers the attitude has been more a pursuit of dominance, an effort to conquer nature and bend her to our will. If the truth be told all too many individual scientists, like so many other hard workers in today's competitive economy, are obsessed with their own personal success, and nature is their tool for getting there. This tendency is magnified by the current alignment between the scientific community and the power centers of government, business, consumer markets, and military machines.

If there is an analogy between love and the experimentalist's attentive observation of the world (as I claimed earlier in this blog), this analogy has its limits, because all too often the end result has been something that looks a lot more like rape than like peaceful harmony. In the small it looks like plastic wrappers in the trash and children and old people alike wasting away in front of TVs; in the large it looks like a planet whose species are devastated, whose hidden treasures are excavated, pumped, and burned, and whose peoples destroy and enslave each other with the most advanced technologies.

Is this tendency for science to result in the abuse of persons and of the environment something external to physics (as many scientists would like to think) or built into physics from its very foundations?

Control Over Experiments - How It Restricts Physics' Vision

So at one level there is no conflict between a physicist's emphasis on repeatable experiments and her interest in being surprised, proved wrong, and forced to learn something new. But this conflict is resolved only at the expense of a restriction of the scientific field of vision, confining one's attention to those things that one can make happen over and over again, at will - i.e. things that are under one's own control. And the fact is that most matters of interest, and those of greatest interest, are not repeatable at all, and would be destroyed by efforts to control them in the way demanded by natural philosophy. Foremost are of course people - each person on this planet is unrepeatable, with his or her own innate dignity, personality, history, will, and feelings. There is no question of repeating a person's intrinsic being, history, or choices, even considering issues of identical twins and cloning. Attempts to control or repeat a person's choices and personality, whether to obtain scientific reproducibility or for any other reason, would be essentially disrespectful and immoral, and if successful would destroy the person in question. Clearly "scientific truth" is very small (not insignificant, just small) compared to the total of what is important and true. For instance, the questions of whether Alison Hinckley down the street is happy, the success of her marriage, her love or neglect of her parents, how she deals with suffering and death of others and in her own life - none of these are the province of scientific truth. Yet these are things of real import.

Control Over Experiments - Why Repeat?

You might conclude that running an experiment for the second or third time is boring and produces no new information. That's not so. The only way to figure out whether a particular result really is scientific truth is by repeating experiments, in different places and times, with different equipment and measurement devices, under the guidance of different scientists. But beyond the effort of obtaining scientific "certainty" one may also find out new things. It is always possible that the original experiment was influenced by something that the experimentalist was not aware of, so repeating the experiment may reveal the need for more a more precise statement of the experimental set up. (For instance, minute impurities in water can cause large changes in its resistance to electricity. Pure water is not a good conductor. If two measurements of water's conductivity give different values, this may reflect need for more control over the water's impurities rather than a fundamental scientific inacuracy.) Repeating an experiment may bring these set up issues to light, as one goes through a trial and error struggle to reproduce the original result.

In addition, even if the first experiment's outcome was observed correctly, the mechanisms which produced that outcome may have been misunderstood. Repetition with differently constructed experimental setups, or with a variety of measuring methods, gives evidence for a robust understanding of how the experiment works. Conversely, a different result obtained using slightly different equipment may be the first step toward a deeper understanding of what's going on.

Control Over Experiments and Scientific Truth

Earlier I said that experiments involve careful observation of nature, trying to see it very accurately, with the overall hope of learning something new and surprising. I also emphasized the fact that nature is external to oneself and not totally under one's own power. Therefore it may seem incongruous that physicists seek experiments that can be repeated at will, under total control.

On one level there is no contradiction: we create experiments that can be repeated - however the first time we run the experiment we are in suspense about what will actually be observed. The certainty and repeatability is in our preparation of the experiment; the surprise is in the experiment's actual outcome, the details or whole of which may be different than expected.

The point of having totally repeatable control over an experiment is that the experiment's outcome should be exactly the same every time it is performed. Once an experiment is done once, the surprises should be over, and further repetitions of the experiment only serve to verify the scientific truth of the original result. In fact the only "truth" that physicists care to recognize while acting as physicists is those observations that can be repeated experimentally, as well as any mathematical techniques whose predictions have been repeatedly checked experimentally. If you repeat an experiment and obtain a different result than what was originally found, this casts doubt on whether the original result actually was "scientific truth."

For instance, the failure by many to reproduce cold fusion is said to have "discredited" the original experiment which observed cold fusion, leading most physicists to think that probably cold fusion did not occur even in the original experiment. Of course it is possible that fusion actually occurred the first time but not other times - but even if this were true it would not be a "scientific truth," simply because it can not be reproduced on demand by everyone. The only ways to establish the truth or falsity of this possibility would be similar to the procedures used when investigating and judging a crime - collection of historical evidence about the equipment that was used in the first cold fusion experiment and the data that was obtained, rethinking how to interpret all that was observed, judgments about the trustworthiness of the scientists, etc. There may also be reasoning based on currently accepted ideas of how the universe works, and efforts to establish whether or not these ideas indicate any possible way that fusion might have happened in the first cold fusion experiment. In any case, the result of this sort of process would not be "scientific truth," simply because it would be confining itself to a particular time, place, and set of scientists and observations. Physics does not deny the the possibility of truths of a particular, non-repeatable nature - the shape of a particular rock, the sound of a specific person's voice, etc. - but neither does it pay much attention to these things.

Sunday, February 17, 2008

Control Over Experiments - Hard Sciences vs. Soft Science

It is precisely this repeatability by anybody, at any time, as many times as desired, and under perfect control, that physicists prize in their experiments and consider to be the hallmark of "scientific truth." Conversely, if something does not meet these standards, then we refuse to think about it or discuss it, at least not as physics per se. We leave these questions to other disciplines, and we uses the words "hard" vs. "soft" to describe how well a discipline conforms to the scientific ideals of repeatability and control, with physics on the "hard" end of the spectrum. ("Hard" vs. "soft" has nothing to do with how difficult the fields actually are.) For instance, astronomy has the problem that the stars are not under our control and we can not make them repeat their behavior; however if ten astronomers look at the same star at ten different times they will almost certainly see the same thing, which is a sort of repeatability. There is also a statistical repeatability in astronomy: picking a thousand stars at random, you always find roughly the same number of red giants, white dwarfs, Sun-type stars, etc. So astronomy is not as "hard" a science as physics; we can also say that it is a "softer" science than physics, which means the same thing. Going softer, one can speak of sociology, the study of large groups of people. From a scientific point of view this is worse: not only are world's people out of the scientist's control, but their actions, demographics, characteristics, opinions, etc. change from year to year and even day to day. The only sort of repeatability a sociologist can hope for is by running two or more similar measurements/surveys/censuses at roughly the same time. Softer yet would be psychology/psychiatry, where one finds a few things which recur, like the addict's acquired physical dependence on drugs, or oedipal complexes, but these recurring elements occur in a multitude of variations unique to each subject and constitute only a small portion of the overall field of study.

Then there are many fields which are not properly science at all. Most of these have their roots decidedly outside of philosophy, and emphasize the practical or functional side of things: law, engineering, the arts, history, accounting, etc. These are often called professions. However there are at least three disciplines which are rooted in philosophy and therefore are not in the same class as the practical professions, but are not science either. One is philosophy itself, which has parted ways from natural philosophy by steering away from experiment. Another discipline is theology, which is rooted in philosophy and does emphasize very careful attention and thought about the world around us, but focuses on unrepeatable aspects of that world, namely persons and what they do, say, and write. If natural philosophy is the philosophy of repeatable things, theology is the philosophy of unrepeatable things, of persons. A third philosophical but non-scientific discipline is mathematics, which concerns certain results which can be reproduced on demand, but which are not part of the physical observable world.

Of course a lot of times there is a secret to repeating something; you have to figure out all the necessary preconditions. Finding out how to make something repeat can be part of hard science. For instance a few years ago someone reported observing a fusion reaction occurring fairly slowly, in smallish laboratory. Previously fusion had been observed only in the sun, thermonuclear bombs, and large experiments involving very large amounts of energy and heat, so the new observation was very exciting. Over the next years many many physicists spent a lot of time trying to make fusion happen in their own labs, using similar equipment. Some report that they found evidence for cold fusion, though their evidence was pretty subtle, the sort that requires very special measurement equipment, quite far from nuclear explosions. However many physicists failed entirely to reproduce cold fusion, and this happened so often that the scientific community as a whole remains sceptical of those who continue to report cold fusion in their labs. So here we see that the question - is cold fusion repeatable on demand? - is a valid question for physics. However as it became clear that many skilled researchers are unable to reproduce the original result, cold fusion moved out of the domain of hard science, and the physics community stopped thinking about it. If someday in the future someone did figure out a recipe for reproducing cold fusion on demand, then suddenly it would become again a physics question.

Saturday, February 16, 2008

Control Over Experiments

We started out by introducing philosophy, and then saying that natural philosophy (physics) made a break from other philosophy by emphasizing three things: scientific experiments, control over experiments, and numbers. We have just finished discussing scientific experiments, which involve a real attentive observation of nature and readiness to be both surprised and wrong, which has some similarities to love between people. However the analogy to loving relationships is not complete,: the second major characteristic of natural philosophy (physics) is its emphasis on repeatability and total control.

Natural philosophers restrict their inquiries and do not study a lot of things, saying by definition that many things are just not their problem. This may come as a surprise to many who understand that science gives explanations of everything and considers the whole world as its domain. This is not really true: scientists restrict themselves to studying things that they can repeat at will, things that they can make happen over and over again, and that their colleagues can duplicate. For instance, if I fill a balloon with cold air and then heat it, the balloon will grow bigger. I can repeat this many times with many balloons, and it will never happen that heating the balloon would make it shrink. Moreover my friends, my neighbors, and even you my reader can fill balloons and heat them and observe the same behavior. The balloons are fully under our control: we can keep them at a particular temperature as long as we like, and measure their size, temperature, composition, etc.

Experimental Verification - Summary

To sum up about scientific experiments, I think you have to really love the nature that you're trying to learn about and the tools that help you learn. Day to day it may not feel like love, and I don't know too many physicists who talk about being in love with nature, but the sort of attention and care given the experimental process, as well as the interest or even excitement about what is learned, is similar to the sort of attentiveness and long term dedication that one finds in certain loves between people. I choose to compare the experimental attitude to love between people rather than love for a skill or hobby, because a good experimentalist has his attention fixed on something outside of himself, rather than on his own activity. Also an experimentalist is deliberately interacting with something that may or may not do what he wants, that can surprise, that needs to be coaxed, and that is hard to understand. Unlike a profession there is no roadmap, instead one is somehow waiting on, listening, and even vulnerable.

Friday, February 15, 2008

Misconceptions about Scientific Experiments

I am afraid that the reader has quietly read the last paragraphs about experiments but still hasn't begun to rethink his ideas of what a scientific experiment is. I taught physics laboratory - pretty intensive with four hour labs once a week - and after fifteen labs the students were just beginning to let go of their misconceptions about the scientific method. So now I want to address three popular misconceptions straight on.

The first misconception is just the popular meaning of the word "experiment." "I experimented with adding nutmeg to the pancakes." "He experimented with drugs." In everyday usage "experiment" means doing something new in hope of obtaining some improvement. Often one doesn't know ahead of time what improvement may be obtained, except perhaps in very general intuitive terms, and in fact one often hopes for a surprise. Along the same lines, we could say that early humans experimented with eating various substances, domesticating animals, and sowing seeds; this was long before natural philosophers and has little to do them. Experimentation in this sense belongs instead to the normal range of activities centered on "getting things done" which I contrasted earlier (link) with philosophy. It is oriented toward results, and at a deeper level it is oriented toward human beings and their interests.

In contrast, scientific experimentation is oriented away from ourselves, toward nature, toward observing nature as it is. Compared to normal experimentation, scientific experimentation involves a lot more planning attention to observing what happens during the experiment or what is produced by it. Experimental scientists spend their entire careers inventing and refining new tools and techniques for observing things - seeing them more clearly, more accurately, with more detail, and extending the range of observation. The observational procedures and tools are checked and rechecked in meticulous detail, calibrated, refined, rebuilt, all to ascertain that the new vision the produce is real and not just fancy or mirages. While readying a new experimental tool one plans exactly how to use it, what to measure, so that afterwards one can check and rethink whether your observational procedure really did what you thought it was doing. Also one writes out in detail one's expectations about the results of the observation, in order to be able to contrast one's expectations with the actual observation. It is well known that humans are much better at noticing things that change than things that stay the same, so writing out our expectations ahead of time improves our observational abilities.

A second misconception about scientific experiments comes from our "experiments" in school laboratories. One is given some materials (wire, chemicals, roller carts, etc.), some measurement devices (electrical meters, microscopes, rulers, etc.,) and instructions about about what to do with them. The instructions typically require reading and recording one or more numbers, computing something based on those numbers, and then reporting the results of your computation. The emphasis is on following a procedure and producing some desired numbers.

In one way these school laboratories do teach something about scientific experimentation: depending on the lab format, the students may be encouraged to encounter and manipulate objects, perhaps even with some care and attention, and will typically be asked to use at least one number to describe the "outcome" of the experiment. However these labs can also give entirely the wrong impression. Probably their single biggest defect is that they focus on procedure more than observation. I would like to see labs where the students are taught to observe and think clearly about everything before them, to really see the wires and chemicals, sense them, measure everything about them and then measure everything about the measurement devices. A scientist doing an experiment is really interested in the thing she is measuring, and wants to know everything about it, and finally to understand it. She won't be content with a single number, or a hundred numbers. Preliminary studies of a newly encountered material or phenomenon usually involve many different measuring instruments, each producing large quantities of information. A large part of a scientist's life is sorting through the information, checking it and the way it was produced, processing it, piecing it together to get a full vision of the thing being observed. The end results may be in a synthetic summary form, or may highlight the most striking information, but this conciseness belies the care that has been taken to observe as much as possible, as comprehensively as possible. A good scientist really wants to get know what she is measuring, through and through.

Of course this is not an innate skill: if you tell a typical student that you want him to understand everything about a particular experiment including the measurement apparatus, he will look at it for some minutes, maybe measure a couple of things, write down a few sentences and numbers, and be done. The observational skills, and curiosity to think of things to measure, are not built in. Neither is the ability to check one's own measuring devices and procedures and invent and refine new measurement procedures as necessary. So I haven't figured out yet exactly how to make a school laboratory that really duplicates the experience of a scientific experiment. Probably the best one can do is to help the student to grow in the right direction, beyond procedures and a few numbers toward real observation and real care for what is being observed.

The third misconception about scientific experiments is exemplified in movies, where the scientist spends some time and effort, builds a new device or something, and tada! she discovers a new thing. It's presented almost as a guarantee: tinker around some, build something strange and new, and then - guaranteed! - you'll make a Discovery! I sometimes get the same feeling when we talk about national spending on research - spend x billion dollars and you'll get a proportionate return in discoveries. It's as if you could build science factories: build twice as many factories and you'll get twice as many discoveries. This sort of reasoning is true for engineering and industry where you know how things work already. It's not true about discovery: if it is really a discovery then that means that you did not know ahead of time what you were going to discover, or whether you would discover anything at all. And really the emphasis on Discovery! is inappropriate because of its emphasis on achievement and being right: really a scientist's business is to somehow discover where she is wrong - and the atmosphere is much more one of desperate hope for enlightenment. The more triumphalist one gets, the less one is humble about the mysterious depths one is just beginning to touch, the less one is able to do real science.

Tuesday, February 12, 2008

Experimental verification part II - Running Into Walls

I am reminded of episodes of Star Trek (I'm most familiar with its first incarnation) where it seemed like in every episode our intrepid explorers encountered an entirely new physical phenomenon. Gazing at his instruments and the starship's view screen, Spock says "Fascinating, Captain! A being of pure energy!" A minute later they begin conversing with the being. This is not faithful to human nature. When we encounter a physical phenomenon which we had not imagined before hand, as a rule we don't even notice it. We presume things are exactly the way we imagined them, and the only uncertainties are the ones we've already thought of. The process of noticing something is different than we imagine it to be requires not minutes but centuries - and the main way that it occurs is by us collectively running our heads into a brick wall many many times until our stubborness releases its clutch for a minute and our minds begin to bend around the newly perceived fact. Humans are not good at being surprised.

Long before the advent of physics many people including philosophers spent lifetimes and many manuscripts reasoning about the physical world and how it must be, developing elegant accounts of motion and inertia, heat and cold, germination and death, the stars and planets. These were smart people and after millenia their reasoning about politics, geometry, math, engineering, architecture, art, literature, and logic continues to be a foundation stone for the human race. However their reasoning didn't do so well when applied to the physical world around us, and after the advent of natural philosophy - physics - their ideas about motion and inertia, heat and cold, etc., have been swept away.

One key to natural philosophy's success was, I believe, that natural philosophers started to try to deliberately force their ideas and themselves into collision with nature. It was as if they realized that the only way to get through human thick-headedness was to have head first collisions with facts, and therefore decided to have as many collisions as possible. Natural philosophers deliberately construct situations where they have a very clear and precise idea of what nature will do, and then check that nature actually does what they expect. The human spirit - individually and collectively - wants to be right in these situations, and to obtain confirmations of one's rightness, and has a hard time recognizing evidence to the contrary. This is really the opposite of scientific progress, which is the process of getting one's wrong-ness smashed into one's intellect until one surrenders to the facts of what one is actually observing. Therefore natural philosophers spend a lot of time and effort - whole careers - trying to outwit their own hunger for rightness. This process is called experiments, or the experimental method. The main idea is to force yourself to actually see what is in front of your eyes, to really observe nature. You make a detailed plan of exactly what parts and chemicals etc. will be used, how they will be put together, and all of this gets written very carefully in a lab notebook. You also think out very meticulously what you expect to see, touch, smell, and why you expect it. You make sure to think of and write out as many details as possible - you are not interested in just one number, but in the entire apparatus, everything you will see not just one detail. If you are not attentive to every detail of what you observe then you can not be a good scientist. Then you actually do the experimental procedure, and keep careful records of everything. Later you compare your records of what you actually observed with your records of what you originally expected - you do this comparison in the spirit of an accountant, sweating over every missing penny. There is a theoretical possibility that you the individual researcher may notice something that clearly teaches you something new about the real world, if you're lucky. But much more likely the things she notices seem to to be matters of refining and perfecting her technique, of needing to think things out more clearly the second time, third time, thousandth time. The real learning occurs as many scientists run headfirst at the same wall over and over again, comparing notes as they go, perfecting their technique, and argueing their reasoning out with each other, until finally the group as a whole begins to catch on to a way they might be wrong, and to develop a feel for the real surprise in what they are observing.

Saturday, February 9, 2008

Experimental verification part I - Mental models II

The same applies to every other physics topic - energy, acceleration, momentum, collisions, and many more. Each person has an interior "mental model" of each topic which accounts for a few of its most salient and noticeable characteristics - the things which really grabbed that person's attention. For instance, collisions: tomatoes will splash, balls will bounce, cars will bend and break, glass will shatter. Often the mental model is implicit; perhaps you've never stated or explained it, but you feel confident in applying it to real life collisions and conversing about them. Yet if someone were to engage you in a careful conversation about collisions, even simple things like what happens when a small ball hits a large ball, and what if one is sitting still to start with, or if one ball is catching up with the other one, then if you are like most people then you will run into trouble pretty quickly, and typically without knowing it. Most people will not even be able to correctly describe the details of things that they have experienced thousands of times already - like the trajectory of a ball falling off a table. (If you doubt this, try working through a unit of Physics By Inquiry.) Our mental models are not fundamentally observational or descriptive; neither are they reasoned and self-consistent; instead are functional and confined to only a few broad outlines. I know how to flip a switch; I know that sometimes I need to call an electrician; I know that there are wires and power plants; I know not to touch certain wires; what else do I need to know about electricity?

The problem is not a lack of intelligence - people who do through Physics By Inquiry and reason their way through the questions it asks, with someone to coach them through, develop much more accurate and detailed mental models. Instead the problem is something very human, part of the way we are, the way that we observe the world around us.

The point of this lesson about human nature is that it is perfectly natural that for millennia the human race believed that the universe revolves around the earth, heavy objects fall faster than slow ones, nature abhors a vacuum, and so on. Individually and as a race, we have an unending ability to construct functional but limiting and inaccurate mental models, and then in the face of contrary evidence either justify our models or else just not notice the evidence.

Friday, February 8, 2008

Experimental verification part I - Mental models

First, experimental verification. During graduate studies at the University of Washington, I had the privilege of working as a teacher's aide under the direction of Lilian McDermott's physics education group. They spend a lot of time in careful interviews with college students both before and after physics lectures, trying to draw out precisely how the students understand various things they encounter in the real world, like speed, velocity, electricity, forces, momentum, etc. This means actual interviews with individual students, paying attention to what they are saying, carrying on an attentive and probing conversation about their understanding of a specific physics topic, taping and transcribing the whole conversation, trying afterward to understand the what the student was thinking of, and then repeating the process with many other students. I have observed the same results myself in a less scientific manner by guiding students through units of McDermott's workbook "Physics by Inquiry," which uses Socrates' method (a lot of carefully posed questions challenging the reader to think through specific examples) to help the reader reason through a full understanding of particular topics.

The surprising result of McDermott's research is that even when people talk about scientific concepts like speed, velocity, forces, or momentum, they as a rule understand them in a much different way than scientists do. What a scientist means by velocity is much different than what the average person means. In other words, everyone carries around a mental model of the world - for instance they have ideas about falling objects. Everything falls, and that is because of gravity. Usually these ideas are not that precise, and it's easy for a scientist to ask questions that puzzle others. (And vice versa, but that's another story.) For instance, consider a ball on top of a table, which is pushed, and moves off the side of the table and falls. If you are beside the table and observe the trajectory of the ball as it moves past you, off the table, and toward the ground, what sort of curve does it make? Take a minute and think about it; draw a picture of the table and the floor (looking from the side so that the ball is moving past you not towards you), and then draw the trajectory of the ball.

Experimental evidence with people answering this question shows that a large fraction of college students (and by extension most adults) answer this question incorrectly. In fact they do have some correct ideas about falling (everything falls, roughly how long, gravity), but the overall mental model of falling and how it works is incorrect. Given a few simple but precise questions - obvious ones not head in clouds ones - almost everyone will give an incorrect answer to one or more, revealing an incorrect understanding of falls. Some will feel a bit puzzled or uncertain as they answer, others not; some will be able to give long and detailed explanations of their reasoning and evidence and predictions, others not - but irregardless they will be consistently wrong. This despite daily and long term experience with falling objects, including one's own body.

Wednesday, February 6, 2008

Natural Philosophy

Of course natural philosophers - physicists - have the same philosophical bent. As a case in point, consider the efforts to come up with a Theory Of Everything, or a Grand Unified Theory. In those efforts physicists are trying to understand something that is far beyond human experience, with almost no connection to the real world, so that we have to build billion dollar machines if we want to hear even the slightest whisper from nature about these matters. Not practical at all.

But going back to the natural philosophers, you can imagine how it looked at the time when a person asked whether heavy things really fall faster than light things, or debated the commonplace knowledge that vacua can not exist in nature, or claimed that everything is made out of very small invisible indivisible pieces. This last was proposed by the Indians and Greeks but had no connection with real world evidence until two millenia later. These people clearly had an unworldly bent, the sort of attitude that is epitomized in so many pictures of Einstein.

But there was something a bit different about these natural philosophers, which made them far different from other philosophers, and still lies between the two like a canyon. The natural philosophers emphasized numbers, experimental verification of their ideas against nature's actual behavior, and complete control over experiments. I'll expand on all three.

Tuesday, February 5, 2008

What is philosophy?

In contrast, there have always been some people who wanted to ask questions. All sorts of questions that weren't necessarily useful, didn't necessarily get anything done, but often enough were still very relevant. What are we: animal or spirit? Is every object fundamentally different, or is everything made out of the same stuff, just prepared or formed a bit differently? And beauty, what is that? Is the beauty of a woman the same as the beauty of a sunset? Is there a way for the two beauties (that of a woman and that of a sunset) to be the same and different at the same time? Is beauty in the eye of the beholder (subjective), or is it instead an objective reality? What do we mean by subjective vs. objective; are some things more real than others? How about energy, matter, movement, change - is one more real than another? How about love, is that subjective or objective? What is love anyway? How do you love? Are there different kinds of love?

One can go on and on in this direction - and with many different styles. Some people do it because they really want to know the truth of things, to have very attentive eyes. Others are trying to gain power or just love to play mind games. It's very hard to tell the two orientations apart, and there are so many other variations, so many philosophers that have already lived with so many different styles and attitudes.

Perhaps these questions are ones that occur now and then to everyone, and everyone has to make some sort of response. As an easy example, probably we all at one time or another question whether taking a particular action, past or future, would be loving. And from day one we are trying to figure out who loves us. But our answers to these questions are typically very practical, experiential, applied on a case by case basis. A philosopher typically will try to go deeper, and broader, and beyond. Her questions and search will be for something that is a little less practical, and may even inconvenience us if the answers conflict with what is expedient and desired.

Sunday, February 3, 2008

The Beginning - Philosophy

We'll start at the beginning, and the beginning of physics is philosophy. For a long time we called ourselves "natural philosophers." In fact the first physicists were just philosophers. So, a few words about philosophy, because I think that most people dislike it or feel very disassociated from it, think of it as something repellant like the number of angels on the head of pin, and think it belongs to the past. Whether or not I'm right about a common dislike for philosophy in the populace at large, I am right about a dislike for philosophy among today's physicists. Many physicists look down on philosophy; Feynman had some choice words about it of basically total disdain. So let's unearth the truth about philosophy and what it's about, and then see how physics grew out of that.

There is a very practical way of approaching life - one that emphasizes getting things done. This is the mode that most of us spend most of our time in. I know how to walk, the sky and what that tells me about how to keep myself warm and safe from the weather, how to use a sponge, soap, and water to scrub and clean dishes, how to make my room beautiful, how to communicate with others and participate in family ties, the rules for my local government/groups and how to work those rules to get things done, and many many other things. At every stage in history most people have been engaged in getting things done. It's still that way today. We put a lot of thought into it and are constantly challenging ourselves and learning more into order to get new things done. It requires immense time and talent, and the majority of people have focused on this sort of life and work, and many have lived very satisfying lives doing so.


This blog will be focused on how physicists think, what we think about, what we are excited about, and how we solve problems. If there is one thing physicists are good at, it is solving certain types of problems. I'm a theoretical physicist, so what we'll talk about things from a theorist's point of view. Also I believe that if you can't actually calculate numbers pertaining to real life then you don't know much (on a scientific level, no implications about other levels of knowledge), so I will often bring numbers and computer concepts into the discussion. There will be some equations but they will always be at the service of numbers.

If you examine the introductory college level physics textbooks, and review their history, you will find that the entire text is devoted to things that were already well known in 1945 - in fact the large majority of the material belongs to the 19th century - forces, heat, levers, angular momentum, gravity, and the like. In some sense, when you read a physics text book, you are not reading physics; you are reading history. If you ask an average physicist what she's excited about, it won't be the things in those text books. This means that you are missing the physics - physics is a process, a way of thinking, a way of solving problems, and it's a community. When physicists are done with something, it becomes engineering or some other discipline. In fact if you look who is really interested in forces nowadays, it's not physicists, it's engineers. Same thing with electricity. To capture the real feeling of physics, we need to be more up to date, and look at some of the themes of the last few decades.

The spirit of this text will be fundamentally one of story telling - I am telling the story of physics, of who we physicists are as a community, introducing you as much to our heart as to our head - where we think we are coming from and where we think we are going. As a story teller I will not be checking all my sources, reading up on the meaning of every word and sentence in this blog before actually blogging. And often I will insert my own opinions. At the same time I will tell the truth as best I know it, and only say things I'm pretty sure of. If you see a mistake, please feel free to point that out to me, politely. And just as important, if something needs clarification, if I could explain something better, then please let me know.

This blog will be draft quality, not finished copy. I have presented the material once before, in an introductory physics course in Manila. You can find the notes at - but often the notes diverged worlds away from the actual lecture contents.