The philosophy of science, and science in the 20th century

This is from Bryan Magee’s 15-part series The Great Philosophers, broadcast on BBC2 in 1987. Here he talks with Hilary Putnam about the philosophy of science.

Alan Kay has talked about how most people don’t understand how science worked in the 20th century, much less the present century. Our schools still teach science in a 19th century fashion in terms of how people can approach knowledge. This episode of the show amply demonstrates this disconnect.

As I studied what was said here about scientific thinking up until the late 19th century, it reminded me a lot of how I was taught computer science. It was thought to be a process of adding on to existing knowledge, and sorting out any inconsistencies. With rare exceptions, alternatives to existing models were not discussed, or even made known to students.

I’m going to put the notes I took from this episode below each section of video, because I found it hard to follow the arguments without going through them slowly, and looking at what Magee and Putnam said explicitly.

Magee: The religious world view has been largely replaced by a world view purportedly derived from science, since the 17th century.

Science was seen as a process of “adding” and sorting for 300 years, up until the late 19th century. The view of knowledge was that it grew by accumulation. Science was seen as getting its success from an inductive method. For 300 years educated people thought of the Universe as just matter in motion. They thought if we went on long enough, we’d find out everything about the Universe there was to know. This whole idea has been abandoned by science, but non-scientists think that scientists still think this way.

Kant challenged the “correspondence” view of truth, that theories correspond directly to reality without nuances, that the world makes its truths apparent, and scientists just find out what that is and write it down. Kant said there’s a contribution of the thinking mind. Truth depends on what exists, and on the mind of the observer. Scientists have come to a similar view, that theories are not merely dictated to us by the “facts.”

The categories and interpretations we use, the ideas within which we organize our observations, are our contributions. The world that’s perceived by us is partly contributed to by external effects, and is partly made up of categories and ways of seeing things that come from us. [Mark says: I think Plato’s notion of “forms” also applies here, in terms of our theories. We could equate a theory of a phenomenon to its form in our own minds, and we could recognize that if a phenomenon is unfamiliar enough, different people will create different forms of it in their own minds.]

In the late 19th century the views of scientists changed to realize that the old theories could be wrong. The more modern view is that not only is our view of reality partly mind-dependent, but there are alternatives, and the concepts we impose on the world may not be the right ones, we may have to change them, and there is an interaction between what we contribute and what we find out. It was realized that there were alternative descriptions of some things that were equally as valid.

The new conception of science is that theories are constantly being replaced by newer and better ones, which are richer, that explain phenomena more fully, and there’s a mystery to our universe which will never be completely discovered. The view about “truth” that Putnam said was coming into use more and more in science is the idea that there cannot be a separation between what’s considered true and what our standards of assertability are. So the way that mind-dependence comes in is the fact that what’s true and what’s false is partly a function of what our standards of truth and falsity are. That depends on our interests, which change over time. Putnam defined “interests” in a cultural context, such as, in our modern world we’d recognize that there’s a policeman on the corner. Someone from a tribal culture, which may have no formal social services, wouldn’t recognize a policeman, but would instead see “someone in blue” on the corner.

Even facts within theories can have alternatives, as was evidenced by the theory of relativity.

A scientific theory can be useful even if nobody really understands what it means (quantum mechanics). [Mark says: You could also say the same about Newton’s theory of gravity.]

Putnam thinks the way in which the old scientific view (pre-19th century) was destructive was that since it saw scientific findings as objective facts which were accumulated over time, then everything else was considered non-knowledge, that couldn’t even be considered true or false.

Real interesting! Putnam and Magee talk about how computer science, through an interaction with computer simulations, has created a growth of knowledge about the human mind. This relates to what I’ve read about Licklider’s use of computers at MIT in the 1950s, in Waldrop’s book, “The Dream Machine.”

Edit 5-4-2011: I had a brief conversation with Alan Kay about the main theme of this program, and I put particular focus on this part, where Magee and Putnam discussed the role that computer science has played in the advancement of knowledge in other areas of research. He zeroed in on this part, saying that it was a misperception of what really happened, at least in relation to Licklider (and Engelbart). He said the advances in knowledge from computer science have been paradigm shifts, not advancements by interaction. He pointed out that the theory of evolution did not begin in the field of biology, as Magee asserts. He also said that computers did not begin as “a self-conscious analogy to the human mind,” but rather as machines to run calculations. I knew that. I thought Magee’s description of this was rather romantic, and other historical accounts have agreed with his assessment, so I let it slide, but I have since had second thoughts about that.

Magee: Most people with college degrees have no idea what Einstein’s theory of relativity is all about, more than 70 years after it was published. It’s done very little to influence their view of the world. Isn’t there a danger that science and mathematics are racing ahead, and the whole range of insight that that’s giving us into the Universe simply isn’t filtering through to the layman?

Putnam: There was a text on Special Relativity called “Space-Time Physics” that was designed for the first month of the first college physics course, and the authors hoped that someday it would be taught in high schools.

The question and answer above really struck a chord with me. First of all, I didn’t encounter Einstein’s theory of relativity in my first semester physics course in college. All we covered, that I remember, was Newtonian mechanics, though at a more detailed and advanced level than what we got in high school.

The discussion that Magee and Putnam had about General Relativity, and the risk we take with science “racing past” the rest of society, I think, makes a good case for Alan Kay’s efforts to teach more advanced math concepts to children, because without that, they’re never going to understand it. To put this in perspective, take a look at General Relativity, and think about the understanding of mathematics that would be required to understand it.

Strangely enough, I got more exposure to Einstein’s theories of relativity when I was in Jr. high school (1982-’85) than I got at any other time. We watched parts of Carl Sagan’s Cosmos series. In it Sagan talked about Einstein’s theories of relativity, and included Einstein’s notion of gravity as warped space-time. Farther back than that, I had been fascinated by the idea of black holes, since I was in 4th grade. I read all I could on them, and I learned some very strange things: that not even light could escape from them, and that matter was destroyed upon entering them, for all intents and purposes, though I think the evidence still supports the idea of conservation of matter. It’s just that the matter gets separated into its component parts, and some of the matter is converted into energy.

I got exposed a bit to a theory of gravity that was different from Einstein’s or Newton’s outside of school, by a toy inventor, of all people. So I knew there were other theories besides those that were commonly accepted. What became clear to me after exposure to these ideas was that gravity is a fascinating mystery. We didn’t know what caused it then, and we don’t know now, not really, except for mass. The question that would not go away for me was what about mass causes it? The idea that mass causes it just because it exists never satisfied me. The other forces were explained through phenomena I could relate to, but gravity was different.

(Update 12-15-2013: I’ve updated the paragraph below with what I think is a more accurate description of the theory, and I’ve added a couple paragraphs to further explain. I was mistaken in saying that astrophysicists think that the distortion in space-time causes us to “slide” in towards the gravity well.)

What Einstein’s theory explains is that gravity is not a force in the way that we think about other forces. His theory said that matter warps space-time, and it is this warping which creates the perception of a force acting on objects and energy. The way Sagan explained it is that we are all “sliding” being pushed inward towards the center of the gravity well, on by this distortion, and what keeps us from going to the center of the well is the outward force exerted by the earth we stand on. Scientists have tried to explain it using an analogy of a large ball setting on a piece of taut fabric, which creates a dip in it. If you toss a marble onto the fabric, it will fall towards the larger ball, due to the anomaly in the fabric. This is not a great analogy, because in it, gravity is pulling the larger ball down creating the dip in the fabric. If you can disregard that fact, what they are trying to get across is its the distortion of the fabric that alters the path of the marble, not any force. Another way this analogy is imperfect is it doesn’t illustrate how space-time is being drawn inward by something that is not yet explained. What Einstein’s theory says is that there is something about matter that causes this distortion in space-time. That could be attributed to a force, but from everything I’ve studied about the theory so far, Einstein didn’t say that. That’s left as “a problem for the reader,” so to speak.

The strange thing about the theory that might seem confusing is it explains that while we are “pushed” inward towards the well, it’s not a push in the Newtonian sense. This “push” is coming from what is called “space-time” itself. It’s a push on everything that constitutes matter and energy, down to our body’s subatomic particles, and photons of light.

Looking at how it is we stand on earth, rather than all matter being drawn into the well, it’s rather like standing on stretchy material that’s constantly being drawn into something, with a “wall” in our way (which does not “catch” the fabric). The closer the material gets to whatever is pulling on it, the more stretched it becomes. As it becomes stretched, so are we, and all the matter around us, because, as we understand, matter is “situated” in space-time. There may be some “friction,” if you will, between us and the material (space-time), that causes us to be drawn in with it, but it’s not total, allowing this “material” to slide past us, while we are repelled outward by the “wall” (forces in the matter we stand on). Hopefully my attempt to explain this isn’t too confusing. I’m groping at understanding it myself.

An example of the way school gets science wrong

High school physics was odd to me, because we talked about stuff like how electrons had both the property of a particle and a wave (as Putnam discussed above), a very interesting idea, but when it came to gravity, all we focused on was Galileo’s and Newton’s notions of it, particularly Newton’s Universal Law of Gravitation. One of the things I remember being emphasized was that “this law is the same throughout the Universe.” For the sake of argument, from our perspective, being on Earth, I was willing to accept that claim, but I remember being a bit skeptical that it was really true. I knew that we hadn’t really explored the whole universe, and that we hadn’t even come close to testing this notion everywhere. I was open to the idea that someday we might find an exception to this notion if we were to theoretically explore the Universe, which is something that may never happen (I didn’t even know about Mercury’s orbit, which doesn’t fit Newton’s theory as well as the orbits of the other planets). So, for practical purposes, we could assume that it’s “universal.”

We talked about Einstein’s theory of Special Relativity, and what was really fascinating about that was E = mc2, that there’s a relationship between matter and energy that’s only “separated” by the square of the speed of light. My memory, though, is we hardly talked about General Relativity at all, except perhaps in a historical context. Looking back on this, it’s rather obvious to see why. In high school science we were expected to get a little more into the details of scientific theories, and work with the math concepts more. The school system hadn’t prepared us to work with the notion of General Relativity at that level. So in effect we skipped it, but the conceit that was presented in class was that Newton’s law of gravity was “the truth.”

I remember being asked a question on a physics test that asked, “If aliens visited Earth, would we find that they have the same knowledge of gravity as we do?” I paused. This was an interesting question to me, because I thought it was asking me to consider what understanding another race of intelligent beings would have about this phenomenon. I asked myself, if space aliens existed that were intelligent enough to build craft for interstellar travel, would they have the same ideas about gravity as we do? I answered, “Maybe.” I added something about how since the aliens had managed to make the journey from whatever star system they came from, that their technology was probably more advanced than ours (I mean, we haven’t tried this yet, so that was a good guess), and maybe they had a better understanding of gravity than we did, particularly what caused it. I hedged a bit, but I guessed that there was probably a link between technological development and greater scientific understanding of our universe. Granted, this was a totally speculative answer, but it was a speculative question, as far as I was concerned.

My physics teacher marked this answer wrong. I was floored! I wondered, “What did she expect?” I asked her about it after class, and she said the answer she expected was something along the lines of, “Yes, because the Law of Gravity is universal.” I was so disappointed (in her). It immediately hit me that, “Oh, yeah. I remember we talked about that.” I could’ve almost kicked myself for thinking that she had asked a thought-provoking question, and falling for it! I was supposed to remember to recall what we had talked about in class. I wasn’t supposed to think on it! Duh! How could I have been so stupid? That’s really how perverse and offensive this was. It brings to mind the fictional short story of “Harrison Bergeron,” now that I think about it… However, trying not to see that she was telling me not to think, I tried to talk her through my reasoning, because I thought I gave a legitimate answer. I told her about the other notions of gravity I knew about, and the questions they raised for me. She wouldn’t hear of it. I think I said in a final protest, “Do you really think we’ve discovered everything there is to know about gravity?!” In any case, she didn’t answer me. I walked out of the classroom exasperated. It was one of the most disillusioning experiences of my life. It made me fume!

Looking back on things like this, she probably didn’t even understand what a good question she had asked. Secondly, there were other instances where this happened in my schooling. Sometimes I wanted to think through things and come up with original answers, not merely regurgitate what I had been fed, and I got penalized for it. She and I had not been getting along for most of the time while I was in her class, and I think it was over issues like this. So this was nothing new, but this incident revealed a disturbing fact to me in a way that was so obvious, I couldn’t just brush it off as a misunderstanding between us: Her approach to science was that we were supposed to accept what she said as truth. We were not supposed to think about it, or question it. The only thinking we were supposed to do was in calculating results from experiments, but a lot of that was applying the “correct” formulas. More memorization. Nevertheless, I got an “A” in her class.

Looking at this from a “mountaintop” view, I think this example shows the split between 20th century scientific thinking, and the 19th century thinking that’s been used to teach science in schools. I saw a discussion recently where Alan Kay talked about this with the No Child Left Behind policy, that for students who were developing an understanding of scientific thinking, they had to, on the one hand, gain real understanding, and on the other, remember to answer “wrongly” on the test. That summed up the experience I describe above! I’ve used my example sometimes when I’ve heard people complain about this, because I can say to them I got the same treatment when I was in my high school science classes, more than 20 years ago. As far as I’m concerned, this policy is just taking that idea of instruction, which has been around for years, to its logical conclusion. It’s now metastasized throughout the public education system, at least in the areas that are tested for proficiency, whereas in my day there were exceptions.

—Mark Miller,