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Misconceptions about Science [talk]

Vinay

While visiting home earlier this year, I was asked to speak at the Indian Public School Principals’ Conference at Manipal by Mr. Acharya of the Sharada Residential School. It was the first time I was facing a Headmaster since getting out of high school, and the prospect of facing some 50 of them at once didn’t quite make for a relaxing vacation. But they heard me out and allowed me to retreat in good order.

What could I speak about to people who have likely already heard everything? Being a scientist, I thought I should talk about science and what students ought to learn in order to be able to do it well. It turned into an examination of what I hope we will be able to do at CREATE Gurukula: we want to train students to understand and follow the scientific process. But what is the scientific process?

Consider this my manifesto.


Draft of talk delivered by Vinay Kashyap at IPSC, Manipal, 2011 Jan 5.

I am an astrophysicist. As a working, professional scientist, I have noticed that there is a big difference in how my colleagues and I look upon science and what everyone else thinks we do. There are a lot of misconceptions about science, and I would like to take this opportunity to discuss that with you all. You are in the best position to do something about it!

There is a saying that goes “science is what scientists do”, and I will try and describe what that means, how science really works and why it is desperately important to inculcate the scientific mindset.

The first thing I want to point out is that people generally think of science as a noun. For us, instead, it is a verb. We speak of “doing science”, rather than treat science as a subject.

I want to keep this short and give you the opportunity to ask questions, because what I am going to say is necessarily highly incomplete.

First let me lay out what is the typical view of science that is generally taught to everybody. There are two viewpoints I usually encounter.

***

The first is that science is knowledge. This is not entirely surprising, because the word comes from the Latin root “scientia”, which means “to know”. Even in Sanskrit, the word “vignana” has “gnana”, or knowledge, as its root. So it is not surprising that people have this idea that good science means one knows a lot of facts. People are generally impressed if you know the answers to questions like

* how many planets are there in our solar system?
* how big is our Galaxy?
* how old is the Universe?
* how many chromosomes does a human cell have?
* what is the speed of light?

etc. But that’s not science, that’s a quiz show!

Scientists do tend to know a lot of facts, but that’s incidental. It’s a symptom of the process, and it is not a defining characteristic.

Isaac Newton didn’t know what the speed of light was. Albert Einstein didn’t know there was a supermassive black hole at the center of our Galaxy. James Clerk Maxwell didn’t know about atomic lines. Charles Darwin didn’t know about DNA!

There are incentives for us to know a lot, because if we don’t, we end up wasting time covering the same ground someone else already has, making the same mistakes they did. There is no percentage in reinventing the wheel. If I may paraphrase Newton, we can see further if we stand on the shoulders of giants.

So it is not surprising that people have this idea that good science means one knows a lot of facts.

But this is not science.

Oh, before I go on to the next point, just for completeness, here are the answers to those questions I asked before —

* there are 8 classical planets in our solar system, and a bunch of dwarf planets of the Pluto class that are just beginning to be discovered
* our Galaxy is about 20 kpc, or about 70000 light-years, wide
* the Universe is 13.4 billion years old
* I didn’t pay much attention in biology classes, but I believe there are 23 pairs of chromosomes in a human cell
* the speed of light, in units that may make more sense here and now, is about 1 foot per nanosecond

***

The second viewpoint is more sophisticated and is held by people who have thought some about it, and is generally what philosophers of science say. They recognize that science is a process, and they know exactly how it is laid out:

* first, define the terms
* second, formulate a hypothesis
* then, make predictions based on the hypothesis
* then, conduct experiments to test the predictions
* and finally, reject or accept the hypothesis

To me, this is too facile. Too antiseptic. The reality is much more complicated, and interesting.

Let me be clear, the point about confronting ideas with experimental data is crucial, and is at the heart of doing science. Without that step, there is no mechanism to prevent us from fooling ourselves. It is essential.

Let me give you an example of how science really happens. We all know now that the Earth and the other planets rotate around the Sun in elliptical orbits. When did we find out about this? When Galileo started looking through a telescope? When Kepler formulated his laws of planetary motion?

There’s this famous story about when Galileo was put on trial in 1633 by the Inquisition. He was forced to recant his anti-Aristotelean teachings that the Earth moves around the Sun. He acquiesced, and is said to have meekly accepted his punishment, but just as he was about to step down, defiantly muttered “E pur si muove” — “And yet it moves”.

It is an inspiring story, and is part of the mythology of modern science. But here’s the thing — he couldn’t have known, for sure, for certain, at that time! Demonstrable proof did not come until the mid-19th century, by way of Foucalt’s pendulum.

(Foucalt’s pendulum is just a simple pendulum — you set it going along one direction, but as the day progresses, you find that the plane of the oscillations shifts, because the earth is rotating underneath it! — the effect is at its maximum at the poles, and nothing at the Equator. This was the first real proof that we live on a rotating frame of reference.)

But long before this proof was at hand, everyone had switched over to thinking in terms of a heliocentric system, with planets in elliptical orbits around the Sun. I want to emphasize this, because it is hard to put ourselves in the shoes of those people — people who had lived by Ptolemaic and Aristotelean precepts for nearly two millenia, had, over a few decades, completely switched over to the Copernican heliocentric system, without proof! That tells you something… Why did they do this? Were they idiots? No, it was because they realized that this was a sensible thing to do.

Let me quote for you from Owen Gingerich, a professor at the Smithsonian Astrophysical Observatory, who is an expert at the history of science. While discussing the Copernican revolution, he addresses the mythology that has grown up around it:

Owen Gingerich:
Here we have the fourth of the myths, that Galileo’s telescopic observations finally proved the motion of the earth and thereby, at last, established the truth of the Copernican system.
What I want to assure you is that, in general, science does not operate by proofs. You hear that an awful lot, about science looking for propositions that can be falsified, that proof plays this big role.. uh-uh. It is coherence of explanation, understanding things that are well-knit together; the broader the framework of knitting the things together, the more we are able to believe it.

So, we build models, often with little justification in terms of experimental proof, and muddle along trying to make it fit into a sensible narrative. The point that Prof. Gingerich was making is simply that scientists tend to make progress based on a coherent “story” without waiting for a formal Kuhnian revolution. And usually when a final proof of a worldview does arrive, it is rather anti-climactic (he refers to Foucalt’s pendulum as an example).

Same thing about Kepler’s “proof” of the elliptical orbit of planets. He had no proof! For him, it was just convenient mathematical trickery that made things easier to calculate.

So this is how science works — as a persistent process of continuous revision, and at every iteration, the product — which is: our understanding of how the world works — is left slightly better than before.

***

In reality — and we must remember here that scientists are human, with all the imperfections that entails — the process is organic, and very chaotic.

And this brings me to the real problem with the way the scientific method is formalized. Let me remind you of the first major step — all our ignorance of the scientific method is pretty much buried in this step — “formulate a hypothesis”. Sounds great, but .. How?!

There is unfortunately no clear description of the real scientific process because philosophers of science tend to try and fit everything into neat pigeonholes, and when they do, they end up excluding like 90% of what goes on.

The starting point in almost all scientific enquiry is to discern a connection between apparently unrelated events.

The biggest moments of discovery in science are not “Eureka!” moments. No, not at all, the most common thrill of discovery is when you look at some result and say “hmm.. that’s odd..”! That’s when the experiment you designed didn’t give the results you anticipated, neither one to confirm nor reject the stated hypothesis, but rather something altogether unexpected.

Newton did it when he connected the fall of an apple to the orbit of the Moon. Maxwell when he realized that electricity and magnetism were two sides of the same coin. Darwin noticed that the beaks of finches in different islands of the Galapagos were nicely suited for what the birds were doing, and that resulted in the theory of evolution by natural selection! Einstein, who had heard of this strange problem with the speed of light — nobody could find any changes in it — took that as a given and ran with it, and ended up with E=mc^2. Subramanya Chandrasekhar made the connection between the force between atoms that we are all familiar with — this is what, when I put my hand on the table, stops it from going through, despite atoms being mostly empty space — and then he asked what would happen when there was so much matter that gravity overwhelmed this force, and imagined black holes.

We literally just try out stuff and check if it works. If it works, then yay! we have made progress! And if it doesn’t, then OK, let’s not do *that* again.

You need the inventiveness and the ability to see the connections between previously unrelated things, and you need to follow it up with careful analysis and unrelenting efforts to make sure you are not fooling yourself. That is how science works.

Once upon a time, back in the middle ages, multiplication was taught in advanced level courses. Nowadays, students learn that in primary school. And now students are being taught the formal scientific method in high schools, but the real stuff is still something you figure out on your own in graduate school. I hope someday soon we can codify the way science is done properly that it can be taught at elementary levels, and everyone will be able to “do science”.

And I believe that that way of looking at things is absolutely essential to the continued prosperity of our civilization. This is a recipe for problem solving, and it is a self-correcting mechanism that avoids ideological blind spots. This kind of thinking is necessary to solve the looming problems that face us — whether it is climate change, or energy independence, or pollution control, or bio-diversity, or you name it. The next generation of students must be educated to develop the scientific habit.

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  1. Gurukula › Teaching vs Learning [pedagogy] on Sunday, February 27, 2011 at 2:09 am

    […] In the talk, he describes in detail what the difference is between learning the traditional way and learning to do science, and even more importantly, gives pointers to how one might go about achieving the latter. It is a sad fact that even with the best teachers, the way things are taught in classes now results in the students regressing in their command of the subject. He talks about how to avoid the trap of cognitive limitations, and get students to learn the right things. In this, he actually gives concrete suggestions about methods and processes on how to teach “doing science” that I had alluded to vaguely in my talk to the IPSC. […]