Friday, December 24, 2010

The Documentary Debate

So here's another debate story. This one is between me and my friend Vatsal; we'll call him Vats for brevity's sake.

Vats is a good mathematician and physicist. However, he belongs to the group which I call as the "derivationalists", which means to say that Vats does not find any fun in science that is explained without the rigor of mathematical derivations and deep physical laws. In short, Vats is quite against popular science.

I have had this debate with Debanjan (Deb) earlier too. Deb is also a "derivationalist" and completely against pop-sci. He feels that it is a complete waste to time to read about an overview of something from a magazine or Wikipedia without starting from the basic principles of physics (we are talking about physics here), reading tens of publications and deriving everything in that field out by yourself.

As a result of these views, we often have clashes on our view of scientific documentaries that are presented in educational media like Discovery or NatGeo. We are specifically talking about documentaries in pure science rather than engineering ("Megastructures" and "Extreme Engineering") because we do agree that the presenting of enigineering design on-screen, be it a Porsche car or the Tokyo Int airport, does hold some merit, because these constructions are "nice to see", and there is really no big point in telling people how an IC engine works or how the strength of materials is calculated to bolster the beams and columns.

Vats (and I believe Deb too) has a strict no-no on pure science documentaries. Being "derivationalist", he raises objections on the way the content is organized. It is obscured in several perspectives. Supposing the documentary starts from the basic principles, then it is difficult to cover the latest philosophies in the course of a single hour. If they intend to touch the latter, they begin half-way, and the uninitiated viewer has no clue about what hit him, and he goes for the schoolboy's approach of "accepting what is on the board to be god-gifted truth". Well, it is true that certain in-depth documentaries have attempted to span the entire horizon of historical development of the subject matter - like the set of 6 documentaries on Astrophysics and Stephen Hawking's theory, which started from the days of Tycho Brahe and ended with Black Hole radiation. But in going into such a vast coverage, one risks the fundamental point of "jumping the steps", as it were.

In such documentaries it is not unusual to come across Einstein's General Theory of relativity explaining gravitation as a "cloth fabric on which the heavenly bodies are located". If you have watched these, you would know that the narrator proceeds to say that the "weight" of the Sun depresses the "fabric" - creating a funnel-like curvature, into which the planet gets pulled in, and the revolution of that planet may be shown to counter the gravitational attraction of the Sun. You might have seen a construct like this at science fairs or exhibitions too, although I doubt whether they did mention Einstein.

At any rate, this interpretation may be looked upon as a culmination of Vats' dissatisfaction with documentaries. And its not without reason. About 90% of the viewers who have been wowed at such a lucid explanation of such deep principles have not considered the most obvious flaw in this argument. The reason we think that a sphere placed on a stretched extent of cloth would depress it is becuase we are used to thinking the sphere having some "weight" which is nothing but a manifestation of the Earth's gravitational force on the sphere. So essentially you are using gravity to explain gravity.

Even if we did accept it as a "visualization aid", the curvature that mass essentially produces is a curvature in space-time, and nothing in this analogy can bring that factor in (unless you carefully describe a light synchronized clocking mechanism in each intersection point of the grid). Furthermore, and Vats tells me this for at this point it really gets beyond my knowledge, there are fundamental roadblocks to one's thought processes if one starts with the belief that gravitation is like the depressing of a fabric. He tells me there is some matrix, when when diagonalized and blah blah gives some parameters. From these parameters emerge the gravitational constant and other factors, which tell you the effect of a mass on space-time. Vats being a derivationalist, this over-simplified approach disturbs him a lot, as it misses out on key concepts and insights into the true origins and ramifications of the theory. The viewer feels that he has "got the thing" when he is as far away from it as he always was, if not more.

Vats' points are logical and true. I do not challenge his points, for being trained in science (though not to his level of detail in these matters), I can see how the links are missing in such documentaries. But my basic argument is not about the excellence of the content, but about the people who watch these documentaries.

So who watches documentaries? Students for one, both from high school and universities. With university students, the trend lies more in watching documentaries from a different area of human knowledge rather than their own. And, mostly, common people who have an interest in science. Imagine this. You were once greatly interested in physics and math. You were an ardent student of these in school. You moved on study engineering, and then in due course of fortune you ended up working to develop algorithms to calculate risk in stock market trading (think GS or MS). Now you have neither the time nor the level of training to indulge yourself in all those topics in physics that they never taught in school. From your perspective, what would such a documentary bring? A refreshing way to fulfill all those dreams, in my opinion. Sure, you cant go teach relativity in the next college lecture. Neither can you sit and derive all those wonderful laws and principles. But if nothing else, you could manage to hear and know a little about those things which you would have otherwise forsaken for good. You did not become an expert, but you had the fun of reliving your physics days, and gain a little more perspective in the process, for all of it is not hogwash.

From the point of view of students, we have to be a more careful. And this is where a good documentary stands out from the rest. For students, documentaries do serve as some of our first insights into the subject matter in many cases, and the concepts and ideas gained thereof stick with us like childhood memories. So some day if we end up actually studying those topics in detail, we would not want our mental roadblocks to get in the way - like the sphere on the cloth conundrum. Neither would we like to talk about half-learned ideas before an educated audience, if the occasion so arises.

In this way, a good documentary is like a good teacher. It sets inquisitiveness aflame. It does not claim that what it is saying is the sacrosanct facsimile of the philosophies of the topic. It tells you, "Well, this thing is actually complicated, but just for starters, you might want to imagine it like this..." It always tells you what is the flaw in its simplified view of looking at it, and warns you against taking it too literally. In doing so, one must be very ingenious and crafty in thinking of the most apt analogies, so that they capture as much of the complexity of the real scenario as possible. Where such analogies are impossible  - like the "spin" of an electron - they should be avoided for good. At the same time, a good documentary does not go into unnecessary piles of math to try and be precise. That is not the intent of the show, and in more ways than one, a documentary with truck-loads of data and number-crunching turns out to be boring, non-intuitive and scares people's interest out of the topic by telling them "This is just not your cup of tea".

As a citation, I'll point to the BBC4 documentary called "The Music of the Primes" - a show on the search of pattern in prime-numbers. This documentary caught my eye in terms of content and organization. It started from the fundamentals, introducing why prime numbers are important, why there are an infinite number of them, etc. Then they spoke of how Gauss went about trying to find a rhythm in the probability of a prime number showing up in logarithmic progression of numbers, and how it did not turn out to be perfect. Then they spoke of the Riemann zeta function, and most tactfully avoided saying anything about plotting functions on Argand planes and all, yet they said that the "valleys" (zeros) of the "contours" of this function in "that other world" (complex domain) held the key to correcting Gauss's step-approximation to precision. They spoke of the conjecture of alignment of zeros, and the difficulty people have faced in trying to prove it. Yet they did not let the show reach a dead end, and spoke about the immense importance of primes in code breaking (Alan Turing), nuclear energy levels and online commerce (encryption). The other show - on the final proof of Fermat's last theorem - did have a definite ending, but was not that well organized and had too many logical "jumps" to make me feel comfortable.

For that matter, books have suffered from the same flaws. Nobody told us that Gauss' Law was more fundamental that Coulomb's Law (some state boards left it out for good). Nobody said that the "g" is actually the gravitational field of the planet. Some even said that an electron "spins about its axis", and went on to equate the atomic structure to the solar system (its like believing Santa Claus actually spends out of his pockets to give children gifts). Just like we have to be wise in our choice of books to learn the correct and the best, so is it when it comes to documentaries. And the joy of a well-set documentary is a lifelong interest in a subject matter that may have just completely eluded us in this lifetime.


  1. Its a worthy debate no doubt. I would like to point out a mistake in there. Gravity was part of General theory of Relativity not the Special Theory.

    I personally have always believed the point of documentaries is to entertain the layman. And if an engineer has now started working with GS or MS he has certainly become the layman in deep physical theories. So these documentaries would definitely suit him. But for someone who wants to rekindle those old flames of curiosity towards actual physics they should avoid these documentaries whole heartedly and start from basics just like a proper scientist would. One doesn't have to look too far, since with the advent of the internet MIT's OCW is freely available.

    For those who wants to get a brief knowhow of today's physics I would recommend the book "The Road To Reality" by Roger Penrose. Its awesome, lucid and perfect for us-who have some basic knowledge of physics and mathematics.

  2. @Sudipto
    Can't agree more... :)

    I guess at times I would differ slightly from your depiction of my idea. :P

    Firstly, no, I don't advocate suffocating new students with mathematics unless they are serious about the topic. So, you might read all you want about cosmology and quantum mechanics, but once you want to talk about it to someone in that field (esp me :P), you need to know how it actually works, at least have an outline of the derivation and such. What irritates me is people who don't actually know anything about a field pretending to know and "explain" things (And I guess this phenomenon is applicable to things beyond science.)

    Second, my idea of explaining a topic is at least start with some backgound, so that you don't make things sound ad hoc. So, this is especially true with String theory docus, they just tell you that someone thought using strings sounds kewl, and just out of the blue someone worked out the theory. It doesn't work that way in physics, I think.

    Last, and probably the weakest point logically, but the most important point is regarding the philosophy of physics (:O). The documentaries stop making sense the moment they start talking about abstract things in fancy language with fancy graphics around. In that context, I would totally agree with the point you raised about "The Music of Primes", and I remember another one on neutrinos, which follows this approach. Fair enough, and I like these documentaries. But the kind that troubles me is like "The Elegant Universe". We don't have a fancy picture of the universe in modern physics, what we have is a simply a bizarre thing we're trying to make sense of. So while these documentaries completely fail to explain the dynamics, all they induce is an idea about a "fancy" sort of physics which, in fact, does not exist.

    And finally, when they say something is "counterintuitive", it actually means something.
    (I hope you remember the context. :P)

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  4. You might have a look at this:
    for a fairly lucid explanation of a pretty complicated idea and

    and the following:

    The way these `stupid' documentaries do work is that they help you get interested in the subject. Anyone with the right mind for it will see the fallacies and go look for the answers. For others I am guessing it is fine to entertain themselves as mentioned by everyone else above.

  5. @Sudipto: bad typing mistake in the Relativity thingi. Corrected. Thanks for pointing out.

    In general: keep it going. You guys are rocking the post on :P