Friday, July 8, 2011

The Value of Uncommon Sense

Einstein once said that "common sense is the collection of prejudices acquired by age eighteen."  I don't know that I'd put that fine a point on it, but the general idea is pretty accurate.  Let's first think about that term -- "common sense."  Specifically, the "common" part.  Common, as in everyday...  as in experiences we run across regularly and very often... things we might have dealt with so many times that it just seems like second nature...  things we know forwards and backwards and can just deal with again without having to put much thought into it.  How useful is that in day-to-day life?  I think most people would agree that it is pretty useful...  to say nothing of wishing they had more of it.  How useful is it in science?  A lot of people would still think it's useful...  a lot of people are dead wrong.  It's about as useless as things get in a scientific context.

A very common avenue of objection to a lot of scientific principles lies in an appeal to common sense.
Apparently, common sense is so rare in science, it's considered a super-power
Oh yes, we see it all.  The Intelligent Design argument consists entirely of arguing that "common sense" tells us that complexity is impossible by way of nature alone.  The global warming deniers tell us that "common sense" shows the Earth can't be warming if I see snow in my backyard in March.  Geocentrists say that "common sense" tells us that if the planet was moving, we'd all fall off (yes, I've had my tussles with geocentrists).  Anti-vaccine activists all say that it's just "common sense" that mercury is dangerous, so vaccines must cause autism.

All fine examples of how, when it comes to science, one should never ever defer to common sense.

If I take my job as an example, I don't think it is possible for me to really thoroughly explain what it is I do for a living in any terms that fall within common sense.  Even before I was doing this kind of work for movies, I was doing a similar type of work for video games.  Back then, if anybody asked me what I do...  I would simply say I was a programmer or software engineer.  I wouldn't specify anything about being in games, because "common sense" associates video games with playing and leisure -- thereby leading to the assumption that I get paid to play games.  Oh, dear.  When I say I work in animated films, people either have these fanciful images that I occasionally walk the red carpet and hobnob with Hollywood celebrities, or that I work in some sort of uber-kid-friendly environment with cartoon characters and toys everywhere which makes it sound as if I program computers in a daycare center or something.  I can only sigh and facepalm.

Conversely, if I try to explain what I do for a living to some other engineer, or someone who knows a thing or two about optics, it's not that difficult for them to get a clear idea.  These sorts of people already have the background knowledge to be able to get an idea of how these concepts tie together and what they are, even if only at a broad level.  It's not within the realm of common sense to associate animated films with multivariable calculus, signal processing theory, and quantum mechanics.  Why not?  Well, these things aren't within common everyday purview.  Sure, we all understand that a glazed porcelain cup is shiny, but not why it is shiny or what that shininess implies at a microscopic level or how light behaves when it hits that cup.  The former bit is a matter which falls within common sense.  The latter is most certainly not.  And yet, both of them are true and ultimately prove to be connected to one another at some level.

The deeper truths of how things work in science are never the sort of thing that really falls under our day-to-day experiences.  Certainly not growing up.  Sure, we all know that the Earth orbits the sun and the cycle of day and night is caused by the rotation of the planet about its axis, but that's actually not an obvious conclusion to make based on the cursory level of observation we all tend to make.  If all you do is look outside at the surroundings, you'd be hard-pressed to even determine that the Earth is not flat...  unless you happened to be on the open sea or at Bonneville or something where you can actually see the curvature of the Earth.  Within a glance at our backyards, all indications are that the Earth is flat.  It was only by observing at a completely different scale than one's backyard and noticing something that didn't quite add up with a flat Earth hypothesis that it was possible to see that the Earth is curved.  Whether it be by the length of shadows as Eratosthenes did, or by the curvature of the Earth's shadow on the moon, as Aristotle or Aryabhatta both saw, there are a few simple observations that can indicate the roundness of the planet, but to do it takes some effort and curiosity to actually follow through on.

To assume that the world is flat because it looks flat is something anybody can do.  It's common sense that the world is flat.  In our everyday view on it, it clearly appears to be flat.  We accept that the world is round, not on common sense, but on common knowledge.  This is a clear case, though, where common sense is wrong, and common knowledge has it more correct.  When it comes to matters of science, though, it's rare that there is anything common to go on, and that leads to a terrible pitfall in thinking.

Indeed, Einstein got it right when he described common sense as a collection of prejudices.  Take for instance, the "Intelligent Design" argument, which is really nothing more than a "look at how complex it is" argument.  Within our normal day-to-day lives, everything we see that we recognize to be complex is man-made.  Everything we see that serves a specific purpose is generally man-made and designed specifically for that purpose.  Therefore, people see something that does serve a purpose in a natural context -- like a heart, which appears specially designed to pump blood...  and then make the jump to say that it must have been designed in the same way a microwave oven is.  This is, in effect, a prejudice because you are making up your mind that some sort of "designer" has to exist by analogy, rather than even putting any sort of effort to analyze the claims about how it might have come about otherwise.  In debate against creationists, it's very common for us to attack the fact that all creationists invariably mischaracterize the theory of evolution, and pretty much all of science as well, but leave out the other factor that such an appeal to common sense analogy is an admission that science is not even among the considerations.

If I tell you that you could pour liquid nitrogen on your bare hands and be perfectly safe, would you believe me?  Well, okay, liquid nitrogen is not among our normal day-to-day experiences, but touching stuff that's really cold to the point of being painful is.  So would you believe you can pour liquid nitrogen, at a temperature of -321 oF or -196 oC, on your bare hands and be perfectly fine?  Well, common sense would lead you to think that something that extremely cold could be extremely painful or downright damaging or cause frostbite.  For that matter, if you've ever seen a demonstration of things like fruits or flowers dipped in liquid nitrogen and frozen solid to the point of being brittle, you might think that's what will happen to your hand.  In fact, what will happen is that the heat of your hand will actually cause the nitrogen to boil so vigorously that a blanket of nitrogen gas will form around it that protects you from direct exposure to the liquid.  It's a phenomenon called the Leidenfrost effect.  If you've ever seen water drops dance around wildly on a hot pan, it's the exact same effect, only your hand is the hot pan.

The point is that common sense is in every way useless in science, and in most cases, is a hindrance.  You need to be prepared to look a lot deeper than what is apparent at a cursory glance.  You cannot look at the snow on your driveway and make a judgment about the average temperatures throughout the entire world.  You cannot look at one animal and another and say they can't possibly be connected by evolution.  You cannot say that symptoms of autism presented after early childhood vaccines, and therefore autism is caused by vaccination.  To do so involves a complete disregard for any other pertinent information.  That is prejudice, pure and simple -- a prejudice that betrays not only outright ignorance of the facts, but a brazen refusal ever not to be ignorant.  It takes a certain uncommon sensibility to be able to actually give a damn about reality.

If you don't care about reality...  well, then...  don't kid yourself into believing that you deserve to be a part of it.  That said, I don't mean to say that everybody in this world should be required to understand quantum tunneling or even that it's a necessary component of how the sun is able to shine at all.  The real point is that when you are scientifically literate, everything about the world looks different to you.  You don't have to know the actual mathematics of stellar dynamics to appreciate the night sky, but when you have some basic idea about what stars actually are really like, at least you'll be able to appreciate the night sky on the basis of things it actually is.  It is when you have no idea whatsoever about stars that you are prepared to believe that their apparent position in the sky at the time and place you were born determine your personality and future.  You don't need to understand semiconductor physics to appreciate the power of your computer, but having some idea about it means you also have the ability to appreciate all the work that went into making it and the sheer magnitude of advancements which have come about since the very first P-N junction was made.  That is a very different perspective on reality.

Common sense has its place.  Science is not it.  If your gut is telling you that a certain scientific principle makes no sense, then chances are you shouldn't be listening to your gut.  The gut is not the seat of the intellect.  It is the gut that invented gods, astrology, vaccines that cause autism, ghosts, heaven/hell, moon hoaxes, government conspiracies, the shooter on the grassy knoll, alien abductions, and just about everything else which is demonstrably idiotic.  The question I have for you is...  do you also want to fall in the category of the demonstrably idiotic?  If not, then try to show a little uncommon sense.