Science vs. common sense

A regular reader of my blog commented to me, rather offhand, "To read your posts, you sound awfully sure of yourself.  A little arrogant, even."

I'll leave the last part to wiser heads than mine to answer; I may well have an arrogant streak, and in fact I've remarked more than once that to have a blog at all implies a bit of arrogance -- you have to believe, on some level, that what you think and write will be interesting to enough people to make it worth doing.  But I'd like to leave my own personality flaws aside for a moment, and take a look at the first part of the statement, which is saying something quite different, I think.

In saying that I sound "sure of myself," the fellow who made the comment was saying, so far as I can tell, that I sound like I've got all the answers; that my pronouncements on ghosts and faces on grilled cheese sandwiches and Bigfoot, and -- on a more serious level -- science, ethics, politics, philosophy, and religion, are somehow final pronouncements of fact.  I come across, apparently, as if I'm the last word on the subject, that I've said fiat lux in a booming voice, and now all is light.

Let There Be Light by Shigeru Aoki (1906) [Image is in the Public Domain]

Nothing could be further from the truth, both in fact and in my own estimation.

It's because I have so little certainty in my own senses and my brain's interpretation of them that I have a great deal of trust in science.  I am actually uncertain about most everything, because I'm constantly aware about how easily tricked the human brain is, and how often our "common sense" is wrong.  Here are five examples of just how counter-intuitive nature is -- how easily we'd be misled if it weren't for the tools of science.  I'll present you with some explanations of commonly-observed events -- see if you can tell me which are true and which are false based upon your own observations.

1. Homing pigeons, which can find their way home from amazing distances, are navigating using visual cues such as the positions of the sun, stars, and topographic landmarks.
2. Herding behavior in collies and other sheepdogs is learned very young; herding-breed puppies reared by non-herding breed mothers (e.g. a collie puppy raised by a black lab mother) never learn to herd.
3. A marksman shoots a gun horizontally over a level field, and simultaneously drops a bullet from the same height as the gun barrel. The dropped bullet will hit the ground before the shot bullet because it has far less distance to cover.
4. Flowering plants are temperature-sensitive, and spring-flowering plants like daffodils and tulips recognize the coming of spring (and therefore time to make flowers) when the earth warms up as the days lengthen.
5. Time passes at the same rate for everyone; time is the one universal constant.  No matter where you are in the universe, no matter what you're doing, everyone's clock ticks at exactly the same rate.

Ready for the answers?

All of them are false.

1. Homing pigeons are remarkably insensitive to visual cues.  An experiment, conducted at Cornell University, showed that pigeons' tiny little brains allow them to navigate by picking up the magnetic field of the earth -- i.e., they have internal magnetic compasses.  This ability, called magnetoreception, is shared with a handful of other species (including various turtles, salamanders, fish, bees, and at least one group of motile bacteria).
2. Herding behavior in collies is entirely genetic, not learned (although they refine the skill with training).  Most amazingly, researchers have actually identified the genetic pathways that are responsible for the behavior.  A dog with defects in one or more of those pathways can't learn to herd.  Scientists are still trying to figure out how one set of genes can control a complex behavior like herding ability.  This sheds some interesting light on the nature-vs.-nurture question, though, doesn't it?
3. In this classic thought experiment, the two bullets hit the ground at precisely the same moment.  Vertical velocity and horizontal velocity are entirely independent of each other; the fact that the one bullet is moving very quickly in a horizontal direction, and the other isn't, is completely irrelevant.
4. Temperature has very little to do with the timing of flowering, although a prolonged period of cold can slow down early-flowering plants some.  It used to be thought that flowering plants were timing their flowering cycles based on relative day length, and whether day length was increasing or decreasing; this response (called photoperiodism) clearly has something to do with it, but the mechanism controlling it is still poorly understood.
5. The General Theory of Relativity, which has been experimentally confirmed countless ways, actually says exactly the opposite of this.  What it does say is that the speed of light is constant in all frames of reference, and this has, as one of its bizarre outcomes, that time is completely relative.  Not only might your clock be ticking at a different rate than mine, depending on our relative motion, but events that look simultaneous to you might look sequential to me.  No wonder Einstein won the Nobel, eh?

All of this is just to indicate that our intuition, our "common sense," and even our sensory information, can sometimes be very misleading.  Science is our only way out of this mess; it has proven itself, time and again, to be the very best tool we have for not falling into error because of the natural mistakes made by our brains, the fallacy of wishful thinking and confirmation bias, and being suckered by charlatans and frauds.

A charge levied against science by some people is that it changes; the "truths" of one generation may be different from those of the next.  (I call this the "They Used to Believe the Earth Was Flat" argument.)  Myself, I find this a virtue, not a flaw.  Science, by its nature, self-corrects.  Isn't it better to put your trust in a world view that has the capacity to fix its own errors, rather than one which promises eternal truths, and therefore doesn't change regardless of the discovery of contrary evidence?

I realize that this line of reasoning approaches some very controversial thin ice for many people, and I've no intent to skate any nearer to the edge.  My own views on the subject are undoubtedly abundantly clear.  I firmly believe that everyone buys into the world view that makes the best sense of his/her world, and it would be arrogant for me to tell another person to change -- the most I can do is to present my own understanding, and hope that it will sell itself on its own merits.  And for me, the scientific model may not be perfect, but given the other options, it's the best thing the market has to offer.

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As I've mentioned before, I love a good mystery, which is why I'm drawn to periods of history where the records are skimpy and our certainty about what actually happened is tentative at best.  Of course, the most obvious example of this is our prehistory; prior to the spread of written language, something like five thousand years ago, most of what we have to go by is fossils and the remnants of human settlements.

Still, we can make some fascinating inferences about our distant ancestors.  In Lost Civilizations of the Stone Age, by Richard Rudgely, we find out about some of the more controversial ones -- that there are still traces in modern languages of the original language spoken by the earliest humans (Rudgely calls it "proto-Nostratic"), that the advent of farming and domestication of livestock actually had the effect of shortening our average healthy life span, and that the Stone Age civilizations were far more advanced than our image of "Cave Men" suggests, and had a sophisticated ability to make art, understand science, and treat illness.

None of this relies on any wild imaginings of the sort that are the specialty of Erich von Däniken, Zecharia Sitchin, and Giorgio Tsoukalos; and Rudgely is up front with what is speculative at this point, and what is still flat-out unknown.  His writing is based in archaeological hard evidence, and his conclusions about Paleolithic society are downright fascinating.

If you're curious about what it was like in our distant past, check out Lost Civilizations of the Stone Age!

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Patterns out of noise

We all have intuition and common sense about how the world works, and it is fascinating how often that intuition is wrong.

Not that I like having my worldview called into question, mind you; but I have to admit there's a certain thrill in discovering that there are subtleties I had never considered.  Take, for example, Benford's Law, that I first heard about a while back while listening to the radio program Freakonomics.  In any reasonably unrestricted data set, what should be the relative frequencies of the first digit?  Put another way, if I was to take a set of numbers (like the populations of all of the incorporated villages, towns, and cities in the United States) and look only at the first digits, how many of them would be 1s, 2s, 3s, and so on?

On first glance, I saw no reason that the distribution shouldn't be anything but equal.  That's what a set of random numbers means, right?  And how are the populations of municipalities ranging from ten people all the way up to several million anything other than a collection of random numbers?

Well, you've probably already guessed this isn't right.  Lining up the frequencies of 1s through 9s in order, you get a perfect inverse relationship.  About 30% of the first digits are 1s, all the way down to only 5% being 9s.

Why is this?  Well, the simple answer is that the statisticians are still arguing about it.  But it does give a way to catch when a supposedly real data set has been altered or fudged; the real data set will conform to Benford's Law, and (very likely) the altered one won't.

Another interesting one, and in fact the reason why I was thinking about this topic, is Zipf's Law, named after American linguist George Kingsley Zipf, who first attempted a mathematical explanation of why it works.  Zipf's Law looks at the frequencies of different words in long passages of text, and finds that there's an inverse relationship, similar to what we saw with Benford's Law.  In English, the most commonly used word is "the."  The next most common ("of") has half that frequency.  The third ("and") has one-third the frequency.  And on down the line; the tenth most frequent word occurs at one-tenth the frequency of the most common one, and so forth.

Zipf's Law has been tested in dozens of different languages, including conlangs like Esperanto, and it always holds.  So does the related pattern called the Brevity Law (there's an inverse relationship between the length of a word and how commonly it's used), and -- to me the most fascinating -- the Law of Hapax Legomenon, which states that in long passages of text, about half of the words will only occur once (the name comes from the Greek ἅπαξ λεγόμενον, meaning "being said once").

Where things get really interesting is that these three laws -- Zipf's Law, the Brevity Law, and the Law of Hapax Legomenon -- may have relevance to the search for extraterrestrial intelligence.  Say we pick up what seems like radio-wave-encoded language from another star system.  The difficulty is obvious; translating a passage from another language when we don't know the sound-to-meaning correspondence is mind-bogglingly difficult (although it has been accomplished, most famously Alice Kober's and Michael Ventris's decipherment of the Linear B script of Crete).  

The task seems even more hopeless for an alien language, that shares no genetic roots with any human language, and thus the most useful tool we have -- noting similarities with known related languages -- is a non-starter.  Just like Dr. Ellie Arroway in Contact, we'd be faced first with the seemingly insurmountable problem of figuring out if it is an actual alien language, and not just noise or gibberish.

The three laws I mentioned may solve at least that much of the problem.  The fact that they've been shown to govern the frequency distribution of every language tested, including completely unrelated ones like Japanese and Swahili, suggests that they might represent a universal tendency.  Just as Benford's Law can help statisticians identify falsified data sets, the three laws of word frequency distribution might help us tell if what we've picked up is truly language.

It still leaves the linguists with the daunting task of figuring out what it all means, but at least they won't be working fruitlessly on something that turns out to be mere noise.

I find the whole thing fascinating, not only from the alien angle (which you'd probably predict I'd love) but because it once again demonstrates that our intuition about things can lead us astray.  Who would have guessed, for example, that half of the words in a long passage of text would occur only once?  I love the way science, and scientific analysis, can correct our fallible "common sense" about how things work.

And, as with Zipf, Brevity, and Hapax Legomenon, open up doors to understanding things we never dreamed of.

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Ever get frustrated by scientists making statements like "It's not possible to emulate a human mind inside a computer" or "faster-than-light travel is fundamentally impossible" or "time travel into the past will never be achieved?"

Take a look at physicist Chiara Marletto's The Science of Can and Can't: A Physicist's Journey Through the Land of Counterfactuals.  In this ambitious, far-reaching new book, Marletto looks at the phrase "this isn't possible" as a challenge -- and perhaps, a way of opening up new realms of scientific endeavor.

Each chapter looks at a different open problem in physics, and considers what we currently know about it -- and, more importantly, what we don't know.  With each one, she looks into the future, speculating about how each might be resolved, and what those resolutions would imply for human knowledge.

It's a challenging, fascinating, often mind-boggling book, well worth a read for anyone interested in the edges of scientific knowledge.  Find out why eminent physicist Lee Smolin calls it "Hugely ambitious... essential reading for anyone concerned with the future of physics."

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

 

Science vs. common sense

A regular reader of my blog commented to me, rather offhand, "To read your posts, you sound awfully sure of yourself.  A little arrogant, even."

I'll leave the last part to wiser heads than mine to answer; I may well have an arrogant streak, and in fact I've remarked more than once that to have a blog at all implies a bit of arrogance -- you have to believe, on some level, that what you think and write will be interesting to enough people to make it worth doing.  But I'd like to leave my own personality flaws aside for a moment, and take a look at the first part of the statement, which is saying something quite different, I think.

In saying that I sound "sure of myself," the fellow who made the comment was saying, so far as I can tell, that I sound like I've got all the answers; that my pronouncements on ghosts and faces on grilled cheese sandwiches and Florida Skunk Apes, and -- on a more serious level -- ethics, politics, philosophy, and religion, are somehow final pronouncements of fact. I come across, apparently, as if I'm the last word on the subject, that I've said fiat lux in a booming voice, and now all is light.

Nothing could be further from the truth, both in fact and in my own estimation.

It's because I have so little certainty in my own senses and my brain's interpretation of them that I have a great deal of trust in science.  I am actually uncertain about most everything, because I'm constantly aware about how easily tricked the human brain is.  Here are five examples of just how counter-intuitive nature is -- how easily we'd be misled if it weren't for the tools of science.  I'll present you with some explanations of commonly-observed events -- see if you can tell me which are true and which are false based upon your own observations.

1. Homing pigeons, which can find their way home from amazing distances, are navigating using visual cues such as the positions of the sun and stars.
2. A marksman shoots a gun horizontally over a level field, and simultaneously drops a bullet from the same height as the gun barrel.  The dropped bullet will hit the ground before the shot bullet because it has far less distance to cover.
3. Flowering plants are temperature-sensitive, and spring-flowering plants like daffodils and tulips recognize the coming of spring (and therefore time to make flowers) when the earth warms up as the days lengthen.
4. Time passes at the same rate for everyone; time is the one universal constant.  No matter where you are in the universe, no matter what you're doing, everyone's clock ticks at exactly the same rate.
5. Herding behavior in collies and other sheepdogs is learned very young; herding-breed puppies reared by non-herding breed mothers (e.g. a collie puppy raised by a black lab mother) never learn to herd.

Ready for the answers?

All of them are false.

1. Homing pigeons are remarkably insensitive to visual cues.  A paper by R. Wiltschko and W. Wiltschko of J.W.Goethe-Universität Frankfurt describes research showing showed that pigeons' tiny little brains allow them to navigate by picking up the magnetic field of the earth -- i.e., they have internal magnetic compasses.  These compasses take the form of magnetite crystals near the trigeminal nerve in the face, and the crystals' movements tells the birds not only what direction is north, but their inclination tell them how far north (i.e., the latitutde).  This ability, called magnetotaxis, is shared with only a few other species, including at least one species of motile bacteria.
2. In this classic thought experiment, the two bullets hit the ground at precisely the same moment.   Vertical velocity and horizontal velocity are entirely independent of each other; the fact that the one bullet is moving very quickly in a horizontal direction, and the other isn't, is completely irrelevant.
3. Temperature has very little to do with the timing of flowering, although a prolonged period of cold can slow down early-flowering plants some.  What actually is cueing plants to flower is the relative lengths of day and night; this response is called photoperiodism.  It used to be thought that flowering plants were timing their flowering cycles using a chemical called phytochrome that oscillates between two different forms in the light and in the dark; this clearly has something to do with it, but the mechanism controlling it is still poorly understood.
4. The General Theory of Relativity, which has been experimentally confirmed countless ways, actually says exactly the opposite of this.  What it does say is that the speed of light is constant in all frames of reference, and this has, as one of its bizarre outcomes, that time is completely relative.  Not only might your clock be ticking at a different rate than mine, depending on our relative motion, but events that look simultaneous to you might look sequential to me.  No wonder Einstein won the Nobel, eh?
5. Herding behavior in collies is entirely genetic, not learned (although they refine the skill with training).  Most amazingly, it seems to be caused by very small number of genes (possibly only a single gene, but that point isn't settled).  A dog with a specific genetic makeup can be trained to herd; a dog without it can't.  Scientists are still trying to figure out how such a small chunk of DNA can control a complex behavior like herding ability.  This sheds some interesting light on the nature-vs.-nurture question, though, doesn't it?

[image courtesy of the Wikimedia Commons]

All of this is just to indicate that our intuition, our "common sense," and even our sensory information, can sometimes be very misleading.  Science is our only way out of this mess; it has proven itself, time and again, to be the very best tool we have for not falling into error because of the natural mistakes made by our brains, the fallacies of wishful thinking and confirmation bias, and being suckered by charlatans and frauds.

A charge levied against science by some people is that it changes; the "truths" of one generation may be different from those of the next.  (I call this the "They Used to Believe the Sun Went Around the Earth" argument.)  Myself, I find this a virtue, not a flaw.  Science, by its nature, self-corrects.  Isn't it better to put your trust in a world view that has the capacity to fix its own errors, rather than one which promises eternal truths, and therefore doesn't change regardless of the discovery of contrary evidence?

I realize that this line of reasoning approaches some very controversial thin ice for many people, and I've no intent to skate any nearer to the edge.  My own views on the subject are undoubtedly abundantly clear.  I firmly believe that everyone buys into the world view that makes the best sense of his/her world, and it would be arrogant for me to tell another person to change -- the most I can do is to present my own understanding, and hope that it will sell itself on its own merits.  And for me, the scientific model may not be perfect, but given the other options, it's the best thing the market has to offer.

Uncommon sense

One statement that completely makes me crazy -- right up there with "evolution is only a theory" -- is "scientists have been wrong before, so everything science says could be proven wrong tomorrow."

The latest person to make this infuriating pronouncement as a way of ignoring what the science actually does say is Anthony Scaramucci, aide to President-elect Trump and member of his Transition Team Executive Committee.  Here's what Scaramucci said:

I know that the current president believes that human beings are affecting the climate.  There are scientists that believe that that's not happening...  I'm not suggesting that we're not affecting the change.  I honestly don't know. 

There was overwhelming science that the earth was flat and there was an overwhelming science that we were the center of the world.  We get a lot of things wrong in the scientific community.  You've got a very common-sense oriented president at the top of the chain now.  Some of the stuff you're reading and some of the stuff I'm reading is very ideologically-based about the climate.  We don't want it to be that way...

What I want to do is I want to have a problem solving-oriented, common sense, solution-based administration, because that’s what the president-elect has given us a directive to do here at Trump Tower...  [Y]ou’re saying the scientific community knows, and I’m saying people have gotten things wrong throughout the 5,500-year history of our planet. 

Scaramucci hastens to add, in case there was any doubt in that regard, "I am not a scientist."

*brief pause to punch a wall*

There are so many wrong things packed into this short statement that I barely know where to begin.  First, as I've said 253,892 times before, the argument over whether climate change is (1) happening and (2) anthopogenic in origin is over, at least among the scientific community.  That's not "ideologically-based," that's as close to a certainty as you want to get.  The only arguments any more among climate scientists are how bad, how much, and how fast.

Then there's the "scientists get things wrong" trope.  First, of course scientists get things wrong.  They're human, so they make mistakes, fall for their own biases, and on rare occasion become so wedded to their theories that they falsify results.  But the point here is that this is why science exists.  It gives us a rigorous way to catch this kind of stuff, to self-correct, to make sure that errors aren't perpetuated.  Some errors do persist -- to pick one that actually did (i.e. not Scaramucci's "the Earth is flat" bullshit, which was disproven in the time of the ancient Greeks and not widely accepted by the learned after that time), there's the geocentric model and its cousin, the idea that heavenly objects move in perfect circles.  That one did take a while to knock to pieces, but it's significant that the resistance didn't come from the scientists, it came from the religious authorities.  But the work of Copernicus, Galileo, and especially Tycho Brahe and Johannes Kepler left no room for argument.  Confronted with the data, the model has to change.  And far from being a weakness in the scientific approach, its ability to self-correct is its greatest strength.

[image courtesy of the Wikimedia Commons]

Then there's the subtlest mistake in Scaramucci's statement, which is that Trump's adherence to "common sense" is some kind of virtue, that common sense should win over science.  The problem is that common sense is sometimes wrong -- our intuition doesn't always steer us in the right direction.  Here's a simple example from physics:

Someone shoots a gun held perfectly level/parallel to the ground.  At the same moment that the gun is fired, a bullet is dropped from the same height.  Which bullet hits the ground first?

Intuition -- i.e. common sense -- usually leads people to figure that since the dropped bullet travels a much shorter distance, it must hit the ground first.  It's hard to picture the real situation, which is that the fired bullet actually travels in an arc, and drops vertically at exactly the same rate as the dropped bullet does.  In fact, the two bullets hit the ground at precisely the same time, something that has been demonstrated in every high school physics class in the world (although hopefully using something other than an actual gun).

This is why we need a rigorous system for determining whether a claim is true.  Our common sense is what's flawed, leads us astray.  Science catches its own errors, and has a stepwise process for winnowing out poor data and bad thinking.  It doesn't work 100% of the time -- nothing does -- but it's by far the best thing we've got.

Oh, and about the "5,500 year history of our planet:" *brief pause to punch a wall again*

So I don't recommend that you listen to the clip, which you can access at the link I posted above, both for your knuckles' sake and your wall's.  But if you do, you will be listening to one of the best examples of political doublespeak I've ever heard.

So for fuck's sake, let's listen to the scientists instead of the talking heads like Anthony Scaramucci blathering on about common sense and ideological climate science and the flat Earth.  It's time to trust the people who actually know what they're talking about.