Wednesday, June 5, 2013

[un]Common Sense (Pt. 2) -- The Scientific Method

A woodcut from William Caxton's second edition of The Canterbury Tales printed in 1483 (Wikipedia)
A woodcut from William Caxton's second
edition of The Canterbury Tales
printed in 1483 (Wikipedia)
by Leo Walsh
I would like to start with a statement. That seems a bit too bold at first blush. But is quite profound...

"Science is not common sense. In fact, science often runs contrary to common sense." 

How can I say this? Well, let's run a little Thought Experiment.

Pretend that you suddenly wake up in an imaginary, long ago kingdom. Everyone speaks English flawlessly. But, unlike the Lilliputians, they have no fear of strangers. In fact, they embrace you, and take you in as one of their own.

One evening, you sit with your new friends around a lazy fire after dinner, talking aimlessly. Jovially, you swilling back a few pints of a dark, delicious stout that makes Guinness taste like Bud Light. And, by the by, you throw out a fact well-known to us modern people about the earth revolving around the sun.

And everyone bursts out laughing. "Surely, you jest," they guffaw. They stomp their feet, and grab you by the arm.

Joyfully, they drag you outside. The sun is gliding down, setting over the trees. "You see," they say. "It is the sun moving." And, they jump up and down on the earth. "It is solid. It doesn't move."

Thinking you were playing a trick on them, they clap you on the shoulder. "Let's have another pint. Eh?"

Folks... meet Common Sense. Sad as if is to say, he's sitting by that keg, slightly tipsy and spinning a yarn. Good natured. Down to earth. But, quite often, dead wrong.

Science = The Power of Uncommon Sense

We, of course, have the power of history on our sides. Our knowledge that the earth rotates around the sun is due to thousands of years of careful observation. It took Copernicus, with a lot of help from thousands of observers who charted the skies and thought about the heavens, to put it all together.

Scientists meticulously collect and observe evidence. Based on careful and reasoned analysis, they search for patterns in that evidence. An observed pattern becomes a "hypothesis."

Though this runs contrary to common belief, scientists, by nature and training, do not trust themselves. They are humans, know their limitations, and, thus know that they have made errors. In my considered opinion, it is this essential humility and skepticism of their own conclusions is the foundation of scientific inquiry.

To counteract their potential errors, true scientists release their hypothesis to the world. Other scientists examine the hypothesis' assumptions and conclusions, and try to poke holes in it. If possible, they will look for other data, which will either fit or will not fit the conclusions of the hypothesis. This is essentially what is called "peer review." 

If other scientists' observations fit, or confirm the hypothesis, it graduates to the category of Theory.

Some observations about scientific thinking....
  1. Usually a preponderance of evidence, and not a single great experiment, confirms or "falsifies" a hypothesis.
  2. The hypothesis is shared, and run through a gauntlet by peers.
  3. The term "Theory" is used in a way differently than we us it in normal speaking. In fact, the term "Hypothesis" is closer to what we usually mean when we say theory.

The process is slow and tedious. And, as the Copernican Revolution illustrates, there is immense power in this thinking. Though, one must admit that there is something to be said for drinking grog around the fire...

More in the "[un]Common Sense Series" & Science 

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