Saturday, June 22, 2013

Science and the "Experimental Method?" -- [un]Common Sense (Pt. 3)

Image: The bottle Louis Pasture used to detect bacterial activity
The bottle Louis Pasture used to detect
bacterial activity (Wikimedia Commons)
by Leo Walsh

A lot of science relies on experiments. But not all. Massimo Pigliucci, a professor at the City University of New York, examines this issue in his wonderful book,  Nonsense on Stilts: How to Tell Science from Bunk,

Pigliucci re-considers the notion of experimentation as the "end all" of science. He lists out a series of scientific disciplines that resemble detective work rather than mad scientist, surrounded by test tubes: examples include climate science and geology. In these disciplines, scientists gather data and then "connect the dots," but cannot not run controlled experiments.

The hard sciences, like chemistry and physics, deal with simpler systems according to the author. Biological, cognitive and social sciences, by contrast, study much more complex systems.

An electron, for example, will not have it's trajectory influenced by an argument with its wife. Humans, on the other hand, are messy. 

The key to science, according to Pigliucci, is observation, and peer review. A good scientist forms a hypothesis of the world, and observes realty to see if it confirms or "falsifies" the researcher's hunch.

What is falsification? 

A properly developed scientific theory offers a rather clear way for an investigator to either verify, or prove his or her assumptions (called a Hypothesis). The investigation, experiment and analysis should be clear-cut. And observation will either confirm the theory, or it will not. This "negative" result is called falsification.

Thus, you will notice that this leaves out the majority of common sense: if we operate by wives tales, we can be correct 100% of the time. If Joe Rocker marries Jane Librarian, we say "opposites attract." When Joe Rocker leaves Jane for Janet Punker-Rocker, we say "birds of a feather flock together" -- so common sense cannot be scientific.

The reason why many people focus on experiments as the "end all, be all" of science it because they are powerful because they are controlled, and can be repeated.  And experiments illustrate the concept of "falsification" in a clearly visualized way.

An Experiment 

The basic steps in the experimental method follow.
  1. Observe: "Reality" is observed and measured..
  2. Hunch: Based on observations, a scientist has a hunch about what it causing an action.
  3. Hypothesis: She builds a hypothesis around these assumptions. 
  4. Experiment: She then designs an experiment to test those assumptions.
  5. Evaluate: Most experiments fail to confirm a theory. Scientists welcome this falsification: it frees them to from pursuing a dead-end line of research. 
  6. A Theory is Born: If the experiment confirms the hypothesis over many repeated attempts, it will graduate to a Theory.
Let's apply this framework to the famous discovery of Louis Pasture-that bacteria, already implicated in disease, can be spread by air borne "spores." At the risk of sounding like a middle school text book, here is goes...
  1. Observe: Pasture realized that boiling nutrient broth killed the bacteria. He also noted that if he exposed broth to the air, bacteria would colonize the broth.
    1. Hunch: The bacteria is coming from the air. Dust is likely the source, since the bacterial infestations radiate out from dust motes. 
    2. Hypothesis: Pasture stated, "The bacteria in the sterile broth came from'germs' borne by the dust."
    3. Experiment: Boil nutrient broth in a "swan necked" bottle that would not allow dust,
      Pasture's experiment illustrated
      Pasture's experiment illustrated (Wikimedia Commons)
      and thus 'germs,' to enter the bottle (see illustration to the right). Break the neck off of some of the bottles, allowing dust and air to enter the broth. 
    4. Evaluate: The broth in the broken bottles teamed with bacteria, Those that remained intact did not. This proved that Pasture's hunch was correct.
    5. A Theory is Born: Because of the brilliant simplicity of the experiment, the final verification of the "Germ Theory of Disease" is attributed to Pasture.

    Non-Experimental Sciences

    An important question to ask yourself: Isn't there more to science than this? What about sciences like Evolutionary Biology, Archaeology and Astronomy? The do not have an ability to run experiments over and over again.

    In these sciences, theories tend to be proved with observational data. For instance, Pluto was discovered when Percival Lowell began searching out fluctuations in Uranus's orbit that be assumed was another planet. Lowell dies in 1916, before the planet was discovered. But his clear hypothesis led another researcher,  Clyde Tombaugh, to search for a planet using Lowell's analysis.  Finally, in 1928, Tombaugh located the planet.

    Breaking Down a Non-Experimental Science

    1. Observe: Lowell observed Uranus, and noticed orbital fluctuations.
    2. Hunch: Another planet must be causing the wobble in the orbit. He used accepted astrophysical equations to determine the approximate location of Pluto.
    3. Hypothesis: "There must be a planet causing the orbital flux. So let's observe in this area.
    4. Gather Evidence (Instead of Experimenting):  Tombaugh examined the night sky in the area Lowell indicated, and discovered Pluto.
    Image: Pablo Picasso -- "The Dreamer."
    Pablo Picasso -- "The Dreamer."
    (from Experimental Photo Arts on Blogger)
    Notice that observation could have proved either Lowell's or Pasture's hunches incorrect. If Tombaugh would not have found a planet, Lowell's predictions would have been incorrect. If bacteria grew in the nutrient broth with the unbroken neck, the "Germ Hypothesis" would be proved incorrect.

    Science and Non-Science

    Which leads us to several theories that have the sheen of science, but are not since they cannot be falsified. Freudian psychology is case and point. We cannot see an Id, an Ego, or a Super Ego. Nor can we see repressed memories, or the Oedipus Complex.

    This does not make Freud incorrect. It just makes his theory non scientific.

    I do not think that being "non scientific" is a bad thing, by the way. Science could never produce the lovely painting of Pablo Picasso's, "The Dreamer." It could analyze the pigments, and weigh the canvas -- but would it be near as lovely?

    Nor can science tell me why I love Shakespeare's King Lear. Science can give word counts and linguistic analysis, but can never unravel the beauty and pain that Shakespeare wrings from me when I see this play.

    So, despite my love for science, it is a limited discipline. It is great at what it does well -- observing reality, and figuring out how the manifest world operates. But it does not work well when we need to climb inside things, and feel.

    But that's another story. Which brings us to Richard Wilbur. And holons. And the "Great Chain of Being."

    And I'm lazy. And going for a jog.


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

    No comments:

    Post a Comment