Monday, May 14, 2012

Monty Python and science

Having put up a bunch of more personal posts, here’s something in the way of a serious online article for the environmental/educational types. So you have been warned. The scientists among you should know this already, but if you do happen to teach science classes, feel free to steal, especially the last bit!

Demonstrating the scientific process

Science is fundementally a way of thinking, a way of approaching problems. It's this approach or process that basically what separates science as academic discipline from the others. Most people can see this way of approaching research in the laboratory sciences such as chemistry. But it's this approach to problem solving that puts "science" in the fields of social science (e.g. sociology, psychology), and separates it from the purely descriptive social fields (e.g. ethnography). Although both technically anthropologists in the broadest sense, it's adherance to this process that makes Temperance Brennan (a forensic anthropologist) on the TV show Bones a scientist, whereas, Indiana Jones is not.

What exactally is the scientific process?

The first stage is that scientists makes observations e.g. how a species behaves, where it’s found, when it’s found, where it reproduces etc. Scientists then use these observations to come to conclusions via induction or deduction.

INDUCTION – after making a variety of observations, the combination of the observations suggests a conclusion
            e.g. sharks, sailfish and tuna all have gills.
            →they are also all fish
            →therefore all fish have gills
DEDUCTION – the scientists makes a general statement (usually based on observations), then predicts what the result would be if this statement is correct

            e.g. sharks, sailfish and tuna all have gills.
            →they are all marine organisms
            →therefore all marine organisms may have gills
            →whales are a marine organism

So the deduction is that whales have gills.
Induction and deduction mean that scientists make statements that might be true, or a “hypothesis”.

            e.g.1: “fish have gills”
            e.g.2: “whales have gills”
To find out whether the hypothesis is correct it must then be tested (usually repeatedly). An important consideration for the scientific method is that a hypothesis must be testable
hypothesis: “somewhere in the ocean there are mermaids

This is not testable as if a scientist searched for mermaids and could not find them, it doesn’t mean they don’t exist, he may just have been looking in the wrong place. Therefore, ‘scientific searches’ that search for bigfoot that you see on TV, are a lot of bollocks.

This is also why “intelligent design” is not a scientific hypothesis, it would be impossible to test and prove that there was a “designer”, therefore the hypothesis was not a scientific one. Whether humans can impact the environment and cause climate change, is, however, a scientific hypothesis, that has been tested repeatedly. In short, a scientific hypothesis must be capable (potentially) of being proven false.

But can a hypothesis really be proven to be “true” – as it is impossible to usually prove beyond any doubt that something is true, for example “all fish have gills”  because somewhere , e.g. in the deep sea, there may be an as yet unfound fish that has no gills. This is one of the problems that scientists face in the policy arena. It is really hard to show politicians (especially ones that don’t understand science). But policy makes want a cut and dried, black and white answer from scientists. Which is rather ironic as politicians so frequently work in shades of gray. To get around this scientists usually say that a hypothesis is accepted, if no test yet tried disproves the hypothesis, rather than saying a hypothesis is true. A hypothesis that stands up to repeated testing then it’s said to be a “theory” e.g. the theory of gravity, relativity and evolution. For all intents and purposes, this is the same as a “law”. Anti-evolutionists deliberately misunderstand the use of the word theory, equating it to a prediction that hasn’t been tested. We should really be saying the “law of evolution”.

As a final comment, this is one of the examples of scientific reasoning that I’ve found (I get my students to discuss this - are there examples of inductive and/or deductive reasoning? What is the hypothesis? Is this science?)

Sir Bedevere: There are ways of telling whether she is a witch.
Peasant 1: Are there? Oh well, tell us.
Sir Bedevere: Tell me. What do you do with witches?
Peasant 1: Burn them.
Sir Bedevere: And what do you burn, apart from witches?
Peasant 1: More witches.
Peasant 2: Wood.
Sir Bedevere: Good. Now, why do witches burn?
Peasant 3: ...because they're made of... wood?
Sir Bedevere: Good. So how do you tell whether she is made of wood?
Peasant 1: Build a bridge out of her.
Sir Bedevere: But can you not also build bridges out of stone?
Peasant 1: Oh yeah.
Sir Bedevere: Does wood sink in water?
Peasant 1:: No, no, it floats!... It floats! Throw her into the pond!
Sir Bedevere: No, no. What else floats in water?
Peasant 1: Bread.
Peasant 2: Apples.
Peasant 3: Very small rocks.
Peasant 1: Cider.
Peasant 2: Gravy.
Peasant 3: Cherries.
Peasant 1: Mud.
Peasant 2: Churches.
Peasant 3: Lead! Lead!
King Arthur: A Duck.
Sir Bedevere: ...Exactly. So, logically...
Peasant 1: If she weighed the same as a duck... she's made of wood.
Sir Bedevere: And therefore...
Peasant 2: ...A witch!
Crowd: Oooh.
Sir Bedevere: So, logically...,
Peasant 1: If … she… weighs the same as a duck, she's made of wood.
Sir Bedevere: And therefore--?
Peasant 1: A witch!
Crowd:  A witch!
Sir Bedevere: We shall use my larger scales! Right, remove the supports!

                    [the scales show that she weighs the same as a duck]

Crowd:  A witch!  A witch!
Witch:   It's a fair cop.
Crowd:  Burn her!  Burn her! 
Sir Bedevere: Who are you who are so wise in the ways of science?
King Arthur: I am Arthur, King of the Britons.

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