Monday, 9 December 2013

A Simplified Demonstration of the Scientific Method

You have a glass of water on the table

Pic 1: One of these

You have some food colouring

Pic 2: One of any of these

Out of interest, you add a drop of food colouring into the glass of water, then another one and another one. You realise that the water is changing colour, it's taking on the colour of the food colouring. You stir the water and the colour change is uniform, all the water in the glass is the same shade. You become intrigued and write out a hypothesis (a practical argument that attempts to answer the question "what is happening here?") to explain what is happening. Your hypothesis is that as food colouring spreads through the water it changes the colour of the water and the colour change gets stronger as more food colouring gets added. Stirring the water makes the change uniform because the food colouring becomes evenly distributed. Now you are ready to set up an experiment to test your hypothesis.

You arrange many glasses of water in a row, all the same size and shape and temperature, and you arrange measured tubes of food colouring, again all the same, above the water so that the food colouring drops out at the same rate all along the row (chemists and chem students should know this as a titration set-up). 

Pic 3: Lots of these

Behind each glass of water you place a colour chart so you can track the colour change. In this way you can carry out many experiments at the same time that are the exact same as each other. You find that every glass of water reaches the same colour saturation at, or close around the same amount of food colouring and that in every case, stirring the water makes the change uniform. You find this same result in hundreds of glasses of water. You are happy.
Pic 4: Yes, that happy

You describe your experiments in such a way that anyone in the world can set up the same kind of equipment and materials and get the same result. To this you add your hypothesis, your results, and your conclusions (conclusions being what happens when you compare your original hypothesis to your results). You send off the paper (as this is what you have written) to a scientific journal to be reviewed. The journal sends copies of your paper to several other scientists so they can check what you have written. After testing your results by following the instructions you gave in the paper, the answer is "Yes, the experiment is sound, the results match what we got, we agree with the conclusion, this paper is fit to print." You are now a published scientist and you are delighted.

Pic 5: However you wish to celebrate

You continue your work on food colouring and water, testing all of different factors that can have an impact like changes in temperature, pressure, salinity, chemical composition etc., etc., publishing more papers and working with different groups as you go. You are not the only one doing this anymore. Many scientists all over the world read your original paper and are not only closely following your work and progress but are also doing their own experiments on the premise of food colouring and water. Some have taken different dyes than food colouring, some have taken different liquids than water, but they and you are all pursuing the same goal; how does it work? What makes this happen? What are the mechanics of the process?

Pic 6: Pondering...

Over time the original hypothesis become hypotheses (plural) and they get more and more defined and specialized to explain the results that come from more and more specialized experiments and better instruments that can track the change to a much finer degree. But the original premise of dye + liquid = colour change remains the same because no-one has been able to come up an experiment that proves it wrong. (This, by the way is what you actually do in a scientific experiment, you try to prove things wrong.) Over time, there is enough evidence that you can form a General Theory of Colour Change in Liquids and it is accepted by the general scientific community as it appears to explain what's going on on a large scale.

Now, here comes a new paper that describes an experiment carried out that shows the basic mechanism to be something different than what everyone thought. A research lab working with a new machine with a different detector  method has carried out experiments to show that it is not just the dye but how that dye interacts with the oxygen in the liquid to change the liquid's colour. These new results show that while the original and accepted observation is correct, the mechanics of the process were misunderstood because the observational machinery was not able to get to the lowest layers where the action was taking place. In other words, the liquid changes colour, but not for the reasons everyone thought.

Pic 7: WTF Meatloaf?!

Every lab that has this new machine and new detector copies and expands on these new experiments and the results come back, "Yes, we agree. This is actually how it works." You yourself run the same experiments and come up with the same results and draw the same conclusions. Your theory is proven to be fundamentally flawed. What is your reaction now?

Pic 8:

A real scientist would be happy. Happy because the mechanism of food colouring changing the colour of water is being more accurately described. Because the point of science is to make our knowledge match what is in the real world. If you spend time trying to chase down the wrong idea, you are wasting your time. Your accepted theory on how dyes change the colour of liquids was not accurate, it did not reflect what really happened at the atomic level. Thanks to these new results, you don't have to waste any more of your time running experiments under the old theory. You can go on to something else.

Pic 9: Yep

This is why real science is different from any other discipline. Scientists are expected to chase knowledge, wherever it lies and whatever it leads to. In return, scientists demand proof. They demand replicable experiments and will dismiss anything else. No anecdotes, no personal experiences, no heart-stirring stories. Proof.
Pic 10: Because he says it best...

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