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How Science Works: The Scientific Method

Scientific MethodScience is not a religion, it is not a liberal conspiracy, and it is not an inaccessible language used only by those in academia. Science, at its core, is just a way of looking at the world and testing assumptions. The scientific method is the foundation of this inquiry and provides a framework for how to properly investigate the world in which we live. It allows us to learn new things and build upon the things that we already know.

Steps in the Scientific Method

  1. Ask a question
  2. Take a guess
  3. Test your guess

Obviously, those are very simplified steps but that’s really all there is to it. It starts with a question, usually about a phenomenon that you want to understand better. Then you make a hypothesis about what the answer to your question will be. Then you design and carry out an experiment to test that hypothesis. If your experiment turns out the way you thought it would, you can accept your hypothesis as true. If it turns out differently than you thought, you reject your hypothesis and make a new hypothesis.

Let’s take a deeper look at each of the steps.

Ask a Question

This is fairly self-explanatory: the point of science is to answer questions so you have to start with a question. This can be a simple question like “At what temperature will water boil?” or a complex question like “What causes heart disease?” The scientific method can be used to answer any question (of course, some philosophers and theologians would disagree) regardless of its level of complexity. What’s important is that you have a question. My favorite example is that of Louis Pasteur and his work to disprove the doctrine of spontaneous generation.

Simplified, Pasteur’s question was “Will nutrient broth spoil if it kept sterile?”

Take a Guess

If you ask a question, you did it because you wanted an answer. The scientific method allows you to find the right answer by progressively eliminating the wrong answers. You pick the answer that you think is most likely to be right, and that is called a hypothesis.

Pasteur’s hypothesis to his question above was that the nutrient broth would not spoil if it was not contaminated.

Test Your Guess

This is the most important part of the scientific method. Well-designed experiments are how we, as a species, advance knowledge. They allow us to tell which of our assumptions are correct, and which are fallacies. The goal of all experiments should be to have a few variables as possible so that you can have a greater amount of confidence that the thing you are trying to measure is the thing you are actually measuring.

An example:

You want to know if playing music in the same room as plants will make them grow bigger so you grow some plants in a room with music and some in a room without music. The music-room plants do indeed grow bigger. But, was the temperature in the two rooms the same? Was the amount and intensity of light that the two plants received the same? Did the dirt that the plants were potted in contain exactly the same type and amount of nutrients? Did you provide the two sets of plants with exactly the same amount of water at the same times? Did the cats chew on one plant but not the other?

Without controlling the variables in this experiment, there is no way of knowing if the music was the reason that plant A grew larger than plant B or if it was something else entirely.

To test his guess, Pasteur placed equal amounts of the same batch of nutrient broth into two identical glass bulbs with bent necks. Then both were boiled to sterilize the nutrient broth. One of the glass bulbs had its bent neck removed which allowed for contamination of the nutrient broth.

Unsurprising to us now, but a revelation at the time, the broth that was not allowed to be contaminated never spoiled while the contaminated batch did. This experiment is why we know that food spoilage is caused by bacterial growth.

It is also why most perishable things you buy in the grocery store have been pasteurized (from Pasteur).

Start Over

The scientific method is circular: the last step always leads back to the first. Every time you discover and verify a new piece of information, it leads to another question.

 

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