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The scientific method – physics

The scientific method – physics

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What is a hypothesis?

The scientific method – physics

This is Kim and Philip’s favourite spot to swim. But they can’t seem to agree on one thing. Philip thinks the water is warmer in July than in August but Kim doesn’t agree. Kim thinks it’s warmer in August. How can Philip prove his point?

By doing an experiment. But if he really wants to prove Kim wrong, he has to do it scientifically. Philip starts by writing down the problem: is the lake warmer in July? Or in August? Then he takes a smart guess.

He says ‘The water in the lake is warmer in July than in August’. We call this a hypothesis. It’s an assumption you make that you want to test out. So how can Philip figure this out? He has to design an experiment.

He starts by getting something that can measure the water’s temperature: a thermometer. He decides that the best way to compare the temperature of the water is to measure it every day in July and August. Kim reminds him that the water might be colder or warmer at different times of the day so Philip plans to measure the temperature every day at the same time. He has to take accurate readings in a controlled environment. He starts the experiment.

Each day he takes the temperature at twelve pm and writes it down. He’s collecting data from the experiment. After two months, he has collected just over sixty different temperatures. But it doesn’t prove anything until he analyses it. So he adds up the temperatures for July and divides it by the number of days in July.

He gets an average temperature of seventeen degrees Celsius. He does the same for August and gets an average of nineteen degrees Celsius. He reaches a conclusion: the average temperature of the water is higher in August than in July. Seems he proved his hypothesis to be false. Kim was right!

But that’s okay. When a hypothesis is proved false, you can go back and make up a new hypothesis to test. This process is called the scientific method. It’s all about making assumptions, testing them, interpreting what you find and then concluding whether your hypothesis was true. If it wasn’t, you can go back and formulate a new hypothesis to test out.

In fact, many hypotheses are proven false. Maybe next year the weather will be warmer in July and Philip’s hypothesis will be true. Or it could be that his measurements were not accurate enough. Whatever the case, the scientific method is there to test out ideas and learn new things about the world around us. Where there's a problem, there's the scientific method to find an answer.