How science works

How science works

1. Science tries to how and why things happen. It's all about seeking and gaining knowledge about the world around us. This is done by observing, developing theories, and then testing them to see if they're correct. The scientific process has 5 main stages.

   • 1. Developing theories
     • A theory is a possible explanation for something. Theories usually come about when scientists observe something and wonder how that happens. Models (a simplified picture of what's physically going on)
     • Examples
       • Darwin came up with the theory of evolution by natural after observing wildlife (like finches) and fossils during a trip around south America and the Galapagos Islands.
       • The theory that smoking causes lung cancer was developed after it was observed that many people smoked, also got lung cancer
       • John Snow came up with the idea that cholera was transmitted in water rather than air after observing that lots of cases of cholera clustered around a water pump
   • 2. Testing theories
     • The next step is to make prediction or hypothesis which is a specific testable statement, based on the theory about what will happen in a test situation. Then an experiment or study is carried out to provide the evidence that will support the prediction (or help to disprove it). If it's disproved, the theory is modified or a completely new one is developed.
     • Examples
       • Edward Jenner tested his idea that getting cowpox protected people from getting smallpox by infecting a boy with cowpox, then exposing him to smallpox. The boy didn't get smallpox, which provided evidence to support his theory. This eventually led to the development of a smallpox vaccine.
       • Louis Pasteur designed an experiment to test his idea that 'germs' in the air caused disease and decomposition. He boiled two flasks of broth, both of which were left open to the air. One of the flasks had a curved neck to trap any airborne bacteria so they couldn't get into the broth. The broth in the flask with curved neck stayed fresh whereas the other broth went off. This provided evidence to support his theory. After more evidence like this, modern microbiology was born.
   • 3. Communicating results
     • The results are then published to let other scientists know about their work. They publish their work in scientific journals. They undergo a peer review before they're published and they are sent out to peers who are other scientists and experts in the same area. But this doesn't guarantee that work is correct so sometimes mistakes are made and flawed work is published. This isn;t perfect but it's one of the best ways to self-regulate their work and to publish their quality reports.
   • 4. Validating the theory testing it further
     • Other scientists read the published theories and results and try to test the theory themselves in order to back it up. This involves repeating the same experiment and using the theory to make new predictions and then testing them with new experiments.
   • 5. The theory is rejected or accepted
     • If multiple experiments show a theory to be incorrect then scientists either have to modify the theory or develop a new one, and then start testing again. If all the experiments in the world provide good evidence to back the theory up, the theory is thought to be as a scientific 'fact' (for now). However, scientific breakthroughs or advances could provide new ways to question or test the theory which could lead to a new evidence. Then the testing starts all over again.