The meaning of the word ‘theory’ can vary depending on whom you ask. In everyday use, the word simply means a hunch or a guess. In science, however, a theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation. That’s why it is called a ‘scientific theory’.
A theory first starts off as a hypothesis – an idea that hasn’t been proven yet. This hypothesis is then tested using the scientific method:
- Ask a Question
- Do Background Research
- Construct a Hypothesis
- Test Your Hypothesis by Doing an Experiment
- Analyze Your Data and Draw a Conclusion
- Communicate Your Results
If this process continues and enough evidence is accumulated to support that hypothesis it moves to the next step – a theory.
It is a common mistake to think that a theory gets proven and once proven it becomes law. Theories don’t become laws. If we were to put them in a hierarchy, they would be higher than laws. They include laws. For example: we can all feel gravity. Objects fall down. We can test it (if you drop an apple, it will fall). Gravity is a fact – it’s there. However, gravity is also a theory. The theory of gravity explains HOW gravity works. Most plausible is Einsein’s theory of General Relativity – this is the current description of gravity used in modern physics.
Another example is evolution. Evolution is the natural process in which biological populations change, develope, adapt and speciate over time. This process continues objectively outside of the influence of man. We can observe it and test it. It is a fact. The theory of evolution is the scientific study of the mechanisms which evolution uses and goes through to create that process. It is the explanation. The most credible is Darwin’s Natural Selection. It states that evolutionary change comes through the production of variation in each generation. Individuals with characteristics which increase their probability of survival will have more opportunities to reproduce and their offspring will also benefit from the heritable, advantageous character. So over time these variants will spread through the population. Evolution is the observable fact and the theory of evolution is the study of the mechanisms of that observable fact.
Theories change. They can be modified or even discarded. Theories explain facts. As long as we keep moving forward in our discoveries change is welcome. We observe the world around us. We gather evidence and through scientific theories we explain those evidence. A scientific theory is the framework of observations and facts.