Theories & Laws

To round out our discussion on experiments, we need to talk about what happens after experiments are finished.  In a work setting, you would do an experiment as research for either industry (a private or publicly shared company) or academia (a university).  Your results would be published in a peer-reviewed journal, like Science, where other scientists would read about your experiment.  (In many ways, journal publication is the life-blood of professors and graduate students, but that’s a story for another day.)

If many other experiments are run that point to the same conclusions, a theory or a law can be formed, and you would generally publish all the results with in a new journal article that proposes your theory or law.

But what’s the difference, you ask.

First, they are two different things.  A popular misconception is that theories turn into laws as more proof becomes available.  A theory is always a theory and a law is always a law.

A scientific law applies to every observation made with regards to a particular event or element.  For example, Newton’s Laws of Motion describe the relationship between the forces acting on a body and the motion of that body.  If an observation is made about the relationship between the forces acting on a body and the motion of that body that doesn’t fit the Laws of Motion, the law or laws have been disproved.

In brief, a law tends to explain what happens.

A scientific theory attempts to explain how or why something happens. For example, the Big Bang Theory attempts to explain how the universe came to exist.  An alternate theory wouldn’t disprove the Big Bang Theory, rather merely offer another explanation.  It is important to realize, however, that the best theories are supported by numerous observations and/or experiments.  To dismiss something as “Oh, that’s just a theory” doesn’t give credit to the scientists who have worked to explain that phenomenon.

Here’s a list of some notable theories.  And another of some laws.