 |
|
|
| Shared Idea |
 |
| Laws and Theories
|
| Laws and theories have different meanings in common use and in science. The common definition of a law is a system of rules that regulates actions and maybe enforced. Similarly, a theory is an idea that is used to account for a situation or to justify a course of action. The terms have very different meanings in science.
|
| When I ask student to identify how these terms differ, I receive many alternatives, but almost all of them are false. They suggest that laws are proven, but theories are not. That is not true. They suggest that theories can be changed, but such is not the case for laws. Similarly, that is not true. They suggest that lots of evidence supports laws, but that is also true for theories. They suggest that theories can change with new evidence, but that is similarly true for laws. (Consider how Einstein’s work modified the laws that matter and energy can neither be created nor destroyed. His work added the modification that they can be interchanged.)
|
| So how do they differ? Consider some examples of each. There are the Ideal Gas Law, the Law of Conservation of Matter, Newton’s Law of Motion, the Law of Gravity and the Law of Superposition, which states that older rocks are found below newer rocks. On the other hand, there are the Kinetic Molecular Theory, the Atomic Theory, the Big Bang Theory, the Theory of Evolution and the Theory of Plate Tectonics. Looking at these two lists, what differences can be distinguished?
|
| Consider the Kinetic Molecular Theory and the Atomic Theory. Atoms and molecules are too small to be observed directly. In the case of the Big Bang Theory, you would have to travel back in time to observe it. Time travel – at least for now – is not an actual option. To observe the Theory of Evolution and the Theory of Plate Tectonics, you would have to be around a lot longer than any individual exists.
|
| Despite these limitations, the evidence supporting a theory is extensive. It has a major impact on the things we can observe and test, even if it is limited to observing this via indirect means. Overcoming the common use definitions is critical, as both play equally important roles in the world of science!
|
|
|
|
|
|
