Theory vs Law
According to science, a law is a generalized statement set after a number of observations. A law has no explanations or exceptions when it is framed. It is an obvious fact recorded after observations.
A good example of this may be the force of gravity. It is observed that an apple falls down on the surface of the Earth. It is an undeniable fact. This observation has no exceptions also. No one has ever observed a reverse or alternative phenomenon. Hence it is considered to be a law.
There is another misconception about the hierarchical level of law. A group of scientists is of the idea that there is a hierarchy of hypothesis, theory, and law, but this is only an erroneous statement. Laws are obvious and simple statements.
A theory is the explanation of the observational data set forward in the form of a law. In simple words, a theory is the reasoning behind a law. It may also be put as an advanced or evolved hypothesis. “Hypothesis” is a probable reason behind any observation. A hypothesis has to undergo various tests. If the hypothesis holds well in different conditions, it may be accepted as a theory.
Taking account of the previous example of the law of gravity, in 1687 Sir Isaac Newton put forward the inverse square law in his journal. It was till then a hypothesis. This law was put to a test by different scientists in the study of planetary motion. With some of the planets the hypothesis held good but exceptions were there. At this stage, Newton’s hypothesis was accepted as a theory, “the gravitational theory.” This theory was later superseded by Einstein’s Theory of Relativity.
A theory can be a strong one if it has a lot of evidence to back it. It may also be regarded as a weak theory if the amount of accuracy in its prediction is low. A theory may become obsolete with time and be replaced by a better one. A law, however, is a universally observable fact. It is undeniable and never fades away with the stretch of time.
1.A law is an observation; a theory is the explanation of that observation.
2.A theory requires experimentation under various conditions. A law has no such requirements.
3.A theory may become obsolete with time. This is not the case with a law.
4.A theory can be replaced by another better theory; however, this never happens with a law.
5.A theory may be strong or weak according to the amount of evidence available. A law is a universally observable fact.