That is determined by how well the theory stands up under experimental scrutiny.
By testing out the theory
They start experimenting.
Scientific Theory is tested by observations and experiments predicted by the theory. If the observations confirm the theory the theory is validated if not the theory is not validated. Experiments themselves need validation, often there are errors in the experiments or observations, e.g Michaelson and Morley Aether experiment and red shift observations.
-- Does it explain things that have already been observed ?-- Does it make predictions that can be tested, and when tested, are found to be true ?
A scientific theory is a theory that explains the scientist's observations, whereas a scientific law is a repeated pattern in the world that we have not sought an explanation for.Also, a scientific theory is proven correct in this time, but may not be correct during future times.
A scientific law is one that has been tested throughout hypothesis and theory and proven to be true all the time.
hypothesis
Scientific Theory is tested by observations and experiments predicted by the theory. If the observations confirm the theory the theory is validated if not the theory is not validated. Experiments themselves need validation, often there are errors in the experiments or observations, e.g Michaelson and Morley Aether experiment and red shift observations.
-- Does it explain things that have already been observed ?-- Does it make predictions that can be tested, and when tested, are found to be true ?
The statement that it is characteristic of a scientific theory is that is well tested is false. A scientific theory is a proposed explanation of certain circumstances in nature.
Yes, a theory is what is then tested.
If by "why" you mean "what," a well tested framework that explains a wide range of observations in science is called a theory.
validity and reliability
Experimentation, look at the Scientific Method
A SCIENTIFIC THEORY is a well-tested concept that explains a wide range of observation. (IF YOU ARE USING THIS TO CHEAT ON YOUR SCIENCE HOMEWORK, THEN YOU'RE NOT ALONE) lol
The theory has been tested (against reality).
It is a scientific theory.
A theory is a proposed idea as an explaination to a problem. A scientific law is a tested and experimentally proven idea that can be considered as truth; until experimentally disproven. Newton's law of gravity was law, proven by experimental observations, right up until Einstein developed special relativity and it was experimentally proven. Thus disproving Newton's "law". String theory is an idea that is quite appealing to physicists, but there is no experimental proof to its validity, so it remains as just a theory.
A scientific hypothesis can become a theory if the hypothesis is tested extensively and competing hypotheses are eliminated.