Scientific_Method

The scientific method consists in four steps.

Observe the world

Make a guess at some fundamental rule that governs the world (hypothesis)

Find some experiment which result could show that your guess was wrong

Make the experiment.

Repeat steps 3 and 4.

If no experiment disproves your theory, you can talk about it and hopefully convince other people of its validity. If your theory is similar to an already established one except in some point and your experiment shows that reality follows your theory instead of the old one, it is likely that many people will listen to you. If they can reproduce your experiment, they will be convinced of the validity of the new theory. Contrast PseudoScience.

Note that claims that cannot be disproved, such as "there exist something outside of the world that we cannot see nor interact with" are not scientific because they fail the third criterion. Also, note that theories determined by the scientific method are not necessarily true. Later experiments may prove that the theory in fact wrong, and replace it with a newer theory.