In one of Karl Raimund Popper’s works, he discussed the demarcation that differentiate the sciences from the non-sciences or those that are merely subjects of faith and pseudo-sciences. Popper believes that sciences are falsifiable. If something can be falsified it can be considered as a science. He argued that unlike the work of Einstein which is “capable of conflicting with possible, or conceivable, observations”, the works of Freud, Marx and Adler proves every event as compatible to their theories which in Popper’s argument was not scientific.
No matter what the situation is, Freud, Marx and Adler would explain it in terms of their theory which is somehow a subjective way of explaining or looking into things. For instance, a selfish capitalist could be analyzed as someone who was fixated to a certain Freudian psychosexual stage or was suffering from Adler’s concept of inferiority. Marx would analyze the man from a class-struggle perspective.
Popper believes that although there are evidences and observable facts that could prove the three theories through experimentation, these experiments are not falsifiable and are therefore merely based on faith and subjective judgments. In the case of the Big Bang theory, it argues that the universe is expanding. The theory stated that the universe had started from an initial bang or explosion of a very dense material.
The impact of the explosion, according to the theory, is still observable today. Evidences shows that the space was expanding as quasars and galaxies are perceived to shift in their perceivable wavelengths. Hubble assumed, with respect to his observations, that either the universe is moving away from a center were an explosion had originated or that the universe was in constant expansion. Unlike the three theories mentioned above, the Big Bang theory left space for debate and possible changes.
The three previous theories would always hold true in past and future circumstances and would always have an explanation about the phenomena that they are concerned with (personality or human nature). On the other hand, the Big Bang theory may be false whenever a new discovery proves that a Big Bang had not occurred. Big Bang theory passed the falsifiable criterion set by Popper. References: Balashov, Y. & Rosenberg, (2002). A. Philosophy of Science Contemporary Readings. Routledge. Pages 294-300. Edwards, R. E. (2001). What Caused the Big Bang? New York; Rodopi B. V.