Falsificationism is very straightforward. If we observe a black swan, then this falsifies the theory that ‘All swans are white.’ The problem with this is that reality is much more complicated and not as straightforward as Popper propose.
We use multiple premises when testing cosmological theories. If we were to predict the positions of planets, then the following assumptions would be in play, the orientation of the telescope necessary for a sighting, previous positions of planets, and the list goes on. If the positions of planets do not follow our predictions then at least one of the premises must be false. A theory cannot, therefore, be conclusively falsified.
Brahe and the Copernican theory – Falsificationism
The Danish astronomer Tycho Brahe claimed to have falsified the Copernican theory. The Copernican theory states that the earth orbits around the sun and Brahe tested if the position of the stars could verify this theory. Brahe failed to do so and therefore concluded that the Copernican theory was false, but in reality, it was his auxiliary assumptions, which caused him to falsify the theory. The Copernican theory was correct but Brahe had given wrong estimates of the distance of the fixed stars.
The example of Brahe shows that it is not possible to blindly follow Poppers falsificationism because it is difficult to spot the errors in complex tests. If a person drops a stone from the top of a tower and it falls straight down then logically the statement ‘The earth spins’ could be falsified because the stone was not affected by the rotation of the earth. At the time the Copernican theory seemed like a straightforward theory to falsify because the astronomers did not understand the complexity of the test.
It is essential not to falsify incorrectly. A weakness of Popper’s theory is that it is too easy to falsify complex theories and wrongly classify them as non-science/pseudoscience. Therefore, theories should be falsifiable, but not falsified. It is allowed to hold on to theories such as the Copernican theory in spite of apparent falsification in the hope that we can solve the problem in the future. Popper himself confronted the critique of falsification by the following passage.
“I have always stressed the need for some dogmatism: the dogmatic scientist has an important role to play. If we give in to criticism too easily, we shall never find out where the real power of our theories lies.” Popper (1974, p. 55).
Popper emphasizes that it can be necessary to retain theories in spite of apparent falsifications. Ruthless criticism of theories is required, but dogmatism still has a decisive role to ensure that we do not mistakenly disregard theories such as the Copernican.