? ? Newton's flame laser sword? In philosophy (in fact, it was originally for theology), in order to choose between different hypotheses, the famous Occam razor was born: don't add entities unless necessary. In other words, if both theories can explain the actual phenomenon, the one with fewer conditions is more correct. For example, celestial movement, this wheel balance theory needs dozens of wheels to fit the laws of planetary motion, while Kepler's law can be solved by an elliptical orbit, so Occam's razor shaved off this wheel balance system. On this basis, scientists introduced another weapon: Newton's flame laser sword. This criterion holds that all problems that cannot be confirmed and observed by experiments are not worth discussing. So this sword cut the invisible dragons, pink unicorns, Russell teapots and God out of the research scope, further purifying the team of scientists. This is the most powerful technical term I have ever heard personally.