1 Ideal experiment: the “ideal experiment” in the mind. Based on the facts and life experience of observation, using the scientific knowledge already mastered, theoretical speculation and logical reasoning in the mind, mainly using conjecture to propose axioms, and then using mathematical methods for logical reasoning, thus establishing certain theories. Einstein's theory of relativity is a shining example of ideal experimental research.
2 Observing the experiment: Obtaining a scientific observation of the object in a natural occurrence. This method has a wide range of applications in biology, geology, and geography. For example, biologists collect specimens to discover new species, paleontologists collect fossils to demonstrate biological evolution, and geologists observe geological section demonstration structures. Darwin founded the theory of biological evolution, mainly thanks to extensive field observation experiments. He defined science as: "Inductive experience in order to discover the law from it."
3 Simulation experiments: experiments relying on mathematical models and computer simulations. The research process is as follows: collecting data and information of things, using mathematical models and computers to conduct simulation analysis under the guidance of certain theories or assumptions, and understanding the nature and laws of things.
4 Control experiment: In the laboratory, in the artificial control environment, the experiment is carried out by physical or chemical methods, which is the most common in physical and chemical science and environmental science. This is also a narrow experiment that everyone usually calls.