Einstein had a witty saying about his scientific research process, "in order to punish my contempt for authority, fate turned me into authority". On the one hand, this sentence shows the difference between science and religion. Science can be refuted or falsified, and authoritative scholars in science are not always correct. On the other hand, science encourages the collision of different ideas and the competition among scholars, which promotes the continuous progress of science. Undergraduate and graduate students who have just begun to contact scientific research need to change their thinking and cultivate the habit of independent thinking and critical thinking in scientific research, which can deepen their understanding of scientific research problems. On the other hand, they can face some critical opinions of peer review with more confidence.

Researchers need to have the self-restraint of independent thinking. If the spirit of science is questioning, how can we refute and expand this assertion, which seems 100% correct, so as to deepen understanding? Luo Zhitian said, "newspapers in the late Qing Dynasty once said that the lack of material is the manifestation of people's poverty, but no matter how rich the material is, if they lack the ability and habit of independent thinking, then 'all thoughts, comments and behaviors are poor', which is the real 'people's poverty'. If they lose themselves and don't want to be independent, they can't rely on others." [1] if they can't think independently, they must rely on others. If every opponent's opinion is opposed and every friend's opinion is supported, it is likely that when our friends agree with our opponents, we will fall into a self contradictory situation and can't think. It would be absurd if every time the opponent changes his opinion, we have to change our opinion in order to oppose it [2]. "If you don't have enough self-confidence, you care too much about what others say. If you say something, you will respond immediately, and sometimes you can't help laughing back." [1] this reactive thinking mode is not desirable. Similarly, scientific researchers also need to have their own self-confident independent thinking, so that they will not fall into the dilemma of running and repeating when thinking.

From individual to society, in the progress of civilization, we can see the importance of individual self-confidence and independent thinking. "(self-esteem) enables him to feel that he may be right when the world is against him. If a person does not have this quality, he will feel that the opinions of most people... Are absolutely correct, and if this way of emotion is popularized, no moral and ideological progress is possible." [3] if no one is like Einstein, If you have the courage and self-confidence to challenge authority, the likely result is that "... Society has entered a stagnant stage. People praise the achievements of their predecessors, but they can no longer compare with them; art has become conventional, and science has been destroyed because of compliance with authority." [1, p.35] the self-confidence of independent thinking promotes the competition between people, Competition promotes the continuous progress of science.

From undergraduate to graduate, the transformation of thinking mode is huge. When the undergraduate study just turned to the graduate stage, perhaps many people have similar ideas: anyway, it's science and engineering. Just show the correct answer and logical reasoning process directly. Aren't the correct and wrong clear at a glance, and isn't research and discussion a waste of time? Poincare pointed out that, "Pure logic can never make us get anything other than synonymy and repetition; it can't create anything new; no science can come out of it alone... To form arithmetic, to form geometry or any science, we need something other than pure logic. In order to call this kind of thing, we have to use the word intuition." [4] During the learning process before scientific research, we have given a lot of tips on the conditions and stem of the questions in the exercises or exams, indicating that the search scope of the answers is roughly in the questions, and the required knowledge base can often get the results in a few hours in the contents taught in this semester or before. However, scientific research is different, because it is more open questions, so search The strength of the cable is much higher. Sometimes the tools (or lemmas) to solve problems have not been developed. We should prepare tools first. Easy questions may be answered in a few months, and difficult questions sometimes require the efforts of generations of scientists.

Scientific research is a bit like walking in the dark. When you can't see the destination, use a flashlight to illuminate a small section of the road ahead. The road ahead is full of forks. You need to move forward after eliminating the forks, and even retreat back. Students need to have a guess overlooking the overall situation, otherwise they are easy to get lost in the local. Intuition and independent thinking can help grasp the overall situation. A person with programming foundation can read or execute Other people's programs are sometimes slow because they can't grasp the primary and secondary (for example, whether there is an error due to the omission of a discussion of a situation in the program) On the contrary, on the basis of understanding the algorithm, self programming will be faster. Jump from the initial knowledge to the conclusion or intermediate results, and then supplement the details, so as to grasp the primary and secondary. After having a certain foundation, self independent thinking ability will achieve more efficient results than traversing a large number of previous research results.

Critical thinking plays an important role in some non scientific fields. "(Hu Qiuyuan believes) the function of literary criticism is to 'objectively' understand literature, not to dictate literary creation." [5] Although literary criticism does not directly interfere with literature, and although some literary critics cannot write popular literary works by themselves, the overall atmosphere of criticism can also promote the evolution of the overall ecology of literature and guide the progress of literature. However, different from literature, is criticism or critical thinking necessary in the field of science? Popper gave a brief introduction to scientific theory A way of judgment, "just because our goal is to establish as good theories as possible, we must try our best to test them; we must try our best to find their shortcomings and try our best to prove and refute them. Only when we still can't prove them after doing our best, can we say that the theory has withstood the strict test." [6] A good scientific theory is a theory that can withstand repeated tempering, so rational science must encourage criticism.

Science encourages criticism, which is not only the requirement of the discipline itself, but also the requirement for the people performing scientific research. "Thinking occurs in favoritism. To complete the task of thinking, we must have a certain detached and impartial attitude. If a general allows his hopes and desires to affect his observation and interpretation of the current situation, he will inevitably make wrong estimates." [7] People are more inclined to spend time on things they care about. For example, if you think this scientific research problem is interesting or meaningful, you will spend time on it. But because this problem has our preferences (or interests) Therefore, people need to correct their mistakes in the process of scientific research. It is clear that we have seen a lot of arguments, such as whether house prices rise or fall, many people who do not buy houses hope that house prices fall, and people who buy houses hope that house prices rise, which leads to a lot of arguments. The point of view is to wear filters. From a psychological point of view, scientific research practitioners may also have expectation effects, "The threat of experimenter's expectation effect to scientific research obviously exists. Trained researchers will use more rigorous test procedures to avoid these expectation effects as much as possible (for example, using double-blind experiments, in which the experimenter in contact with the participants does not know the research hypothesis)." [8] there are subtle differences between sentiment and opinion [9] , researchers should avoid being impulsive. During scientific research and exploration, we need to correct our position with the help of critical thinking.

Because scientific research is a new research result, it is often criticized in the form of peer review to persuade peers before it can be published in academic journals. However, because peer scientists are also human and may have their own preferences, the peer review model limits academic freedom to a certain extent. People often take Perelman's Poincare conjecture as an example The result is that it is published on arXiv, a preprint website without peer review, to express that peer review is not required to ensure quality. Although peer review inhibits innovation to a certain extent, there will be great problems if it is cancelled. In the era of information explosion, the reading literature of some novices in scientific research may be a lot of irrelevant information, false information and spam , wrong research results mislead and waste time. Peer review may filter out outstanding ideas that surpass the times, but more often it filters out useless junk information. When graduate students face more rigorous journal review, they can use Kalman filter (one of the most important algorithms in the 20th century) The inventor Kalman gained some comfort from his experience. Kalman's idea was criticized by his peers, so he chose to publish his paper in the Journal of mechanical engineering rather than the Journal of electronic engineering. The second paper on continuity with his collaborators was even rejected by the review. His suggestion is, "When you are worried about stepping on the sacred land bound by solid interests, you'd better take the path nearby." [10] when doing scientific research, you can strive to pursue good magazines and periodicals, but if you don't achieve the goal, don't be too sad. The quality of scientific research articles may be recognized by people over time.

Scientific research grows in competition, which is similar to the progress of both sides of military exercises in the competition without setting up a field. "The spirit of science is cautious, tentative and trivial; it does not think that it knows all the truth, or even its best knowledge is completely correct. It knows that any theory must be revised sooner or later, and such necessary revision requires the freedom of research and discussion." [11] In scientific research, we need to think independently and have a certain degree of self-confidence to challenge others' ideas; at the same time, we also need to remain modest, accept the criticism of ourselves and others, and make continuous progress.