When szilard was studying at the University of Berlin, the first row seats in the prestigious physics seminar in the university were traditionally reserved for big-name physicists such as Einstein, Laue and Planck. However, student szilard insisted on running to the front row because he had some ideas to talk to Einstein. Einstein left a deep impression on the young man, and later they became good friends. 1928, they all applied for and obtained the refrigerator patent in Britain. The cause of the incident is that they read a news in the newspaper that a family in Berlin was all poisoned overnight because of the leakage of the newly bought refrigerator coolant. The two were very moved and wanted to design a safer refrigerator. Their plan is to replace the toxic coolant used in the refrigerator with suspended metal particles and drive it with a magnetic pump. A German company named AEG made a prototype refrigerator based on this patent, but the prototype refrigerator was too noisy. Faced with this problem, Einstein and szilard were not discouraged. From 1928 to the end of 1930, they registered 29 patents related to refrigerators or magnetic pumps. However, none of the companies were interested in their patents.
Many years later, during the Manhattan Project, scientists such as Enrico Fermi and szilard began to study the peaceful use of atomic energy. The first nuclear reactor they trial-produced once encountered the problem of poor heat dissipation in the core. At this moment, szilard suddenly remembered the magnetic pump in the prototype refrigerator made by AEG, which happened to be the ideal core heat pump. By improving the design and adopting more advanced motors, the noise of the cooling pump they developed is much less than that of the original magnetic pump. So, szilard and physicist Fermi applied for and obtained the patent of the world's first nuclear fission reactor. However, his most important contribution may not be in the field of physics, but in that he was the first driving force of the Manhattan Project. During World War II, he strongly persuaded Einstein to write to President Roosevelt and suggested that the United States develop an atomic bomb before Nazi Germany. Einstein's letter was actually dictated by szilard.