165438+20071On the afternoon of October 7, Academician Jason, President of Shanghai Jiaotong University, gave a lecture entitled "Interaction between Ultra-short and Ultra-intense Laser and Matter" in the lecture hall of Physics Department, and the general course "Physics" entered the life of Jiaotong University students. In front of 160 audiences of different grades and majors, Academician Jason gave a keynote speech in 80 minutes, introduced the formation principle and future development of laser, and answered many questions from students 10 in 20 minutes. The atmosphere is very warm.
"The laser is actually very close to us"
In the view of Academician Jason, laser is one of the greatest inventions in the 20th century, which has greatly changed human life. "Who can tell me how to make a laser?" No one raised their hands at the scene. Academician Jason outlined the principle of laser production, and then took a sixth-grade pupil as an example to show that laser is not far away from us, and ordinary students can do it.
Pupils want to use air to generate lasers. She knows that the basic principle is to directionally excite air molecules, so she has made many attempts. Finally, she found two blades, placed opposite each other at a certain distance, and then powered on. Theoretically, air molecules have been excited by this time, but why can't we see the laser? Jason analyzed for her: "The laser has been generated, but you didn't see it." He put a piece of white paper on one end of the blade and saw the fluorescence brought by the laser, which confirmed the success of the experiment.
Academician Jason pointed to the little girl on the screen and said, "You may know that she looks a bit like me." He admitted that it was his daughter. This method of making laser is very simple and has been included in some experimental textbooks.
When approaching the weak laser, Academician Jason listed his daughter's example. Speaking of intense laser, he described his scientific research course since returning to China, which was tortuous and rewarding. Academician Jason's report was simple and fascinating, and won applause.
Leading students to the forefront of science and technology
"High-power laser physics is an unknown field in the world, and the theory in this field is basically blank. I hope that interested students can advance despite difficulties and show their talents in this field. " Academician Jason said that physics experienced rapid development in the 20th century, and there are still many difficulties and hot spots to be explored by rising stars.
Academician Jason pointed out that physics looks simple, but it is also beautiful. With the help of the two simple laws of conservation of momentum and conservation of energy, many phenomena in the frontier research of physics can be explained. He described the charm of physics research in this way: "Physicists challenge human puzzling problems, and that kind of satisfaction is beyond the understanding of people in other professions."
There are nine topics in the general course Physics Horizon, which belongs to the natural science course in the general course. The person in charge of the course invites experts at home and abroad to teach. The general course will review and prospect the history and frontier of physics, help students broaden their horizons, improve their scientific quality and cultivate their interest in physics.
According to reports, Shanghai Jiaotong University has formed a complete teaching plan, inviting academicians and experts in biology, mathematics, physics, chemistry and other fields to explain the cutting-edge issues in related fields to undergraduates in popular language. Academician Jason told reporters: "The school hopes that through this kind of teaching, undergraduates can understand that what they have learned is related to the frontier of science and technology, thus stimulating their interest in science and actively pursuing it."