Li Kangping was brewing his thoughts when he suddenly saw a person walking towards him.

This person has black pants and white shirts, is not tall, has a thin body, his hair is neatly combed, and he looks like a scholar.

Li Kangping stood up solemnly, he stretched out his hand and paced over: "Brother Qisun, look up for a long time!" ”

This gentleman is none other than Ye Qisun, the measurer of the latest version of Planck's constant.

Ye Qisun shook hands with Li Kangping, and he said happily: "Kangping is very capable, a paper on spatial quantization, and his skills are astonishing." ”

Li Kangping said sincerely: "Brother Qisun's Planck constant paper also fascinated me. ”

When two Chinese students studying physics met here, they really met late and had a lot of words.

Ye Qisun stuttered a little, but stuttering did not affect his expression.

Brother Qisun is logical, well-organized, and has his unique views on physics.

"New applications do not only rely on applied research in the narrow sense, but also require continuous pure research." Ye Qisun briefly talked about his academic attitude.

Li Kangping agreed: "What Brother Qisun said is that pure research and applied research complement each other, so that they can be widely used. ”

"At the time of the European War, Britain used the newly invented tank car, which gave it an advantage and won the war. The speed of progress in the modern world is terrifying. Ye Qisun said this, and couldn't help but feel worried.

Brother Qisun is deeply aware that the power of science and technology can affect the situation on the battlefield, and the situation on the battlefield is related to the security of the country and the survival of the nation.

However, China's scientific and technological strength is extremely weak, and the scientific and technological strength of the great powers is growing day by day.

They're advancing, and we're not retreating.

But standing still has widened the gap between us and the great powers.

This topic is extremely heavy, but it is impossible to avoid it.

The two walked and talked, the clear and shallow sand beach spread out on the shore of the rainbow lake in the highlands, and a few dozen yards from the shore was a dense pine forest, and the sun leaked down, shining on the pine resin flowing from the trunks of the pine trees.

Looking up at the clouds seems to be within reach, the mountains are breezy and accompanied by the fragrance of flowers and birds, the ripples of the lake urge the blue and emerald green, and the mountains are stacked horizontally and vertically. Li Kangping and Ye Qisun sat by the lake, looking at the magnificent scenery of the lakes and mountains in the United States, and thinking about the day when China's land of suffering will be healthy and peaceful.

"Brother Ren Guang has just returned to China after completing his studies, and the physics research of Nanjing University can still be carried out with difficulty, although Peking University is famous all over the world, scientific research is difficult."

Ye Qisun mentioned two gentlemen, one is Hu Jun Gangfu, and the other is Yan Jun Ren Guang.

Hu Gangfu and Yan Renguang are both students in the United States, and the two are the first generation of physicists in China, and they are called "South Hu and North Yan".

After returning to China, Hu Gangfu founded China's first physics laboratory for scientific research at Nanjing Normal University.

As Brother Qisun said, although the physical research of Nanjing University is difficult to carry out, it is better than nothing.

After returning to China, Yan Renguang presided over the Department of Physics of Peking University, although Peking University is famous all over the world, it cannot provide the most basic scientific research conditions for Yan Renguang to display his scientific research talents.

Due to the constraints of the conditions, Mr. Yan could not do scientific research in China, so he focused on education and tried his best to cultivate more physics youths in theoretical knowledge education.

Li Kangping studied in New York, Ye Qisun studied in Massachusetts, and it was not easy for the two to meet, so in the next week, they got along day and night, walking, eating, drinking tea, inseparable, and talking about China and the West.

There is no banquet in the world, the APS annual meeting is over, Li Kangping and Ye Qisun go north and south, the two know each other's mailing addresses, and they should maintain correspondence and contact from time to time in the future.

After Li Kangping returned to New York, he decided to apply for a patent for the steady-state separation of atomic and molecular beams after consulting with Professor Woodgate.

In the paper "Silver Atomic Beam Method Validates the Theory of Space Quantization", Li Kangping described the details of their experiments in a very detailed way.

In other words, anyone who has read this paper and has some experimental skills can repeat this experiment.

We allow and we hope that physicists all over the world can master the technology of steady-state separation of atomic and molecular beams, and we have registered patents to prevent people from using the technology for commercial gain. This is the attitude of Li Kangping and Woodgate.

Of course, the steady-state separation of atomic and molecular beams is a purely academic experimental technology, which has no commercial value in the short term and is difficult to transform into commercial products.

Li Kangping went to the patent office, submitted a patent application for the steady-state separation technology of atomic and molecular beams, and became familiar with the process of patent registration in the United States.

Although the master's diploma has not yet been issued, this does not prevent Li Kangping from drafting the application form for doctoral students + experimental assistants at the Columbia University Research Institute.

Li Kangping is very familiar with Professor Woodgate, and of course it is more convenient to follow an acquaintance to study for a doctorate.

There is no need to pay tuition fees for doctoral studies, and after becoming an experimental assistant in the graduate school, Li Kangping can also receive a subsidy of 5~8 US dollars per week.

In August, the latest issue of Physical Review was published.

Li Kangping's paper and Ye Qisun's paper were both published in this issue of Physical Review.

The newspaper also reported the scientific news by Robert Milligan.

Here's what Professor Milligan wrote:

W.T. Woodgate and K.P. Lee of Columbia University invented and used the steady-state separation technology of atomic and molecular beams to obtain the world's first experimental evidence of spatial quantization. This is a remarkable scientific achievement. ”

W. Duane, H. H. Palmer, and C. S. Ye of Harvard University, through reasonable and credible experimental methods, measured Planck's constant as (6.556±0.009) ×10^-27 Erg·s. The new Planck constant is more accurate than what I measured in 1917, which is also a remarkable scientific achievement. ”

This newspaper article by Professor Milligan is intended for non-specialists outside the physics community.

In any case, Professor Milligan has made outstanding contributions to the cause of science popularization in the United States.

For publishing "Silver Atomic Beam Method to Verify Space Quantization Theory", Li Kangping received a manuscript fee of $1,000. Yes, you read that right, a full thousand dollars, and no taxes.

What would you do with a thousand dollars?

Buying a new car?

Feasting?

Traveling?

Investing in bonds?

Donate to charity?

Or a few nice and open friends to celebrate wildly?

Li Kangping saved the $1,000, and the savings did not have too high a profit, nor did he have to take too high a risk.

On the day he got the Physical Review, Li Kangping wrote a letter, written in German.

"Dear Mr. Sommerfeld, I attach the experimental evidence of the quantization of space that we have obtained. We congratulate you on the confirmation of your theory. ”

Mr. Sommerfeld's most recent paper was published in March 1921 and shows his mailing address, the Department of Physics at the University of Munich, Munich, Germany.

Li Kangping sent his letter in the same envelope as Physical Review to the University of Munich.

Physicists in the United States subscribe to the Annals of Physics in Germany, Nature in the United Kingdom, and Acta Physica in France, and physicists in Europe also subscribe to Physical Review and Science in the United States.

Even if Li Kangping does not send Mr. Sommerfeld to Physical Review, I believe that Mr. Sommerfeld will be able to see this issue of Physical Review in a month or a few months.

Li Kangping did this out of respect for Mr. Sommerfeld.

The Columbia Graduate School Degree Senate approved Kangping Li's application for a master's degree, and Kangping Li received a master's degree from Columbia University.

At this time, there are still many American science students who hope to go to Europe to gild gold at the master's and doctoral levels.

Li Kangping also had this idea, he wanted to go to Germany to recharge and receive education from German bigwigs.

After comprehensive consideration, Li Kangping decided to stay in the United States for the time being, continue to study for a doctorate at Columbia University, and receive the education of Professor William Woodgate, a famous American experimental physicist.

Within 1921, Li Kangping published two papers in the Physical Review, which appeared in newspapers, and was described by the famous Professor Milligan as "a remarkable scientific achievement".

Therefore, Li Kangping successfully became a doctoral student in physics + physics experiment assistant at the Columbia University Research Institute.

Surprisingly, the Columbia Research Institute made an exception to pay Li Kangping, a physics laboratory assistant at the institute, $12 a week!

Knowledge changes destiny, and knowledge changes finances.

Li Kangping came to the familiar and friendly laboratory for which he had stayed up all night and struggled to report to Professor Woodgate.

"Professor, I'm here again, I'm reporting to you again." Li Kangping said with a smile.