Lu Jiaxi (mathematician) facts for kids

Lu Jiaxi (simplified Chinese: 陆家羲; traditional Chinese: 陸家羲; pinyin: Lù Jiāxī; June 10, 1935 – October 31, 1983) was a brilliant Chinese mathematician. He taught himself advanced math. He made very important discoveries in a field called combinatorics. This is a part of math that deals with counting and arranging things.

Lu Jiaxi was a high school physics teacher. He lived in a faraway city. In his free time, he worked on a super hard math problem. It was about "large sets of disjoint Steiner triple systems". This problem had puzzled mathematicians for a long time.

Lu Jiaxi's Life Story

Early Life and Education

Lu Jiaxi was born in Shanghai, China, in 1935. His family was very poor. His father sold soy sauce. Lu Jiaxi was the only one of four children to survive. His older siblings died young from illness.

When he was in middle school, his father also passed away. His family could not afford his father's treatment. So, Lu Jiaxi had to start working in 1949. He became an apprentice at a car parts company.

In 1951, he joined a statistics training course. He finished at the top of his class. Then, he was sent to work at a motor factory.

While working, he studied high school subjects on his own. He also learned Russian at night school. Later, he taught himself English and Japanese. This helped him read math books from other countries. In 1956, he helped fight a big flood. He was praised for his efforts. In 1957, he passed the college entrance exam. He was accepted into Northeast Normal University.

After graduating in 1961, he became a teaching assistant. This was at a place now called Inner Mongolia University of Science and Technology. In 1962, he became a physics teacher. He taught at several middle schools in Baotou. He worked at Baotou Ninth Middle School until he died in 1983. He also managed a school factory. This factory made radio parts. He got married in 1972. His wife was a doctor.

His Amazing Math Work

In 1956, Lu Jiaxi read a math book. It was about a famous problem called Kirkman's schoolgirl problem. He found it very interesting. He decided to try and solve a harder version of it. He studied math on his own. He spent a lot of time on this research.

In 1961, he wrote a paper about his solution. He sent it to the Chinese Academy of Sciences. They replied in 1963. They told him to check his work. They also suggested he send it to journals if it was new.

He sent his paper to a math journal in 1963. But it was too long and complex for them. After more changes, he sent it to Acta Mathematica Sinica in 1965. In 1966, he got a rejection letter. It said his work was "worthless." We now know this was a big mistake. He was very sad about this. He wrote in his diary that he would stop sending papers.

After the Cultural Revolution, he tried again. He sent revised papers, but they were still not accepted. In 1979, he borrowed some old journals. He found out that the problem he solved in 1965 had already been published. It was solved by other mathematicians in 1971. This was a huge disappointment for him.

But Lu Jiaxi did not give up. He started working on an even harder problem. This was about "large sets of disjoint Steiner triple systems." This problem was known to be extremely difficult. Many top mathematicians had tried to solve it.

A math professor named Zhu Lie saw how important Lu's work was. He told Lu to send his papers to an international journal. It was called Journal of Combinatorial Theory, Series A. Lu wrote to the journal's editors. He said he had solved the problem. The editors were very excited. They said it would be a major achievement if true.

Lu Jiaxi then worked very hard. He improved his English. He borrowed a typewriter. He typed nearly 200 pages of his math work. It was a huge task for him. He could only type a few pages each night.

The journal received six of his papers between 1981 and 1983. They published the first three in March 1983. They also planned to publish his next three papers. He also sent another important paper to Acta Mathematica Sinica. It was published in 1984. Experts around the world thought it was equally important.

Lu Jiaxi had many teaching duties. But he kept doing his math research at home. He often worked late into the night. He also traveled to Beijing sometimes. He went there to find math books in libraries. He told his friends that physics needed special equipment. But for math, he only needed paper.

Challenges and Recognition

Lu Jiaxi's hard work and tough living conditions affected his health. His family of four lived in a tiny house. It was only about 10 square meters. He had to do his math on a broken kang bed-stove. This was because his daughters used the only table.

When he traveled to Beijing, he bought cheap train tickets. He could not afford sleeping berths. He ate dry food in the library during the day. At night, he slept on a bench at the train station. He sometimes wrote in his diary about being tired. He knew he needed to be healthier for his research. His family and friends told him to rest. But he said he did not have much time. He wanted to move to a university. He tried for years, but he could not find a suitable job.

Most Chinese mathematicians did not know about Lu Jiaxi. But his work was getting noticed in other countries. In July 1983, a math conference was held in China. Two Canadian mathematicians, Eric Mendelsohn and John Adrian Bondy, came. They were referees for Lu's papers. They asked for Lu Jiaxi. One organizer thought they meant someone else. This was the first time Chinese mathematicians learned about him.

Lu gave a talk at the conference. Everyone was very impressed. He was invited to give another talk. In August, he gave another talk at a workshop.

Even though he was gaining fame, he was still poor. His school leaders did not like his research. They thought it took him away from his teaching duties. They even gave him more tasks. For example, he had to time sports events. The principal once told him, "We are a middle school. If someone wants to be a scientist, he should go to the Academy of Sciences."

When he was invited to math conferences, his school would not pay for his travel. They said they only paid for teaching activities. He had to borrow money from friends to attend.

The conferences helped him connect with other mathematicians. He was invited to speak at a big national math conference. Several universities wanted to hire him. He decided to go to South China Normal University. The Canadian mathematicians also planned to invite him to visit the University of Toronto.

His Passing and Legacy

The national math conference ended on October 27, 1983. Lu Jiaxi hurried back to Baotou by train. He did not want to miss his classes. He stopped briefly in Beijing to visit libraries. He arrived home on October 30. He was very happy. He told his wife about the praise he had received. He also talked about his future research plans.

But at about 1 AM that night, he had a sudden heart attack. He died in his sleep. His wife was a doctor, but she had no equipment to save him. There was no phone at home to call for help. He left behind his wife, Zhang Shuqin, and two daughters.

Just two days before he died, his middle school got a letter. It was from David Strangway, the President of the University of Toronto. He asked the school to let Lu transfer to a university. He said it would help Chinese mathematics. After Lu's death, David Strangway sent a letter of sympathy. He said people would greatly miss "Prof. Lu Jiaxi" for his knowledge.

In January 1984, a math journal invited Lu to be a reviewer. They did not know he had passed away.

After his death, the Inner Mongolia government helped his family. They paid off their debts. They honored him for his achievements. A year after he died, a memorial was held. The government chairman issued a document. It was called "Learn from Comrade Lu Jiaxi." He also received a special award in 1985.

Chinese mathematicians investigated his research. His early papers from 1961 and 1963 were lost. But they found his 1965 paper. They confirmed that he was the first to fully solve the generalized Kirkman's schoolgirl problem. His solution was even stronger than the one published later by others.

Eric Mendelsohn, a Canadian mathematician, praised Lu's work. He called it one of the most important achievements in the field. He wrote that Lu Jiaxi should have had a great career. But he spent too many years as a high school teacher. He had little time for research. He also had almost no contact with other researchers.

Lu Jiaxi had been working on the last part of his big theorem. He had announced he solved it. But he left it unfinished when he died. It was a 24-page manuscript. Other mathematicians tried to finish it. Finally, in 1989, Luc Teirlinck completed the proof. He used some of Lu's ideas.

In 1987, Lu Jiaxi was given a special award after his death. It was the First Class Award of the State Natural Science Award. This was the highest science honor in China. It was for his amazing work on large sets of disjoint Steiner triple systems.