Einstein was a heavy smoker, never wore socks and married his cousin......

As most people know, Einstein was a famous scientist who came up with the famous formula e = mc2. But here are 10 things you may not know.

10. Love sailing

While studying at the Zurich Institute of Technology in Switzerland, Einstein fell in love with sailing. He would often take a boat out on the lake, take out a notebook, and relax and think. Although Einstein never learned to swim, sailing stayed with him.

9. Einstein's brain

When Einstein died in 1955, his body was cremated and his ashes dispersed in accordance with his will. Before the body could be cremated, however, Thomas Harvey, a pathologist at Princeton Hospital, performed an autopsy on Einstein and removed his brain. In the end, Harvey didn't put the brain back in the body, but kept it for research. Although Harvey's practice was illegal, a few days later he finally convinced Einstein's son that it was a contribution to the cause of science. Shortly thereafter, Harvey was fired from Princeton because he refused to hand over Einstein's brain.

For the next 40 years, Harvey kept slices of Einstein's brain (Harvey cut it into more than 200 pieces) traveling across the United States. Every once in a while, he would give a piece of it to a scholar to study. In 1998, Harvey finally returned Einstein's brain to Princeton Hospital.

8. Einstein and the Violin

Einstein's mother, Pauline, an accomplished pianist, also wanted her son to enjoy music, so she began to teach him to play the violin when he was 6 years old. Unfortunately, Einstein hated playing the violin and would rather build a house out of cards (he once built a 14-story house out of cards) than anything else. But when Einstein was 13 years old, he happened to hear Mozart's music and changed his mind about the violin. Einstein maintained his passion for the violin until the last years of his life. Einstein played the violin for nearly seven decades, and not only did he relax with it, he also performed for the district or joined impromptu bands such as the choir that stopped at his house on Christmas Day.

7. President of Israel

Within days of the death of Zionist leader and first President of Israel Weizmann on November 9, 1952, Einstein was invited to serve as the second president of Israel. Einstein, then 73, turned down the offer. In his letter, he refused, saying that not only did he not have the "wisdom and experience to properly care for the people," but that he was too old.

6. No socks

Einstein's shapeless look also attracted many people. In addition to his unkempt hair, his other special habit is that he never wears socks. Whether it was boating or a formal dinner at the White House, Einstein wore bare shoes. For him, socks are a pain, because they often have holes in them. In addition, Einstein also felt that the function of socks and shoes is the same, so why wear two?

5. Inspired by the simple compass

When Albert Einstein was five years old, he was ill and his father showed him a simple pocket compass in his hospital bed. Einstein was fascinated. What is it that keeps pulling little Pointers in the same direction? This question puzzled Einstein for many years, and it is now believed that it set him on the path to science.

4. Designed a refrigerator

Twenty-one years after the completion of special relativity, Einstein invented a refrigerator that ran on alcohol gas. The refrigerator was patented in 1926, but never put into production because his design was outdated. Einstein invented this refrigerator after watching a family die of sulfur dioxide poisoning from the refrigerator.

3. Smoking binge

Einstein liked to smoke. When he walks to work or home, people can often see a trail of smoke behind him. To people, Einstein's image is messy hair and loose clothes, but who knows that the clothes have a pipe he never left. In 1950, Einstein said, "I think that smoking a pipe helps to be calm and to judge affairs objectively," and although he liked pipes, he did not mind smoking a cigar or a cigarette.

2. Married your cousin

When Einstein divorced his first wife, Milevama Ricci, in 1919, he married his cousin, Elsa Lowenthal Einstein. How close are they by blood? That's pretty close. Elsa was actually related to both of Einstein's parents. Einstein's mother and Elsa's mother were sisters, while Einstein's father and Elsa's father were Cousins. When Elsa and Einstein were little, the two of them used to play together. However, their romance only began after Elsa divorced her original husband Max Lowenthal.

1. An illegitimate daughter

In 1901, Albert Einstein and Mileva Maric were not officially married, but the two of them took a romantic trip to Lake Como in Italy. After this vacation, Mileva found out she was pregnant. At that time, having children out of wedlock, while not uncommon, was still socially unacceptable. Einstein had neither the money to marry nor the money to raise children, so they did not become a couple until Einstein got a job at the Patent Office a year later. In order not to tarnish Einstein's reputation, Maric gave birth to a baby girl, named Lieserl, to her parents.

Although we know that Einstein recognized the daughter, no one knows what happened to the girl. Einstein mentioned her only a few times in his letters, the last time in September 1903. It is said that Lieserl died of scarlet fever at an early age, or perhaps she survived the illness and was adopted by another family. Both Einstein and Mileva were tight-lipped about the existence of Lieserl, a secret Einstein scholars only discovered in recent years.