Albert Einstein: Father of General Relativity

Albert Einstein
Albert Einstein was one of several scientists working with quantum theories. He is credited with devising the theory of relativity. Hulton Archive / Stringer/ Getty Images

Albert Einstein was a theoretical physicist and one of the geniuses of 20th Century physics. His work has helped along our understanding of the universe. He was born and lived much of his life in Germany, before emigrating to the United States in 1933.

Growing a Genius

When he was five years old, Einstein's father showed him a pocket compass. Young Einstein realized that something in "empty" space affected the needle.

He said the experience was one of the most revelatory of his life. About a year later, Albert's education began. 

Although he was clever and built models and mechanical devices for fun, he was also considered a slow learner. It's possible he was dyslexic, or he may have simply been shy. He was good at mathematics, especially calculus.

In 1894, the Einsteins moved to Italy, but Albert stayed in Munich. The following year, he failed an exam which determined whether he could study for a diploma in electrical engineering in Zurich. In 1896, he renounced his German citizenship, not becoming a citizen of any other country until 1901. Also in 1896 he entered the Swiss Federal Polytechnic School in Zurich and trained as a teacher in physics and mathematics. He received his degree in 1900.

Einstein worked from 1902 to 1909 as a technical expert at the patent office. During that time, he and Mileva Maric, a mathematician, had a daughter Lieserl, born in January 1902.

(What eventually happened to Lieserl is not know. It's possible she died in infancy or was put up for adoption.) The couple wasn't married until 1903. On May 14, 1904, the couple's first son, Hans Albert Einstein was born.

During this part of his life, Einstein began writing about theoretical physics.

He also earned a doctorate from the University of Zurich in 1905 for a thesis called On a new determination of molecular dimensions.

Developing a Theory of Relativity

The first of Albert Einstein's three 1905 papers looked at a phenomenon discovered by Max Planck. Planck's discovery indicating that electromagnetic energy seemed to be emitted from radiating objects in discrete quantities. This energy was directly proportional to the frequency of the radiation. Einstein's paper used Planck's quantum hypothesis for a description of the electromagnetic radiation of light.

Einstein's second 1905 paper laid the groundwork for what would eventually become the special theory of relativity. Using a reinterpretation of the classical principle of relativity, which said that the laws of physics had to have the same form in any frame of reference, Einstein proposed that the speed of light remained constant in all frames of reference, as required by Maxwell's theory. Later that year, as an extension of his theory of relativity, Einstein showed how mass and energy were equivalent.  

Einstein held several jobs from 1905 to 1911, while still developing his theories. In 1912, he began a new phase of research, with the help of mathematician Marcel Grossmann.

He called his new work the "general relativity theory", which he was able to publish in 1915. It deals with the specifics of space-time theory as well as something called the "cosmological constant".

In 1914 Einstein became a German citizen and was appointed Director of the Kaiser Wilhelm Physical Institute and Professor at the University of Berlin. The Einsteins divorced on February 14, 1919. Albert then married his cousin Elsa Loewenthal.

He received the Nobel Prize in 1921 for his 1905 work on the photoelectric effect. 

Fleeing World War II

Einstein renounced his citizenship for political reasons and emigrated to the United States in 1935. He became Professor of Theoretical Physics at Princeton University, and a United States citizen in 1940, while retaining his Swiss citizenship.

Albert Einstein retired in 1945.

In 1952, the Israeli government offered him the post of second president, which he refused. On March 30, 1953, he released a revised unified field theory.

Einstein died on April 18, 1955. He was cremated and his ashes were scattered at an undisclosed place.

Edited by Carolyn Collins Petersen.