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Albert Einstein
Einstein 1921 by F Schmutzer - restoration.jpg
Einstein in 1921
Born (1879-03-14)14 March 1879
Died 18 April 1955(1955-04-18) (aged 76)
Princeton, New Jersey, United States
Known for
Mileva Marić
(m. 1903; div. 1919)

Elsa Löwenthal
(m. 1919; died 1936)
Children "Lieserl" Einstein
Hans Albert Einstein
Eduard "Tete" Einstein
Scientific career
Fields Physics, philosophy
Thesis Eine neue Bestimmung der Moleküldimensionen (A New Determination of Molecular Dimensions) (1905)
Doctoral advisor Alfred Kleiner
Other academic advisors Heinrich Friedrich Weber
Albert Einstein signature 1934.svg

Albert Einstein (14 March 1879 – 18 April 1955) was a German-born scientist. He worked on theoretical physics. He developed the theory of relativity. He received the Nobel Prize in Physics in 1921 for theoretical physics. His famous equation is E = mc^2 (E = energy, m = mass, c = speed of light).

At the beginning of his career, Einstein did not think that Newtonian mechanics was enough to bring together the laws of classical mechanics and the laws of the electromagnetic field. Between 1902–1909 he developed the theory of special relativity to correct that.

Einstein also thought that Isaac Newton's idea of gravity was not completely correct. So, he extended his ideas on special relativity to include gravity. In 1916 he published a paper on general relativity with his theory of gravitation.

In 1933, Einstein was visiting the United States. In Germany, Adolf Hitler and the Nazis came to power. Einstein, being of Jewish ethnicity, did not return to Germany due to Hitler’s anti-Semitic policies.

He lived in the United States and became an American citizen in 1940. At the beginning of World War II, he sent a letter to President Franklin D. Roosevelt explaining to him that Germany was in the process of making a nuclear weapon; so Einstein recommended that the US should also make one. This led to the Manhattan Project, and the US became the first nation in history to create and use the atomic bomb (not on Germany though but Japan). Einstein and other physicists like Richard Feynman who worked on the Manhattan project later regretted that the bomb was used on Japan.

Einstein lived in Princeton and was one of the first members invited to the Institute for Advanced Study, where he worked for the remainder of his life. He is widely considered one of the greatest scientists of all time. His contributions helped lay the foundations for all modern branches of physics, including quantum mechanics and relativity.

Most scientists think that Einstein's theories of special and general relativity work very well, and they use those ideas and formulas in their own work.

He spent much of his later life trying to find a "unified field theory" that would include his general relativity theory, Maxwell's theory of electromagnetism, and perhaps a better quantum theory but didn't succeed in his life time.

Early life

Albert Einstein at the age of three (1882)
Einstein as a child in 1882

Einstein was born in Ulm, Württemberg, Germany, on 14 March 1879. His family was Jewish, but was not very religious. However, later in life Einstein became very interested in his Judaism.

Einstein did not begin speaking until he was 2 years old. According to his younger sister, Maja, "He had such difficulty with language that those around him feared he would never learn".

When Einstein was around 4 years old, his father gave him a magnetic compass. He tried hard to understand how the needle could seem to move itself so that it always pointed north. The needle was in a closed case, so clearly nothing like wind could be pushing the needle around, and yet it moved. So in this way Einstein became interested in studying science and mathematics. His compass gave him ideas to explore the world of science.

When he became older, he went to a school in Switzerland. After he graduated, he got a job in the patent office there. While he was working there, he wrote the papers that first made him famous as a great scientist.

Einstein married a 20-year-old Serbian woman Mileva Marić in January 1903.

In 1917, Einstein became very sick with an illness that almost killed him. His cousin Elsa Löwenthal nursed him back to health. After this happened, Einstein divorced Mileva in 14 February 1919, and married Elsa on 2 June 1919.


Einstein's first daughter was "Lieserl" (her real name may have been Marta). She was born in Novi Sad, Vojvodina, Austria-Hungary on January 27, 1902. She spent her first years with her Serbian grandparents because Einstein did not want to bring her to Switzerland, where he had a job offer at the patent office. Some historians believe she died from scarlet fever.

Einstein's two sons were Hans Albert Einstein and Eduard "Tete" Einstein. Hans Albert was born in Bern, Switzerland in May 1904. He became a professor in Berkeley (California). Eduard was born in Zürich, Switzerland in July 1910. He died at 55 years old of a stroke in the Psychiatric University Hospital Zurich "Burghölzli".

Later life

Einstein tongue
The famous image of Einstein taken by United Press photographer Arthur Sasse in 1951

In spring of 1914, he moved back to Germany, and became an ordinary member of the Prussian Academy and director of a newly established institute for physics of the Kaiser-Wilhelm-Gesellschaft.

He lived in Berlin and finished the paper on the General Theory of Relativity in November 1915.

In the german Weimar republic he was politically active for socialism and zionism.

In 1922 , he received the Nobel prize for Physics for his explanation of the photoelectric effect in 1905. He then tried to formulate a general field theory uniting gravitation and electromagnetism, without success.

He had reservations about the quantum mechanics invented by Heisenberg (1925) and Schrödinger (1926).

In spring 1933 Einstein and Elsa were traveling in the USA when the Nazi party came to power. The Nazis were violently antisemitic. They called Einstein´s relativity theory "Jewish physics".

After their return to Belgium, considering the threats from the Nazis, Einstein resigned from his position in the Prussian Academy in a letter from Oostende. Einstein and Elsa decided not to go back to Berlin and moved to Princeton, New Jersey in the United States, and in 1940 he became a United States citizen.

Before World War II, in August 1939, Einstein, at the suggestion of Leó Szilárd, wrote to the U.S. President, Franklin D. Roosevelt, to say that the United States should invent the atomic bomb so that the Nazi government before the Nazi's did. He signed the letter, however, he was not part of the Manhattan Project, which was the project that created the atomic bomb.

Einstein, a Jew but not an Israeli citizen, was offered the Israeli presidency in 1952 but turned it down, stating "I am deeply moved by the offer from our State of Israel, and at once saddened and ashamed that I cannot accept it."

He did his research on gravitation at the Institute for Advanced Study at Princeton, New Jersey until his death on 18 April 1955 of a burst aortic aneurysm. He was still writing about quantum physics hours before he died.

He was awarded the Nobel Prize in Physics.

Theory of special relativity

The Theory of special relativity was published by Einstein in 1905, in a paper called "On the Electrodynamics of Moving Bodies". It says that both distance measurements and time measurements change near the speed of light. This means that as you get closer to the speed of light, lengths appear to get shorter, and clocks tick more slowly.

Special relativity also relates energy with mass, in Albert Einstein's E=mc2 formula.

Mass-energy equivalence

E=mc2, also called the mass-energy equivalence, is one of the things that Einstein is most famous for. It is a famous equation in physics and math that shows what happens when mass changes to energy or energy changes to mass.

The "E" in the equation stands for energy. "E" is a number which you give to objects depending on how much they can change other things. For instance, a brick hanging over an egg can put enough energy onto the egg to break it. A feather hanging over an egg does not have enough energy to hurt the egg.

The General Theory of Relativity

General relativity
General relativity illustrates how gravity is bending space

The General Theory of Relativity was published in 1915, ten years after the special theory of relativity was created.

General relativity is a theory of space and time.

The central idea of general relativity is that space and time are two aspects of spacetime.

Spacetime is curved when there is matter, energy, and momentum resulting in what we perceive as gravity. The links between these forces are shown in the Einstein field equations.

According to the general theory of relativity, any mass causes spacetime to curve, and any other mass follows these curves. Bigger mass causes more curving. This was a new way to explain gravitation (gravity).

General relativity explains that light bends when it comes near a massive object such as the sun.


Albert Einstein Head
Albert Einstein in 1947

Many scientists only care about their work, but Einstein also spoke and wrote often about politics and world peace. He liked the ideas of socialism and of having only one government for the whole world. He also worked for Zionism, the effort to try to create the new country of Israel.

Einstein's family was Jewish, but Einstein never practiced this religion seriously. He liked the ideas of the Jewish philosopher Baruch Spinoza and also thought that Buddhism was a good religion.

Even though Einstein thought of many ideas that helped scientists understand the world much better, he disagreed with some scientific theories that other scientists liked. Einstein did not like some parts of quantum theory which he called “spooky action at a distance." Einstein disagreed that the phenomena in quantum mechanics can happen out of pure chance. He believed that all natural phenomena have explanations that do not include pure chance. He once said, "I do not believe that God plays dice with the Universe."

Awards and honors

Einstein received numerous awards and honors, and in 1922, he was awarded the 1921 Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect".

A unit used in photochemistry was named after him. It is equal to Avogadro's number multiplied by the energy of one photon of light.

The chemical element Einsteinium is named after the scientist as well. In slang, we sometimes call a very smart person an "Einstein."

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