German-born Albert Einstein, known for his theory of relativity, was the 20th century's most notable and influential physicist. He turned the classical concept of physics upside down in his day and was considered a genius by many, although some of his contemporaries thought his ideas were iconoclastic and did not accept them. It was allegedly said that only three people in the world at that time understood Einstein's theory of relativity.
Born in 1879 in the kingdom of Wurttemberg, now present day Baden-Wurttemberg, Einstein's father, Hermann, was a salesman and engineer and his mother Pauline the daughter of a wealthy trader. When Albert was six weeks old the family moved to Munich where his father partnered with his uncle in an electrical engineering business but, when years later the business failed, the family moved to Italy.
As a young boy, Albert's fascination with science was stirred when his father showed him a compass. Einstein realised that something was causing the needle to move through the empty space. He became interested in building models and mechanical devices for fun and showed a talent for mathematics. At the age of 10, Einstein was introduced to key science, mathematics and philosophy writings, including those from Critique of Pure Reason and Euclid's Elements which Einstein nicknamed his 'holy little geometry book'.
When Einstein was in his teens, he applied to finish his secondary education in Zurich, Switzerland. He failed the entrance exam for his first choice of school and ended up in Aarau in northern Switzerland. He studied for a mathematics and physics teaching diploma at the polytechnic in Zurich. His future wife, Mileva, was the only woman in the maths and physics section.
Einstein gave up his German citizenship for a Swiss one in 1901 and worked as a technical assistant in the Patent Office in Berne after graduation. In 1905, he published three papers that were important to the development of modern physics. In his works, he formulated the special theory of relativity, interpreted the photoelectric effect by quantum nature of light and explained the nature of Brownian motion. Later, he developed the general theory of relativity providing a unified description of gravity as a geometric property of space and time.
Einstein received the 1921 Nobel Prize in Physics for his services to theoretical physics and especially for his discovery of the law of the photoelectric effect, which has been pivotal in establishing the quantum theory within physics.