Albert Einstein

Theoretical physicist, 1879–1955

Albert Einstein (14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory of relativity, but he also made important contributions to quantum mechanics.

Relativity and quantum mechanics are together the two pillars of modern physics. His mass–energy equivalence formula E = mc², which arises from relativity theory, has been called "the world's most famous equation".

Overview

Einstein's work is also known for its influence on the philosophy of science. He 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", a pivotal step in the development of quantum theory. His intellectual achievements and originality resulted in "Einstein" becoming synonymous with "genius".

The most beautiful experience we can have is the mysterious. It is the fundamental emotion that stands at the cradle of true art and true science.

Albert Einstein, The World As I See It, 1931

Early life and education

Albert Einstein was born in Ulm, in the Kingdom of Württemberg in the German Empire, on 14 March 1879 into a family of secular Ashkenazi Jews. His parents were Hermann Einstein, a salesman and engineer, and Pauline Koch. In 1880, the family moved to Munich's borough of Ludwigsvorstadt-Isarvorstadt, where Einstein's father and his uncle Jakob founded Elektrotechnische Fabrik J. Einstein & Cie, a company that manufactured electrical equipment based on direct current.

Early education

Einstein attended a Catholic elementary school in Munich from the age of five. When he was eight, he was transferred to the Luitpold Gymnasium (now known as the Albert Einstein Gymnasium), where he received advanced primary and secondary school education until he left the German Empire seven years later.

• Elementary school: Catholic school in Munich (1884–1887)
• Luitpold Gymnasium: secondary education (1887–1894)
• Aarau Cantonal School: Switzerland (1895–1896)
• Swiss Federal Polytechnic: Zurich (1896–1900)

Discovery through music

Contrary to popular belief, Einstein did not fail at mathematics in school. In fact, he excelled at it. He also showed considerable musical talent, beginning violin lessons at age five under his mother's encouragement. Music remained a significant part of Einstein's personal life throughout his career.

On the role of curiosity

Einstein often spoke about the role of curiosity and questioning in scientific discovery. He considered the willingness to ask naive questions — questions that seem childish or obvious — a fundamental asset for any theoretical physicist.

The patent office years

After graduating in 1900, Einstein spent almost two years searching for a teaching post. He acquired Swiss citizenship in February 1901 but was not conscripted for medical reasons. With the help of Marcel Grossmann's father, he secured a job in Bern at the Federal Office for Intellectual Property — the patent office — as an assistant examiner, level III.

The position was perfect. It gave him financial security while leaving his mind free to pursue theoretical problems. Much of his work at the patent office related to questions about transmission of electric signals and electrical-mechanical synchronization of time, two technical problems that show up conspicuously in the thought experiments that led Einstein to his conclusions about the nature of light and the connection between space and time.

The miracle year papers

In 1905, sometimes described as Einstein's annus mirabilis ('miracle year'), he published four groundbreaking papers, each of which would alter the course of modern physics:

1. On a Heuristic Viewpoint Concerning the Production and Transformation of Light — introducing the concept of light quanta (later called photons).
2. On the Motion of Small Particles Suspended in a Stationary Liquid — explaining Brownian motion and providing evidence for atoms.
3. On the Electrodynamics of Moving Bodies — introducing special relativity.
4. Does the Inertia of a Body Depend Upon Its Energy Content? — establishing mass–energy equivalence, E = mc².

Time-dilation code example

Here is a trivial Python example that computes time dilation for an observer at velocity v relative to a stationary frame:

import math

def time_dilation(proper_time, velocity, c=299_792_458):
    """Return dilated time seen by a moving observer.
    proper_time: seconds in the rest frame
    velocity: metres per second
    c: speed of light in m/s
    """
    gamma = 1 / math.sqrt(1 - (velocity ** 2) / (c ** 2))
    return proper_time * gamma

# One hour at 50% the speed of light
dilated = time_dilation(3600, 0.5 * 299_792_458)
print(f"{dilated:.2f} seconds elapse for the moving observer")
# → 4156.92 seconds elapse for the moving observer

General relativity

In 1915, Einstein published his general theory of relativity. This theory reconciled Newtonian mechanics with the laws of the electromagnetic field, and extended special relativity to include gravity. His equations predicted that the path of light could be bent by massive objects — confirmed by observations of the 1919 solar eclipse.

Legacy

Einstein died on 18 April 1955 at the age of 76. His work continues to inspire physicists, engineers, and writers today. The Einstein Papers Project at Caltech has been working since 1986 to edit, annotate, and publish Einstein's complete scientific and personal writings.