Module VI·Article I·~2 min read
Physics of the 20th Century: Quantum Mechanics and the Theory of Relativity
Science and Society in the 20th Century
Turn this article into a podcast
Pick voices, format, length — AI generates the audio
The Revolution of 1905
1905 was the “miraculous year” (annus mirabilis) for the young Einstein. In a single year he published four articles, each of which would have merited a Nobel Prize. Brownian motion (confirmation of the atomic theory). The photoelectric effect (light as quanta — the foundation of quantum mechanics). The special theory of relativity ($E=mc^2$, space-time). The equivalence of mass and energy.
The special theory of relativity destroyed Newtonian absolute simultaneity: time flows differently in different frames of reference. $E=mc^2$ is not just a formula, but the discovery that mass and energy are the same thing in different forms. The atomic bomb is an applied demonstration of this equivalence.
General theory of relativity (1915): gravity is not a force (Newton), but the curvature of space-time by massive bodies. Confirmed by the observation of the bending of light near the Sun during the eclipse of 1919. This was the first experimental verification — and a global sensation.
Quantum Mechanics and Its Interpretations
Quantum mechanics (Bohr, Heisenberg, Schrödinger, Dirac, 1920s) describes the behavior of microparticles — and radically differs from classical mechanics. Particles do not have definite coordinates and momenta at the same time (Heisenberg’s uncertainty principle). Before measurement, a particle is in a “superposition” of states — collapse occurs upon measurement. This is the “Copenhagen interpretation” (Bohr).
“Schrödinger’s cat” is a thought experiment: a cat in a sealed box with poison, released by a quantum event, is simultaneously alive and dead until the box is opened. This demonstrates the absurdity of applying quantum mechanics to the macroscopic world.
Einstein refused to accept the probabilistic interpretation: “God does not play dice.” The debate between Einstein and Bohr is one of the great scientific dialogues of the 20th century. Today, most physicists work with quantum mechanics without asking about its “meaning.”
Question for reflection: Quantum mechanics describes a reality that cannot be “understood” in the classical sense — only calculated. Are there areas in your field that work, but are “incomprehensible”? How do you deal with this?
§ Act · what next