This article is part of a special series celebrating the 100th anniversary of the birth of quantum theory. Click here for more details
The species of quantum theory were sown in 1905 by Albert Einstein and others. However, the theory was put together appropriately 100 Many years ago, in 1925 – as this timeline shows, it has had an impact ever since.
> 1905 In a riff in a previous work by Max Planck, Albert Einstein suggests that light is made of particles with a specific energy. These “quantums of light” were early steps in the path to quantum theory.
> 1913 Niels Bohr produces quantum descriptions of atoms where only electrons can exist in a particular orbital with fixed energy.
> 1919 Physicist Hendrika Johanna van Leeuwen writes a paper that proposes that magnetism is also a quantum mechanical phenomenon.
> 1925 In Windswept Island of Helgoland, Werner Heisenberg performs calculations that treat electron properties as tables of values rather than as single values. With this, his supervisor, Max Born, discovers the important truths of quantum mechanics (see Carlo Robery on what we are wrong about the origins of quantum theory).
> 1926 Erwin Schrödinger develops an alternative quantum framework that paints electrons as waves using a mathematical construct called wave functions.
> 1935 Schrödinger devises a thought experiment that can be considered alive and dead while cats in closed boxes are not observed. Einstein, Nathan Rosen and Boris Podolski write articles on Quantum Entanglement.
