Books etc

Elementary particles

Around 2,500 years ago, the Greek philosophers Leucippus and Democritus suggested that matter (= everything that has weight and takes up space) is made up of extremely small building blocks surrounded by empty space. These fundamental elements, which contained no smaller components withi...…
in history
Elementary particles

Discovery of the electron

In the article on elementary particles, we read that, in 1804, John Dalton demonstrated the existence of atoms, which he imagined as hard spheres. More than 90 years later, in 1897, the experiments of Joseph John Thomson, a British physicist, showed that atoms contain electrons, tiny particles...…
in history
Discovery of the electron

Discovery of the electron as a wave

The first physicist to suggest that electrons could also exhibit wave-like behavior was the French nobleman Louis De Broglie. In 1924, De Broglie proposed the principle of wave-particle duality for all components of matter, not just electrons. This principle means that the particles that constitut...…
in history
Discovery of the electron as a wave

Double-slit experiment

The double-slit experiment was invented in 1801 by Thomas Young to study the nature of light. Young was convinced that light behaved like a wave, while other scientists, such as Isaac Newton, preferred to think of it as composed of corpuscles (= light particles). Young decided to pass a beam o...…
in history
Double-slit experiment

Schroedinger's cat

Schrödinger's cat is the most well-known thought experiment in quantum physics. A thought experiment is like an imagination game! It’s when you use your imagination to think about a situation, even if you can’t actually do it in real life. Schrödinger used it to illustrate the strange world of qua...…
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Schroedinger's cat

Discovery of electron spin

In 1922, Otto Stern and Walther Gerlach, two German physicists, conducted a groundbreaking experiment that demonstrated that electron spin and magnetism were related. To understand it, let’s imagine you have a strong magnet and a bunch of tiny beads. If you throw the non-magnetic beads through the m...…
in history
Discovery of electron spin