New tools such as special microscopes and the cyclotron take research to higher levels, while average citizens enjoy novel amenities such as the FM radio.


Permanent alloy magnets

The first permanent alloy magnets of aluminum, nickel and cobalt (alnico magnets) are produced.

Superconductors and insulators

British physicist Alan Wilson applies the band-gap theory of energy to account for the behavior of superconductors and insulators.

Frst cyclotron

The first cyclotron, a circular particle accelerator in which subatomic particles are accelerated by an alternating high-frequency electric field in a fixed magnetic field, is built.

First electron lens

German physicist Ernst Ruska, while still a student in Berlin, constructs the first electron lens, using an electromagnet to focus a beam of electrons just as a lens focuses a beam of light. By 1933, he uses several electron lenses in a series to make the first electron microscope with better definition than a light microscope.

Discovering the neutron

James Chadwick of England discovers the neutron, a particle with mass similar to a proton, but that does not have an electrical charge.

Discovering the positron

American physicist Carl Anderson discovers the positron, a particle with mass similar to an electron, but with a positive rather than negative charge.

Meissner effect

Walther Meissner and Robert Oschenfeld of Germany discover that as a material loses its resistance to electricity when its temperature is dropped below a certain temperature, the magnetic field inside the material is completely or partly expelled. Characteristic of all superconductors, this phenomenon came to be commonly known as the Meissner effect or the Meissner-Oschenfeld effect.

Sodium vapor lamps

Sodium vapor lamps come into use to light highways.

Tape recorder

German inventor Semi Joseph Begun constructs the first magnetic tape recorder used for broadcasting.

Fluorescent lamp

The fluorescent lamp is introduced in Europe.

Coiled-coil filament

In the United States, the coiled-coil filament is invented, resulting in brighter and more energy-efficient electric light bulbs.

Audio recording

Magnetic tape for audio recording becomes available commercially in Germany following its introduction at the Berlin Radio Exhibition.


French physicist Louis Néel develops the concept of antiferromagnetism, a temperature-dependent form of magnetism in which adjacent ions arrange themselves in antiparallel formations so that nearly no overall external magnetism can be detected.

Earth & eddy currents

Walter Elsasser, a German-born American physicist, proposes that the Earth’s observable magnetic field is the result of rotation-related eddy currents in the liquid core of the planet.
More in this category: « 1910-1929 1940-1959 »