Thread by @RAS_Diversity

Lise Meitner was an Austrian-Swedish physicist. She became the second woman to gain a PhD in physics at @univienna in 1905. In 1917, Meitner and Otto Hahn discovered the first long-lived isotope of protactinium while at the Kaiser-Wilhelm-Institut (KWI). #STEMlegends #WomenInSTEM

In 1922, Meitner discovered the Auger emission process. This describes how a photon or electron is emitted from an atom when the inner-shell is filled by an electron. This effect is named after Pierre Auger who made the same discovery as Meitner independently, the following year.

After the discovery of the neutron in 1932, physicists realised it might be possible to create new elements by adding neutrons to uranium. A race to create the first new element ensued between Meitner and Hahn, and Ernest Rutherford, Irène Joliot-Curie, and Enrico Fermi.

Hitler came to power in 1933, and almost all Jewish scientists who were not Austrian citizens, or had not fought on the side of Germany during World War I, were removed from their posts. Meitner was Jewish but was also Austrian and so chose to stay, a decision she regretted.

Meitner escaped Nazi Germany for the Netherlands in 1938 - with the help of Dutch physicists Dirk Coster and Adriaan Fokker - leaving all of her possessions behind. Meitner reunited with Hahn in Copenhagen, where they discussed experiments he could perform with Fritz Strassmann.

Strassmann conducted the first experiment that provided evidence for nuclear fission. This was proven by Meitner and Otto Robert Frisch, who explained how the nucleus of an atom could be split into smaller parts, and why there are no stable elements beyond uranium.

By the end of 1938, Meitner was the first to realise that Albert Einstein's theory of special relativity explained why a tremendous amount of energy was released during fission. Hahn and Strassman published their results in 1939.

The realisation that this knowledge was in German hands led to the formation of the Manhattan Project. Frisch and Hahn were both involved in the Manhattan Project. Meitner refused an offer to work on the project and stayed in Sweden.

After the WWII, Meitner criticised Hahn, Heisenberg, and others for staying in Nazi Germany for as long as they did, offering only passive resistance. In 1945, it was announced that Hahn had been awarded the 1944 Nobel Prize in Chemistry for the discovery of nuclear fission.