Emil Johann Wiechert (26 December 1861 – 19 March 1928) was a German physicist and geophysicist who made many contributions to both fields, including presenting the first verifiable model of a layered structure of the Earth and being among the first to discover the electron.

[3] Whilst at Königsberg, Wiechert was investigating the nature of X-rays and became one of the first to discover that cathode rays are made up of particle streams.

[2] Wiechert was also interested in fields outside of fundamental physics and in 1896, he published the first verifiable model of the Earth's interior as a series of shells.

He would remain there for the rest of his career, mentoring many students who became world-leading geophysicists and seismologists, including Karl Bernhard Zoeppritz and Beno Gutenberg.

[2] During his career he made many other important contributions, writing a number of scientific papers, including a pioneering work on how seismic waves propagate through the Earth.