Fritz Zwicky

Fritz Zwicky was an iconoclastic Swiss astronomer and astrophysicist at Caltech whose audacious theoretical insights anticipated many of the central pillars of modern astrophysics. Known for his abrasive wit and unconventional personality, Zwicky pioneered the use of wide-angle Schmidt telescopes at Palomar Mountain to survey the heavens for transient cosmic phenomena.

In 1933, by applying the virial theorem to the orbital velocities of galaxies in the Coma cluster, Zwicky discovered that the galaxies were moving far too fast to remain bound by the gravitational pull of their visible stars. He boldly deduced the presence of massive, invisible dunkle Materie ('dark matter')—making him the true discoverer of dark matter. With Walter Baade, he coined the term supernova and presciently proposed that supernovae represent the collapse of normal stars into ultra-dense neutron stars. In 1937, Zwicky also predicted that massive galaxy clusters would act as natural gravitational lenses magnifiying distant objects, decades before it was observed.