About Micro- and Milli-Zwickies
(Translated by Arne Rau, MPE)
http://www.deutschlandfunk.de/astronomie-von-mikro-und-milli-zwickys.732.de.html?dram:article_id=326903

The Swiss Fritz Zwicky belongs to the most important astronomers
of the previous century. After receiving his education in Zurich
he immigrated to California in 1925 and worked among other places
at the Palomar Observatory.

Different than many of his colleagues performed his research projects
without preconceived notions and was also open to very unusual
thoughts.

As an example, after studying galaxy clusters, Zwicky postulated
that the Universe must be filled with a large amount of dark matter,
meaning matter that cannot be seen but instead only noticed through
its gravity.

Fritz Zwicky also studied the gravitational lens effect. Here, the
gravitational field of a galaxy acts like a lense and distort ths
light from objects located behind it.

Albert Einstein thought that this effect was unobservable. But
Zwicky hat work on a detailed theory,  which was validated with the
first discovery of a gravitational lens a few years after his death.

His brilliant thoughts, often far ahead of his time, and his often
rather unrefined social interaction brought Fritz Zwicky the
reputation of being eccentric. He died 1974 at an age of nearly 76
years.

Shri Kulkarni, direktor of the Palomar Observatory and himself a
rather unconventionally working researcher uses the unit "Zwicky"
to measure the scientific excellence of  astronomers.

He complains that there are nearly only micro Zwickies - already a
milli Zwicky is a rare phenomenon.