Paul Niggli
Encyclopedia
Paul Niggli was a Swiss
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

 crystallographer
Crystallography
Crystallography is the experimental science of the arrangement of atoms in solids. The word "crystallography" derives from the Greek words crystallon = cold drop / frozen drop, with its meaning extending to all solids with some degree of transparency, and grapho = write.Before the development of...

 who was a leader in the field of X-ray crystallography
X-ray crystallography
X-ray crystallography is a method of determining the arrangement of atoms within a crystal, in which a beam of X-rays strikes a crystal and causes the beam of light to spread into many specific directions. From the angles and intensities of these diffracted beams, a crystallographer can produce a...

.

Niggli was born in Zofingen
Zofingen
Zofingen is a city in the canton of Aargau in Switzerland. It is the capital of the district of Zofingen. Zofingen is a walled city and home of an ancient monastic settlement.-Geography:...

 and studied at the Swiss Federal Institute of Technology
ETH Zurich
The Swiss Federal Institute of Technology Zurich or ETH Zürich is an engineering, science, technology, mathematics and management university in the City of Zurich, Switzerland....

 in Zurich
Zürich
Zurich is the largest city in Switzerland and the capital of the canton of Zurich. It is located in central Switzerland at the northwestern tip of Lake Zurich...

 and the University of Zurich
University of Zurich
The University of Zurich , located in the city of Zurich, is the largest university in Switzerland, with over 25,000 students. It was founded in 1833 from the existing colleges of theology, law, medicine and a new faculty of philosophy....

, where he obtained a doctorate. His 1919 book, Geometrishe Kristillographie des Diskontinuums, played a seminal role in the refinement of space group theory. In this book, Niggli demonstrated that although X-ray reflection conditions do not always uniquely determine the space group to which a crystal belongs, they do reveal a small number of possible space groups to which it could belong. Niggli used morphological methods to account for internal structure and, in his 1928 Kristallographische und Strukturtheoretische Grundbegriffe, he took up what is essentially the reverse process, the task of establishing the connection between space lattices and external crystal morphology. The great aim of his life was to integrate the whole field of Earth science
Earth science
Earth science is an all-embracing term for the sciences related to the planet Earth. It is arguably a special case in planetary science, the Earth being the only known life-bearing planet. There are both reductionist and holistic approaches to Earth sciences...

s.

In 1920, Niggli became the lead scientist at the Institut für Mineralogie und Petrographie, where he brought his systematic approach to the study of crystal morphologies using X-ray diffraction. In 1935, Niggli and his doctoral student Werner Nowacki determined the 73 three-dimensional arithmetic crystal classes (symmorphic space groups
Space group
In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...

). Niggli retired from the Institute in 1949. He was also professor of mineralogy at the Eidgenössische Technische Hochschule and at the University of Zurich.

Niggli succeeded Paul Heinrich von Groth (1843 - 1927)
Paul Heinrich von Groth
Paul Heinrich von Groth was a German mineralogist. His most important contribution to science was his systematic classification of minerals based on their chemical compositions and crystal structures....

 as editor of Zeitschrift für Kristallographie.

In 1948, Niggli was awarded the Roebling Medal
Roebling Medal
The Roebling Medal is the highest award of the Mineralogical Society of America for scientific eminence as represented primarily by scientific publication of outstanding original research in mineralogy. The award is named for Colonel Washington A. Roebling who was an engineer, bridge builder,...

 of the Mineralogical Society of America
Mineralogical Society of America
The Mineralogical Society of America is a scientific membership organization. MSA was founded in 1919 for the advancement of mineralogy, crystallography, geochemistry, and petrology, and promotion of their uses in other sciences, industry, and the arts...

.

The Paul Niggli Foundation awards medals to outstanding Swiss mineral scientists below the age of 35 with a strong perspective for an academic career.

Dorsum Niggli
Dorsum Niggli
Dorsum Niggli is a wrinkle ridge at in Oceanus Procellarum on the Moon. It is 50 km long and was named after Paul Niggli in 1976....

 on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

was named after him.
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