Hendrik Christoffel "Henk" van de Hulst (19 November 1918 – 31 July 2000) was a Dutch
astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...
and
mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems.
Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change.
History
On ...
.
In 1944, while a student in Utrecht, he predicted the existence of the
21 cm hyperfine line of neutral interstellar
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
. After this line was discovered, he participated, with
Jan Oort
Jan Hendrik Oort ( or ; 28 April 1900 – 5 November 1992) was a Dutch astronomer who made significant contributions to the understanding of the Milky Way and who was a pioneer in the field of radio astronomy. His ''New York Times'' obituary ...
and C.A. Muller, in the effort to use
radio astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The first detection of radio waves from an astronomical object was in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation comin ...
to map out the neutral hydrogen in our
galaxy, which first revealed its spiral structure. Motivated by the scattering in
cosmic dust
Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are c ...
, he studied
light scattering by spherical particles and wrote his doctoral thesis on the topic,
subsequently formulating the
anomalous diffraction theory.
He spent most of his career at
Leiden University, retiring in 1984. He published widely in astronomy, and dealt with the solar corona, and interstellar clouds. After 1960 he was a leader in international space research projects.
In 1956 he became member of the
Royal Netherlands Academy of Arts and Sciences.
Books
*van de Hulst, H.C., ''Light Scattering by Small Particles'', New York, (
Wiley
Wiley may refer to:
Locations
* Wiley, Colorado, a U.S. town
* Wiley, Pleasants County, West Virginia, U.S.
* Wiley-Kaserne, a district of the city of Neu-Ulm, Germany
People
* Wiley (musician), British grime MC, rapper, and producer
* Wiley Mil ...
, 1957;
Dover, 1981), .
*van de Hulst, H.C., ''Multiple Light Scattering'', New York,
Academic Press
Academic Press (AP) is an academic book publisher founded in 1941. It was acquired by Harcourt, Brace & World in 1969. Reed Elsevier bought Harcourt in 2000, and Academic Press is now an imprint of Elsevier.
Academic Press publishes referen ...
, 1980, .
Honors
Awards
*
Henry Draper Medal
The Henry Draper Medal is awarded every 4 years by the United States National Academy of Sciences "for investigations in astronomical physics". Named after Henry Draper, the medal is awarded with a gift of USD $15,000. The medal was established ...
of the
National Academy of Sciences (1955)
*
Eddington Medal
The Eddington Medal is awarded by the Royal Astronomical Society for investigations of outstanding merit in theoretical astrophysics. It is named after Sir Arthur Eddington. First awarded in 1953, the frequency of the prize has varied over the year ...
of the
Royal Astronomical Society
(Whatever shines should be observed)
, predecessor =
, successor =
, formation =
, founder =
, extinction =
, merger =
, merged =
, type = NG ...
(1955)
*
Rumford Medal of the
Royal Society
The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
(1964)
*
Bruce Medal
The Catherine Wolfe Bruce Gold Medal is awarded every year by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy. It is named after Catherine Wolfe Bruce, an American patroness of astronomy, and was fi ...
of the
Astronomical Society of the Pacific (1978)
*
Karl Schwarzschild Medal The Karl Schwarzschild Medal, named after the astrophysicist Karl Schwarzschild, is an award presented by the Astronomische Gesellschaft (German Astronomical Society) to eminent astronomers and astrophysicists.
Recipients
SourceGerman Astronomica ...
of the
Astronomische Gesellschaft
__NOTOC__
The ''Astronomische Gesellschaft'' is an astronomical society established in 1863 in Heidelberg, the second oldest astronomical society after the Royal Astronomical Society.
In 1882, the ''Astronomische Gesellschaft'' founded the Centra ...
(1995)
Named after him
*
Asteroid 2413 van de Hulst
*
van de Hulst approximation
Honors
* elected to the
American Philosophical Society
The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...
(1960)
* elected to the
American Academy of Arts and Sciences
The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...
(1960)
* elected to the United States
National Academy of Sciences (1977)
References
Bibliography
*
1918 births
2000 deaths
20th-century Dutch astronomers
Utrecht University alumni
Leiden University faculty
Scientists from Utrecht (city)
Foreign Members of the Royal Society
Foreign associates of the National Academy of Sciences
Members of the Royal Netherlands Academy of Arts and Sciences
{{Europe-astronomer-stub
Members of the American Philosophical Society