Forest Ray Moulton (April 29, 1872 – December 7, 1952) was an American

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, natural satellite, moons, comets and galaxy, g ...

Biography

He was born in

Le Roy, Michigan LeRoy is a village in Osceola County of the U.S. state of Michigan. The population was 256 at the 2010 census. The village is located within LeRoy Township. History A post office in LeRoy has been in operation since 1871, with James E. Bevins ...

, and was educated at

Albion College Albion College is a private liberal arts college in Albion, Michigan. The college was founded in 1835 and its undergraduate population was approximately 1,500 students in 2014. They participate in NCAA Division III and the Michigan Intercolle ...

. After graduating in 1894 (

A.B. Bachelor of arts (BA or AB; from the Latin ', ', or ') is a bachelor's degree awarded for an undergraduate program in the arts, or, in some cases, other disciplines. A Bachelor of Arts degree course is generally completed in three or four yea ...

), he performed his graduate studies at the

University of Chicago The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park neighborhood. The University of Chicago is consistently ranked among the b ...

and gained a

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is a ...

in 1899. At the University of Chicago he was associate in astronomy (1898–1900), instructor (1900–03), assistant professor (1903–08), associate professor (1908–12), and

professor Professor (commonly abbreviated as Prof.) is an Academy, academic rank at university, universities and other post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a "person who pr ...

after 1912. He is noted for being a proponent, along with Thomas Chamberlin, of the

Chamberlin–Moulton planetesimal hypothesis The Chamberlin–Moulton planetesimal hypothesis was proposed in 1905 by geologist Thomas Chrowder Chamberlin and astronomer Forest Ray Moulton to describe the formation of the Solar System. It was proposed as a replacement for the Laplacian versio ...

that the planets coalesced from smaller bodies they termed

planetesimal Planetesimals are solid objects thought to exist in protoplanetary disks and debris disks. Per the Chamberlin–Moulton planetesimal hypothesis, they are believed to form out of cosmic dust grains. Believed to have formed in the Solar System a ...

s. Their hypothesis called for the close passage of another star to trigger this condensation, a concept that has since fallen out of favor. In the first decades of the twentieth century, some additional small satellites were discovered to be in orbit around

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...

. Dr. Moulton proposed that these were actually gravitationally-captured planetesimals. This theory has become well-accepted among astronomers. The crater

Moulton Moulton may refer to: Places in the United Kingdom ;In England *Moulton, Cheshire *Moulton, Lincolnshire **Moulton Windmill * Moulton St Mary, Norfolk *Moulton, Northamptonshire **Moulton College, agricultural college **Moulton Park, industria ...

on the Moon, the

Adams–Moulton methods Linear multistep methods are used for the numerical solution of ordinary differential equations. Conceptually, a numerical method starts from an initial point and then takes a short step forward in time to find the next solution point. The proce ...

for solving differential equations and the

Moulton plane In incidence geometry, the Moulton plane is an example of an affine plane in which Desargues's theorem does not hold. It is named after the American astronomer Forest Ray Moulton. The points of the Moulton plane are simply the points in the real pl ...

in geometry are named after him. Moulton was a critic of Albert Einstein's

theory of relativity The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena in ...

. He was in charge of ballistics at

Aberdeen Proving Ground Aberdeen Proving Ground (APG) (sometimes erroneously called Aberdeen Proving ''Grounds'') is a U.S. Army facility located adjacent to Aberdeen, Harford County, Maryland, United States. More than 7,500 civilians and 5,000 military personnel work at ...

in Maryland during

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. According to Craig A. Stephenson:

Selected publications

He became an associate editor of the ''

Transactions of the American Mathematical Society The ''Transactions of the American Mathematical Society'' is a monthly peer-reviewed scientific journal of mathematics published by the American Mathematical Society. It was established in 1900. As a requirement, all articles must be more than 15 p ...

'' in 1907 and a research associate of the

Carnegie Institution The Carnegie Institution of Washington (the organization's legal name), known also for public purposes as the Carnegie Institution for Science (CIS), is an organization in the United States established to fund and perform scientific research. Th ...

in 1908. He served for several terms as secretary of the

American Association for the Advancement of Science The American Association for the Advancement of Science (AAAS) is an American international non-profit organization with the stated goals of promoting cooperation among scientists, defending scientific freedom, encouraging scientific respons ...

(AAAS), and edited more than twenty AAAS symposia. Besides various contributions to mathematical and astronomical journals he was the author of: * ''An Introduction to Celestial Mechanics'' (1902; second, revised edition, 1914) * ''An Introduction to Astronomy'' (1906
2nd, revised edition, 1916
* ''Descriptive Astronomy'' (1912) * ''

Periodic Orbits In mathematics, specifically in the study of dynamical systems, an orbit is a collection of points related by the evolution function of the dynamical system. It can be understood as the subset of phase space covered by the trajectory of the dynamic ...

'' (1920) * ''New Methods in Exterior Ballistics'' (1926) * ''Differential Equations'' (1930) * ''Astronomy'' (1931) * ''Consider the Heavens'' (1935)"Dr. Moulton Finds There Is Order in the Universe"
''The New York Times''. Retrieved 2 February 2021.

References

External links

* * *

* (slides from talk at SRE Inter-Departmental Science Workshop, Aranjuez, Spain) {{DEFAULTSORT:Moulton, Forest Ray 1872 births 1952 deaths Albion College alumni American astronomers American science writers Ballistics experts Members of the United States National Academy of Sciences People from Osceola County, Michigan Relativity critics University of Chicago alumni University of Chicago faculty