Manuel Sandoval Vallarta (11 February 1899 – 18 April 1977) was a Mexican

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...

. He was a Physics professor at both

MIT The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the m ...

and the Institute of Physics at the

National Autonomous University of Mexico The National Autonomous University of Mexico ( es, Universidad Nacional Autónoma de México, UNAM) is a public research university in Mexico. It is consistently ranked as one of the best universities in Latin America, where it's also the bigges ...

(UNAM).

Biography

Sandoval Vallarta was born in

Mexico City Mexico City ( es, link=no, Ciudad de México, ; abbr.: CDMX; Nahuatl: ''Altepetl Mexico'') is the capital and largest city of Mexico, and the most populous city in North America. One of the world's alpha cities, it is located in the Valley o ...

into a family that descended from

Ignacio Vallarta Ignacio Luis Vallarta Ogazón (25 August 1830, Guadalajara, Jalisco – 31 December 1893, Mexico, D.F.) was a Mexican jurist and governor of the Mexican state of Jalisco (1872–1876). His baptismal name was José Luis Miguel Ignacio Vallar ...

, a prominent liberal leader during the

War of Reform The Reform War, or War of Reform ( es, Guerra de Reforma), also known as the Three Years' War ( es, Guerra de los Tres Años), was a civil war in Mexico lasting from January 11, 1858 to January 11, 1861, fought between liberals and conservativ ...

. He received his B.S. in physics from MIT in 1921; in 1924, MIT awarded him his Ph.D. He joined MIT's physics faculty in 1923, eventually rising to the rank of full professor. In 1927, Vallarta received a two-year

Guggenheim Fellowship Guggenheim Fellowships are grants that have been awarded annually since by the John Simon Guggenheim Memorial Foundation to those "who have demonstrated exceptional capacity for productive scholarship or exceptional creative ability in the ar ...

to study physics in Germany. The Universities of

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

and

Leipzig Leipzig ( , ; Upper Saxon: ) is the most populous city in the German state of Saxony. Leipzig's population of 605,407 inhabitants (1.1 million in the larger urban zone) as of 2021 places the city as Germany's eighth most populous, as wel ...

hosted him, and he was able to learn from

Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...

Max Planck Max Karl Ernst Ludwig Planck (, ; 23 April 1858 – 4 October 1947) was a German theoretical physicist whose discovery of energy quanta won him the Nobel Prize in Physics in 1918. Planck made many substantial contributions to theoretical p ...

Erwin Schrödinger Erwin Rudolf Josef Alexander Schrödinger (, ; ; 12 August 1887 – 4 January 1961), sometimes written as or , was a Nobel Prize-winning Austrian physicist with Irish citizenship who developed a number of fundamental results in quantum theo ...

, and

Werner Heisenberg Werner Karl Heisenberg () (5 December 1901 – 1 February 1976) was a German theoretical physicist and one of the main pioneers of the theory of quantum mechanics. He published his work in 1925 in a breakthrough paper. In the subsequent series ...

. While at MIT, Vallarta was a mentor to

Richard Feynman Richard Phillips Feynman (; May 11, 1918 – February 15, 1988) was an American theoretical physicist, known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superflu ...

and Julius Stratton. In fact, he was the co-author of Feynman's first scientific publication, a letter to

Physical Review ''Physical Review'' is a peer-reviewed scientific journal established in 1893 by Edward Nichols. It publishes original research as well as scientific and literature reviews on all aspects of physics. It is published by the American Physical S ...

concerning the scattering of

cosmic rays Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own ...

. This led to an interesting Feynman story:

Vallarta let his student in on a secret of mentor-protégé publishing: the senior scientist's name comes first. Feynman had his revenge a few years later, when Heisenberg concluded an entire book in cosmic rays with the phrase: "such an effect is not to be expected according to Vallarta and Feynman." When they next met, Feynman asked gleefully whether Vallarta had seen Heisenberg's book. Vallarta knew why Feynman was grinning. "Yes," he replied. "You're the last word in cosmic rays."

With

Georges Lemaître Georges Henri Joseph Édouard Lemaître ( ; ; 17 July 1894 – 20 June 1966) was a Belgian Catholic priest, theoretical physicist, mathematician, astronomer, and professor of physics at the Catholic University of Louvain. He was the first to t ...

, a

Belgian Belgian may refer to: * Something of, or related to, Belgium * Belgians, people from Belgium or of Belgian descent * Languages of Belgium, languages spoken in Belgium, such as Dutch, French, and German *Ancient Belgian language, an extinct languag ...

physicist and Catholic priest, Vallarta discovered that the intensity of cosmic rays varied with latitude because these charged particles are interacting with the Earth's magnetic field. They also worked on a theory of primary cosmic radiation and applied it to their investigations of the sun's magnetic field and the effects of the galaxy's rotation. From 1943 to 1946, he divided his time between MIT and

UNAM The National Autonomous University of Mexico ( es, Universidad Nacional Autónoma de México, UNAM) is a public research university in Mexico. It is consistently ranked as one of the best universities in Latin America, where it's also the bigge ...

. By 1946, he chose to remain with UNAM full-time. While at UNAM, he worked with Luis Alvarez and Arthur Compton on experiments to show that cosmic rays were composed of

proton A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...

s. Later in life, Vallarta became involved in administration. In 1946, he became a member of the governing board of UNAM, and was director of the

National Polytechnic Institute National may refer to: Common uses * Nation or country ** Nationality – a ''national'' is a person who is subject to a nation, regardless of whether the person has full rights as a citizen Places in the United States * National, Maryland, ...

from 1944 to 1947. He served on and led a number of commissions for the Mexican government, mostly relating to science policy, and represented his country at numerous international conferences.

Biography

References

See also