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 cau ...

. He was a Physics professor at both

MIT The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and sc ...

and the Institute of Physics at the

National Autonomous University of Mexico The National Autonomous University of Mexico (, UNAM) is a public university, public research university in Mexico. It has several campuses in Mexico City, and many others in various locations across Mexico, as well as a presence in nine countri ...

(UNAM).

Biography

Sandoval Vallarta was born in

Mexico City Mexico City is the capital city, capital and List of cities in Mexico, largest city of Mexico, as well as the List of North American cities by population, most populous city in North America. It is one of the most important cultural and finan ...

into a family that descended from Ignacio Vallarta, a prominent liberal leader during the

War of Reform The Reform War (17 December 185711 January 1861) or War of Reform (), also known as the Three Years' War (), and the Mexican Civil War, was a complex civil war, civil conflict in Mexico fought between Mexican liberals and conservatives with re ...

. 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 Grant (money), grants that have been awarded annually since by the John Simon Guggenheim Memorial Foundation, endowed by the late Simon Guggenheim, Simon and Olga Hirsh Guggenheim. These awards are bestowed upon indiv ...

to study physics in Germany. The Universities of

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

and

Leipzig Leipzig (, ; ; Upper Saxon: ; ) is the most populous city in the States of Germany, German state of Saxony. The city has a population of 628,718 inhabitants as of 2023. It is the List of cities in Germany by population, eighth-largest city in Ge ...

hosted him, and he was able to learn from

Albert Einstein Albert Einstein (14 March 187918 April 1955) was a German-born theoretical physicist who is best known for developing the theory of relativity. Einstein also made important contributions to quantum mechanics. His mass–energy equivalence f ...

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

Erwin Schrödinger Erwin Rudolf Josef Alexander Schrödinger ( ; ; 12 August 1887 – 4 January 1961), sometimes written as or , was an Austrian-Irish theoretical physicist who developed fundamental results in quantum field theory, quantum theory. In particul ...

, and

Werner Heisenberg Werner Karl Heisenberg (; ; 5 December 1901 – 1 February 1976) was a German theoretical physicist, one of the main pioneers of the theory of quantum mechanics and a principal scientist in the German nuclear program during World War II. He pub ...

. He was elected to the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (The Academy) 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, and other ...

in 1928. While at MIT, Vallarta was a mentor to

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

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. The journal was 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 Ame ...

concerning the scattering of

cosmic rays Cosmic rays or astroparticles 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 ...

. 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, and mathematician who made major contributions to cosmology and astrophysics. He was the first to argue that the ...

, a Belgian physicist and Catholic priest, Vallarta theoretically predicted that the intensity of cosmic rays should vary with latitude because these charged particles are interacting with the Earth's magnetic field. However, they were unaware that

Bruno Rossi Bruno Benedetto Rossi ( , ; 13 April 1905 – 21 November 1993) was an Italian-American experimental physicist. He made major contributions to particle physics and the study of cosmic rays. A 1927 graduate of the University of Bologna, he ...

had already predicted such latitude effect (along with the East-West effect) a few years before, in 1930. 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 (, UNAM) is a public research university in Mexico. It has several campuses in Mexico City, and many others in various locations across Mexico, as well as a presence in nine countries. It also has 34 ...

. By 1946, he chose to remain with UNAM full-time. While at UNAM, he worked with Luis Alvarez and

Arthur Compton Arthur Holly Compton (September 10, 1892 – March 15, 1962) was an American particle physicist who won the 1927 Nobel Prize in Physics for his discovery of the Compton effect, which demonstrated the particle nature of electromagnetic radiati ...

on experiments to show that cosmic rays were composed of

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

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, ce ...

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. He was elected to the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

in 1954.

Biography

References

See also