World Library  
Flag as Inappropriate
Email this Article

Manuel Sandoval Vallarta

Manuel Sandoval Vallarta
Born (1899-02-11)11 February 1899
Mexico City
Died 18 April 1977(1977-04-18) (aged 78)
Mexico City
Residence Mexico
United States
Nationality Mexican
Institutions MIT
Alma mater MIT
Notable students Richard Feynman and Julius Stratton
Known for Cosmic ray research
Notable awards Légion d'honneur (France, 1952); National Prize for Exact Sciences (Mexico, 1961)[1]
Spouse María Luisa Margain

Manuel Sandoval Vallarta (11 February 1899 – 18 April 1977) was a Mexican physicist. He was a Physics professor at both MIT and the Institute of Physics at the National Autonomous University of Mexico (UNAM).[2]


Sandoval Vallarta was born in Mexico City into a family that descended from Ignacio Vallarta, a prominent liberal leader during the War of Reform.[1] He received his S.B. 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 to study physics in Germany. The Universities of Berlin and Leipzig hosted him, and he was able to learn from Albert Einstein, Max Planck, Erwin Schrödinger, and Werner Heisenberg.

While at MIT, Vallarta was a mentor to Richard Feynman and Julius Stratton. In fact, he was the co-author of Feynman's first scientific publication, a letter to Physical Review concerning the scattering of cosmic rays. 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." [3]

With Belgian physicist and churchman, 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. 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 protons.

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 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.


  1. ^ a b
  2. ^
  3. ^

See also

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.