Manuel Sandoval Vallarta, Mexican physicist (Ciudad de Mexico 11 February 1899 – Ciudad de Mexico 18 April 1977)

Regarded as world authority on cosmic rays  

Authored about 70 works

Determinated coincidence conditions for classical and ondulatory mechanics results (1927)

With N. Rosen introduced past and future asymmetry in a field theory  

Obtained evidence that cosmic radiation presented electrical charge and determined its sign

With G. Lemaitre demonstrated that if particles flow distribution of cosmic radiation is isotropic magnetic field outside, the intensity of cosmic radiation that reaches a point on Earth surface is the same in all permitted directions for each given energy and that in any solid angle that contains only permitted directions, the intensity will be the same which in an identical solid angle

With Lemaitre predicted East-West asymmetry of cosmic radiation intensity to low geomagnetic altitudes (W.L. Alvarez confirmed it in 1933)

Explained the longitude effect on cosmic rays

HONOURS 

Physics Nobel Prize nominee

Invited Lecturer, International Congress of Mathematicians (1936)