Question: Walter Alvarez's father was born in what year?

full_context: Document 1: Rheasilvia: Rheasilvia is the most prominent surface feature on the asteroid Vesta, it is the tallest mountain in the Solar System and is thought to be an impact crater. It is 505 km in diameter, which is 90% the diameter of Vesta itself, and is 95% the mean diameter of Vesta, 529 km . However, the mean is affected by the crater itself. It is 89% the mean equatorial diameter of 569 km , making it one of the largest craters in the Solar System, and at 75°S latitude, covers most of the southern hemisphere. The peak in the center of the crater rises 20-25 km from its base, the tallest mountain known in the Solar System.
Document 2: Walter Alvarez: Walter Alvarez (born October 3, 1940) is a professor in the Earth and Planetary Science department at the University of California, Berkeley. He is most widely known for the theory that dinosaurs were killed by an asteroid impact, developed in collaboration with his father, Nobel Prize winning physicist Luis Alvarez.
Document 3: Murray Gell-Mann: Murray Gell-Mann ( ; born September 15, 1929) is an American physicist who received the 1969 Nobel Prize in physics for his work on the theory of elementary particles. He is the Robert Andrews Millikan Professor of Theoretical Physics Emeritus at the California Institute of Technology, a Distinguished Fellow and co-founder of the Santa Fe Institute, Professor in the Physics and Astronomy Department of the University of New Mexico, and the Presidential Professor of Physics and Medicine at the University of Southern California.
Document 4: Albert Einstein Award: This award should not be confused with many others named after the famous physicist, such as the Albert Einstein World Award of Science given by the World Cultural Council (since 1984), the Albert Einstein Medal given by the Albert Einstein Society (since 1979), nor with the Hans Albert Einstein Award, named after his son and given by the American Society of Civil Engineers (since 1988). It was established much earlier than these, when Einstein was still alive and was a professor at the Institute for Advanced Study. It has been called "the highest of its kind in the United States" by "The New York Times". Some considered it as "the prestigious equivalent of a Nobel Prize".
Document 5: Albert A. Michelson: Prof Albert Abraham Michelson (surname pronunciation anglicized as "Michael-son") FFRS HFRSE LLD (December 19, 1852 – May 9, 1931) was an American physicist known for his work on measuring the speed of light and especially for the Michelson–Morley experiment. In 1907 he received the Nobel Prize in Physics, becoming the first American to win the Nobel Prize in a science.
Document 6: Alvarez hypothesis: The Alvarez hypothesis posits that the mass extinction of the dinosaurs and many other living things during the Cretaceous–Paleogene extinction event was caused by the impact of a large asteroid on the Earth. Prior to 2013, it was commonly cited as having happened about 65 million years ago, but a 2013 paper by Renne et al. gave an updated value of 66 million years. Evidence indicates that the asteroid fell in the Yucatán Peninsula, at Chicxulub, Mexico. The hypothesis is named after the father-and-son team of scientists Luis and Walter Alvarez, who first suggested it in 1980.
Document 7: Alvarezsauroidea: Alvarezsauroidea is a group of small maniraptoran dinosaurs. Alvarezsauroidea, Alvarezsauridae, and Alvarezsauria are named for the historian Don Gregorio Alvarez, not the more familiar physicist Luis Alvarez, who proposed that the Cretaceous–Paleogene extinction event was caused by an impact event. The group was first formally proposed by Choiniere and colleagues in 2010, to contain the family Alvarezsauridae and non-alvarezsaurid alvarezsauroids, such as "Haplocheirus", which is the basalmost of the Alvarezsauroidea (from the Late Jurassic, Asia). The discovery of "Haplocheirus" extended the stratigraphic evidence for the group Alvarezsauroidea about 63 million years further in the past. The division of Alvarezsauroidea into the Alvarezsauridae and the non-alvarezsaurid alvarezsauroids is based on differences in their morphology, especially in their hand morphology.
Document 8: Donald B. Campbell: Donald B. Campbell is an Australian-born astronomer and Professor of Astronomy at Cornell University. Prior to joining the Cornell faculty he was Director of the Arecibo Observatory in Puerto Rico for seven years. Campbell's research work is in the general area of planetary studies with a concentration on the radio-wavelength-scattering properties of planets, planetary satellites, and small bodies. His work includes studies of Venus, the Moon, the Galilean satellites of Jupiter, Titan, as well as comets and asteroids. Campbell observed near-Earth asteroid 433 Eros, which was the first asteroid detected by the Arecibo Observatory radar system.
Document 9: Steven Chu: Steven Chu (, born February 28, 1948) is an American physicist. He is known for his research at Bell Labs and Stanford University regarding the cooling and trapping of atoms with laser light, for which he won the Nobel Prize in Physics in 1997, along with his scientific colleagues Claude Cohen-Tannoudji and William Daniel Phillips.
Document 10: Luis Walter Alvarez: Luis Walter Alvarez (June 13, 1911 – September 1, 1988) was an American experimental physicist, inventor, and professor who was awarded the Nobel Prize in Physics in 1968. The American Journal of Physics commented, "Luis Alvarez was one of the most brilliant and productive experimental physicists of the twentieth century."
Document 11: Clinton Davisson: Clinton Joseph Davisson (October 22, 1881 – February 1, 1958), was an American physicist who won the 1937 Nobel Prize in Physics for his discovery of electron diffraction in the famous Davisson-Germer experiment. Davisson shared the Nobel Prize with George Paget Thomson, who independently discovered electron diffraction at about the same time as Davisson.
Document 12: Ernest Lawrence: Ernest Orlando Lawrence (August 8, 1901 – August 27, 1958) was a pioneering American nuclear scientist and winner of the Nobel Prize in Physics in 1939 for his invention of the cyclotron. He is known for his work on uranium-isotope separation for the Manhattan Project, as well as for founding the Lawrence Berkeley National Laboratory and the Lawrence Livermore National Laboratory.
Document 13: Chien-Shiung Wu: Chien-Shiung Wu (; May 31, 1912 – February 16, 1997) was a Chinese-American experimental physicist who made significant contributions in the field of nuclear physics. Wu worked on the Manhattan Project, where she helped develop the process for separating uranium metal into uranium-235 and uranium-238 isotopes by gaseous diffusion. She is best known for conducting the Wu experiment, which contradicted the hypothetical law of conservation of parity. This discovery resulted in her colleagues Tsung-Dao Lee and Chen-Ning Yang winning the 1957 Nobel Prize in physics, and also earned Wu the inaugural Wolf Prize in Physics a mere two decades later in 1978. Her expertise in experimental physics evoked comparisons to Marie Curie. Her nicknames include "the First Lady of Physics", "the Chinese Madame Curie", and the "Queen of Nuclear Research".
Document 14: Frank Asaro: Frank Asaro (born Francesco Asaro, July 31, 1927 – June 10, 2014) was an Emeritus Senior Scientist at the Lawrence Berkeley National Laboratory associated with the University of California at Berkeley. He is best known as the chemist who discovered the iridium anomaly in the Cretaceous–Paleogene boundary layer that led the team of Luis Alvarez, Walter Alvarez, Frank Asaro, and Helen Michel to propose the Asteroid-Impact Theory, which postulates that an asteroid hit the Earth sixty-five million years ago and caused mass extinction during the age of the dinosaurs.
Document 15: 3581 Alvarez: 3581 Alvarez (1985 HC) is a Mars-crossing asteroid discovered on April 23, 1985, by Shoemaker, C. and Shoemaker, E. at Palomar. Based upon lightcurve data, it has a synodic rotation period of  hours with an amplitude variation of in magnitude. With a diameter of ~14 km, it is one of the largest Mars-crossing asteroids. However, due to the high inclination of its orbit, it never actually passes through the orbit of Mars since at perihelion it is well away from the plane of Mars' orbit. The asteroid is named after planetary scientist Walter Alvarez and his Nobel-prize winning father, physicist Luis Alvarez.
ground_truth: 1911