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{{Short description|American physicist, inventor and professor (1911–1988)}}
{{About|the American physicist|his grandfather, the Spanish physician|Luis F. Álvarez|other people of the same name|Luis Álvarez (disambiguation)}}
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{{Infobox scientist
| name              = Luis Walter Alvarez
| image             = File:Luis Alvarez with a magnetic monopole detector - Restoration.jpg
| caption           = Alvarez with a [[magnetic monopole]] detector in 1969
| birth_date        = {{birth date|1911|6|13| mf=y}}
| birth_place       = [[San Francisco, California]], U.S.
| death_date        = {{death date and age|1988|9|1|1911|1|13}}
| death_place       = [[Berkeley, California]], U.S.
| field             = [[Physics]]
| education         = [[University of Chicago]] ([[Bachelor of Science|BS]], [[Master of Science|MS]], [[Doctor of Philosophy|PhD]])
| doctoral_advisor  = [[Arthur Compton]]
| known_for         = {{plainlist|
* [[Accelerator mass spectrometry]], 
* [[Alvarez hypothesis]],
* [[AN/CPS-1]],
* [[Electron capture]],
* [[Exploding-bridgewire detonator]], 
* [[Ground-controlled approach]],
* [[Linear particle accelerator]],
* [[Liquid hydrogen]] [[bubble chamber]],
* [[Muon-catalyzed fusion]],
* [[Muography#First muogram|Muon tomography]],
* Isolation of [[helium-3]],
* Isolation of [[tritium]],
* Measurement of [[neutron magnetic moment]]
}}
| work_institution  = [[University of California, Berkeley]]
| prizes            = {{nowrap|[[Collier Trophy]] {{small|(1945)}}<br>[[Medal for Merit]] {{small|(1947)}}<br />[[John Scott Medal]] {{small|(1953)}}<br />[[Albert Einstein Award]] {{small|(1961)}}<br>[[National Medal of Science]] {{small|(1963)}}<br />[[Pioneer Award (Aviation)|Pioneer Award]] {{small|(1963)}}<br/>[[Michelson–Morley Award]] {{small|(1965)}} <br />[[Nobel Prize in Physics]] {{small|(1968)}}<br />[[Enrico Fermi Award]] {{small|(1987)}}}}
| spouse            = {{plainlist|
* {{marriage|Geraldine Smithwick|1936|1957<!-- approximate --> | reason=divorced}}
* {{marriage|Janet L. Landis|1958}}
}}
| signature         = Luis Alvarez signature.jpg
|children=[[Walter Alvarez]]
|father=[[Walter C. 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 for his discovery of [[resonance (particle physics)|resonance states]] in particle physics using the [[Bubble chamber|hydrogen bubble chamber]].<ref>{{cite web | title = The Nobel Prize in Physics 1968 | publisher = Nobel Foundation | url = http://nobelprize.org/nobel_prizes/physics/laureates/1968/index.html | access-date = October 9, 2008 | archive-url = https://web.archive.org/web/20081024052547/http://nobelprize.org/nobel_prizes/physics/laureates/1968/index.html | archive-date = October 24, 2008 | url-status = live }}</ref> In 2007 the ''[[American Journal of Physics]]'' commented, "Luis Alvarez was one of the most brilliant and productive experimental physicists of the twentieth century."<ref name=AJP>{{cite journal | last=Wohl | first=C. G. | year=2007 | title=Scientist as detective: Luis Alvarez and the pyramid burial chambers, the JFK assassination, and the end of the dinosaurs | journal=[[American Journal of Physics]] | volume=75 | issue=11 | page=968 | bibcode=2007AmJPh..75..968W | doi=10.1119/1.2772290| url=https://zenodo.org/record/1236124 }}</ref>

After receiving his [[PhD]] from the [[University of Chicago]] in 1936, Alvarez went to work for [[Ernest Lawrence]] at the [[Lawrence Berkeley National Lab|Radiation Laboratory]] at the [[University of California, Berkeley]]. Alvarez devised a set of experiments to observe K-[[electron capture]] in [[radioactivity|radioactive nuclei]], predicted by the [[beta decay]] theory but never before observed. He produced [[tritium]] using the [[cyclotron]] and measured its lifetime. In collaboration with [[Felix Bloch]], he measured the [[Neutron magnetic moment|magnetic moment of the neutron]].

In 1940, Alvarez joined the [[MIT Radiation Laboratory]], where he contributed to a number of [[World War II]] [[radar]] projects, from early improvements to [[Identification friend or foe]] (IFF) radar beacons, now called [[transponder]]s, to a system known as VIXEN for preventing enemy submarines from realizing that they had been found by the new airborne [[microwave]] radars. The radar system for which Alvarez is best known and which has played a major role in aviation, most particularly in the post war [[Berlin airlift]], was [[Ground Controlled Approach]] (GCA). Alvarez spent a few months at the [[University of Chicago]] working on [[nuclear reactor]]s for [[Enrico Fermi]] before coming to [[Los Alamos National Laboratory|Los Alamos]] to work for [[Robert Oppenheimer]] on the [[Manhattan Project]]. Alvarez worked on the design of [[explosive lens]]es, and the development of [[exploding-bridgewire detonator]]s. As a member of [[Project Alberta]], he observed the [[Trinity (nuclear test)|Trinity nuclear test]] from a [[B-29 Superfortress]], and later the [[atomic bombing of Hiroshima and Nagasaki|bombing of Hiroshima]] from the B-29 ''[[The Great Artiste]]''.

After the war Alvarez was involved in the design of a [[liquid hydrogen]] [[bubble chamber]] that allowed his team to take millions of photographs of particle interactions, develop complex computer systems to measure and analyze these interactions, and discover entire families of new particles and resonance states. This work resulted in his being awarded the Nobel Prize in 1968. He was involved in a project to [[x-ray]] the [[Egyptian pyramids]] to search for unknown chambers. With his son, geologist [[Walter Alvarez]], he developed the [[Alvarez hypothesis]] which proposes that the [[Cretaceous–Paleogene extinction event|extinction event]] that wiped out the non-avian dinosaurs was the result of an asteroid impact.

== Early life ==
Luis Walter Alvarez was born into a [[Roman Catholic]] family in San Francisco on June 13, 1911, the second child and oldest son of [[Walter C. Alvarez]], a physician, and his wife Harriet née Smyth, and a grandson of [[Luis F. Álvarez]], a Spanish physician, born in Asturias, Spain, who lived in Cuba for a while and finally settled in the United States, who found a better method for diagnosing [[Leprosy#Classification|macular leprosy]]. He had an older sister, Gladys, a younger brother, Bob, and a younger sister, Bernice.{{sfn|Alvarez|1987 | pp=9–10}} His aunt, [[Mabel Alvarez]], was a California artist specializing in [[oil painting]].<ref name="AAA">{{cite web | last=Fernandez | first=R. M. | date=September 2011 | title=A Finding Aid to the Mabel Alvarez Papers, 1898–1987, in the Archives of American Art | url=http://www.aaa.si.edu/collections/mabel-alvarez-papers-5410/more | publisher=[[Archives of American Art]] | access-date=June 15, 2011}}</ref>

He attended Madison School in San Francisco from 1918 to 1924, and then [[San Francisco Polytechnic High School]].{{sfn|Trower|1987 | p=259}} In 1926, his father became a researcher at the [[Mayo Clinic]], and the family moved to [[Rochester, Minnesota]], where Alvarez attended Rochester High School. He had always expected to attend the [[University of California, Berkeley]], but at the urging of his teachers at Rochester, he instead went to the [[University of Chicago]],{{sfn|Alvarez|1987 | pp=12–16}} where he received his bachelor's degree in 1932, his master's degree in 1934, and his [[PhD]] in 1936.<ref name=Nobel /> As an undergraduate, he belonged to the [[Phi Gamma Delta]] [[Fraternities and sororities|fraternity]]. As a postgraduate he moved to [[Gamma Alpha]].{{sfn|Alvarez|1987 | pp=23–24}}

In 1932, as a [[graduate student]] at Chicago, he discovered the field of physics and had the rare opportunity to use the equipment of legendary physicist [[Albert A. Michelson]].<ref name="Bortz2007">Alfred B. Bortz. ''[https://books.google.com/books?id=TKx7uAAACAAJ Physics: Decade by Decade]''. Facts On File, Incorporated; 2007. {{ISBN|978-0-8160-5532-6}}. p. 168.</ref> Alvarez also constructed an apparatus of [[Geiger counter]] tubes arranged as a [[Cosmic-ray observatory|cosmic ray telescope]], and under the aegis of his faculty advisor [[Arthur Compton]], conducted an experiment in Mexico City to measure the so-called [[Cosmic ray#Identification|East–West effect of cosmic rays]]. Observing more incoming radiation from the west, Alvarez concluded that primary cosmic rays were positively charged. Compton submitted the resulting paper to the ''[[Physical Review]]'', with Alvarez's name at the top.{{sfn|Alvarez|1987 | pp=25–27}}

Alvarez was an agnostic even though his father had been a deacon in a Congregational church.<ref>Alvarez: adventures of a physicist. Basic Books. 1987. p. 279. {{ISBN|9780465001156}}. "Physicists feel that the subject of religion is taboo. Almost all consider themselves agnostics. We talk about the big bang that started the present universe and wonder what caused it and what came before. To me the idea of a Supreme Being is attractive, but I'm sure that such a Being isn't the one described in any holy book. Since we learn about people by examining what they have done, I conclude that any Supreme Being must have been a great mathematician. The universe operates with precision according to mathematical laws of enormous complexity. I'm unable to identify its creator with the Jesus to whom my maternal grandparents, missionaries in China, devoted their lives."</ref><ref>{{Cite book|url=https://books.google.com/books?id=Ax9rAAAAMAAJ&q=congregational|title = Incurable Physician: An Autobiography|year = 1963|publisher = Prentice-Hall}}</ref>

== Early work ==
[[File:Alvarez and Compton.jpeg|thumb|Nobel Laureate [[Arthur Compton]], left, with young graduate student Luis Alvarez at the University of Chicago in 1933. Compton served as his doctoral adviser.]]
Alvarez's sister, Gladys, worked for Berkeley physicist [[Ernest Lawrence]] as a part-time secretary, and mentioned Alvarez to Lawrence. Lawrence then invited Alvarez to tour the [[Century of Progress]] exhibition in Chicago with him.{{sfn|Alvarez|1987 | p=31}} After he completed his [[oral exam]]s in 1936, Alvarez, now engaged to be married to Geraldine Smithwick, asked his sister to see if Lawrence had any jobs available at the [[Lawrence Berkeley National Lab|Radiation Laboratory]]. A telegram soon arrived from Gladys with a job offer from Lawrence. This started a long association with the [[University of California, Berkeley]]. Alvarez and Smithwick were married in one of the chapels at the University of Chicago and then headed for California.{{sfn|Alvarez|1987 | p=38}} They had two children, [[Walter Alvarez|Walter]] and Jean.{{sfn|Alvarez|1987 | p=284}} They were divorced in 1957. On December 28, 1958, he married Janet L. Landis, and had two more children, Donald and Helen.{{sfn|Alvarez|1987 | pp=205–207, 281}}

At the Radiation Laboratory he worked with Lawrence's experimental team, which was supported by a group of theoretical physicists headed by [[Robert Oppenheimer]].{{sfn|Alvarez|1987 | pp=46–48}} Alvarez devised a set of experiments to observe K-[[electron capture]] in [[radioactivity|radioactive nuclei]], predicted by the [[beta decay]] theory but never observed. Using [[magnet]]s to sweep aside the [[positron]]s and [[electron]]s emanating from his radioactive sources, he designed a special purpose Geiger counter to detect only the "soft" [[X-rays]] coming from K capture. He published his results in the ''[[Physical Review]]'' in 1937.<ref>{{cite journal | last=Alvarez | first=L. W. | year=1937 | title=Nuclear ''K'' Electron Capture | journal=[[Physical Review]] | volume=52 | issue=2 | pages=134–135 | bibcode=1937PhRv...52..134A | doi=10.1103/PhysRev.52.134}}</ref>{{sfn|Alvarez|1987 | pp=54–55}}

When [[deuterium]] (hydrogen-2) is bombarded with deuterium, the [[fusion reaction]] yields either [[tritium]] (hydrogen-3) plus a [[proton]] or [[helium-3]] plus a [[neutron]] ({{nowrap|{{SimpleNuclide|Hydrogen|2}} + {{SimpleNuclide|Hydrogen|2}} → {{SimpleNuclide|Hydrogen|3}} + p or {{SimpleNuclide|Helium|3}} + n}}). This is one of the most basic [[fusion reaction]]s, and the foundation of the [[thermonuclear weapon]] and the current research on [[controlled thermonuclear fusion|controlled nuclear fusion]]. At that time the stability of these two reaction products was unknown, but based on existing theories [[Hans Bethe]] thought that tritium would be stable and helium-3 unstable. Alvarez proved the reverse by using his knowledge of the details of the 60-inch [[cyclotron]] operation. He tuned the machine to accelerate doubly ionized helium-3 nuclei and was able to get a [[ion beam|beam of accelerated ions]], thus using the cyclotron as a kind of super [[mass spectrometer]]. As the accelerated helium came from deep [[gas well]]s where it had been for millions of years, the helium-3 component had to be stable. Afterwards Alvarez produced the radioactive tritium using the cyclotron and the {{nowrap|{{SimpleNuclide|Hydrogen|2}} + {{SimpleNuclide|Hydrogen|2}}}} reaction and measured its lifetime.<ref>{{cite journal | last1=Alvarez | first1=L. W. | last2=Cornog |first2=R. | year=1939 | title=Helium and Hydrogen of Mass 3 | journal=[[Physical Review]] | volume=56 | issue=6 | pages=613 | bibcode=1939PhRv...56..613A | doi=10.1103/PhysRev.56.613}}</ref>{{sfn|Trower|2009 | p=6}}{{sfn|Alvarez|1987 | pp=67–71}}

In 1938, again using his knowledge of the cyclotron and inventing what are now known as [[time-of-flight]] techniques, Alvarez created a mono-energetic beam of [[thermal neutron]]s. With this he began a long series of experiments, collaborating with [[Felix Bloch]], to measure the [[Neutron magnetic moment|magnetic moment of the neutron]]. Their result of {{nowrap|μ<sub>0</sub> {{=}} {{val|1.93|0.02|u=[[Nuclear magneton|μ<sub>N</sub>]]}}}}, published in 1940, was a major advance over earlier work.<ref>{{cite journal | last1=Alvarez | first1=Luis W. | last2=Bloch |first2=F. | year=1940 | title=A Quantitative Determination of the Neutron Moment in Absolute Nuclear Magnetons | journal=[[Physical Review]] | volume=57 | issue=2 | pages=111–122 | bibcode=1940PhRv...57..111A | doi=10.1103/PhysRev.57.111}}</ref>

== World War II ==

=== Radiation Laboratory ===
The British [[Tizard Mission]] to the United States in 1940 demonstrated to leading American scientists the successful application of the [[cavity magnetron]] to produce short wavelength pulsed [[radar]]. The [[National Defense Research Committee]], established only months earlier by President [[Franklin Roosevelt]], created a central national laboratory at the [[Massachusetts Institute of Technology]] (MIT) for the purpose of developing military applications of microwave radar. Lawrence immediately recruited his best "cyclotroneers", among them Alvarez, who joined this new laboratory, known as the [[Radiation Laboratory]], on November 11, 1940.{{sfn|Alvarez|1987 | pp=78–85}} Alvarez contributed to a number of [[radar]] projects, from early improvements to [[Identification Friend or Foe]] (IFF) radar beacons, now called [[transponders]], to a system known as VIXEN for preventing enemy submarines from realizing that they had been found by the new airborne microwave radars.{{sfn|Alvarez|1987 | pp=90–93}} Enemy submarines would wait until the radar signal was getting strong and then submerge, escaping attack. But VIXEN transmitted a radar signal whose strength was the cube of the distance to the submarine so that as they approached the sub, the signal—as measured by the sub—got progressively weaker, and the sub assumed the plane was getting farther away and did not submerge.<ref>Alvarez, L. W. (1987). ''Alvarez: Adventures of a Physicist''. Basic Books, p.92, last paragraph, et seq., {{ISBN|0-465-00115-7}}.</ref><ref>''Fractals, Chaos and Power Laws'', Manfred Schroeder, Dover, 1991, p.33.</ref>

One of the first projects was to build equipment to transition from the British long-wave radar to the new microwave centimeter-band radar made possible by the [[cavity magnetron]]. In working on the [[Microwave Early Warning]] system (MEW), Alvarez invented a [[phased array|linear dipole array antenna]] that not only suppressed the unwanted [[side lobe]]s of the radiation field but also could be electronically scanned without the need for mechanical scanning. This was the first microwave phased-array antenna, and Alvarez used it not only in MEW but in two additional radar systems. The antenna enabled the Eagle [[precision bombing]] radar to support precision bombing in bad weather or through clouds. It was completed rather late in the war; although a number of [[B-29]]s were equipped with Eagle and it worked well, it came too late to make much difference.{{sfn|Alvarez|1987 | pp=101–103}}

[[File: Luis Alvarez with president Harry Truman.jpg|thumb|Receiving the [[Collier Trophy]] from President [[Harry Truman]], White House, 1946]]
The radar system for which Alvarez is best known and which has played a major role in aviation, most particularly in the post-war [[Berlin airlift]], was [[Ground Controlled Approach]] (GCA). Using Alvarez's dipole antenna to achieve a very high [[angular resolution]], GCA allows ground-based radar operators to watch special precision displays to guide a landing airplane to the runway by transmitting verbal commands to the pilot. The system was simple, direct, and worked well, even with previously untrained pilots. It was so successful that the military continued to use it for many years after the war, and it was still in use in some countries in the 1980s.{{sfn|Alvarez|1987 | pp=96–100}} Alvarez was awarded the [[National Aeronautic Association]]'s [[Collier Trophy]] in 1945 "for his conspicuous and outstanding initiative in the concept and development of the Ground Control Approach system for safe landing of aircraft under all weather and traffic conditions".<ref>{{cite web | title=Collier 1940–1949 Winners | url=http://naa.aero/html/awards/index.cfm?cmsid=156 | publisher=[[National Aeronautic Association]] | access-date=March 21, 2013 | archive-url=https://web.archive.org/web/20131203122514/http://naa.aero/html/awards/index.cfm?cmsid=156 | archive-date=December 3, 2013 | url-status=dead }}</ref><ref>{{cite news|url=https://www.newspapers.com/clip/38806783/the_courierjournal/|title=Radar Expert will Receive Collier Trophy|date=December 13, 1946|newspaper=The Courier-Journal|location=Louisville, Kentucky|page=16|via=Newspapers.com|agency=Associated Press}}</ref>

Alvarez spent the summer of 1943 in England testing GCA, landing planes returning from battle in bad weather, and also training the British in the use of the system. While there he encountered the young [[Arthur C. Clarke]], who was an RAF radar technician. Clarke subsequently used his experiences at the radar research station as the basis for his novel ''[[Glide Path]]'', which contains a thinly disguised version of Alvarez.{{sfn|Alvarez|1987 | pp=104–110}} Clarke and Alvarez developed a long-term friendship.{{sfn|Alvarez|1987 | pp=110}}

=== Manhattan Project ===
[[File:Alvarez-luis.jpg|thumb|Luis Alvarez's Los Alamos badge]]
In the fall of 1943, Alvarez returned to the United States with an offer from [[Robert Oppenheimer]] to work at [[Los Alamos National Laboratory|Los Alamos]] on the [[Manhattan Project]]. However, Oppenheimer suggested that he first spend a few months at the [[University of Chicago]] working with [[Enrico Fermi]] before coming to Los Alamos. During these months, General [[Leslie Groves]] asked Alvarez to think of a way that the US could find out if the Germans were operating any [[nuclear reactor]]s, and, if so, where they were. Alvarez suggested that an airplane could carry a system to detect the radioactive gases that a reactor produces, particularly [[xenon 133|xenon-133]]. The equipment did fly over Germany, but detected no radioactive xenon because the Germans had not built a reactor capable of a chain reaction. This was the first idea of monitoring [[fission product]]s for [[intelligence gathering]]. It would become extremely important after the war.{{sfn|Alvarez|1987 | pp=114–121}}

[[File:Luis Alvarez - Flak Jacket.JPG|thumb|left|Wearing a helmet and [[flak jacket]] and standing in front of the bomber, ''[[The Great Artiste]]'', [[Tinian]] island in 1945]]
As a result of his radar work and the few months spent with Fermi, Alvarez arrived at Los Alamos in the spring of 1944, later than many of his contemporaries. The work on the "[[Little Boy]]" (a uranium bomb) was far along so Alvarez became involved in the design of the "[[Fat Man]]" (a plutonium bomb). The technique used for uranium, that of forcing the two sub-[[critical mass]]es together using a [[Gun-type fission weapon|type of gun]], would not work with plutonium because the high level of background [[spontaneous fission|spontaneous neutrons]] would cause fissions as soon as the two parts approached each other, so heat and expansion would force the system apart before much energy has been released. It was decided to use a nearly critical sphere of [[plutonium]] and compress it quickly by explosives into a much smaller and denser [[plutonium core|core]], a technical challenge at the time.{{sfn|Alvarez|1987 | pp=123–128}}

To create the symmetrical [[nuclear weapon design|implosion]] required to compress the plutonium core to the required density, thirty-two explosive charges were to be simultaneously detonated around the spherical core. Using conventional explosive techniques with [[blasting cap]]s, progress towards achieving simultaneity to within a small fraction of a microsecond was discouraging. Alvarez directed his graduate student, [[Lawrence H. Johnston]], to use a large [[capacitor]] to deliver a [[high voltage]] charge directly to each [[explosive lens]], replacing blasting caps with [[exploding-bridgewire detonator]]s. The exploding wire detonated the thirty-two charges to within a few tenths of a microsecond. The invention was critical to the success of the [[implosion-type nuclear weapon]]. He also supervised the [[RaLa Experiment]]s.{{sfn|Alvarez|1987 | pp=131–136}} Alvarez later wrote that:
{{blockquote|With modern weapons-grade uranium, the background neutron rate is so low that terrorists, if they had such material, would have a good chance of setting off a high-yield explosion simply by dropping one half of the material onto the other half. Most people seem unaware that if separated [[uranium-235|U-235]] is at hand, it's a trivial job to set off a nuclear explosion, whereas if only plutonium is available, making it explode is the most difficult technical job I know.{{sfn|Alvarez|1987 | p=125}} }}

[[File:Agnew on Tinian.jpg|thumb|Alvarez (top right) on Tinian island with [[Harold Agnew]] (top left), [[Lawrence H. Johnston]] (bottom left) and [[Bernard Waldman]] (bottom right)]]

Again working with Johnston, Alvarez's last task for the [[Manhattan Project]] was to develop a set of calibrated [[microphone]]/[[transmitter]]s to be parachuted from an aircraft to measure the strength of the blast wave from the atomic explosion, so as to allow the scientists to calculate the bomb's energy. After being commissioned as a [[Lieutenant Colonel (United States)|lieutenant colonel]] in the [[United States Army]], he observed the [[Trinity (nuclear test)|Trinity nuclear test]] from a [[B-29 Superfortress]] that also carried fellow [[Project Alberta]] members [[Harold Agnew]] and [[Deak Parsons]] (who were respectively commissioned at the rank of [[Captain (United States O-3)|captain]]).{{sfn|Alvarez|1987 | pp=137–142}}

Flying in the [[B-29 Superfortress]] ''[[The Great Artiste]]'' in formation with the ''[[Enola Gay]]'', Alvarez and Johnston measured the blast effect of the [[Little Boy]] bomb which was [[atomic bombing of Hiroshima and Nagasaki|dropped on Hiroshima]].{{sfn|Alvarez|1987 | pp=6–8}} A few days later, again flying in ''The Great Artiste'', Johnston used the same equipment to measure the strength of the [[Nagasaki bomb|Nagasaki]] explosion.{{sfn|Alvarez|1987 | pp=144–146}}

Following the conclusion of the [[Second World War]] in 1945 Alvarez would become a professor of physics at the school he had originally desired to attend, the University of California, Berkeley and in 1978 he would be granted the title of professor emeritus.<ref>{{Cite web |title=Luis Alvarez {{!}} Biography, Research, Nobel Prize, & Facts {{!}} Britannica |url=https://www.britannica.com/biography/Luis-Alvarez |access-date=2025-03-13 |website=www.britannica.com |language=en}}</ref>

== Bubble chamber ==
[[File:Luis Alvarez - Nobel with Balloon.jpg|thumb|upright|Celebrating winning the Nobel Prize, October 30, 1968. The balloons are inscribed with the names of subatomic particles that his group discovered.]]

Returning to the University of California, Berkeley as a [[full professor]], Alvarez had many ideas about how to use his wartime radar knowledge to improve [[particle accelerator]]s. Though some of these were to bear fruit, the "big idea" of this time would come from [[Edwin McMillan]] with his concept of [[Synchrocyclotron|phase stability]] which led to the [[synchrocyclotron]]. Refining and extending this concept, the Lawrence team would build the world's then-largest proton accelerator, the [[Bevatron]], which began operating in 1954. Though the Bevatron could produce copious amounts of interesting particles, particularly in secondary collisions, these complex interactions were hard to detect and analyze at the time.{{sfn|Alvarez|1987 | pp=153–159}}

Seizing upon a new development to visualize particle tracks, created by [[Donald A. Glaser|Donald Glaser]] and known as a [[bubble chamber]], Alvarez realized the device was just what was needed, if only it could be made to function with [[liquid hydrogen]]. [[Hydrogen]] nuclei, which are [[proton]]s, made the simplest and most desirable target for interactions with the particles produced by the Bevatron. He began a development program to build a series of small chambers, and championed the device to Ernest Lawrence.{{sfn|Alvarez|1987 | pp=185–189}}

The Glaser device was a small glass cylinder ({{nowrap|1 cm × 2 cm}}) filled with [[diethyl ether|ether]]. By suddenly reducing the pressure in the device, the liquid could be placed into a temporary [[superheated]] state, which would boil along the disturbed track of a particle passing through. Glaser was able to maintain the superheated state for a few seconds before spontaneous boiling took place. The Alvarez team built chambers of 1.5&nbsp;in, 2.5&nbsp;in, 4&nbsp;in, 10&nbsp;in, and 15&nbsp;in using liquid hydrogen, and constructed of metal with glass windows, so that the tracks could be photographed. The chamber could be cycled in synchronization with the accelerator beam, a picture could be taken, and the chamber recompressed in time for the next beam cycle.{{sfn|Alvarez|1987 | pp=190–194}}

This program built a liquid hydrogen bubble chamber almost {{convert|7|ft|m|abbr=off|sp=us}} long, employed dozens of physicists and graduate students together with hundreds of engineers and technicians, took millions of photographs of particle interactions, developed computer systems to measure and analyze the interactions, and discovered families of new particles and [[resonance (particle physics)|resonance states]]. This work resulted in the [[Nobel Prize in Physics]] for Alvarez in 1968,{{sfn|Alvarez|1987| pp=196–199}} "For his decisive contributions to elementary particle physics, in particular the discovery of a large number of resonant states, made possible through his development of the technique of using hydrogen bubble chambers and data analysis."<ref name= Royal>{{cite web | title=The Nobel Prize in Physics 1968 | url=https://www.nobelprize.org/nobel_prizes/physics/laureates/1968/ | publisher=[[The Nobel Foundation]] | access-date=March 21, 2013}}</ref>

== Scientific detective work ==
[[File:Luis Alvarez, Ahmed Fakhry, Jerry Anderson - Pyramid Project.JPG|thumb|left|X-Raying the Pyramids with Egyptologist [[Ahmed Fakhry]] and Team Leader Jerry Anderson, Berkeley, 1967]]

In 1964, Alvarez proposed what became known as the [[High Altitude Particle Physics Experiment]] (HAPPE), originally conceived as a large [[superconducting magnet]] carried to high altitude by a [[balloon]] in order to study extremely high-energy particle interactions.<ref name="Memo503">{{cite journal | last=Alvarez | first=L. W. | year=1964 | title=A Study of High Energy Interactions Using a "Beam" of Primary Cosmic Ray Protons | url=http://alvarezphysicsmemos.lbl.gov/physics_pdfs/APM501-510.pdf | journal=[[Alvarez Physics Memo]] | issue=503 | access-date=March 21, 2013}}</ref> In time the focus of the experiment changed toward the study of [[cosmology]] and the role of both particles and radiation in the [[early universe]]. This work was a large effort, carrying detectors aloft with [[high-altitude balloon]] flights and high-flying [[Lockheed U-2|U-2]] aircraft, and an early precursor of the [[Cosmic Background Explorer|COBE]] satellite-born experiments on the cosmic background radiation (which resulted in the award of the 2006 Nobel Prize, shared by [[George Smoot]] and [[John C. Mather|John Mather]]<ref name="Memo503" />).

Alvarez proposed [[muon tomography]] in 1965 to search the [[Egyptian pyramids]] for unknown chambers. Using naturally occurring [[cosmic ray]]s, his plan was to place [[spark-chamber detector|spark chambers]], standard equipment in the high-energy [[particle physics]] of this time, beneath the [[Pyramid of Khafre]] in a known chamber. By measuring the counting rate of the cosmic rays in different directions the detector would reveal the existence of any void in the overlaying rock structure.<ref>{{cite journal | last=Alvarez | first=L. W. | year=1965 | title=A Proposal to "X-Ray" the Egyptian Pyramids to Search for Presently Unknown Chambers | url=http://alvarezphysicsmemos.lbl.gov/physics_pdfs/APM541-550.pdf | journal=[[Alvarez Physics Memo]] | issue=544 | access-date=March 21, 2013}}</ref>

Alvarez assembled a team of physicists and archeologists from the United States and Egypt, the recording equipment was constructed and the experiment carried out, though it was interrupted by the 1967 [[Six-Day War]]. Restarted after the war, the effort continued, recording and analyzing the penetrating cosmic rays until 1969, when he reported to the [[American Physical Society]] that no chambers had been found in the 19% of the pyramid surveyed.{{sfn|Alvarez|1987 | pp=232–236}}

In November 1966, ''[[Life (magazine)|Life]]'' magazine published a series of photographs from the 1963 "[[Zapruder film]]", believed to be the most complete document of the [[assassination of John F. Kennedy]]. Alvarez, an expert in optics and [[photoanalysis]], became intrigued by the pictures and began to study what could be learned from the film. Alvarez demonstrated both in theory and experiment that the backward snap of the President's head was consistent with his being shot from behind being called the "jet-effect" theory. Alvarez's theory was later refined and corroborated by other researchers.<ref>{{cite journal |last1=Nalli |first1=Nicholas R. |title=Gunshot-wound dynamics model for John F. Kennedy assassination |journal=Heliyon |date=April 30, 2018 |volume=4 |issue=4 |pages=e00603 |doi=10.1016/j.heliyon.2018.e00603 |doi-access=free |pmid=29736430 |pmc=5934694 |bibcode=2018Heliy...400603N }}</ref><ref>{{cite journal |last1=Nalli |first1=Nicholas R. |title=Corrigendum to 'Gunshot-wound dynamics model for John F. Kennedy assassination' [Heliyon 4 (2018) e00603] |journal=Heliyon |date=October 2018 |volume=4 |issue=10 |pages=e00831 |doi=10.1016/j.heliyon.2018.e00831 |doi-access=free |pmid=30294686 |pmc=6171073 |bibcode=2018Heliy...400831N }}</ref> Alvarez also investigated the timing of the gunshots and the shockwave that disturbed the camera, and the speed of the camera, pointing out a number of details that the FBI photo analysts either overlooked or got wrong. He produced a paper intended as a tutorial, with informal advice for the physicist intent on arriving at the truth of the case.{{sfn|Alvarez|1987 | pp=239–250}}

== Dinosaur extinction hypothesis ==
{{Main|Alvarez hypothesis}}

[[File:LWA with Walt.JPG|thumb|right|Luis and [[Walter Alvarez]] at the [[Cretaceous–Paleogene boundary|K-Pg Boundary]] in [[Gubbio, Italy]], 1981]]

In 1980 Alvarez and his son, geologist [[Walter Alvarez]], along with nuclear chemists [[Frank Asaro]] and [[Helen Michel]], "uncovered a calamity that literally shook the Earth and is one of the great discoveries about Earth's history".<ref name=AJP />

During the 1970s, Walter Alvarez was doing geologic research in central Italy. There he had located an outcrop on the walls of a gorge whose [[limestone]] layers included [[strata]] both above and below the [[Cretaceous–Paleogene boundary]]. Exactly at the boundary is a thin layer of [[clay]]. Walter told his father that the layer marked where the [[dinosaur]]s and much else became extinct and that nobody knew why, or what the clay was about—it was a big mystery, and he intended to solve it.<ref name=AJP />

Alvarez had access to the [[nuclear chemistry|nuclear chemists]] at the [[Lawrence Berkeley Laboratory]] and was able to work with [[Frank Asaro]] and [[Helen Michel]], who used the technique of [[neutron activation analysis]] to study the clay. In 1980, Alvarez, Alvarez, Asaro, and Michel published a seminal paper proposing an extraterrestrial cause for the Cretaceous-Paleogene extinction (then called the Cretaceous-Tertiary extinction).<ref>{{cite journal | last1=Alvarez | first1=L. W. | last2=Alvarez | first2=W. | last3=Asaro | first3=F. | last4=Michel | first4=H. V. | year=1980 | title=Extraterrestrial Cause for the Cretaceous-Tertiary Extinction: Experiment and Theory | url=http://www.es.ucsc.edu/~pkoch/EART_206/09-0305/Alvarez%20et%2080%20Science%20208-1095.pdf | journal=[[Science (journal)|Science]] | volume=208 | issue=4448 | pages=1095–1108 | bibcode=1980Sci...208.1095A | doi=10.1126/science.208.4448.1095 | jstor=1683699 | pmid=17783054 | s2cid=16017767 | access-date=September 13, 2015 | archive-date=September 24, 2015 | archive-url=https://web.archive.org/web/20150924001940/http://www.es.ucsc.edu/~pkoch/EART_206/09-0305/Alvarez%20et%2080%20Science%20208-1095.pdf | url-status=dead }}</ref> In the years following the publication of their article, the clay was also found to contain [[soot]], [[glass]]y spherules, [[shocked quartz]] crystals, microscopic [[diamond]]s, and rare minerals formed only under conditions of great temperature and pressure.<ref name= AJP />

Publication of the 1980 paper brought criticism from the geologic community, and an often acrimonious scientific debate ensued. Ten years later, after Alvarez's death, evidence was found of a large [[Chicxulub crater|impact crater off the coast of the Yucatán peninsula]] in Mexico, providing support for the theory. Other researchers later found that the [[Cretaceous–Paleogene extinction event|end-Cretaceous extinction]] of the dinosaurs may have occurred rapidly in geologic terms, over thousands of years, rather than millions of years as had previously been supposed. While alternative extinction theories have been proposed, including increased [[volcanism]] at the [[Deccan Traps]], the impact crater theory remains dominant among relevant scholars.<ref name="Schulte10">{{cite journal | last=Schulte | first=P. | year=2010 | title=The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous- Paleogene Boundary | journal=[[Science (journal)|Science]] | volume=327 | issue=5970 | pages=1214–1218 | bibcode=2010Sci...327.1214S | doi=10.1126/science.1177265 | pmid=20203042| s2cid=2659741 |display-authors=etal| url=http://doc.rero.ch/record/210367/files/PAL_E4389.pdf }}</ref>

== Aviation ==
In his autobiography, Alvarez said, "I think of myself as having had two separate careers, one in science and one in aviation. I've found the two almost equally rewarding." An important contributor to this was his enjoyment of flying. He learned to fly in 1933, later earning [[instrument rating|instrument]] and multi-engine ratings. Over the next 50 years he accumulated over 1000 hours of flight time, most of it as pilot in command.{{sfn|Alvarez|1987|pp=30–31}} He said, "I found few activities as satisfying as being pilot in command with responsibility for my passengers' lives."{{sfn|Alvarez|1987|pp=268}}

Alvarez made numerous professional contributions to aviation. During World War II he led the development of multiple aviation-related technologies. Several of his projects are described above, including Ground Controlled Approach (GCA) for which he was awarded the Collier Trophy in 1945. He also held the basic patent for the radar [[transponder]], for which he assigned rights to the U.S. government for $1.{{sfn|Alvarez|1987|pp=30–31}}

Later in his career Alvarez served on multiple high level advisory committees related to civilian and military aviation. These included a [[Federal Aviation Administration]] task group on future [[air navigation]] and [[air traffic control]] systems, the [[President's Science Advisory Committee]] Military Aircraft Panel, and a committee studying how the scientific community could help improve the United States' capabilities for fighting a nonnuclear war.{{sfn|Alvarez|1987|pp=218–223}}

Alvarez's aviation responsibilities led to many adventures. For example, while working on GCA he became the first civilian to fly a low approach with his view outside the cockpit obstructed. He also flew many military aircraft from the co-pilot's seat, including a [[B-29 Superfortress]]{{sfn|Alvarez|1987 | pp=268}} and a [[Lockheed F-104 Starfighter]].{{sfn|Alvarez|1987 | pp=224}} In addition, he survived a crash during World War II as a passenger in a [[Miles Master]].{{sfn|Alvarez|1987 | pp=108}}

==Other activities==
Alvarez was a member of the [[JASON (advisory group)|JASON Defense Advisory Group]] and the [[Bohemian Club]].{{sfn|Trower|2009|p=13}}

== Death ==
Alvarez died on September 1, 1988, of complications from a succession of recent operations for [[esophageal cancer]].<ref>{{cite news |last1=Sullivan |first1=Walter |title=Luis W. Alvarez, Nobel Physicist Who Explored Atom, Dies at 77 |url=https://www.nytimes.com/1988/09/02/obituaries/luis-w-alvarez-nobel-physicist-who-explored-atom-dies-at-77.html |work=The New York Times |date=September 2, 1988 }}</ref> His remains were cremated, and his ashes were scattered over [[Monterey Bay]].<ref>{{cite web | title=Luis W. Alvarez | url=http://www.nndb.com/people/803/000099506/ | publisher=[[Soylent Communications]] | access-date=March 21, 2013}}</ref> His papers are in [[The Bancroft Library]] at the [[University of California, Berkeley]].<ref>{{cite web | title=Finding Aid to the Luis W. Alvarez Papers, 1932–1988, bulk 1943–1987 | url=http://www.oac.cdlib.org/findaid/ark:/13030/kt967nd685/ | publisher=[[Online Archive of California]] | access-date=March 21, 2013}}</ref>

==In popular culture==

A thinly-disguised version of Alvarez appears in Sir [[Arthur C. Clarke]]'s 1963 novel ''[[Glide Path]]''.

In the 2023 film ''[[Oppenheimer (film)|Oppenheimer]]'', directed by [[Christopher Nolan]], Alvarez was portrayed by actor [[Alex Wolff]].<ref>{{cite magazine |first1=Molly |last1=Moss |first2=Lewis |last2=Knight |date=July 22, 2023 |title=Oppenheimer cast: Full list of actors in Christopher Nolan film  |magazine=Radio Times |url=https://www.radiotimes.com/movies/oppenheimer-cast-christopher-nolan-murphy/ |access-date=July 24, 2023}}</ref>

== Awards and honors ==
* Fellow of the [[American Physical Society]] (1939) and President (1969){{sfn|Trower|1987 | p=259}}
* [[Collier Trophy]] of the [[National Aeronautics Association]] (1946)<ref name=Collier>{{cite web | title=Collier Trophy: Collier 1940–1949 Winners | url=http://naa.aero/html/awards/index.cfm?cmsid=156 | work=National Aeronautical Association | access-date=April 17, 2011 | archive-url=https://web.archive.org/web/20131203122514/http://naa.aero/html/awards/index.cfm?cmsid=156 | archive-date=December 3, 2013 | url-status=dead }}</ref>
* Member of the [[National Academy of Sciences]] (1947)<ref name=NAS>{{cite web | title=Luis Walter Alvarez 1911–1988 | url=http://books.nap.edu/html/biomems/lalvarez.pdf | work=[[National Academy of Sciences]] | access-date=April 17, 2011}}</ref>
* [[Medal for Merit]] (1947)<ref name=Nobel>{{cite web | title=Luis W. Alvarez – Biography | url=http://nobelprize.org/nobel_prizes/physics/laureates/1968/alvarez-bio.html | work=Nobelprize.org | access-date=April 17, 2011}}</ref>
* Fellow of the [[American Philosophical Society]] (1953)<ref name=APS>{{cite web | title=Dr. Luis Walter Alvarez – Public Profile | url=http://www.amphilsoc.org/public-profile/1EF7719A-D697-DE11-A8C4-0013724C588C | work=American Philosophical Society | access-date=April 17, 2011 | archive-url=https://web.archive.org/web/20120319173607/http://www.amphilsoc.org/public-profile/1EF7719A-D697-DE11-A8C4-0013724C588C | archive-date=March 19, 2012 | url-status=dead }}</ref>
* Fellow of the [[American Academy of Arts and Sciences]] (1958)<ref name=AAAS>{{cite web | title=Book of Members, 1780–2010: Chapter A | url=http://www.amacad.org/publications/BookofMembers/ChapterA.pdf | publisher=American Academy of Arts and Sciences | access-date=April 17, 2011}}</ref>
* California Scientist of the Year (1960)<ref>{{cite web | url=http://www.californiasciencecenter.org/GenInfo/NewsAndEvents/SpecialPrograms/ScientistOfTheYear/PastSotY/PastSotY.php | title=California Scientist of the Year Award Recipients | publisher=California Science Center | access-date=March 21, 2012 | url-status=dead | archive-url=https://web.archive.org/web/20120205104853/http://www.californiasciencecenter.org/GenInfo/NewsAndEvents/SpecialPrograms/ScientistOfTheYear/PastSotY/PastSotY.php | archive-date=February 5, 2012 | df=mdy-all }}</ref>
* [[Albert Einstein Award]] (1961)<ref name=Nobel />
* Golden Plate Award of the [[Academy of Achievement|American Academy of Achievement]] (1961)<ref>{{cite web|title= Golden Plate Awardees of the American Academy of Achievement |website=www.achievement.org|publisher=[[American Academy of Achievement]]|url=  https://achievement.org/our-history/golden-plate-awards/#science-exploration}}</ref>
* [[National Medal of Science]] (1963)<ref>{{cite web | url=http://www.aip.org/history/acap/institutions/inst.jsp?nms | title=National Medal of Science | publisher=[[American Institute of Physics]] | access-date=March 21, 2012 | archive-url=https://web.archive.org/web/20160808115117/https://www.aip.org/history/acap/institutions/inst.jsp?nms | archive-date=August 8, 2016 | url-status=dead }}</ref>
* [[Michelson-Morley Award|Michelson Award]] (1965)<ref>{{cite web | url=http://www.phys.cwru.edu/history/book%20pdfs/App%20D%20Events.pdf | title=The Michelson Lectures and Award | publisher=[[Case Western Reserve University]] | access-date=March 21, 2012 | archive-date=November 13, 2015 | archive-url=https://web.archive.org/web/20151113180148/http://www.phys.cwru.edu/history/book%20pdfs/App%20D%20Events.pdf | url-status=dead }}</ref>
* [[Nobel Prize in Physics]] (1968)<ref name="Nobel" />
* Member of the [[National Academy of Engineering]] (1969)<ref name=NAE>{{cite web | title=Dr. Luis W. Alvarez | url=http://www.nae.edu/MembersSection/Directory20412/29779.aspx | work=National Academy of Engineering | access-date=April 17, 2011}}</ref>
* University of Chicago Alumni Medal (1978)<ref>{{cite web | url=http://alumniandfriends.uchicago.edu/site/c.mjJXJ7MLIsE/b.4773411/k.6DFB/Alumni_Award_winners.htm | title=Alumni Awards winners | publisher=[[University of Chicago]] | access-date=March 21, 2012 | archive-date=October 18, 2014 | archive-url=https://web.archive.org/web/20141018184417/http://alumniandfriends.uchicago.edu/site/c.mjJXJ7MLIsE/b.4773411/k.6DFB/Alumni_Award_winners.htm | url-status=dead }}</ref>
* [[National Inventors Hall of Fame]] (1978)<ref>{{cite web | url=http://www.invent.org/hall_of_fame/4.html | title=Hall of Fame / Inventor Profile – Luis Walter Alvarez | publisher=National Inventors Hall of Fame | access-date=March 21, 2012 | archive-url=https://web.archive.org/web/20100706042642/http://www.invent.org/hall_of_fame/4.html | archive-date=July 6, 2010 | url-status=dead }}</ref>
* [[Enrico Fermi award]] of the [[United States Department of Energy|US Department of Energy]] (1987)<ref name=Fermi>{{cite web | title=Luis Alvarez, 1987 | url=http://www.er.doe.gov/fermi/html/Laureates/1980s/luisa.htm | work=The Enrico Fermi Award | publisher=US Department of Energy | access-date=April 17, 2011 | archive-url=https://web.archive.org/web/20141101061828/http://www.er.doe.gov/fermi/html/Laureates/1980s/luisa.htm | archive-date=November 1, 2014 | url-status=dead }}</ref>
* [[IEEE Honorary Membership]] (1988)<ref name=IEEEhon>{{cite web | title=IEEE Honorary membership recipients | url=http://www.ieee.org/documents/hon_mem_rl.pdf | archive-url=https://web.archive.org/web/20100619213624/http://ieee.org/documents/hon_mem_rl.pdf | url-status=dead | archive-date=June 19, 2010 | work=[[IEEE]] | access-date=April 17, 2011}}</ref>
* The Boy Scouts of America named their Cub Scout SUPERNOVA award for Alvarez (2012)<ref>{{cite web | title=Boy Scout award requirements | url=http://bsaseabase.org/Scouting/stem/Awards/CubScout.aspx#supernova | access-date=January 20, 2015 | archive-url=https://web.archive.org/web/20160730080600/http://bsaseabase.org/Scouting/stem/Awards/CubScout.aspx#supernova | archive-date=July 30, 2016 | url-status=dead }}</ref>
* Minor planet [[3581 Alvarez]] is named after him and his son, [[Walter Alvarez]].<ref>{{cite book|chapter-url=https://link.springer.com/referenceworkentry/10.1007%2F978-3-540-29925-7_3580 |chapter=(3581) Alvarez |publisher=Springer |date=2003 |pages=301 |isbn=978-3-540-29925-7 |doi=10.1007/978-3-540-29925-7_3580 |title=Dictionary of Minor Planet Names }}</ref>

== Selected publications ==
* [https://patents.google.com/patent/US3305294 "Two-element variable-power spherical lens"], Patent US3305294A (December 1964)

==Patents==
* Golf training device<ref>Alvarez, Luis W. (March 4, 1958). "Golf training device". U.S. Patent No. 2,825,569. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Electronuclear Reactor<ref>Lawrence, E. O., McMillan, E. M., & Alvarez, L. W. (1960). Electronuclear Reactor (No. US 2933442).</ref>
* Optical range finder with variable angle exponential prism<ref>Alvarez, L. W. (January 24, 1967). "Optical range finder with variable angle exponential prism". U.S. Patent No. 3,299,768. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Two-element variable-power spherical lens<ref>Alvarez, Luis W. (February 21, 1967). "Two-element variable-power spherical lens". U.S. Patent 3,305,294. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Variable-power lens and system<ref>Alvarez, Luis W., and William E. Humphrey. (April 21, 1970). "Variable-power lens and system". U.S. Patent No. 3,507,565. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Subatomic particle detector with liquid electron multiplication medium<ref>Alvarez, Luis W., Stephen E. Derenzo, Richard A. Muller, Robert G. Smits, and Haim Zaklad. (April 25, 1972). "Subatomic particle detector with liquid electron multiplication medium". U.S. Patent No. 3,659,105. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Method of making [[Fresnel]]led optical element matrix<ref>Alvarez, L. (June 19, 1973). "Method of making fresnelled optical element matrix". U.S. Patent No. 3,739,455. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Optical element of reduced thickness<ref>Alvarez, L. (August 6, 1974). "Optical element of reduced thickness". U.S. Patent No. 3,827,798. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Method of forming an optical element of reduced thickness<ref>Alvarez, L. (August 13, 1974). "Method of forming an optical element of reduced thickness". U.S. Patent No. 3,829,536. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Deuterium tagged articles such as explosives and method for detection thereof<ref>Alvarez, Luis W.,(February 17, 1981). "Deuterium tagged articles such as explosives and method for detection thereof". U.S. Patent No. 4,251,726. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Stabilized zoom binocular<ref>Alvarez, Luis W., and Schwemin, Arnold J. (February 23, 1982). "Stabilized zoom binocular". U.S. Patent No. 4,316,649 . Washington, DC: U.S. Patent and Trademark Office.</ref>
* Stand alone collision avoidance system<ref>Alvarez, Luis W. (February 23, 1982). "Stand alone collision avoidance system". U.S. Patent No. 4,317,119. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Television viewer<ref>Alvarez, Luis W., (August 16, 1983). "Television viewer". U.S. Patent No. 4,399,455. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Stabilized zoom binocular<ref>Alvarez, Luis W., and Schwemin, Arnold J. (November 29, 1983). "Stabilized zoom binocular". U.S. Patent No. 4,417,788. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Optically stabilized camera lens system<ref>Alvarez, Luis W., and Schwemin, Arnold J. (October 7, 1986).  "Optically stabilized camera lens system". U.S. Patent No. 4,615,590. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Nitrogen detection<ref>Alvarez, Luis W. (July 12, 1988). "Nitrogen detection". U.S. Patent No. 4,756,866. Washington, DC: U.S. Patent and Trademark Office.</ref>
* Inertial pendulum optical stabilizer<ref>Alvarez, Luis W., and Sporer, Stephen F. (March 27, 1990). "Inertial pendulum optical stabilizer". U.S. Patent No. 4,911,541. Washington, DC: U.S. Patent and Trademark Office.</ref>

== Citations ==
{{Reflist|30em}}

== General references ==
* {{cite book | last=Alvarez | first=L. W. | year=1987 | title=Alvarez: Adventures of a Physicist | publisher=[[Basic Books]] | isbn=0-465-00115-7| url=https://archive.org/details/isbn_0465001165 |url-access = registration |via = [[Internet Archive]]}}
* {{cite book | last1=Heilbron | first1=J. L. | last2=Seidel | first2=R. W. | year=1989 | title=Lawrence and His Laboratory | publisher=[[University of California Press]] | isbn=0-520-06426-7 | url=https://archive.org/details/lawrencehislabor00heil }}
* {{cite book | last=Trower | first=W. P. | title=Luis Walter Alvarez 1911–1988 | year=2009 | url=http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/alvarez-luis-w.pdf | series=Biographical Memoirs | publisher=[[National Academy of Sciences]] | access-date=March 21, 2013}}
* {{cite book | last=Trower | first=W. P. | year=1987 | title=Discovering Alvarez: Selected Works of Luis W. Alvarez with Commentary by His Students and Colleagues | publisher=[[University of Chicago Press]] | isbn=0-226-81304-5| url-access=registration | url=https://archive.org/details/discoveringalvar0000alva }}

== External links ==
{{Commons category|Luis W. Alvarez|Luis Walter Alvarez}}
* {{Nobelprize}} including the Nobel Lecture, December 11, 1968, "Recent Developments in Particle Physics"
* [https://web.archive.org/web/20040305091952/http://www.nobel-winners.com/Physics/luis_walter_alvarez.html About Luis Alvarez]
* [https://web.archive.org/web/20030804191859/http://www.ieee.org/organizations/history_center/oral_histories/transcripts/johnston.html IEEE interview with Johnston, patentholder of the exploding-bridgewire detonator]
* {{ScienceWorldBiography | urlname=Alvarez | title=Alvarez, Luis W. (1911–1988)}}
* [http://alsos.wlu.edu/qsearch.aspx?browse=people/Alvarez,+Luis Annotated bibliography for Luis Alvarez from the Alsos Digital Library for Nuclear Issues] {{Webarchive|url=https://web.archive.org/web/20060828130404/http://alsos.wlu.edu/qsearch.aspx?browse=people%2FAlvarez%2C+Luis |date=August 28, 2006 }}
* Garwin, Richard L., 1992, "[https://fas.org/rlg/alvarez.htm Memorial Tribute For Luis W. Alvarez]" in ''Memorial Tributes, National Academy of Engineering, Vol. 5''. Washington, D.C.: National Academy Press.
* [http://www.osti.gov/accomplishments/alvarez.html Biography and Bibliographic Resources], from the [[Office of Scientific and Technical Information]], [[United States Department of Energy]]
* [https://www.aip.org/history-programs/niels-bohr-library/oral-histories/4483-1 Oral History interview transcript with Luiz Alvarez on 14 Feb 1967, American Institute of Physics, Niels Bohr Library and Archives]
* [https://www.aip.org/history-programs/niels-bohr-library/oral-histories/4483-2 Oral History interview transcript with Luiz Alvarez on 15 February 1967, American Institute of Physics, Niels Bohr Library and Archives]

{{Nobel Prize in Physics Laureates 1951–1975}}
{{1968 Nobel Prize winners}}
{{Winners of the National Medal of Science}}
{{Presidents of the American Physical Society}}
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