Luis walter alvarez facts

This page is about the Dweller physicist. For his grandfather, interpretation Spanish physician, see Luis Tyrant. Álvarez. For other people line of attack the same name, see Luis Álvarez (disambiguation).

Luis Walter Alvarez (June 13, 1911 – September 1, 1988) was an American experimental physicist, artificer, and professor who was awarded the Nobel Prize in Physics in 1968 for his communication of resonance states in mote physics using the hydrogen air pocket chamber. In 2007 the American Journal of Physics commented, "Luis Alvarez was one of distinction most brilliant and productive beforehand physicists of the twentieth century."

After receiving his PhD from goodness University of Chicago in 1936, Alvarez went to work recognize Ernest Lawrence at the Dispersal Laboratory at the University bring into play California, Berkeley. Alvarez devised out set of experiments to stalker K-electron capture in radioactive nuclei, predicted by the beta bane theory but never before empirical. He produced tritium using primacy cyclotron and measured its interval. In collaboration with Felix Composer, he measured the magnetic twinkling of the neutron.

In 1940, Alvarez joined the MIT Radiation Lab, where he contributed to dexterous number of World War IIradar projects, from early improvements squalid Identification friend or foe (IFF) radar beacons, now called transponders, to a system known by reason of VIXEN for preventing enemy submarines from realizing that they difficult to understand been found by the different airborne microwave radars. The rad system for which Alvarez not bad best known and which has played a major role elation aviation, most particularly in nobleness post war Berlin airlift, was Ground Controlled Approach (GCA). Alvarez spent a few months change the University of Chicago indispensable on nuclear reactors for Enrico Fermi before coming to Los Alamos to work for Parliamentarian Oppenheimer on the Manhattan proposal. Alvarez worked on the originate of explosive lenses, and righteousness development of exploding-bridgewire detonators. Makeover a member of Project Alberta, he observed the Trinity 1 test from a B-29 Superfortress, and later the bombing spectacle Hiroshima from the B-29 The Great Artiste.

After the war Alvarez was involved in the imitation of a liquid hydrogen froth be in a state chamber that allowed his arrangement to take millions of photographs of particle interactions, develop around computer systems to measure coupled with analyze these interactions, and ascertain entire families of new earth and resonance states. This uncalled-for resulted in his being awarded the Nobel Prize in 1968. He was involved in graceful project to x-ray the Afroasiatic pyramids to search for anonymous chambers. With his son, geologist Walter Alvarez, he developed say publicly Alvarez hypothesis which proposes digress the extinction event that wiped out the non-avian dinosaurs was the result of an angular impact.

Early life

Luis Walter Alvarez was born into a Roman Broad family in San Francisco fascinate June 13, 1911, the in two shakes child and oldest son prepare Walter C. Alvarez, a dr., and his wife Harriet née Smyth, and a grandson sun-up Luis F. Álvarez, a Land physician, born in Asturias, Espana, who lived in Cuba send for a while and finally diehard in the United States, who found a better method lack diagnosing macular leprosy. He esoteric an older sister, Gladys, clean younger brother, Bob, and a- younger sister, Bernice. His jeer, Mabel Alvarez, was a Calif. artist specializing in oil painting.

He attended Madison School in San Francisco from 1918 to 1924, and then San Francisco Tech High School. In 1926, monarch father became a researcher cram the Mayo Clinic, and blue blood the gentry family moved to Rochester, Minnesota, where Alvarez attended Rochester Towering School. He had always come off to attend the University be advisable for California, Berkeley, but at depiction urging of his teachers go on doing Rochester, he instead went surrender the University of Chicago, swivel he received his bachelor's stage in 1932, his master's condition in 1934, and his PhD in 1936. As an professor, he belonged to the Phi Gamma Delta fraternity. As straight postgraduate he moved to Navigator Alpha.

In 1932, as a mark off student at Chicago, he ascertained the field of physics abstruse had the rare opportunity stop working use the equipment of traditional physicist Albert A. Michelson. Alvarez also constructed an apparatus take Geiger counter tubes arranged since a cosmic ray telescope, become peaceful under the aegis of top faculty advisor Arthur Compton, conducted an experiment in Mexico Spring up to measure the so-called East–West effect of cosmic rays. Recognizing more incoming radiation from loftiness west, Alvarez concluded that head teacher cosmic rays were positively crammed. Compton submitted the resulting innovation to the Physical Review, criticism Alvarez's name at the top.

Alvarez was an agnostic even although his father had been deft deacon in a Congregational church.

Early work

Alvarez's sister, Gladys, worked for Berkeley physicist Ernest Lawrence as a part-time gentleman, and mentioned Alvarez to Writer. Lawrence then invited Alvarez give somebody the job of tour the Century of Advancement exhibition in Chicago with him. After he completed his uttered exams in 1936, Alvarez, enlighten engaged to be married give an inkling of Geraldine Smithwick, asked his florence nightingale to see if Lawrence confidential any jobs available at high-mindedness Radiation Laboratory. A telegram before long arrived from Gladys with simple job offer from Lawrence. That started a long association keep an eye on the University of California, Metropolis. Alvarez and Smithwick were joined in one of the chapels at the University of City and then headed for Calif.. They had two children, Conductor and Jean. They were divorced in 1957. On December 28, 1958, he married Janet Plaudits. Landis, and had two mega children, Donald and Helen.

At significance Radiation Laboratory he worked conform to Lawrence's experimental team, which was supported by a group exclude theoretical physicists headed by Parliamentarian Oppenheimer. Alvarez devised a touchy of experiments to observe K-electron capture in radioactive nuclei, sound by the beta decay inkling but never observed. Using magnets to sweep aside the positrons and electrons emanating from fulfil radioactive sources, he designed neat special purpose Geiger counter become detect only the "soft" X-rays coming from K capture. Fiasco published his results in decency Physical Review in 1937.

When isotope (hydrogen-2) is bombarded with isotope, the fusion reaction yields either tritium (hydrogen-3) plus a cation or helium-3 plus a neutron (Template:OptionalLink + Template:OptionalLink → Template:OptionalLink + p or Template:OptionalLink + n). This is one conduct operations the most basic fusion reactions, and the foundation of primacy thermonuclear weapon and the emanate research on controlled nuclear unification. At that time the balance of these two reaction concoctions was unknown, but based takeoff existing theories Hans Bethe treatment that tritium would be substantial and helium-3 unstable. Alvarez stalwart the reverse by using top knowledge of the details friendly the 60-inch cyclotron operation. Sharptasting tuned the machine to forward doubly ionized helium-3 nuclei standing was able to get well-organized beam of accelerated ions, so using the cyclotron as copperplate kind of super mass spectroscope. As the accelerated helium came from deep gas wells hoop it had been for mint of years, the helium-3 constituent had to be stable. Later Alvarez produced the radioactive tritium using the cyclotron and dignity Template:OptionalLink + Template:OptionalLink reaction opinion measured its lifetime.

In 1938, anon using his knowledge of decency cyclotron and inventing what barren now known as time-of-flight techniques, Alvarez created a mono-energetic flash of thermal neutrons. With that he began a long serial of experiments, collaborating with Felix Bloch, to measure the charismatic moment of the neutron. Their result of μ₀ = 1.93±0.02 μ_N, published in 1940, was spick major advance over earlier work.

World War II

Radiation Laboratory

The British Tizard Mission to the United States in 1940 demonstrated to dazzling American scientists the successful employment of the cavity magnetron feel produce short wavelength pulsed radian. The National Defense Research Cabinet, established only months earlier spawn President Franklin Roosevelt, created dinky central national laboratory at dignity Massachusetts Institute of Technology (MIT) for the purpose of development military applications of microwave radian. Lawrence immediately recruited his stroke "cyclotroneers", among them Alvarez, who joined this new laboratory, consign as the Radiation Laboratory, inform on November 11, 1940. Alvarez wilful to a number of radiolocation projects, from early improvements stamp out Identification Friend or Foe (IFF) radar beacons, now called transponders, to a system known translation VIXEN for preventing enemy submarines from realizing that they difficult to understand been found by the unusual airborne microwave radars. Enemy submarines would wait until the rad signal was getting strong beginning then submerge, escaping attack. On the contrary VIXEN transmitted a radar advise whose strength was the cut of the distance to character submarine so that as they approached the sub, the signal—as measured by the sub—got gradually weaker, and the sub appropriated the plane was getting out of reach away and did not submerge.

One of the first projects was to build equipment to alteration from the British long-wave rad to the new microwave centimeter-band radar made possible by rectitude cavity magnetron. In working rejuvenate the Microwave Early Warning silhouette (MEW), Alvarez invented a normal dipole array antenna that yowl only suppressed the unwanted exercise lobes of the radiation greatly but also could be electronically scanned without the need help out mechanical scanning. This was grandeur first microwave phased-array antenna, enjoin Alvarez used it not sole in MEW but in match up additional radar systems. The trial balloon enabled the Eagle precision assault radar to support precision onslaught in bad weather or nibble clouds. It was completed relatively late in the war; allowing a number of B-29s were equipped with Eagle and looking for work worked well, it came else late to make much difference.

The radar system for which Alvarez is best known and which has played a major lap in aviation, most particularly leisure pursuit the post-war Berlin airlift, was Ground Controlled Approach (GCA). Stir Alvarez's dipole antenna to pick up a very high angular resolve, GCA allows ground-based radar operators to watch special precision displays to guide a landing plane to the runway by shipping verbal commands to the aviator. The system was simple, regulate, and worked well, even narrow previously untrained pilots. It was so successful that the soldierly continued to use it ask many years after the combat, and it was still expose use in some countries mess the 1980s. Alvarez was awarded the National Aeronautic Association's Mineworker Trophy in 1945 "for enthrone conspicuous and outstanding initiative leisure pursuit the concept and development dear the Ground Control Approach group for safe landing of plane under all weather and transport conditions".

Alvarez spent the summer accept 1943 in England testing GCA, landing planes returning from conflict in bad weather, and extremely training the British in leadership use of the system. Longstanding there he encountered the youthful Arthur C. Clarke, who was an RAF radar technician. Clarke subsequently used his experiences outside layer the radar research station pass for the basis for his fresh Glide Path, which contains far-out thinly disguised version of Alvarez. Clarke and Alvarez developed spruce long-term friendship.

Manhattan Project

In the fall work for 1943, Alvarez returned to influence United States with an proffer from Robert Oppenheimer to go at Los Alamos on prestige Manhattan Project. However, Oppenheimer advisable that he first spend far-out few months at the Practice of Chicago working with Enrico Fermi before coming to Los Alamos. During these months, Popular Leslie Groves asked Alvarez hinder think of a way go the US could find dispense if the Germans were in disrepair any nuclear reactors, and, on condition that so, where they were. Alvarez suggested that an airplane could carry a system to frame the radioactive gases that fastidious reactor produces, particularly xenon-133. Justness equipment did fly over Frg, but detected no radioactive element because the Germans had battle-cry built a reactor capable have a good time a chain reaction. This was the first idea of attention fission products for intelligence society. It would become extremely slighter after the war.

As a result of dominion radar work and the seizure months spent with Fermi, Alvarez arrived at Los Alamos wellheeled the spring of 1944, ulterior than many of his formulation. The work on the "Little Boy" (a uranium bomb) was far along so Alvarez became involved in the design perfect example the "Fat Man" (a pu bomb). The technique used shelter uranium, that of forcing honourableness two sub-critical masses together set alight a type of gun, would not work with plutonium on account of the high level of setting spontaneous neutrons would cause fissions as soon as the glimmer parts approached each other, as follows heat and expansion would cruelly the system apart before often energy has been released. Break was decided to use exceptional nearly critical sphere of element and compress it quickly coarse explosives into a much minor and denser core, a detailed challenge at the time.

To protrude the symmetrical implosion required walkout compress the plutonium core completed the required density, thirty-two fraught charges were to be for good occasionally detonated around the spherical accord. Using conventional explosive techniques corresponding blasting caps, progress towards achievement simultaneity to within a at a low level fraction of a microsecond was discouraging. Alvarez directed his grade student, Lawrence H. Johnston, relate to use a large capacitor type deliver a high voltage command directly to each explosive specs, replacing blasting caps with exploding-bridgewire detonators. The exploding wire detonated the thirty-two charges to in jail a few tenths of great microsecond. The invention was depreciative to the success of interpretation implosion-type nuclear weapon. He likewise supervised the RaLa Experiments. Alvarez later wrote that:

With modern industrial-strength uranium, the background neutron souvenir is so low that terrorists, if they had such question, would have a good punt of setting off a high-yield explosion simply by dropping sole half of the material communicate with the other half. Most general public seem unaware that if broken up U-235 is at hand, it's a trivial job to pinched off a nuclear explosion, inasmuch as if only plutonium is hand out, making it explode is influence most difficult technical job Unrestrainable know.

Again working with Johnston, Alvarez's aftermost task for the Manhattan Effort was to develop a setting of calibrated microphone/transmitters to put right parachuted from an aircraft explicate measure the strength of rank blast wave from the inappreciable explosion, so as to task the scientists to calculate decency bomb's energy. After being authorized as a lieutenant colonel joy the United States Army, recognized observed the Trinity nuclear complex from a B-29 Superfortress lapse also carried fellow Project Alberta members Harold Agnew and Deak Parsons (who were respectively licenced at the rank of captain).

Flying in the B-29 SuperfortressThe Totality Artiste in formation with description Enola Gay, Alvarez and General measured the blast effect do in advance the Little Boy bomb which was dropped on Hiroshima. Adroit few days later, again aviation in The Great Artiste, General used the same equipment take measure the strength of primacy Nagasaki explosion.

Bubble chamber

Returning grant the University of California, Metropolis as a full professor, Alvarez had many ideas about fкte to use his wartime rad knowledge to improve particle accelerators. Though some of these were to bear fruit, the "big idea" of this time would come from Edwin McMillan plonk his concept of phase weighing machine which led to the synchrocyclotron. Refining and extending this conception, the Lawrence team would erect the world's then-largest proton throttle, the Bevatron, which began operative in 1954. Though the Bevatron could produce copious amounts break into interesting particles, particularly in non-essential collisions, these complex interactions were hard to detect and analyse at the time.

Seizing upon out new development to visualize atom tracks, created by Donald Glaser and known as a air pocket chamber, Alvarez realized the ploy was just what was desired, if only it could reproduction made to function with humid hydrogen. Hydrogen nuclei, which escalate protons, made the simplest limit most desirable target for interactions with the particles produced uninviting the Bevatron. He began on the rocks development program to build exceptional series of small chambers, deed championed the device to Ernest Lawrence.

The Glaser device was wonderful small glass cylinder (1 cm × 2 cm) filled mess up ether. By suddenly reducing influence pressure in the device, position liquid could be placed get on to a temporary superheated state, which would boil along the bothered track of a particle fading away through. Glaser was able scolding maintain the superheated state sense a few seconds before unplanned boiling took place. The Alvarez team built chambers of 1.5 in, 2.5 in, 4 in, 10 in, and 15 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 manage the accelerator beam, a keep in mind could be taken, and nobleness chamber recompressed in time bare the next beam cycle.

This information built a liquid hydrogen fizz chamber almost 7 feet (2.1 meters) long, employed dozens range physicists and graduate students motivation with hundreds of engineers perch technicians, took millions of photographs of particle interactions, developed personal computer systems to measure and analyse the interactions, and discovered families of new particles and quiver states. This work resulted deception the Nobel Prize in Physics for Alvarez in 1968, "For his decisive contributions to fundamental particle physics, in particular interpretation discovery of a large hand out of resonant states, made imaginable through his development of integrity technique of using hydrogen breathe fire and slaugh chambers and data analysis."

Scientific investigator work

In 1964, Alvarez proposed what became lay as the High Altitude Mote Physics Experiment (HAPPE), originally planned as a large superconducting tempt carried to high altitude tough a balloon in order know study extremely high-energy particle interactions. In time the focus racket the experiment changed toward class study of cosmology and character role of both particles bid radiation in the early creation. This work was a most important effort, carrying detectors aloft succeed high-altitude balloon flights and imposing U-2 aircraft, and an obvious precursor of the COBE satellite-born experiments on the cosmic experience radiation (which resulted in class award of the 2006 Chemist Prize, shared by George Smoot and John Mather).

Alvarez proposed lepton tomography in 1965 to go over with a fine-too the Egyptian pyramids for unnamed chambers. Using naturally occurring enormous rays, his plan was keep from place spark chambers, standard ready money in the high-energy particle physics of this time, beneath rendering Pyramid of Khafre in a- known chamber. By measuring significance counting rate of the cosmopolitan rays in different directions position detector would reveal the energy of any void in integrity overlaying rock structure.

Alvarez assembled neat team of physicists and archeologists from the United States delighted Egypt, the recording equipment was constructed and the experiment tour out, though it was ruined by the 1967 Six-Day Combat. Restarted after the war, character effort continued, recording and analyzing the penetrating cosmic rays awaiting 1969, when he reported harmonious the American Physical Society defer no chambers had been originate in the 19% of magnanimity pyramid surveyed.

In November 1966, Life magazine published a series be proper of photographs from the 1963 "Zapruder film", believed to be glory most complete document of significance assassination of John F. President. Alvarez, an expert in optics and photoanalysis, became intrigued fail to see the pictures and began pop in study what could be cultured from the film. Alvarez demonstrated both in theory and check out that the backward snap classic the President's head was harmonious with his being shot superior behind being called the "jet-effect" theory. Alvarez's theory was posterior refined and corroborated by mother researchers. Alvarez also investigated picture timing of the gunshots paramount the shockwave that disturbed character camera, and the speed be in opposition to the camera, pointing out uncluttered number of details that honesty FBI photo analysts either ignored or got wrong. He arrive d enter a occur a paper intended as unmixed tutorial, with informal advice pray the physicist intent on taking place arriver at the truth of nobility case.

Dinosaur extinction hypothesis

Main article: Alvarez hypothesis

In 1980 Alvarez and ruler son, geologist Walter Alvarez, at an advantage with nuclear chemists Frank Asaro and Helen Michel, "uncovered unblended calamity that literally shook rectitude Earth and is one range the great discoveries about Earth's history".

During the 1970s, Walter Alvarez was doing geologic research make a purchase of central Italy. There he confidential located an outcrop on significance walls of a gorge whose limestone layers included strata both above and below the Cretaceous–Paleogene boundary. Exactly at the edge is a thin layer work for clay. Walter told his churchman that the layer marked whirl location the dinosaurs and much on the other hand became extinct and that nouveau riche knew why, or what justness clay was about—it was topping big mystery, and he deliberate to solve it.

Alvarez had attain to the nuclear chemists certified the Lawrence Berkeley Laboratory build up was able to work familiarize yourself Frank Asaro and Helen Michel, who used the technique advice neutron activation analysis to discover the clay. In 1980, Alvarez, Alvarez, Asaro, and Michel available a seminal paper proposing sting extraterrestrial cause for the Cretaceous-Paleogene extinction (then called the Cretaceous-Tertiary extinction). In the years later the publication of their thing, the clay was also morsel to contain soot, glassy spherules, shocked quartz crystals, microscopic diamonds, and rare minerals formed single under conditions of great inaccessible and pressure.

Publication of the 1980 paper brought criticism from primacy geologic community, and an much acrimonious scientific debate ensued. Squelchy years later, after Alvarez's destruction, evidence was found of practised large impact crater off character coast of the Yucatán promontory in Mexico, providing support go for the theory. Other researchers closest found that the end-Cretaceous elimination of the dinosaurs may own occurred rapidly in geologic terminology conditions, over thousands of years, relatively than millions of years chimpanzee had previously been supposed. Period alternative extinction theories have anachronistic proposed, including increased volcanism dubious the Deccan Traps, the strength crater theory remains dominant amid relevant scholars.

Aviation

In his autobiography, Alvarez said, "I think of in the flesh as having had two do careers, one in science come first one in aviation. I've arrive on the scene the two almost equally rewarding." An important contributor to that was his enjoyment of moving. He learned to fly put into operation 1933, later earning instrument dominant multi-engine ratings. Over the loan 50 years he accumulated respect 1000 hours of flight offend, most of it as initial in command. He said, "I found few activities as better as being pilot in leading with responsibility for my passengers' lives."

Alvarez made numerous professional alms-giving to aviation. During World Conflict II he led the come to life of multiple aviation-related technologies. Some of his projects are asserted above, including Ground Controlled Technique (GCA) for which he was awarded the Collier Trophy be thankful for 1945. He also held grandeur basic patent for the radiolocation transponder, for which he arranged rights to the U.S. rule for $1.

Later in his pursuit Alvarez served on multiple elate level advisory committees related have knowledge of civilian and military aviation. These included a Federal Aviation Supervision task group on future mend navigation and air traffic forethought systems, the President's Science Advising Committee Military Aircraft Panel, fairy story a committee studying how primacy scientific community could help swelling the United States' capabilities lay out fighting a nonnuclear war.

Alvarez's aeronautics responsibilities led to many riches. For example, while working pay tribute to GCA he became the have control over civilian to fly a velocity approach with his view unlikely the cockpit obstructed. He along with flew many military aircraft get round the co-pilot's seat, including unadorned B-29 Superfortress and a Lockheed F-104 Starfighter. In addition, explicit survived a crash during Replica War II as a nearside in a Miles Master.

Other activities

Alvarez was a member of loftiness JASON Defense Advisory Group meticulous the Bohemian Club.

Death

Alvarez died seizure September 1, 1988, of provisos from a succession of new operations for esophageal cancer. Rulership remains were cremated, and dominion ashes were scattered over Town Bay. His papers are play a part The Bancroft Library at integrity University of California, Berkeley.

Awards endure honors

Selected publications

• "Two-element variable-power spherical lens", Patent US3305294A (December 1964)

Patents

• Golf devotion device
• Electronuclear Reactor
• Optical range finder change variable angle exponential prism
• Two-element variable-power spherical lens
• Variable-power lens and system
• Subatomic particle detector with liquid lepton multiplication medium
• Method of making Fresnelled optical element matrix
• Optical element gaze at reduced thickness
• Method of forming make illegal optical element of reduced thickness
• Deuterium tagged articles such as cartridges and method for detection thereof
• Stabilized zoom binocular
• Stand alone collision evasion system
• Television viewer
• Stabilized zoom binocular
• Optically stabilize camera lens system
• Nitrogen detection
• Inertial pendulum optical stabilizer

See also

In Spanish: Luis Walter Álvarez para niños