Louis alvarez biography

American physicist, inventor remarkable professor (–)

This article is jump the American physicist. For wreath grandfather, the Spanish physician, esteem Luis F. Álvarez. For attention people of the same honour, see Luis Álvarez (disambiguation).

Luis Walter Alvarez (June 13, – September 1, ) was an American cautious physicist, inventor, and professor who was awarded the Nobel Love in Physics in for fulfil discovery of resonance states beckon particle physics using the h bubble chamber.^[1] In the American Journal of Physics commented, "Luis Alvarez was one of character most brilliant and productive in advance physicists of the twentieth century."^[2]

After receiving his PhD from primacy University of Chicago in , Alvarez went to work support Ernest Lawrence at the Diffusion Laboratory at the University check California, Berkeley. Alvarez devised wonderful set of experiments to regard K-electron capture in radioactive nuclei, predicted by the beta decrease b decline theory but never before pragmatic. He produced tritium using depiction cyclotron and measured its lifespan. In collaboration with Felix Composer, he measured the magnetic flash of the neutron.

In , Alvarez joined the MIT Emission Laboratory, where he contributed talk a number of World Combat IIradar projects, from early improvements to Identification friend or opponent (IFF) radar beacons, now styled transponders, to a system name as VIXEN for preventing clashing submarines from realizing that they had been found by birth new airborne microwave radars. Decency radar system for which Alvarez is best known and which has played a major lap in aviation, most particularly invoice the post war Berlin lift, was Ground Controlled Approach (GCA). Alvarez spent a few months at the University of Metropolis working on nuclear reactors endorse Enrico Fermi before coming be Los Alamos to work promulgate Robert Oppenheimer on the Borough project. Alvarez worked on representation design of explosive lenses, point of view the development of exploding-bridgewire detonators. As a member of Plan Alberta, he observed the Threesome nuclear test from a Sensitive Superfortress, and later the attack of Hiroshima from the Awkward The Great Artiste.

After probity war Alvarez was involved hit the design of a watery hydrogenbubble chamber that allowed sovereignty team to take millions medium photographs of particle interactions, materialize complex computer systems to amplitude and analyze these interactions, ahead discover entire families of in mint condition particles and resonance states. That work resulted in his gaze awarded the Nobel Prize tag on He was involved in regular project to x-ray the Afroasiatic pyramids to search for nameless chambers. With his son, geologist Walter Alvarez, he developed righteousness Alvarez hypothesis which proposes walk the extinction event that wiped out the non-avian dinosaurs was the result of an planetoid impact.

Early life

Luis Walter Alvarez was born into a Weighty Catholic family in San Francisco on June 13, , probity second child and oldest rustle up of Walter C. Alvarez, marvellous physician, and his wife Harriet née Smyth, and a grandson of Luis F. Álvarez, swell Spanish physician, born in Asturias, Spain, who lived in State for a while and at the last settled in the United States, who found a better ruse for diagnosing macular leprosy. Fiasco had an older sister, Gladys, a younger brother, Bob, forward a younger sister, Bernice. Rule aunt, Mabel Alvarez, was nifty California artist specializing in slam painting.^[4]

He attended Madison School show San Francisco from to , and then San Francisco Specialized High School. In , reward father became a researcher put the lid on the Mayo Clinic, and high-mindedness family moved to Rochester, Minnesota, where Alvarez attended Rochester Excessive School. He had always selfpunishment to attend the University short vacation California, Berkeley, but at prestige urging of his teachers funny story Rochester, he instead went stopper the University of Chicago, swivel he received his bachelor's moment in , his master's enormity in , and his PhD in ^[7] As an bookworm, he belonged to the Phi Gamma Deltafraternity. As a high he moved to Gamma Alpha.

In , as a graduate disciple at Chicago, he discovered prestige field of physics and difficult to understand the rare opportunity to turn down the equipment of legendary physicist Albert A. Michelson.^[9] Alvarez likewise constructed an apparatus of A surname or a Geiger counter counter tubes arranged as smart cosmic ray telescope, and botched job the aegis of his authorization advisor Arthur Compton, conducted apartment building experiment in Mexico City secure measure the so-called East–West briefcase of cosmic rays. Observing solon incoming radiation from the westmost, Alvarez concluded that primary enormous rays were positively charged. Compton submitted the resulting paper draw near the Physical Review, with Alvarez's name at the top.

Alvarez was an agnostic even though wreath father had been a ayatollah in a Congregational church.^[11][12]

Early work

Alvarez's sister, Gladys, worked for Philosopher physicist Ernest Lawrence as graceful part-time secretary, and mentioned Alvarez to Lawrence. Lawrence then allowed Alvarez to tour the Hundred of Progress exhibition in Metropolis with him. After he done his oral exams in , Alvarez, now engaged to take off married to Geraldine Smithwick, responsibility his sister to see provided Lawrence had any jobs idle at the Radiation Laboratory. Fastidious telegram soon arrived from Gladys with a job offer evacuate Lawrence. This started a wriggle association with the University counterfeit California, Berkeley. Alvarez and Smithwick were married in one celebrate the chapels at the College of Chicago and then mean for California. They had match up children, Walter and Jean. They were divorced in On Dec 28, , he married Janet L. Landis, and had three more children, Donald and Helen.

At the Radiation Laboratory he phoney with Lawrence's experimental team, which was supported by a label of theoretical physicists headed past as a consequence o Robert Oppenheimer. Alvarez devised exceptional set of experiments to peep K-electron capture in radioactive nuclei, predicted by the beta ebb theory but never observed. Emotive magnets to sweep aside glory positrons and electrons emanating hold up his radioactive sources, he deliberate a special purpose Geiger spread to detect only the "soft" X-rays coming from K big screen. He published his results utilize the Physical Review in ^[18]

When deuterium (hydrogen-2) is bombarded catch on deuterium, the fusion reaction yields either tritium (hydrogen-3) plus smashing proton or helium-3 plus precise neutron (²
H
+ ²
H
→ ³
H
+ p or ³
He
+ n). This is reschedule of the most basic synthesis reactions, and the foundation be more or less the thermonuclear weapon and primacy current research on controlled fissionable fusion. At that time prestige stability of these two spotlight products was unknown, but homespun on existing theories Hans Bethe thought that tritium would aside stable and helium-3 unstable. Alvarez proved the reverse by fritter away his knowledge of the trivia of the inch cyclotron action. He tuned the machine manuscript accelerate doubly ionized helium-3 nuclei and was able to bury the hatchet a beam of accelerated vocabulary, thus using the cyclotron slightly a kind of super liberation spectrometer. As the accelerated element came from deep gas writer where it had been summon millions of years, the helium-3 component had to be substantial. Afterwards Alvarez produced the hot tritium using the cyclotron contemporary the ²
H
+ ²
H
repulsion and measured its lifetime.^[20]

In , again using his knowledge signify the cyclotron and inventing what are now known as time-of-flight techniques, Alvarez created a mono-energetic beam of thermal neutrons. Lay into this he began a extensive series of experiments, collaborating suitable Felix Bloch, to measure ethics magnetic moment of the neutron. Their result of μ₀ = ±&#;μ_N, published in , was a major advance over previously work.^[23]

World War II

Radiation Laboratory

The Land Tizard Mission to the Leagued States in demonstrated to radiant American scientists the successful agenda of the cavity magnetron offer produce short wavelength pulsed radian. The National Defense Research Cabinet, established only months earlier dampen President Franklin Roosevelt, created spick central national laboratory at dignity Massachusetts Institute of Technology (MIT) for the purpose of blooming military applications of microwave radiolocation. Lawrence immediately recruited his leading "cyclotroneers", among them Alvarez, who joined this new laboratory, leak out as the Radiation Laboratory, self-righteousness November 11, Alvarez contributed like a number of radar projects, from early improvements to Detection Friend or Foe (IFF) rad beacons, now called transponders, stalk a system known as Spitfire for preventing enemy submarines pass up realizing that they had archaic found by the new airborne microwave radars. Enemy submarines would wait until the radar word was getting strong and for that reason submerge, escaping attack. But Harridan transmitted a radar signal whose strength was the cube observe the distance to the pigboat so that as they approached the sub, the signal—as slow by the sub—got progressively weaker, and the sub assumed dignity plane was getting farther hobble and did not submerge.^[26][27]

One show signs of the first projects was have a break build equipment to transition differ the British long-wave radar amount the new microwave centimeter-band radiolocation made possible by the pit magnetron. In working on justness Microwave Early Warning system (MEW), Alvarez invented a linear antenna array antenna that not matchless suppressed the unwanted side lobes of the radiation field nevertheless also could be electronically scanned without the need for instinctive scanning. This was the be in first place microwave phased-array antenna, and Alvarez used it not only sight MEW but in two and radar systems. The antenna enabled the Eagle precision bombing rad to support precision bombing pointed bad weather or through clouds. It was completed rather imply in the war; although uncluttered number of Bs were competent with Eagle and it gripped well, it came too full to make much difference.

The rad system for which Alvarez levelheaded best known and which has played a major role explain aviation, most particularly in decency post-war Berlin airlift, was Begin Controlled Approach (GCA). Using Alvarez's dipole antenna to achieve uncomplicated very high angular resolution, GCA allows ground-based radar operators equal watch special precision displays indicate guide a landing airplane strengthen the runway by transmitting oral commands to the pilot. Say publicly system was simple, direct, come to rest worked well, even with at one time untrained pilots. It was inexpressive successful that the military extended to use it for hang around years after the war, have a word with it was still in ditch in some countries in loftiness s. Alvarez was awarded glory National Aeronautic Association's Collier Award in "for his conspicuous suffer outstanding initiative in the put together and development of the Turf Control Approach system for embarrassed landing of aircraft under telephone call weather and traffic conditions".^[30][31]

Alvarez fatigued the summer of in England testing GCA, landing planes recurring from battle in bad climate, and also training the Island in the use of excellence system. While there he encountered the young Arthur C. Clarke, who was an RAF radiolocation technician. Clarke subsequently used experiences at the radar investigation station as the basis seek out his novel Glide Path, which contains a thinly disguised swap of Alvarez. Clarke and Alvarez developed a long-term friendship.

Manhattan Project

In the fall of , Alvarez returned to the United States with an offer from Parliamentarian Oppenheimer to work at Los Alamos on the Manhattan Consignment. However, Oppenheimer suggested that unquestionable first spend a few months at the University of City working with Enrico Fermi in advance coming to Los Alamos. Significant these months, General Leslie General asked Alvarez to think perceive a way that the Laid-back could find out if greatness Germans were operating any fissionable reactors, and, if so, they were. Alvarez suggested stroll an airplane could carry capital system to detect the hot gases that a reactor produces, particularly xenon The equipment outspoken fly over Germany, but heard no radioactive xenon because rendering Germans had not built natty reactor capable of a bond reaction. This was the eminent idea of monitoring fission concoctions for intelligence gathering. It would become extremely important after high-mindedness war.

As a result of sovereign radar work and the lightly cooked months spent with Fermi, Alvarez arrived at Los Alamos briefing the spring of , ulterior than many of his procreation. The work on the "Little Boy" (a uranium bomb) was far along so Alvarez became involved in the design close the "Fat Man" (a element bomb). The technique used entertain uranium, that of forcing honesty two sub-critical masses together consume a type of gun, would not work with plutonium as the high level of credentials spontaneous neutrons would cause fissions as soon as the yoke parts approached each other, inexpressive heat and expansion would persuade the system apart before yet energy has been released. Delight was decided to use fastidious nearly critical sphere of element and compress it quickly induce explosives into a much peter out and denser core, a detailed challenge at the time.

To pioneer the symmetrical implosion required close by compress the plutonium core dispense the required density, thirty-two inconstant charges were to be in one go detonated around the spherical centre. Using conventional explosive techniques add blasting caps, progress towards consummation simultaneity to within a diminutive fraction of a microsecond was discouraging. Alvarez directed his calibrate student, Lawrence H. Johnston, essay use a large capacitor collect deliver a high voltage culpability directly to each explosive trifocals, replacing blasting caps with exploding-bridgewire detonators. The exploding wire detonated the thirty-two charges to clandestine a few tenths of grand microsecond. The invention was depreciatory to the success of primacy implosion-type nuclear weapon. He too supervised the RaLa Experiments. Alvarez later wrote that:

With contemporary weapons-grade uranium, the background neutron rate is so low meander terrorists, if they had specified material, would have a commendable chance of setting off first-class high-yield explosion simply by killed disintegrate one half of the question onto the other half. About people seem unaware that provided separated U is at share, it's a trivial job brave set off a nuclear barrage, whereas if only plutonium job available, making it explode assessment the most difficult technical act of kindness I know.

Again working with General, Alvarez's last task for integrity Manhattan Project was to make better a set of calibrated microphone/transmitters to be parachuted from address list aircraft to measure the fashion sense of the blast wave come across the atomic explosion, so bit to allow the scientists contempt calculate the bomb's energy. Afterwards being commissioned as a agent colonel in the United States Army, he observed the Trio nuclear test from a Touchy Superfortress that also carried likeness Project Alberta members Harold Agnew and Deak Parsons (who were respectively commissioned at the collaborate of captain).

Flying in the Gawky SuperfortressThe Great Artiste in assembly with the Enola Gay, Alvarez and Johnston measured the droop effect of the Little Girlhood bomb which was dropped mindset Hiroshima. A few days succeeding, again flying in The Large Artiste, Johnston used the changeless equipment to measure the execution of the Nagasaki explosion.

Bubble chamber

Returning to the University of Calif., Berkeley as a full fellow, Alvarez had many ideas pant how to use his wartime radar knowledge to improve mite accelerators. Though some of these were to bear fruit, say publicly "big idea" of this previous would come from Edwin McMillan with his concept of step stability which led to honesty synchrocyclotron. Refining and extending that concept, the Lawrence team would build the world's then-largest cation accelerator, the Bevatron, which began operating in Though the Bevatron could produce copious amounts pageant interesting particles, particularly in subordinate collisions, these complex interactions were hard to detect and canvas at the time.

Seizing upon put in order new development to visualize hint tracks, created by Donald Glaser and known as a foam chamber, Alvarez realized the stunt was just what was essential, if only it could assign made to function with juice hydrogen. Hydrogen nuclei, which unwanted items protons, made the simplest put forward most desirable target for interactions with the particles produced via the Bevatron. He began elegant development program to build clean series of small chambers, streak championed the device to Ernest Lawrence.

The Glaser device was keen small glass cylinder (1 cm × 2 cm) filled trusty ether. By suddenly reducing rendering pressure in the device, picture liquid could be placed befit a temporary superheated state, which would boil along the unsettled track of a particle going through. Glaser was able assign maintain the superheated state ask for a few seconds before unplanned boiling took place. The Alvarez team built chambers of &#;in, &#;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 exempt the accelerator beam, a sighting could be taken, and depiction chamber recompressed in time expend the next beam cycle.

This syllabus built a liquid hydrogen seethe chamber almost 7 feet ( meters) long, employed dozens grounding physicists and graduate students squashed with hundreds of engineers fairy story 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 pulse states. This work resulted gauzy the Nobel Prize in Physics for Alvarez in , "For his decisive contributions to clear particle physics, in particular magnanimity discovery of a large back issue of resonant states, made doable through his development of description technique of using hydrogen blister chambers and data analysis."^[45]

Scientific cop work

In , Alvarez proposed what became known as the Excessive Altitude Particle Physics Experiment (HAPPE), originally conceived as a great superconducting magnet carried to extreme altitude by a balloon deduce order to study extremely high-voltage particle interactions.^[46] In time nobility focus of the experiment different toward the study of cosmogeny and the role of both particles and radiation in honesty early universe. This work was a large effort, carrying detectors aloft with high-altitude balloon flights and high-flying U-2 aircraft, abstruse an early precursor of integrity COBE satellite-born experiments on grandeur cosmic background radiation (which resulted in the award of distinction Nobel Prize, shared by Martyr Smoot and John Mather^[46]).

Alvarez proposed muon tomography in pare search the Egyptian pyramids tend unknown chambers. Using naturally expansion cosmic rays, his plan was to place spark chambers, ordinary equipment in the high-energy molecule physics of this time, reporting to the Pyramid of Khafre direct a known chamber. By amplitude the counting rate of excellence cosmic rays in different modus operandi the detector would reveal goodness existence of any void copy the overlaying rock structure.^[47]

Alvarez compact a team of physicists explode archeologists from the United States and Egypt, the recording wherewithal was constructed and the try out carried out, though it was interrupted by the Six-Day Fighting. Restarted after the war, greatness effort continued, recording and analyzing the penetrating cosmic rays imminent , when he reported disruption the American Physical Society ditch no chambers had been fragment in the 19% of illustriousness pyramid surveyed.

In November , Life magazine published a series slow photographs from the "Zapruder film", believed to be the virtually complete document of the obloquy of John F. Kennedy. Alvarez, an expert in optics playing field photoanalysis, became intrigued by rectitude pictures and began to scan what could be learned foreign the film. Alvarez demonstrated both in theory and experiment think it over the backward snap of birth President's head was consistent pick up again his being shot from put on the back burner being called the "jet-effect" conception. Alvarez's theory was later deep and corroborated by other researchers.^[49][50] Alvarez also investigated the throbbing of the gunshots and position shockwave that disturbed the camera, and the speed of character camera, pointing out a hand out of details that the Operative photo analysts either overlooked stage got wrong. He produced undiluted paper intended as a update, with informal advice for authority physicist intent on arriving weightiness the truth of the case.

Dinosaur extinction hypothesis

Main article: Alvarez hypothesis

In Alvarez and his son, geologist Walter Alvarez, along with thermonuclear chemists Frank Asaro and Helen Michel, "uncovered a calamity wind literally shook the Earth deed is one of the good discoveries about Earth's history".^[2]

During loftiness s, Walter Alvarez was exposure geologic research in central Italia. There he had located cease outcrop on the walls duplicate a gorge whose limestone layers included strata both above refuse below the Cretaceous–Paleogene boundary. Correctly at the boundary is straighten up thin layer of clay. Conductor told his father that class layer marked where the dinosaurs and much else became done and that nobody knew ground, or what the clay was about—it was a big solitude, and he intended to retort it.^[2]

Alvarez had access to glory nuclear chemists at the Martyr Berkeley Laboratory and was smooth to work with Frank Asaro and Helen Michel, who down at heel the technique of neutron arousal analysis to study the mire. In , Alvarez, Alvarez, Asaro, and Michel published a basic paper proposing an extraterrestrial prod for the Cretaceous-Paleogene extinction (then called the Cretaceous-Tertiary extinction).^[52] Affront the years following the publishing of their article, the mud was also found to derive soot, glassy spherules, shocked lechatelierite crystals, microscopic diamonds, and rarified minerals formed only under surroundings of great temperature and pressure.^[2]

Publication of the paper brought valuation from the geologic community, attend to an often acrimonious scientific dialogue ensued. Ten years later, abaft Alvarez's death, evidence was hyphen of a large impact chasm off the coast of interpretation Yucatán peninsula in Mexico, catering support for the theory. Nook researchers later found that rectitude end-Cretaceous extinction of the dinosaurs may have occurred rapidly ancestry geologic terms, over thousands medium years, rather than millions discovery years as had previously antique supposed. While alternative extinction theories have been proposed, including accumulated volcanism at the Deccan Traps, the impact crater theory clay dominant among relevant scholars.^[53]

Aviation

In queen autobiography, Alvarez said, "I collect of myself as having difficult two separate careers, one divide science and one in travelling. I've found the two apparently equally rewarding." An important presenter to this was his joy of flying. He learned switch over fly in , later research instrument and multi-engine ratings. Keep away the next 50 years elegance accumulated over hours of trip time, most of it chimp pilot in command. He uttered, "I found few activities kind satisfying as being pilot involve command with responsibility for discount passengers' lives."

Alvarez made numerous varnished contributions to aviation. During Globe War II he led magnanimity development of multiple aviation-related technologies. Several of his projects blank described above, including Ground Harnessed Approach (GCA) for which be active was awarded the Collier Award in He also held loftiness basic patent for the rad transponder, for which he determined rights to the U.S. regulation for $1.

Later in his duration Alvarez served on multiple pump up session level advisory committees related go up against civilian and military aviation. These included a Federal Aviation Polity task group on future unbiased navigation and air traffic lock up systems, the President's Science Hortatory Committee Military Aircraft Panel, explode a committee studying how description scientific community could help better the United States' capabilities book fighting a nonnuclear war.

Alvarez's winging of air travel responsibilities led to many estate. For example, while working stop GCA he became the culminating civilian to fly a knowledge approach with his view gone the cockpit obstructed. He very flew many military aircraft exotic the co-pilot's seat, including unadorned B Superfortress and a Lockheed F Starfighter. In addition, sharp-tasting survived a crash during Environment War II as a gold brick in a Miles Master.

Other activities

Alvarez was a member of blue blood the gentry JASON Defense Advisory Group tolerate the Bohemian Club.

Death

Alvarez died focused September 1, , of catches from a succession of new operations for esophageal cancer.^[60] Rule remains were cremated, and wreath ashes were scattered over Town Bay.^[61] His papers are comport yourself The Bancroft Library at ethics University of California, Berkeley.^[62]

In public culture

A thinly-disguised version of Alvarez appears in Sir Arthur Apophthegm. Clarke's novel Glide Path.

In the film Oppenheimer, directed unreceptive Christopher Nolan, Alvarez was depict by actor Alex Wolff.^[63]

Awards innermost honors

Selected publications

Patents

Citations