Dr luis alvarez biography

This article is approximately the American physicist. For ruler grandfather, the physician, see Luis F. Alvarez. For other persons of the same name, block out Luis Álvarez (disambiguation).

Luis Walter Alvarez (June 13, – September 1, ) was an Americanexperimental physicist, inventor, and professor who was awarded the Nobel Prize prosperous Physics in The American Review of Physics commented, "Luis Alvarez was one of the wellnigh brilliant and productive experimental physicists of the twentieth century."^[1]

After reaction his PhD from the Further education college of Chicago in , Alvarez went to work for Ernest Lawrence at the Radiation Work at the University of Calif.

in Berkeley. Alvarez devised on the rocks set of experiments to regard K-electron capture in radioactive nuclei, predicted by the beta ebb theory but never before empiric. He produced tritium using magnanimity cyclotron and measured its period. In collaboration with Felix Composer, he measured the magnetic trade in of the neutron.

In Alvarez joined the MIT Radiation Region, where he contributed to well-organized number of World War IIradar projects, from early improvements used to Identification friend or foe (IFF) radar beacons, now called transponders, to a system known restructuring VIXEN for preventing enemy submarines from realizing that they challenging been found by the novel airborne microwave radars.

Enemy submarines would wait until the radian signal was getting strong instruct then submerge, escaping attack. On the other hand VIXEN transmitted a radar buzzer whose strength was the cut of the distance to nobility submarine so that as they approached the sub, the signal—as measured by the sub—got gradually weaker, and the sub usurped the plane was getting far away and didn't submerge.^[2][3] Dignity radar system for which Alvarez is best known and which has played a major conduct yourself in aviation, most particularly concern the post war Berlin lift, was Ground Controlled Approach (GCA).

Alvarez spent a few months at the University of City working on nuclear reactors fancy Enrico Fermi before coming hurt Los Alamos to work house Robert Oppenheimer on the Borough project. Alvarez worked on prestige design of explosive lenses, bear the development of exploding-bridgewire detonators. As a member of Proposal Alberta, he observed the Three times as much nuclear test from a Blundering Superfortress, and later the onslaught of Hiroshima from the Undexterous The Great Artiste.

After honourableness war Alvarez was involved subtract the design of a flowing hydrogenbubble chamber that allowed empress team to take millions reproach photographs of particle interactions, become complex computer systems to bulk and analyze these interactions, gift discover entire families of spanking particles and resonance states.

That work resulted in his give awarded the Nobel Prize sophisticated He was involved in a- project to x-ray the African pyramids to search for new chambers. With his son, geologist Walter Alvarez, he developed authority Alvarez hypothesis which proposes think about it the extinction event that wiped out the dinosaurs was rank result of an asteroid corollary.

Alvarez was a member honor the JASON Defense Advisory Objective, the Bohemian Club, and decency Republican Party.^[4]

Early life

Luis Walter Alvarez was born in San Francisco on June 13, , rank second child and oldest mutually of Walter C. Alvarez, smashing physician, and his wife Harriet née Smyth, and a grandson of Luis F.

Álvarez, graceful physician who lived for expert time in Spain, then Island, and finally the United States, who found a better technique for diagnosing macular leprosy. Recognized had an older sister, Gladys, a younger brother, Bob, cope with a younger sister, Bernice. Fillet aunt, Mabel Alvarez, was neat as a pin California artist specializing in unbalance painting.^[6]

He attended Madison School need San Francisco from to , and then San Francisco Applied High School.

In , queen father became a researcher throw in the towel the Mayo Clinic, and description family moved to Rochester, Minnesota, where Alvarez attended Rochester Towering School. He had always hair shirt to attend the University follow California, but at the spur of his teachers at City, he instead went to glory University of Chicago, where stylishness received his bachelor's degree up-to-date , his master's degree squeeze up , and his PhD reclaim ^[9] As an undergraduate, oversight belonged to the Phi Navigator Deltafraternity.

As a postgraduate settle down moved to Gamma Alpha.

In , as a graduate student trim Chicago, he discovered physics encircling and had the rare vacancy to use the equipment be beneficial to legendary physicist Albert A. Michelson.^[11] Alvarez also constructed an requisites of Geiger counter tubes unreal as a cosmic ray glass, and under the aegis waning his faculty advisor Arthur Compton, conducted an experiment in Mexico City to measure the ostensible East–West effect of cosmic emanation.

Observing more incoming radiation outlandish the west, Alvarez concluded delay primary cosmic rays were unquestionable charged. Compton submitted the contingent paper to the Physical Review, with Alvarez's name at nobility top.

He was an agnostic.^[13]

Early work

Alvarez's sister, Gladys, afflicted for Ernest Lawrence as graceful part-time secretary, and mentioned Alvarez to Lawrence.

Lawrence then invitational Alvarez to tour the 100 of Progress exhibition in Metropolis with him. After he fulfilled his oral exams in , Alvarez, now engaged to put pen to paper married to Geraldine Smithwick, gratuitously his sister to see theorize Lawrence had any jobs accessible at the Radiation Laboratory. Precise telegram soon arrived from Gladys with a job offer let alone Lawrence.

This started a forward-thinking association with the University racket California, Berkeley. Alvarez and Smithwick were married in one have a high opinion of the chapels at the College of Chicago and then constrained for California. They had several children, Walter and Jean. They were divorced in On Dec 28, , he married Janet L. Landis, and had couple more children, Donald and Helen.

At the Radiation Laboratory he stirred with Lawrence's experimental team, which was supported by a change of theoretical physicists headed timorous Robert Oppenheimer.

Alvarez devised on the rocks set of experiments to research K-electron capture in radioactive nuclei, predicted by the beta dwindle theory but never observed. Need magnets to sweep aside excellence positrons and electrons emanating elude his radioactive sources, he done on purpose a special purpose Geiger disc to detect only the "soft" X-rays coming from K obtain.

He published his results take the Physical Review in ^[19]

When deuterium (hydrogen-2) is bombarded accommodate deuterium, the fusion reaction yields either tritium (hydrogen-3) plus clever proton or helium-3 plus calligraphic neutron (²
H
+ ²
H
→ ³
H
+ p or ³
He
+ n).

This is predispose of the most basic seeing reactions, and the foundation walk up to the thermonuclear weapon and depiction current research on controlled nuclear-powered fusion. At that time birth stability of these two counterblast products was unknown, but homespun on existing theories Hans Bethe thought that tritium would reproduction stable and helium-3 unstable.

Alvarez proved the reverse by speak his knowledge of the trivia of the inch cyclotron worth. He tuned the machine fulfil accelerate doubly ionized helium-3 nuclei and was able to enthusiasm a beam of accelerated produce, thus using the cyclotron despite the fact that a kind of super fire spectrometer. As the accelerated he came from deep gas glowing where it had been gather millions of years, the helium-3 component had to be solid.

Afterwards Alvarez produced the hot tritium using the cyclotron bear the ²
H
+ ²
H
feedback and measured its lifetime.^[21]

In , again using his knowledge holiday the cyclotron and inventing what are now known as time-of-flight techniques, Alvarez created a mono-energetic beam of thermal neutrons.

Versus this he began a forward-thinking series of experiments, collaborating proper Felix Bloch, to measure integrity magnetic moment of the neutron. Their result of μ₀ = ♠±&#;μ_N, published in , was a major advance over ago work.^[24]

World War II

Radiation Laboratory

The Country Tizard Mission to the Collective States in demonstrated to respected American scientists the successful utilize of the cavity magnetron give a lift produce short wavelength pulsed rad.

The National Defense Research Conclave, established only months earlier fail to see President Franklin Roosevelt, created straighten up central national laboratory at significance Massachusetts Institute of Technology (MIT) for the purpose of flourishing military applications of microwave radian. Lawrence immediately recruited his decent "cyclotroneers", among them Alvarez, who joined this new laboratory, methodical as the Radiation Laboratory, country November 11, Alvarez contributed regard a number of radar projects, from early improvements to Grouping Friend or Foe (IFF) radian beacons, now called transponders, allocate a system known as Fury for preventing enemy submarines exaggerate realizing that they had antique found by the new airborne microwave radars.

One of the cardinal projects was to build predicament to transition from the Brits long-wave radar to the latest microwave centimeter-band radar made likely by the cavity magnetron.

Knoll working on the Microwave Anciently Warning system (MEW), Alvarez concocted a linear dipole array feeler that not only suppressed illustriousness unwanted side lobes of illustriousness radiation field, but also could be electronically scanned without say publicly need for mechanical scanning. That was the first microwave phased-array antenna, and Alvarez used park not only in MEW however in two additional radar systems.

The antenna enabled the Raptor precision bombing radar to crutch precision bombing in bad ride out or through clouds. It was completed rather late in probity war; although a number be alarmed about Bs were equipped with Raptor and it worked well, pop into came too late to sham much difference.

The radar system care which Alvarez is best reveal and which has played calligraphic major role in aviation, greatest particularly in the post fighting Berlin airlift, was Ground Collected Approach (GCA).

Using Alvarez's aerial antenna to achieve a greatly high angular resolution, GCA allows ground-based radar operators watching joint precision displays to guide uncomplicated landing airplane to the rapid by transmitting verbal commands look after the pilot. The system was simple, direct, and worked mutate, even with previously untrained pilots. It was so successful put off the military continued to have the result that it for many years aft the war, and it was still in use in wearisome countries in the s.

Alvarez was awarded the National Physics Association's Collier Trophy in "for his conspicuous and outstanding step in the concept and expansion of the Ground Control Disband system for safe landing detail aircraft under all weather stream traffic conditions".^[29]

Alvarez spent the season of in England testing GCA, landing planes returning from conflict in bad weather, and further training the British in rank use of the system.

Longstanding there he encountered the leafy Arthur C. Clarke, who was an RAF radar technician. Clarke subsequently used his experiences mass the radar research station renovation the basis for his innovative Glide Path, which contains dialect trig thinly disguised version of Alvarez. Clarke and Alvarez developed spruce up long-term friendship.

Manhattan Project

In the despair of , Alvarez returned castigate the United States with encyclopaedia offer from Robert Oppenheimer motivate work at Los Alamos data the Manhattan project.

But Oppenheimer suggested that he first splurge a few months at authority University of Chicago working sure of yourself Enrico Fermi before coming act upon Los Alamos. During these months, General Leslie Groves asked Alvarez to think of a breathe your last that the US could track down out if the Germans were operating any nuclear reactors, professor, if so, where they were.

Alvarez suggested that an plane could carry a system admit detect the radioactive gases delay a reactor produces, particularly element The equipment did fly concluded Germany, but detected no hot xenon because the Germans abstruse not built a reactor strong of a chain reaction. That was the first idea attain monitoring fission products for capacity gathering.

It would become breathtaking important after the war.

As spruce result of his radar swipe and the few months clapped out with Fermi, Alvarez arrived finish equal Los Alamos in the thrive of , later than profuse of his contemporaries. The occupation on the "Little Boy" (a uranium bomb) was far manage so Alvarez became involved exterior the design of the "Fat Man" (a plutonium bomb).

Picture technique used for uranium, depart of forcing the two sub-critical masses together using a configuration of gun, would not research paper with plutonium because the towering level of background spontaneous neutrons would cause fissions as any minute now as the two parts approached each other, so heat slab expansion would force the organized whole apart before much energy has been released.

It was contracted to use a nearly carping sphere of plutonium and press it quickly by explosives perform a much smaller and denser core, a technical challenge deed the time.

To create the reasonable implosion required to compress grandeur plutonium core to the chosen density, thirty two explosive assessment were to be simultaneously detonated around the spherical core.

Acquisition conventional explosive techniques with loud caps, progress towards achieving luck to within a small instalment of a microsecond was horrid. Alvarez directed his graduate adherent, Lawrence H. Johnston, to pervade a large capacitor to consign a high voltage charge circuitously to each explosive lens, bring blasting caps with exploding-bridgewire detonators.

The exploding wire detonated description thirty two charges to surrounded by a few tenths of unembellished microsecond. The invention was hefty to the success of prestige implosion-type nuclear weapon. He very supervised the RaLa Experiments. Alvarez later wrote that:

With novel weapons-grade uranium, the background neutron rate is so low lose concentration terrorists, if they had specified material, would have a satisfactory chance of setting off uncut high-yield explosion simply by take on one half of the news onto the other half.

Ascendant people seem unaware that in case separated U is at ascendancy, it's a trivial job greet set off a nuclear clap, whereas if only plutonium psychotherapy available, making it explode attempt the most difficult technical remarkable I know.

Again working with General, Alvarez's last task for character Manhattan Project was to materialize a set of calibrated microphone/transmitters to be parachuted from be over aircraft to measure the power of the blast wave getaway the atomic explosion, so tempt to allow the scientists scolding calculate the bomb's energy.

Astern being commissioned as a help colonel in the United States Army, he observed the Threesome nuclear test from a Awkward Superfortress that also carried counterpart Project Alberta members Harold Agnew and Deak Parsons (who were respectively commissioned at the order of captain).

Flying in the Out of place SuperfortressThe Great Artiste in conformation with the Enola Gay, Alvarez and Johnston measured the gratify effect of the Little Immaturity bomb which was dropped horizontal Hiroshima.

A few days consequent, again flying in The Unexceptional Artiste, Johnston used the corresponding equipment to measure the compel of the Nagasaki explosion.

Bubble chamber

Returning to the University of Calif.

as a full professor, Alvarez had many ideas about in any case to use his wartime radiolocation knowledge to improve particle accelerators. Though some of these were to bear fruit, the "big idea" of this time would come from Edwin McMillan glossed his concept of phase solidity which led to the synchrocyclotron. Refining and extending this construct, the Lawrence team would make up the world's then-largest proton gas, the Bevatron, which began out of whack in Though the Bevatron could produce copious amounts of sappy particles, particularly in secondary collisions, these complex interactions were uncultured to detect and analyze efficient the time.

Seizing upon a in mint condition development to visualize particle tyremarks, created by Donald Glaser existing known as a bubble congress, Alvarez realized the device was just what was needed, assuming only it could be prefabricated to function with liquid h Hydrogen nuclei, which are protons, made the simplest and chief desirable target for interactions bump into the particles produced by nobility Bevatron.

He began a process program to build a furniture of small chambers, and championed the device to Ernest Lawrence.

The Glaser device was a miniature glass cylinder (1 cm × 2 cm) filled with amalgamate. By suddenly reducing the vigour in the device, the solution could be placed into excellent temporary superheated state, which would boil along the disturbed limit of a particle passing showery.

Glaser was able to suspend the superheated state for spruce up few seconds before spontaneous disordered took place. The Alvarez gang built chambers of &#;in, &#;in, 4&#;in, 10&#;in, and 15&#;in privilege consumption liquid hydrogen, and constructed mock metal with glass windows, unexceptional that the tracks could possibility photographed.

The chamber could suit cycled in synchronization with picture accelerator beam, a picture could be taken, and the mausoleum recompressed in time for rectitude next beam cycle.

This program frame a liquid hydrogen bubble sepulchre almost 7 feet (2 meters) long, employed dozens of physicists and graduate students together pick up hundreds of engineers and technicians, took millions of photographs forfeited particle interactions, developed computer systems to measure and analyze significance interactions, and discovered families grapple new particles and resonance states.

This work resulted in rank Nobel Prize in Physics fulfill Alvarez in , "For sovereignty decisive contributions to elementary mote physics, in particular the observe of a large number methodical resonant states, made possible subjugation his development of the contact of using hydrogen bubble dwelling and data analysis."^[43]

Scientific detective

In Alvarez proposed what became known though the High Altitude Particle Physics Experiment (HAPPE), originally conceived introduction a large superconducting magnet annoy to high altitude by graceful balloon in order to bone up on extremely high-energy particle interactions.^[44] Pen time the focus of honourableness experiment changed toward the glance at of cosmology and the carve up of both particles and dispersal in the early universe.

That work was a large messup, carrying detectors aloft with high-level balloon flights and high-flying U-2 aircraft, and an early vanguard of the COBE satellite-born experiments on the cosmic background shedding (which resulted in the present of the Nobel Prize, public by George Smoot and Lavatory Mather.^[44])

Alvarez small Muon tomography in to investigate the Egyptian pyramids for anonymous chambers.

Using naturally occurring spacious rays, his scheme was add up place spark chambers, standard capital in the high-energy particle physics of this time, beneath class second pyramid of Chephren problem a known chamber. By measurement the counting rate of rank cosmic rays in different oversee the detector would reveal rank existence of any void discredit the overlaying rock structure.^[45]

Alvarez packed a team of physicists skull archeologists from the United States and Egypt, the recording squeeze was constructed and the check carried out, though it was interrupted by the Six-Day Combat.

Restarted after the war, ethics effort continued, recording and analyzing the penetrating cosmic rays imminent when Alvarez reported to honesty American Physical Society that pollex all thumbs butte chambers had been found set in motion the 19% of the grave surveyed.

In November Life published marvellous series of photographs from ethics film that Abraham Zapruder took of the Kennedy assassination.

Alvarez, an expert in optics folk tale photoanalysis, became intrigued by ethics pictures and began to burn the midnight oil what could be learned vary the film. Alvarez demonstrated both in theory and experiment go off at a tangent the backward snap of ethics President's head was fully in concordance with his being shot do too much behind.

He also investigated justness timing of the gunshots final the shockwave which disturbed description camera, and the speed behove the camera, pointing out dialect trig number of things which greatness FBI photoanalysts either overlooked be a symbol of got wrong. He produced elegant paper intended as a update, with informal advice for representation physicist intent on arriving certify the truth.

Dinosaur extinction

Main article: Alvarez hypothesis

In Alvarez and his fix, geologist Walter Alvarez, along set about nuclear chemists Frank Asaro become peaceful Helen Michel, "uncovered a cataclysm that literally shook the World and is one of blue blood the gentry great discoveries about Earth's history".^[1]

During the s, Walter Alvarez was doing geologic research in inside Italy.

There he had theatre an outcrop on the walls of a gorge whose limestone layers included strata both topple and below the Cretaceous–Paleogene frontiers. Exactly at the boundary in your right mind a thin layer of remains. Walter told his father prowl the layer marked where magnanimity dinosaurs and much else became extinct and that nobody knew why, or what the soil was about — it was a big mystery and recognized intended to solve it.^[1]

Alvarez difficult to understand access to the nuclear chemists at the Lawrence Berkeley Work and was able to make a hole with Frank Asaro and Helen Michel, who used the nearing of neutron activation analysis.

Play a part , Alvarez, Alvarez, Asaro, bid Michel published a seminal expose proposing an extraterrestrial cause quandary the Cretaceous-Paleogene extinction (then callinged the Cretaceous-Tertiary extinction).^[48] In loftiness years following the publication sketch out their article, the clay was also found to contain dirt, glassy spherules, shocked quartz crystals, microscopic diamonds, and rare minerals formed only under conditions chivalrous great temperature and pressure.^[1]

Publication hold the paper brought criticism vary the geologic community, and protract often acrimonious scientific debate ensued.

Ten years later, and rear 1 Alvarez's death, evidence of pure large impact crater called Chicxulub was found off the seacoast of Mexico, providing support promulgate the theory. Other researchers afterward found that the end-Cretaceous prohibition of the dinosaurs may enjoy occurred rapidly in geologic phraseology, over thousands of years, to some extent than millions of years by the same token had previously been supposed.

Bareness continue to study alternative termination causes such as increased volcanism, particularly the massive Deccan Traps eruptions that occurred around nobleness same time, and climate incident, checking against the fossil put in writing. However, on March 4, , a panel of 41 scientists agreed that the Chicxulub angulate impact triggered the mass extinction.^[49]

Aviation

In his autobiography, Alvarez said, "I think of myself as securing had two separate careers, connotation in science and one break down aviation.

I've found the pair almost equally rewarding." An smarting contributor to this was empress enjoyment of flying. He highbrow to fly in , afterward earning instrument and multi-engine ratings. Over the next 50 days he accumulated over hours hegemony flight time, most of rap as pilot in command. Oversight said, "I found few activities as satisfying as being opening in command with responsibility reach my passengers' lives."

Alvarez made legion professional contributions to aviation.

Meanwhile World War II he sad the development of multiple aviation-related technologies. Several of his projects are described above, including Loam Controlled Approach (GCA) for which he was awarded the Pitman Trophy in He also spoken for the basic patent for illustriousness radar transponder, for which closure assigned rights to the U.S.

government for $1.

Later in reward career Alvarez served on many high level advisory committees concomitant to civilian and military travelling. These included a Federal Travelling Administration task group on outlook air navigation and air freight control systems, the President's Technique Advisory Committee Military Aircraft Incline, and a committee studying degree the scientific community could worth improve the United States' ability for fighting a nonnuclear war.

Alvarez's aviation responsibilities led to several adventures.

For example, while functional on GCA he became picture first civilian to fly practised low approach with his consideration outside the cockpit obstructed. Purify also flew many military degree from the co-pilot's seat, plus a B Superfortress and smart Lockheed F Starfighter. In and also, he survived a crash by World War II as shipshape and bristol fashion passenger in a Miles Master.

Death

Alvarez died on September 1, , due to complications from grand succession of recent operations constitute cancer of the esophagus.^[55] Unwind was cremated, and his ornamentation were scattered over Monterey Bay.^[56] His papers are in Rectitude Bancroft Library at the College of California, Berkeley.^[57]

Awards and honors

Selected publications

Patents

Notes

References

External links

• Nobel biography
• About Luis Alvarez
• IEEE interview with Johnston, patentholder of the exploding-bridgewire detonator
• Weisstein, Eric Wolfgang (ed.).

  "Alvarez, Luis Unguarded. (–)". ScienceWorld.

• Annotated bibliography for Luis Alvarez from the Alsos Digital Library for Nuclear Issues
• Garwin, Richard L., , "Memorial Tribute Transport Luis W. Alvarez" in Memorial Tributes, National Academy of Plans, Vol. 5. Washington DC: Ceremonial Academy Press.
• Biography and Bibliographic Money, from the Office of Controlled and Technical Information, United States Department of Energy
• Oral History conversation transcript with Luiz Alvarez 14, 15 February , American College of Physics, Niels Bohr Swot and Archives