60 Fun Facts About Enrico Fermi

Which Italian wine did Eugene Wigner open to toast the first chain reaction at Chicago Pile-1?

Chianti: Wigner produced the bottle once the pile had gone critical on 2 December 1942, and the scientists drank it from paper cups and then signed the bottle as a keepsake.

Fermi's family left Italy for good in December 1938 by travelling first to which city?

Stockholm, where he collected the Nobel Prize in Physics: the trip was the family's way out, and instead of returning from the ceremony they emigrated, so that Fermi did not see Italy again until 1949.

Which workers in Chicago are counted in the classic estimation puzzle credited to Fermi?

Piano tuners: the solver reasons from the city's population to its pianos and how many one tuner can service in a year, landing within a small factor of the truth, and such rough reckonings are still called Fermi problems.

Before the Trinity test, Fermi offered bets on whether the blast would destroy the whole planet or merely which state?

New Mexico: his gallows-humour wager began with whether the explosion would ignite the atmosphere, a danger the project's theorists had already calculated to be all but impossible.

Which close relative of Fermi died suddenly in 1915 during a minor throat operation?

His brother, a year older and his partner in building electric motors, died during the operation; the grieving boy turned to physics books and to a new friend, Enrico Persico, who also became a physicist.

The 1840 physics treatise by a Jesuit priest that the teenage Fermi taught himself from was written in which language?

Latin: Andrea Caraffa's two-volume treatise was one of the secondhand books Fermi bought, and by teaching himself from them he reached the level of an advanced graduate student before leaving high school.

Which brilliant young theorist from Fermi's Rome group vanished in March 1938?

Ettore Majorana is said to have withdrawn his savings shortly beforehand; what became of him is still disputed, and his family never believed that he had taken his own life.

Fermi attended the Scuola Normale Superiore in which Italian city?

Pisa: his entrance essay was so advanced that the examiner called him in to say he would become a famous scientist, and before long it was Fermi who was teaching his professors the new quantum physics.

Which British physicist independently reached Fermi's quantum statistics months later, so that they now carry both names?

Paul Dirac found the same rules a few months after Fermi's 1926 paper and tied them to the new quantum mechanics; they went on to explain how electrons carry current through metals.

Which fellow physics student at university became Fermi's close friend and later his chief assistant in Rome?

Franco Rasetti did not follow Fermi into weapons work: he refused on moral grounds to join the Manhattan Project, in which his old friend played a leading part.

Fermi's 1922 doctorate rested on experiments with which kind of radiation?

X-rays: he was already publishing theory, but Italy did not yet have a single chair of theoretical physics; the first were created a few years later, and Fermi won the one in Rome.

In 1923 Fermi wrote that releasing the vast energy implied by E = mc² was what?

Not possible soon, he wrote, and all to the good, since the blast would first blow to pieces the physicist unlucky enough to manage it; nineteen years later he built the first nuclear reactor himself.

After Göttingen, Fermi spent the autumn of 1924 studying under Paul Ehrenfest in which Dutch city?

Leiden: after an unhappy spell at Göttingen, where he felt the professors ignored him, Fermi found in Ehrenfest a warm friend who encouraged him, and he got to know Samuel Goudsmit there.

Fermions, the particles named after Fermi, are defined by obeying which rule?

Exclusion principle: Wolfgang Pauli's rule that no two such particles can share a quantum state was applied to a gas by Fermi in 1926, and the resulting statistics made the 24-year-old's international name.

With Chicago Pile-1 close to going critical on the big day, what did Fermi calmly call for?

A lunch break: an automatic safety rod had just slammed back into the pile because its trip level was set too low, so he sent everyone off to eat; work resumed at two and the reaction came that afternoon.

The 'Via Panisperna boys' took their nickname from the Rome street that housed which building?

The physics institute of Rome's university stood on that street, and it was there in 1934 that the group found that slowed neutrons trigger far more reactions, the discovery that later made nuclear reactors possible.

Which political party did Fermi join in 1929, nine years before he left Italy for good?

The Fascist Party gained him as a member in 1929, the year Mussolini named him to the new Royal Academy of Italy with its handsome stipend; he was no believer, the membership a professional necessity for a non-political man.

Which name did Fermi bring into physics for the uncharged particle Pauli had proposed to explain beta decay?

Neutrino is an Italian diminutive, in effect 'little neutral one', which set it apart from the far heavier neutron; Fermi's theory showed why it would be so hard to catch, and it was not detected until after his death.

The journal Nature rejected Fermi's beta-decay paper as containing speculations that were what?

'Too remote from physical reality' was the editor's verdict on what became the theory of the weak force, one of nature's four fundamental interactions; Fermi published it in Italian and German instead.

Which physicist, later head of theory at Los Alamos, co-wrote a 1932 paper with Fermi in Rome?

Hans Bethe came on a travelling fellowship in 1931 and again in 1932, one of a stream of young foreigners, Felix Bloch and Rudolf Peierls among them, whose arrival showed how far physics in Rome had risen under Fermi.

Whose discovery of artificial radioactivity in January 1934 prompted Fermi's neutron experiments?

The Joliot-Curies had used alpha particles, which a nucleus repels; Fermi reasoned that neutrons, having no charge, would get in far more easily, and within months his group had made dozens of elements radioactive.

The Rome neutron experiments mysteriously worked better on a table made of what?

Wood, unlike marble, slows the neutrons that pass through it, and slowed neutrons are captured far more readily; puzzling over the two tables led Fermi to try a block of paraffin wax, and the activity soared.

Passing neutrons through paraffin wax increased the radioactivity they induced by roughly how much?

A hundredfold: Fermi had the explanation within hours, and the methods his group built on the effect were the ones he later used to design the first nuclear reactor.

Fermi concluded that neutrons were slowed by collisions with atoms of which element?

Hydrogen: its nucleus is a single proton with almost exactly a neutron's mass, so one collision can rob a neutron of most of its speed, where it would simply bounce off a heavy nucleus such as lead.

Fermi's group named two supposed new elements ausenium and what, the latter after a poetic Greek name for Italy?

Hesperium came from Hesperia, 'the land of the west', as the Greeks called Italy; the real elements 93 and 94 were identified a few years later and named neptunium and plutonium.

During Chicago Pile-1's first run, physicist Norman Hilberry stood by with which tool to drop an emergency control rod?

An axe: the rod hung from a rope, and he was to chop through it if the automatic controls failed, while other men stood ready to drench the pile in a cadmium solution as a last resort.

At which American port did Fermi's family land in January 1939?

New York was where the family's liner docked on 2 January 1939; in complete secrecy, Fermi had lined up an American professorship before leaving Italy, so they came ashore as emigrants, not visitors.

Fermi left Italy in 1938 chiefly because new laws threatened his wife Laura, who was what?

Jewish: Laura Capon came from a respected Roman family, and though Fermi was not Jewish and their two children were Catholics, the laws also put several of his assistants out of work; the family left within months.

Before his years at Chicago, which university did Fermi join on arriving in America in 1939?

Columbia was one of five universities to offer him a post, and within weeks of his arrival a team there that included Fermi ran the first American experiment to split the uranium atom.

Who carried the news of uranium fission across the Atlantic in January 1939, two weeks after Fermi's arrival?

Niels Bohr landed from Copenhagen with the news; within days a team including Fermi had repeated the experiment at his new university, and he turned at once to the idea of a chain reaction.

Fermi's supposed transuranic elements, part of his Nobel citation, turned out to be what?

Fission products: the uranium had been splitting in two all along, as Hahn and Strassmann showed days after the Nobel ceremony; Fermi added a footnote to his prize lecture and later joked about the discovery he had missed.

Which material did Fermi's team choose to slow the neutrons in its first reactors, instead of water?

Graphite captures far fewer neutrons than ordinary water, and unlike heavy water it could be bought by the ton; Fermi's first reactor swallowed nearly 400 tons of it, machined into bricks.

Fermi's first bid for US government backing for atomic research, in March 1939, was a lecture at which department?

Navy officials responded with less than he had hoped, a small grant towards his university's experiments; serious backing came only after Einstein's letter reached President Roosevelt later that year.

Where on the University of Chicago campus was Chicago Pile-1 built?

A squash court beneath the stands of Stagg Field, the university's disused football ground: the building planned for the pile outside the city was running late, so Fermi persuaded Compton it was safe to build it in town.

Arthur Compton's coded call said 'the Italian navigator has just landed in the' what?

New world: no code had been agreed in advance, so Compton made one up on the phone to James Conant, who caught on at once and asked whether the natives had been friendly.

The Hanford B Reactor's mysterious shutdown in 1944 was traced to neutron poisoning by which isotope?

Xenon-135, a by-product of the reaction itself, soaked up neutrons until the pile died, as Fermi and John Wheeler worked out; spare fuel tubes that DuPont had added over the physicists' objections supplied the extra reactivity.

In 1943 Fermi privately proposed using radioactive byproducts of the bomb project to poison what?

The German food supply was the target, floated because he feared Hitler's scientists were ahead; the laboratory's director replied that it was worth pursuing only if it could kill half a million people.

Who led the Super theory branch of Fermi's Los Alamos division?

Edward Teller's group sat inside F Division, set up for Fermi when he moved to Los Alamos in 1944 to gather projects that fitted nowhere else, among them a small reactor nicknamed the water boiler.

How did Fermi estimate the yield of the Trinity test?

Dropping scraps of paper as the blast wave passed, he measured how far they were blown and at once announced about ten thousand tons of TNT, the right order of magnitude for the first atomic bomb.

Which company made the giant cube-shaped balloon that enclosed Chicago Pile-1, without being told what it was for?

Goodyear, better known for its airships, was never told the purpose: security rules forbade it, and the project's top priority rating got the odd order delivered with no questions asked.

After the 1949 Soviet nuclear test, Fermi and Isidor Rabi wrote a report opposing what?

The hydrogen bomb, they wrote, was 'necessarily an evil thing considered in any light'; President Truman ordered it built regardless, and Fermi then helped with the design calculations at Los Alamos.

At whose 1954 security hearing did Fermi testify for the defence?

Robert Oppenheimer had chaired the government advisory committee on which Fermi sat in the late 1940s; despite the support of Fermi and other eminent physicists, the board stripped him of his security clearance.

The 'Fermi paradox' concerns the apparent absence of what?

Extraterrestrial contact was on his mind at a midday table in Los Alamos in 1950, when he suddenly asked his colleagues where everybody was: if intelligent life is common, some of it should have reached us by now.

The element fermium was first identified in the debris of which 1952 nuclear test?

Ivy Mike, a vast explosion on a Pacific atoll, forged elements 99 and 100 in an instant; the find stayed a military secret until 1955, the year after Fermi's death, when the pair were named for Einstein and Fermi.

What nickname did Fermi's young colleagues in Rome give him?

The Pope, because in physics his word was held to be infallible; the joke reached upward too, for the group's patron, Senator Corbino, who conjured up its funds and posts, was known as God Almighty.

Fermi died in Chicago in 1954, aged 53, of what?

Stomach cancer came to light in an exploratory operation that autumn, too late to treat; he died at home weeks later, days after receiving the first of the government prizes that now bear his name.

With which Hungarian-born colleague did Fermi share the patent on the nuclear reactor, finally granted in 1955?

Leo Szilard had conceived the idea of a nuclear chain reaction in 1933, five years before fission was discovered; the two worked on the first reactors together and filed for the patent in 1944, while it was all still secret.

Fermi's first reactor was rebuilt in 1943 at a forest site near Chicago that grew into which national laboratory?

Argonne took its name from the forest where the pile had been meant to stand from the start; labour disputes had delayed the buildings, so the reactor was first run in the city and moved out a few months later.

Which future Nobel laureate, who later worked with Chen Ning Yang on parity, earned his PhD under Fermi at Chicago?

Tsung-Dao Lee arrived from China in 1946 after only two years of college, yet Fermi picked him out as his own doctoral student; eleven years later he shared the Nobel Prize in Physics.

A passing question from Fermi helped Maria Goeppert Mayer crack which model of the atomic nucleus, winning her a Nobel Prize?

Shell: the model fell into place when Fermi, on his way out of her office, asked whether there was any sign of spin-orbit coupling; within ten minutes she had the puzzle solved.

Fermi proposed that cosmic rays arise when material is accelerated by what?

Interstellar magnetic fields, he argued, behave like moving mirrors that knock charged particles to ever higher energies, a giant natural accelerator; the process is known as Fermi acceleration.

In a paper with Chen Ning Yang, Fermi speculated that pions might be what?

Composite particles, each a nucleon bound to an antinucleon, was the 1949 suggestion; the recipe was wrong, but the quark model later showed that pions are indeed built from smaller parts.

After Pearl Harbor, how did the United States officially class Fermi?

An enemy alien: as an Italian citizen he faced strict travel restrictions even while leading secret reactor work for the government; he and his wife became American citizens in July 1944.

Which book did Fermi's wife Laura publish in 1954?

Atoms in the Family, a memoir of their life together, appeared as he was dying; in it she describes his doctoral examiners stifling yawns or giving up trying to follow, his physics being beyond them.

The space telescope NASA named after Fermi in 2008 observes which kind of radiation?

Gamma rays, the most energetic form of light: the telescope was launched under the acronym GLAST, and NASA renamed it for Fermi later that summer, having asked the public to suggest a more memorable name.

Which tiny unit of length do physicists also call a 'fermi', in Enrico Fermi's honour?

The femtometre: a million-billionth of a metre, it is the natural yardstick for the atomic nucleus, which is why the nickname honours a founder of nuclear physics.

In 1953 Fermi helped run one of the first experiments in physics to take place entirely inside what?

A digital computer: the vibrating-string simulation on Los Alamos's MANIAC behaved in a way nobody expected, and Mary Tsingou, who programmed it, went uncredited in its name for fifty years.

Which Florentine basilica, the 'Temple of Italian Glories', carries a plaque commemorating Fermi?

Santa Croce holds the tombs of Michelangelo, Machiavelli and Galileo, who lay in a small side room for 95 years before he was moved to a monument in the main church in 1737.

Unlike almost every reactor since, Fermi's Chicago Pile-1 ran with no cooling system and no what?

Radiation shielding: at about half a watt the pile was too feeble to need either, and Fermi's sums had persuaded Arthur Compton that it could safely run in the middle of a city.

The X-10 pile, modelled on Fermi's Chicago reactor, went critical at which Manhattan Project site?

Oak Ridge: the air-cooled X-10 was a pilot plant, and what its crews learned making the first batches of plutonium there went into the far larger reactors at Hanford.