Science

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Events

Science Timeline

1916

Einstein Submits General Theory of Relativity Paper

Albert Einstein had developed special relativity a decade earlier but struggled to extend it to gravity and accelerated frames. Building on mathematical work by colleagues including Marcel Grossmann and David Hilbert, he formulated a geometric theory of gravity using curved spacetime. On March 20, 1916, Einstein submitted the foundational paper "The Foundation of the General Theory of Relativity" to the journal Annalen der Physik. The work presented the Einstein field equations describing how matter and energy curve spacetime, predicting phenomena like gravitational lensing and the bending of starlight during solar eclipses. It marked the culmination of years of intense effort amid World War I disruptions in Europe.

Event Detail Daily Earth View

1922

Science 20th Century North America

First Successful Insulin Treatment for Diabetes

In the early 1920s, Type 1 diabetes remained a fatal condition with only strict starvation diets offering limited extension of life. Researchers Frederick Banting, Charles Best, and James Collip at the University of Toronto had isolated insulin from pancreatic extracts after years of experimentation. On January 11, 1922, 14-year-old Leonard Thompson, critically ill and weighing about 65 pounds, received the first human injection of insulin at Toronto General Hospital. The initial dose caused an allergic reaction due to impurities, but a refined preparation administered on January 23 dramatically stabilized his blood sugar. Thompson's survival and recovery demonstrated insulin's potential, leading the university to license production royalty-free to pharmaceutical companies.

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1930

Science 20th Century North America

Clyde Tombaugh Discovers Pluto at Lowell Observatory

Astronomers in the early 20th century suspected an undiscovered planet beyond Neptune based on irregularities in the orbits of Uranus and Neptune, leading Percival Lowell to initiate a search for “Planet X” at his observatory in Flagstaff, Arizona. After Lowell’s death, the search continued with improved photographic techniques. On February 18, 1930, 24-year-old Clyde Tombaugh, working as an assistant, identified a moving object on photographic plates taken weeks earlier by comparing images with a blink comparator. Confirmation followed through additional observations, and the discovery was publicly announced in March. The tiny body, later named Pluto, expanded knowledge of the solar system’s outer reaches. Tombaugh’s methodical approach succeeded where prior efforts had failed.

Event Detail Daily Earth View

1938

Science 20th Century Sub-Saharan Africa

Living Coelacanth Found Off South Africa

By the 1930s, paleontologists considered the coelacanth extinct for roughly 70 million years based on fossil records from the Devonian period onward. On December 22, 1938, a trawler captain near the Chalumna River mouth in South Africa hauled up an unusual five-foot fish with distinctive lobed fins, blue scales, and other features unlike modern fish. Museum curator Marjorie Courtenay-Latimer received the specimen at the East London Museum and recognized its significance, preserving it despite holiday timing. She contacted ichthyologist J.L.B. Smith, who confirmed it as a living coelacanth, later named Latimeria chalumnae. The discovery stunned the scientific community and prompted further searches that revealed populations in the Indian Ocean.

Event Detail

1942

Science 20th Century Europe

James Stanley Hey Discovers Solar Radio Waves

During World War II, British physicist James Stanley Hey was investigating unexplained radar interference affecting anti-aircraft defenses along the south coast of England. On February 27, 1942, reports from multiple radar stations showed intense jamming that correlated precisely with sunrise and sunset rather than enemy activity. Hey consulted astronomers at the Royal Observatory, who confirmed a large sunspot group crossing the solar disk at the time. His analysis demonstrated that the sun was emitting radio waves, a finding kept secret until after the war but marking the accidental birth of solar radio astronomy.

Event Detail Daily Earth View

1942

Science 20th Century North America

Fermi Achieves First Self-Sustaining Nuclear Chain Reaction

Amid World War II and fears that Nazi Germany might develop atomic weapons first, the U.S. Manhattan Project pursued controlled nuclear fission. Italian physicist Enrico Fermi led a team constructing Chicago Pile-1, a crude graphite-moderated reactor beneath the stands at the University of Chicago's Stagg Field. On December 2, 1942, the pile achieved the world's first controlled, self-sustaining nuclear chain reaction. Fermi's team carefully monitored neutron levels as cadmium control rods were withdrawn. A coded message relayed success to project leaders, marking the dawn of the atomic age.

Event Detail Guided Physics

1945

Science 20th Century North America

First Atomic Bomb Tested at Trinity Site

In the final months of World War II, the United States raced to develop nuclear weapons through the Manhattan Project amid fears that Nazi Germany might achieve the same capability first. Scientists led by J. Robert Oppenheimer constructed and tested a plutonium implosion device in the remote Jornada del Muerto desert of New Mexico. At 5:29 a.m. on July 16, 1945, the device detonated with a yield of about 21 kilotons, producing a mushroom cloud and glassifying the desert sand into trinitite. The successful test confirmed the feasibility of atomic weapons and ushered in the nuclear age. The blast was visible for hundreds of miles and registered on seismographs across the region.

Event Detail Guided Physics

1952

Science 20th Century Oceania

Britain Conducts First Atomic Bomb Test

After World War II, Britain sought to maintain great-power status by developing independent nuclear capabilities amid Cold War tensions. Scientists under William Penney designed a plutonium implosion device, with the test conducted in cooperation with Australia. The device was detonated aboard the frigate HMS Plym in Main Bay of the Montebello Islands off Western Australia on October 3, 1952. The explosion yielded approximately 25 kilotons and created a distinctive mud-laden cloud. The successful test made Britain the third nuclear power after the United States and Soviet Union. Data from the operation informed subsequent British weapons programs.

Event Detail Guided Physics

1952

Science 20th Century Oceania

U.S. Tests First Thermonuclear Bomb

Following the Soviet Union's first atomic test in 1949, the United States accelerated its hydrogen bomb program under physicist Edward Teller. The device, code-named Ivy Mike, used a fission primary to trigger fusion in liquid deuterium fuel housed in a massive cryogenic apparatus. On October 31, 1952 (local time considerations aligned with the test date in some records), the bomb was detonated on Elugelab Island in Enewetak Atoll in the Marshall Islands. The explosion yielded 10.4 megatons, vaporizing the island and creating a massive crater, far exceeding atomic bomb power.

Event Detail Guided Physics

1953

Science 20th Century Europe

Watson and Crick Model DNA Double Helix

In postwar Britain, molecular biology was advancing rapidly with X-ray diffraction data from Rosalind Franklin and Maurice Wilkins at King's College London, alongside Chargaff's base-pairing rules. At the Cavendish Laboratory in Cambridge, young researchers James Watson and Francis Crick competed to solve DNA's structure using model-building and available evidence. On February 28, 1953, Watson correctly oriented the nucleotide bases in their cardboard models following advice on tautomeric forms, revealing the complementary double-helix configuration with sugar-phosphate backbones and specific base pairing. Crick immediately recognized its implications for genetic replication. They announced the breakthrough informally at a pub that evening and published the landmark one-page paper in Nature two months later. The discovery provided the molecular basis for heredity and launched modern...

Event Detail Peopling Earth

1953

Science 20th Century North America

Jonas Salk Announces Polio Vaccine Success

Poliomyelitis epidemics ravaged the United States and much of the world in the first half of the 20th century, paralyzing thousands of children annually and instilling widespread fear. Medical researcher Jonas Salk, working at the University of Pittsburgh, developed an inactivated polio vaccine after years of laboratory work building on earlier efforts by others. On March 26, 1953, Salk publicly announced that his vaccine had proven safe and effective in initial trials involving children. The announcement came amid ongoing outbreaks and intense public demand for protection. Field trials soon expanded dramatically, leading to mass vaccinations that dramatically reduced polio cases within years.

Event Detail America 250 Atlas

1954

Science 20th Century North America

First Mass Polio Vaccine Inoculations Begin

Polio epidemics ravaged the United States in the early 1950s, paralyzing or killing thousands of children annually and sparking widespread fear. Virologist Jonas Salk developed an inactivated virus vaccine after years of research. On February 23, children at Arsenal Elementary School in Pittsburgh, Pennsylvania, received the first trial injections in a large-scale field test. The program expanded rapidly to over a million participants across the U.S., Canada, and Finland. Results announced in 1955 confirmed its effectiveness, leading to widespread licensing and distribution.

Event Detail America 250 Atlas

1955

Science 20th Century North America

Salk Polio Vaccine Declared Safe and Effective

Polio epidemics had terrorized American children for decades, leaving thousands paralyzed each summer. Jonas Salk's inactivated-virus vaccine underwent the largest medical field trial in history, involving nearly two million children. On April 12, 1955, University of Michigan epidemiologist Thomas Francis Jr. announced the results at a press conference in Ann Arbor: the vaccine was 80–90 percent effective against paralytic polio with no serious side effects. Licensing followed immediately, and mass production began. Within years, polio cases plummeted across the United States and much of the world.

Event Detail America 250 Atlas

1957

Science 20th Century Russia & Central Asia

Sputnik 2 Carries Laika into Earth Orbit

Following the successful launch of Sputnik 1 in October 1957, Soviet leader Nikita Khrushchev sought another propaganda triumph to coincide with the 40th anniversary of the October Revolution. Engineers rapidly adapted the Sputnik design into a larger capsule capable of sustaining a living passenger. On November 3, 1957, the Soviet Union launched Sputnik 2 from the Baikonur Cosmodrome carrying Laika, a stray dog from Moscow streets. The 508-kilogram satellite entered orbit successfully, marking the first time a living creature orbited Earth. Telemetry confirmed Laika survived the launch stresses but died hours later from overheating caused by inadequate thermal control. The mission demonstrated that biological organisms could endure spaceflight conditions despite the tragic outcome for the animal.

Event Detail Daily Earth View

1960

Science 20th Century North America

FDA Approves First Oral Contraceptive Pill

In the 1950s, researchers including Gregory Pincus developed synthetic hormones to suppress ovulation as a reliable contraceptive method, building on earlier work by Margaret Sanger and others. Clinical trials in Puerto Rico demonstrated effectiveness, though with debates over safety and ethics. On May 9, 1960, the U.S. Food and Drug Administration approved Enovid-10 by G.D. Searle as the first oral contraceptive pill for general use. The approval came after the drug had been cleared earlier for menstrual regulation, allowing its contraceptive application. This marked the first widespread pharmaceutical option for birth control in the United States.

Event Detail America 250 Atlas

1960

Science 20th Century Sub-Saharan Africa

Jane Goodall Begins Landmark Chimpanzee Study

In the mid-20th century, primatology relied heavily on captive animals and brief observations, with little understanding of wild chimpanzee behavior. Twenty-six-year-old Jane Goodall, encouraged by anthropologist Louis Leakey, traveled to East Africa despite lacking formal scientific credentials. On July 14, 1960, she arrived by boat at the Gombe Stream Game Reserve on Lake Tanganyika's shore in what is now Tanzania, accompanied by her mother and a cook. Setting up a simple camp, she began patient daily observations of the chimpanzee community. Within months she documented tool use and other behaviors previously thought unique to humans.

Event Detail

1960

Science 20th Century Russia & Central Asia

Sputnik 5 Returns Animals from Orbit Alive

During the intense Space Race of the Cold War, the Soviet Union pursued rapid advances in human spaceflight capabilities. On August 19, 1960, the USSR launched Korabl-Sputnik 2, known in the West as Sputnik 5, carrying two dogs named Belka and Strelka, along with mice, rats, and other biological specimens. The spacecraft completed 18 orbits before successfully reentering Earth's atmosphere and landing safely the following day. This marked the first time living creatures returned from orbital flight unharmed, providing critical data on the effects of space travel on biology. The mission directly informed preparations for the first human orbital flight less than a year later.

Event Detail Daily Earth View

1961

Science 20th Century North America

Ham the Chimpanzee Completes Suborbital Space Flight

In the early years of the U.S. space program, NASA used chimpanzees to test the Mercury spacecraft systems before risking human lives. Ham, a three-year-old chimpanzee, underwent extensive training for the Mercury-Redstone 2 mission. On January 31, 1961, Ham launched aboard a Redstone rocket from Cape Canaveral and experienced 16 minutes of suborbital flight, reaching an altitude of 157 miles. He performed simple tasks during weightlessness and survived the stresses of launch, reentry, and splashdown in the Atlantic Ocean. Ham's successful flight proved that primates could endure space travel conditions. The mission cleared the way for Alan Shepard's historic human suborbital flight three months later.

Event Detail Daily Earth View

1961

Science 20th Century North America

Kennedy Commits U.S. to Moon Landing Goal

The Soviet Union's early lead in the Space Race, highlighted by Sputnik and Yuri Gagarin's flight, alarmed U.S. leaders during the Cold War. On May 25, 1961, President John F. Kennedy addressed a joint session of Congress, urging a national commitment to land a man on the Moon and return him safely by the end of the decade. He requested increased funding for NASA and framed the effort as essential for American prestige and technological supremacy. The speech accelerated the Apollo program, leading to massive investments in rocketry, computing, and materials science. Kennedy's vision was realized with Apollo 11 in 1969.

Event Detail Daily Earth View

1961

Science 20th Century Global

Antarctic Treaty Enters into Force for Peaceful Science

During the International Geophysical Year of 1957–1958, twelve nations conducted extensive scientific research in Antarctica, demonstrating successful international cooperation despite territorial claims. The Antarctic Treaty was signed in Washington, D.C., on December 1, 1959, by Argentina, Australia, Belgium, Chile, France, Japan, New Zealand, Norway, South Africa, the Soviet Union, the United Kingdom, and the United States. It entered into force on June 23, 1961, after ratification by all signatories. The agreement reserved the continent exclusively for peaceful purposes, prohibited military activities and nuclear explosions, and guaranteed freedom of scientific investigation while freezing existing territorial claims.

Event Detail Guided Physics

1962

Science 20th Century North America

John Glenn Orbits Earth in Friendship 7

In the midst of the Cold War space race, the United States aimed to match Soviet achievements in human spaceflight. On February 20, 1962, astronaut John Glenn launched aboard the Mercury-Atlas 6 spacecraft named Friendship 7 from Cape Canaveral. The mission completed three orbits of Earth over nearly five hours, with Glenn manually controlling aspects of the flight after a faulty sensor caused concern. He splashed down safely in the Atlantic Ocean, becoming the first American to achieve orbital flight. The successful mission provided critical data on human performance in space and boosted national confidence in the Mercury program.

Event Detail Daily Earth View

1962

Science 20th Century North America

NASA Launches Mariner 2 to Venus

In the early Space Race, NASA sought to send probes beyond Earth orbit amid competition with the Soviet Union. Mariner 2, part of the Mariner program, was designed as a flyby mission to study Venus after an earlier attempt failed. The spacecraft lifted off from Cape Canaveral on August 27, 1962, aboard an Atlas-Agena rocket. It traveled over 100 million miles, encountering technical issues en route that were overcome through ground commands. On December 14, Mariner 2 flew within 21,600 miles of Venus, becoming the first spacecraft to successfully return data from another planet. Measurements revealed Venus's extreme surface temperatures and confirmed the existence of the solar wind.

Event Detail Daily Earth View

1962

Science 20th Century Global

Mariner 2 Completes First Successful Planetary Flyby

NASA launched Mariner 2 on August 27, 1962, as part of its early interplanetary program following the failure of Mariner 1. The spacecraft traveled 110 days through space, measuring solar wind, cosmic rays, and interplanetary dust en route. On December 14, 1962, it passed within 34,773 kilometers of Venus, becoming the first probe to successfully encounter another planet. Instruments revealed Venus's extremely hot surface temperatures around 500°C, cool cloud layers, and absence of a detectable magnetic field. Data transmission continued briefly after the encounter, confirming the viability of deep-space probes.

Event Detail Daily Earth View

1963

Science 20th Century Russia & Central Asia

Valentina Tereshkova Becomes First Woman in Space

During the early Space Race, the Soviet Union sought to demonstrate technological superiority and gender inclusivity in its space program following Yuri Gagarin's historic flight. On June 16, 1963, cosmonaut Valentina Tereshkova launched aboard Vostok 6 from the Baikonur Cosmodrome. She completed 48 orbits over nearly three days, becoming the first woman to travel into space. Tereshkova, a textile factory worker and amateur parachutist selected from a group of female candidates, manually controlled aspects of the mission and conducted experiments on the effects of spaceflight on the female body. Her safe return on June 19 provided valuable data for future long-duration flights. The mission highlighted Soviet achievements in human spaceflight at a critical juncture in Cold War competition.

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