The year 1979 in science and technology involved some significant events, listed below.

Astronomy and space exploration

* February 7 –

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...

enters a 20-year period inside the orbit of

Neptune Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...

for the first time in 230 years. * March 7 – The largest

magnetar A magnetar is a type of neutron star with an extremely powerful magnetic field (∼109 to 1011 T, ∼1013 to 1015 G). The magnetic-field decay powers the emission of high-energy electromagnetic radiation, particularly X-rays and gamma rays.War ...

(

soft gamma repeater A soft gamma repeater (SGR) is an astronomical object which emits large bursts of gamma-rays and X-rays at irregular intervals. It is conjectured that they are a type of magnetar or, alternatively, neutron stars with fossil disks around them. His ...

) event is recorded. * July 11 – America's first space station, ''

Skylab Skylab was the first United States space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate three-astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Major operations in ...

'', is deliberately allowed to burn up on

atmospheric entry Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the ent ...

over the Indian Ocean due to its decaying orbit and the lack of time to build a new spaceship to boost it up. * September 1 – The American ''

Pioneer 11 ''Pioneer 11'' (also known as ''Pioneer G'') is a robotic space probe launched by NASA on April 5, 1973, to study the asteroid belt, the environment around Jupiter and Saturn, solar winds, and cosmic rays. It was the first probe to encounter ...

'' becomes the first spacecraft to visit

Saturn Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...

when it passes the planet at a distance of 21,000 km. * December 24 – The maiden launch of

Ariane 1 Ariane 1 was the first rocket in the Ariane family of expendable launch systems. It was developed and operated by the European Space Agency (ESA), which had been formed in 1973, the same year that development of the launcher had commenced. A ...

, the first rocket in the Ariane launcher family. *

Amateur Achievement Award of the Astronomical Society of the Pacific The Gordon Myers Amateur Achievement Award, known until 2018 as the Amateur Achievement Award of the Astronomical Society of the Pacific, is one of nine annual astronomical awards managed by the Astronomical Society of the Pacific. It recognize ...

given for the first time.

Biology

Arthur William Baden Powell Arthur William Baden Powell (4 April 1901 – 1 July 1987) was a New Zealand malacologist, naturalist and palaeontologist, a major influence in the study and classification of New Zealand molluscs through much of the 20th century. He was know ...

publishes ''New Zealand Mollusca''.

Computer science

May 8 Events Pre-1600 * 453 BC – Spring and Autumn period: The house of Zhao defeats the house of Zhi, ending the Battle of Jinyang, a military conflict between the elite families of the State of Jin. * 413 – Emperor Honorius signs a ...

Radio Shack RadioShack, formerly RadioShack Corporation, is an American retailer founded in 1921. At its peak in 1999, RadioShack operated over 8,000 worldwide stores named RadioShack or Tandy Electronics in the United States, Mexico, United Kingdom, Austra ...

releases

TRSDOS TRSDOS (which stands for the Tandy Radio Shack Disk Operating System) is the operating system for the Tandy TRS-80 line of eight-bit Zilog Z80 microcomputers that were sold through Radio Shack from 1977 through 1991. Tandy's manuals recommended tha ...

2.3 *

VisiCalc VisiCalc (for "visible calculator") is the first spreadsheet computer program for personal computers, originally released for Apple II by VisiCorp on 17 October 1979. It is often considered the application that turned the microcomputer from a hob ...

becomes the first spreadsheet program. * The

US Federal Government The federal government of the United States (U.S. federal government or U.S. government) is the national government of the United States, a federal republic located primarily in North America, composed of 50 states, a city within a fed ...

releases the initial, draft version of

Ada (programming language) Ada is a structured, statically typed, imperative, and object-oriented high-level programming language, extended from Pascal and other languages. It has built-in language support for '' design by contract'' (DbC), extremely strong typing, exp ...

, a strongly typed, comb-structured language with

exception handler In computing and computer programming, exception handling is the process of responding to the occurrence of ''exceptions'' – anomalous or exceptional conditions requiring special processing – during the Execution (computing), execution of a C ...

s, for embedded systems.

Conservation

* April 5 – First stage of

Kakadu National Park Kakadu National Park is a protected area in the Northern Territory of Australia, southeast of Darwin. It is a World Heritage Site. Kakadu is also gazetted as a locality, covering the same area as the national park, with 313 people recorded liv ...

declared in

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

Earth sciences

* The

RISE project The RISE Project (Rivera Submersible Experiments) was a 1979 international marine research project which mapped and investigated seafloor spreading in the Pacific Ocean, at the crest of the East Pacific Rise (EPR) at 21° north latitude. Using a d ...

first discovers

hydrothermal vent A hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspot ...

s known as 'black smokers', on a

mid-ocean ridge A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about and rises about above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a diverge ...

in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

History of science

Robert Gwyn Macfarlane Robert Gwyn Macfarlane (26 June 1907 – 26 March 1987) was an English hematologist. Life Born in Worthing, Sussex, Gwyn Macfarlane left Cheltenham College in 1924 and a year later entered the Medical School of St Bartholomew's Hospital, L ...

publishes ''Howard Florey: The Making of a Great Scientist''.

Mathematics

* '

Monstrous moonshine In mathematics, monstrous moonshine, or moonshine theory, is the unexpected connection between the monster group ''M'' and modular functions, in particular, the ''j'' function. The term was coined by John Conway and Simon P. Norton in 1979. ...

John Conway John Horton Conway (26 December 1937 – 11 April 2020) was an English mathematician active in the theory of finite groups, knot theory, number theory, combinatorial game theory and coding theory. He also made contributions to many branches ...

and

Simon P. Norton Simon Phillips Norton (28 February 1952 – 14 February 2019)

prove there is a connection between the

Monster group In the area of abstract algebra known as group theory, the monster group M (also known as the Fischer–Griess monster, or the friendly giant) is the largest sporadic simple group, having order 246320597611213317192329314147 ...

''M'' and the ''j''-function in number theory. * The first modern

Sudoku Sudoku (; ja, 数独, sūdoku, digit-single; originally called Number Place) is a logic-based, combinatorial number-placement puzzle. In classic Sudoku, the objective is to fill a 9 × 9 grid with digits so that each column, each row ...

, known as ''Number Place'', appears in ''Dell Pencil Puzzles and Word Games'' (United States), devised by

Howard Garns Howard Garns (March 2, 1905 – October 6, 1989) was an American architect who gained fame only after his death as the creator of Number Place, the number puzzle that became a worldwide phenomenon under the name Sudoku.Zivan, David, ''Indianapol ...

Medicine

* August – The

eating disorder An eating disorder is a mental disorder defined by abnormal eating behaviors that negatively affect a person's physical or mental health. Only one eating disorder can be diagnosed at a given time. Types of eating disorders include binge eating d ...

Bulimia nervosa Bulimia nervosa, also known as simply bulimia, is an eating disorder characterized by binge eating followed by purging or fasting, and excessive concern with body shape and weight. The aim of this activity is to expel the body of calories eate ...

'' is first described and named by British psychiatrist

Gerald Russell Gerald Francis Morris Russell (12 January 1928 – 26 July 2018) was a British psychiatrist. In 1979 he published one of the first descriptions of bulimia nervosa, and Russell's sign has been named after him. Early life and education Gerald ...

. * December 9 – The

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...

certifies the global eradication of

smallpox Smallpox was an infectious disease caused by variola virus (often called smallpox virus) which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) c ...

. * The last naturally occurring cases of

polio Poliomyelitis, commonly shortened to polio, is an infectious disease caused by the poliovirus. Approximately 70% of cases are asymptomatic; mild symptoms which can occur include sore throat and fever; in a proportion of cases more severe s ...

are reported in the United States. * Tumor

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

p53 p53, also known as Tumor protein P53, cellular tumor antigen p53 (UniProt name), or transformation-related protein 53 (TRP53) is a regulatory protein that is often mutated in human cancers. The p53 proteins (originally thought to be, and often s ...

is identified by Lionel Crawford, David Lane,

Arnold J. Levine Arnold Jay Levine (born 1939), is an American Molecular biologist. He was awarded the 1998 Louisa Gross Horwitz Prize for Biology or Biochemistry and was the first recipient of the Albany Medical Center Prize in Medicine and Biomedical Research ...

and

Lloyd J. Old Lloyd John Old (September 23, 1933 – November 28, 2011) was one of the founders and standard-bearers of the field of cancer immunology. When Old began his career in 1958, tumor immunology was in its infancy. Today, cancer immunotherapies are ...

Paleontology

Dinosaur egg Dinosaur eggs are the organic vessels in which a dinosaur embryo develops. When the first scientifically documented remains of non-avian dinosaurs were being described in England during the 1820s, it was presumed that dinosaurs had laid eggs bec ...

s found in the

Two Medicine Formation The Two Medicine Formation is a geological formation, or rock body, in northwestern Montana and southern Alberta that was deposited between and (million years ago), during Campanian (Late Cretaceous) time. It crops out to the east of the Rocky M ...

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

Technology

* March 1 –

Philips Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters i ...

publicly demonstrate a prototype of an optical digital audio disc at a press conference in

Eindhoven Eindhoven () is a city and municipality in the Netherlands, located in the southern province of North Brabant of which it is its largest. With a population of 238,326 on 1 January 2022,Human-powered aircraft A human-powered aircraft (HPA) is an aircraft belonging to the class of vehicles known as human-powered transport. Human-powered aircraft have been successfully flown over considerable distances. However, they are still primarily constructed a ...

Gossamer Albatross The ''Gossamer Albatross'' is a human-powered aircraft built by American aeronautical engineer Dr Paul B MacCready's company AeroVironment. On June 12, 1979, it completed a successful crossing of the English Channel to win the second Kremer pr ...

, built by an

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

team led by

Paul MacCready Paul B. MacCready Jr. (September 25, 1925 – August 28, 2007) was an American aeronautical engineer. He was the founder of AeroVironment and the designer of the human-powered aircraft that won the first Kremer prize. He devoted his life to dev ...

and piloted by Bryan Allen, makes a successful crossing of the

English Channel The English Channel, "The Sleeve"; nrf, la Maunche, "The Sleeve" (Cotentinais) or ( Jèrriais), (Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Kana ...

to win the second

Kremer prize The Kremer prizes are a series of monetary awards, established in 1959 by the industrialist Henry Kremer. Royal Aeronautical Society Human Powered Flight Group The Royal Aeronautical Society's "Man Powered Aircraft Group" was formed in 1959 b ...

. * First sale of

Post-It Note A Post-it Note (or sticky note) is a small piece of paper with a re-adherable strip of glue on its back, made for temporarily attaching notes to documents and other surfaces. A low-tack pressure-sensitive adhesive allows the notes to be easily ...

s in Boise, Idaho.

Awards

Nobel Prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...

s **

Physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

–

Sheldon Glashow Sheldon Lee Glashow (, ; born December 5, 1932) is a Nobel Prize-winning American theoretical physicist. He is the Metcalf Professor of Mathematics and Physics at Boston University and Eugene Higgins Professor of Physics, Emeritus, at Harvard U ...

Abdus Salam Mohammad Abdus Salam Salam adopted the forename "Mohammad" in 1974 in response to the anti-Ahmadiyya decrees in Pakistan, similarly he grew his beard. (; ; 29 January 192621 November 1996) was a Punjabi Pakistani theoretical physicist and a ...

Steven Weinberg Steven Weinberg (; May 3, 1933 – July 23, 2021) was an American theoretical physicist and Nobel laureate in physics for his contributions with Abdus Salam and Sheldon Glashow to the unification of the weak force and electromagnetic interactio ...

Chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...

–

Herbert C. Brown Herbert Charles Brown (May 22, 1912 – December 19, 2004) was an American chemist and recipient of the 1979 Nobel Prize in Chemistry for his work with organoboranes. Life and career Brown was born Herbert Brovarnik in London, to Ukrainian Jewis ...

Georg Wittig Georg Wittig (; 16 June 1897 – 26 August 1987) was a German chemist who reported a method for synthesis of alkenes from aldehydes and ketones using compounds called phosphonium ylides in the Wittig reaction. He shared the Nobel Prize in Che ...

Medicine Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pract ...

– Allan M. Cormack,

Godfrey N. Hounsfield Sir Godfrey Newbold Hounsfield (28 August 1919 – 12 August 2004) was an England, English electrical engineer who shared the 1979 Nobel Prize for Physiology or Medicine with Allan MacLeod Cormack for his part in developing the diagnostic techn ...

Turing Award The ACM A. M. Turing Award is an annual prize given by the Association for Computing Machinery (ACM) for contributions of lasting and major technical importance to computer science. It is generally recognized as the highest distinction in compu ...

–

Kenneth E. Iverson Kenneth Eugene Iverson (17 December 1920 – 19 October 2004) was a Canadian computer scientist noted for the development of the programming language APL. He was honored with the Turing Award in 1979 "for his pioneering effort in programming l ...

Births

* June 29 –

Artur Avila Artur Avila Cordeiro de Melo (born 29 June 1979) is a Brazilian and naturalized French mathematician working primarily in the fields of dynamical systems and spectral theory. He is one of the winners of the 2014 Fields Medal, being the first La ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

ian-born

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

Deaths

* January –

Oscar H. Banker Oscar H. Banker (born Asatour Sarafian; May 31, 1895 – January 1979) was an Armenian American inventor who patented a number of works, including an automatic transmission for automobiles, the needleless inoculation gun, the primary controls of t ...

(b.

1895 Events January–March * January 5 – Dreyfus affair: French officer Alfred Dreyfus is stripped of his army rank, and sentenced to life imprisonment on Devil's Island. * January 12 – The National Trust for Places of Histor ...

Armenian American Armenian Americans ( hy, ամերիկահայեր, ''amerikahayer'') are citizens or residents of the United States who have total or partial Armenian ancestry. They form the second largest community of the Armenian diaspora after Armenians in ...

inventor. * March 11 –

Noël Poynter Frederick Noël Lawrence Poynter FLA (24 December 1908 – 11 March 1979) was a British librarian and medical historian who served as director of the Wellcome Institute for the History of Medicine from 1964 to 1973. In 1958, Poynter was a key p ...

(b.

1908 Events January * January 1 – The British ''Nimrod'' Expedition led by Ernest Shackleton sets sail from New Zealand on the ''Nimrod'' for Antarctica. * January 3 – A total solar eclipse is visible in the Pacific Ocean, and is the 46 ...

), English

medical historian The medical history, case history, or anamnesis (from Greek: ἀνά, ''aná'', "open", and μνήσις, ''mnesis'', "memory") of a patient is information gained by a physician by asking specific questions, either to the patient or to other peo ...

. * March 17 – Henry Aaron Hill (b.

1915 Events Below, the events of World War I have the "WWI" prefix. January * January – British physicist Sir Joseph Larmor publishes his observations on "The Influence of Local Atmospheric Cooling on Astronomical Refraction". *January 1 ...

fluorocarbon Fluorocarbons are chemical compounds with carbon-fluorine bonds. Compounds that contain many C-F bonds often has distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Fluorocarbons and their derivatives are commerci ...

chemist, first

African American African Americans (also referred to as Black Americans and Afro-Americans) are an ethnic group consisting of Americans with partial or total ancestry from sub-Saharan Africa. The term "African American" generally denotes descendants of ens ...

president of the

American Chemical Society The American Chemical Society (ACS) is a scientific society based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has more than 155,000 members at all d ...

. * April 5 –

Eugène Gabritschevsky Eugène (or Eugen) Gabritschevsky (December 1893 – April 5, 1979) was a Russian biologist and artist. He was born into a comfortable family of scientists from Imperial Russia. His father was a renowned bacteriologist, and worked with Louis Pas ...

(b.

1893 Events January–March * January 2 – Webb C. Ball introduces railroad chronometers, which become the general railroad timepiece standards in North America. * Mark Twain started writing Puddn'head Wilson. * January 6 – Th ...

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

biologist A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual Cell (biology), cell, a multicellular organism, or a Community (ecology), community of Biological inter ...

and

artist An artist is a person engaged in an activity related to creating art, practicing the arts, or demonstrating an art. The common usage in both everyday speech and academic discourse refers to a practitioner in the visual arts only. However, th ...

. * May 6 –

Karl Wilhelm Reinmuth Karl Wilhelm Reinmuth (4 April 1892 in Heidelberg – 6 May 1979 in Heidelberg) was a German astronomer and a prolific discoverer of 395 minor planets. Scientific career From 1912 to 1957, Reinmuth was working as an astronomer at the Heide ...

(b.

1892 Events January–March * January 1 – Ellis Island begins accommodating immigrants to the United States. * February 1 - The historic Enterprise Bar and Grill was established in Rico, Colorado. * February 27 – Rudolf Diesel applies for ...

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...

. * June 1 –

Werner Forssmann Werner Theodor Otto Forßmann (Forssmann in English; ; 29 August 1904 – 1 June 1979) was a German researcher and physician from Germany who shared the 1956 Nobel Prize in Medicine (with Andre Frederic Cournand and Dickinson W. Richards) for ...

(b.

1904 Events January * January 7 – The distress signal ''CQD'' is established, only to be replaced 2 years later by ''SOS''. * January 8 – The Blackstone Library is dedicated, marking the beginning of the Chicago Public Library system. * ...

), German

physician A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...

, recipient of the Nobel Prize in Physiology or Medicine. * September 26 – Sir

Barnes Wallis Sir Barnes Neville Wallis (26 September 1887 – 30 October 1979) was an English engineer and inventor. He is best known for inventing the bouncing bomb used by the Royal Air Force in Operation Chastise (the "Dambusters" raid) to attack ...

(b.

1887 Events January–March * January 11 – Louis Pasteur's anti-rabies treatment is defended in the Académie Nationale de Médecine, by Dr. Joseph Grancher. * January 20 ** The United States Senate allows the Navy to lease Pearl Har ...

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

aeronautical engineer Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft. It has two major and overlapping branches: aeronautical engineering and astronautical engineering. Avionics engineering is si ...

. * October 10 –

Guido Fanconi Guido Fanconi () (1 January 1892 – 10 October 1979) was a Swiss pediatrician. He was born in Poschiavo, a small village in the Canton of Grisons. Fanconi is regarded as one of the founders of modern pediatrics. He received his secondary sch ...

(b.

Swiss Swiss may refer to: * the adjectival form of Switzerland * Swiss people Places * Swiss, Missouri * Swiss, North Carolina *Swiss, West Virginia * Swiss, Wisconsin Other uses *Swiss-system tournament, in various games and sports *Swiss Internation ...

pediatrician Pediatrics ( also spelled ''paediatrics'' or ''pædiatrics'') is the branch of medicine that involves the medical care of infants, children, adolescents, and young adults. In the United Kingdom, paediatrics covers many of their youth until the ...

. * October 12 –

Katharine Burr Blodgett Katharine Burr Blodgett (January 10, 1898 – October 12, 1979) was an American physicist and chemist known for her work on surface chemistry, in particular her invention of "invisible" or nonreflective glass while working at General Electric. S ...

(b.

1898 Events January–March * January 1 – New York City annexes land from surrounding counties, creating the City of Greater New York as the world's second largest. The city is geographically divided into five boroughs: Manhattan, B ...

), American physicist and chemist. * December 7 –

Cecilia Payne-Gaposchkin Cecilia Payne-Gaposchkin (born Cecilia Helena Payne; – ) was a British-born American astronomer and astrophysicist who proposed in her 1925 doctoral thesis that stars were composed primarily of hydrogen and helium. Her groundbreaking conclus ...

(b.

1900 As of March 1 ( O.S. February 17), when the Julian calendar acknowledged a leap day and the Gregorian calendar did not, the Julian calendar fell one day further behind, bringing the difference to 13 days until February 28 ( O.S. February 15), 2 ...

), English-born American astronomer and astrophysicist.

References

{{Reflist 20th century in science 1970s in science