Women are massively under-represented in physics and other STEM (science, technology, engineering, and mathematics) subjects at all levels. A report by the Institute of Physics, using data from 2011, showed that 46% of schools in the UK had no girls continue to study physics after the age of 16, although girls were over twice as likely to study physics at A-level if they went to an all girls' school. Girls made up just 20% of all those studying A-level physics in 2011. This is 6 in every class of 30. Only about 6% of physics professors in the UK are female, and only two women have ever won the Nobel Prize in Physics, this is 1%.
There are fewer female physicists because of discrimination against women. It's possible that many great female scientists will never be known, as they would be more likely to have published anonymously or under male pseudonyms, but history is still full of examples of pioneering female scientists and mathematicians. Some of these women are mentioned below, in a timeline of female physicists, chemists, and mathematicians.
Enheduanna (2285-2250 BCE), Akkadian-Sumerian astronomer ↑
Enheduanna was an Akkadian princess (now part of Iraq) and one of the first astronomers and mathematicians. Her father formed the Babylonian Empire from the Sumerian and Akkadian Empires, and she was appointed Priestess of the Moon Goddess in about 2354 BCE. This role required making accurate astronomical predictions. Enheduanna was also one of the first known authors and poets.
Tapputi (c. 1200 BCE), Babylonian perfumer (early chemist) ↑
Tapputi was the first person in history to have recorded chemical experiments, which she performed in her role as a perfumer.
Aglaonike (c. 150 BCE), Ancient Greek astronomer ↑
Cleopatra the Alchemist (c. 250), Egyptian alchemist (early chemist) ↑
Cleopatra is a pseudonym for a female author whose real name has been lost. She published extensive records of her chemical experiments, including drawings of the apparatus used, but much of her work was destroyed in the 3rd or 4th century.
Hypatia (c. 370-415), Ancient Greek mathematician ↑
Hypatia was the first well-documented female mathematician. She also wrote and taught philosophy and astronomy.
1215 - In Britain, King John signed the Magna Carta, which acknowledged that 'free men' are entitled to judgment by their peers.
Sophia Brahe (1556-1643), Danish astronomer and chemist ↑
Brahe studied horticulture, astronomy, chemistry, and medicine but is best known for assisting her elder brother Tycho Brahe, whose astronomical observations led Johannes Kepler to determine how planets orbit the Sun.
Maria Cunitz (1610-1664), German astronomer ↑
Cunitz improved upon the Rudolphine Tables, mathematical tables that Johannes Kepler had published from Tycho Brahe's observations. Cunitz published these tables along with a description of the scientific method in Urania Propitia in 1650.
Despite having published a book in her own name, she often had to correspond with other scientists via her husband, and 50 years after her death she was described by biographer Johan Kaspar Elberti as "so deeply engaged in astronomical speculation that she neglected her household".
Cunitz is now considered one of the most notable female astronomers of the modern era, and has a minor planet and a crater on Venus named after her.
Margaret Cavendish (1623-1673), English natural philosopher ↑
Cavendish wrote philosophy and science as well as science fiction, poetry, and plays. Her work anticipated some of the central views of Thomas Hobbes and David Hume, and she was an early advocate of the idea that matter is capable of thought.
Marie Crous (c. 1640), French mathematician ↑
Crous introduced the decimal system to France, although she was not acknowledged at the time.
Elena Cornaro Piscopia (1646-1684), Italian mathematician ↑
Piscopia was the first known woman to receive a PhD, and went on to lecturer in mathematics at the University of Padua.
Elisabetha Koopman Hevelius (1647-1693), Polish astronomer ↑
Koopman was married to 52-year-old astronomer Johannes Hevelius when she was just 16. Hevelius encouraged her interest in astronomy and in 1690, they jointly published Prodromus Astronomiae, a catalogue of over 1500 stars. Koopman now has a minor planet and a crater on Venus named after her.
Maria Margarethe Kirch (1670-1720), German astronomer ↑
Kirch was an astronomer who produced calendars and almanacs, and was the first woman to discover a comet, although it was named after her husband Gottfried.
Maria Clara Eimmart (1676-1707), German astronomer ↑
Eimmart was the daughter of Georg Christoph Eimmart, the founder of the first astronomical observatory in Nurnberg, and so she was able to train in astronomy and art. Eimmart made hundreds of astronomical drawings and paintings, including depictions of phases of the Moon and Venus, the Moons of Jupiter, and the rings of Saturn.
Jeanne Dumée (unknown-1706), French astronomer ↑
Dumée began training to become an astronomer after becoming a widow at just 17. Dumée analysed the motion of the Earth in order to determine if the heliocentric system advocated by Nicolaus Copernicus and Johannes Kepler was correct. She wrote Discourse on the Opinion of Copernicus Respecting the Mobility of the Earth in about 1680, where she showed that a geocentric view of the universe could not be correct.
Celia Grillo Borromeo (1684-1777), Italian mathematician ↑
Borromeo was an Italian mathematician known for her discovery of the Clélie curve in 1728. This gives the formula for the curves that could be drawn on a rotating sphere.
1689 - In Britain, the English Parliament agreed the English Bill of Rights, which included the right to be free from torture and punishment without a trial.
Émilie du Châtelet (1706-1749), French mathematician and natural philosopher ↑
Du Châtelet was the first to suggest that infrared radiation might exist, and improved on Newtonian mechanics, deriving a proof for the conservation of energy. In 1740, she combined the theories of mathematicians Gottfried Leibniz and Willem 's Gravesande to show that the energy of a moving object is proportional to the square of its velocity. This is an early form of the equation for kinetic energy.
Émilie du Châtelet devised an early form of the equation for kinetic energy. Image credit: Maurice Quentin de La Tour/Public domain.
The Fable of the Bees discussed the division of labour and the 'invisible hand' seventy years before Adam Smith. In the preface to her translation, du Châtelet argued that women should be allowed to be educated to the same level as men, and that by denying women an education, society was preventing them from partaking in the arts and sciences. Du Châtelet now has a crater on Venus named after her.
Laura Bassi (1711-1778), Italian natural philosopher ↑
Bassi was the second woman to receive a PhD, and the first known female Professor in Europe. She helped introduce Newtonian mechanics to Italy, published 28 papers on physics, and was among the 25 scholars chosen to advise Pope Benedict XIV. Bassi now has a crater on Venus named after her.
Maria Gaetana Agnesi (1718-1799), Italian mathematician ↑
Agnesi is known for writing the first book that discussed both differential and integral calculus, Analytical Institutions for the Use of Italian Youth. The French Academy of Sciences stated that this was "the most complete and best made treatise [on mathematics]", and Pope Benedict XIV appointed Agnesi Professor of Mathematics at the University of Bologna in 1750. Agnesi now has a crater on Venus named after her.
Nicole-Reine Lepaute (1723-1792), French astronomer ↑
Lepaute helped construct an astronomical clock that was approved by the French Academy of Science in 1753. She calculated the timing of a solar eclipse, compiled a number of star catalogues, and worked with fellow mathematician Alexis Clairault to predict the return of Halley's Comet. She now has an asteroid and a crater on the Moon named after her.
Caroline Herschel (1750-1848), German astronomer ↑
Herschel caught typhus as a child, which stunted her growth. Her parents assumed this meant that she wouldn't marry, and should remain a house servant. Luckily, Herschel's older brother William Herschel, who is best known for discovering Uranus, had higher hopes for her, and gave her the opportunity to train with him.
William trained Caroline in astronomy, and she later discovered a new galaxy, an asteroid, and at least five new comets. She also compiled a star catalogue and a catalogue of nebula. The Royal Astronomical Society presented her with a Gold Medal in 1828. They would not present another woman with this award until 1996, when they presented it to Vera Rubin.
Herschel was one of the first two women to be given honorary membership of the Royal Astronomical Society in 1835, along with Mary Somerville. Herschel now has an asteroid and a crater on the Moon named after her.
Sophie Germain (1776-1831), French mathematician ↑
Germain was one of the pioneers of elasticity theory. She also worked on number theory, providing a foundation for mathematicians working on Fermat's Last Theorem. Germain corresponded with fellow mathematicians Joseph Louis Lagrange, Adrien-Marie Legendre, and Carl Friedrich Gauss.
Germain did not give her real name at first, so they wouldn't know she was a woman. When she disclosed her true identity to Gauss, he replied: "when a woman, because of her sex, our customs and prejudices, encounters infinitely more obstacles than men in familiarising herself with [number theory's] knotty problems, yet overcomes these fetters and penetrates that which is most hidden, she doubtless has the most noble courage, extraordinary talent, and superior genius".
Mary Somerville (1780-1872), British astronomer ↑
Somerville was one of the first women to be named an honorary member of the Royal Astronomical Society in 1835, along with Caroline Herschel. She became famous for translating mathematician Pierre-Simon Laplace's The Mechanism of the Heavens into English, and went on to publish three books of her own: On the Connexion of the Physical Sciences, Physical Geography, and Molecular and Microscopic Science.
These directly influenced natural philosopher James Clerk Maxwell, and astronomer John Couch Adams, who predicated the location of the planet Neptune due to a discussion in her first book. Somerville now has a crater on the Moon named after her.
1789 - In France, the National Assembly agreed the Declaration of the Rights of Man and of the Citizen.
1791 - In the US, Congress agreed the Bill of Rights.
Elizabeth Fulhame (c. 1794), British chemist ↑
Fulhame published An Essay on Combustion in 1794. Here she detailed experiments on oxidation-reduction reactions and catalysis, as well as theories on combustion. This is considered by some to be a precursor to work by Jons Jakob Berzelius, who is thought of as one of the founders of modern chemistry. Fulhame also experimented with silver salts on fabric. These are light-sensitive and were later used for photography.
Anna Volkova (1800-1876), Russian chemist ↑
Volkova was the first woman known to graduate as a chemist, and the first female member of the Russian Chemical Society. She is regarded as the first modern female chemist, and now has a crater on Venus named after her.
Ada Lovelace (1815-1851), British mathematician ↑
Ada Lovelace was the only legitimate child of Lord Byron, and was tutored by Mary Somerville, who introduced her to the mathematician Charles Babbage. Lovelace was the first to consider the concept of an operating system or software in 1842, while translating and annotating a critique of Babbage's 'analytical engine', an early form of computer.
Lovelace wrote an algorithm for the analytical engine to compute Bernoulli numbers, which would have worked had the machine been built.
Lovelace's notes ended up being longer than the original text, and natural philosopher Michael Faraday praised her work. Lovelace is now known as the first computer programmer.
Ada Lovelace was the world's first computer programmer. Image credit: Science & Society Picture Library/Public domain.
1821 - In the US, some married women were allowed to own property during the incapacity of their spouse.
1833 - The British Parliament abolished slavery in the British Empire.
1839 - In Britain, the Custody of Infants Act made it possible for divorced mothers to be granted custody of their children.
Ellen Swallow Richards (1842-1911), American chemist ↑
Richards attained her first degree at Vassar College, and her second at the Massachusetts Institute of Technology (MIT), where she studied chemistry. She campaigned for women to have the right to a university education, and helped establish the MIT Women's Laboratory in 1876. The laboratory closed in 1883, after MIT began allowing women to undergo the same degree courses as men.
Richards is known for developing Home Economics, where she argued that the work needed to run a home was vital to the economy. Richards applied her knowledge of chemistry to housework in order to improve sanitation and nutrition, and make the process quicker and easier so that women would have time for other pursuits, like education.
Richards published The Chemistry of Cooking and Cleaning: A Manual for Housekeepers in 1882, and provided her time freely to educate the public. She was appointed an instructor at MIT's first laboratory of sanitary chemistry in 1884, and surveyed the quality of water in Massachusetts in 1887. Richard's showed that the scale of pollution was so bad that state water-quality standards were formed, and the first modern municipal sewage treatment plant was built in Massachusetts.
Mary Watson Whitney (1847-1921), American astronomer ↑
Whitney obtained her master's degree from Vassar in 1872. She studied as a 'guest' at Harvard since women could not be admitted at the time, and later spent three years studying at Zurich.
On her return to the United States, Whitney became an assistant to Maria Mitchell at Vassar and, upon Mitchell's retirement in 1888, she became a Professor and was appointed Director of the Vassar Observatory. Whitney specialised in binary stars, variable stars, asteroids, and comets, and over 100 scientific papers were published under her direction.
1848 - In the US, about 200 people met in Seneca Falls, New York, and drafted a 'bill of rights' for women.
Margaret Lindsay Murray Huggins (1848-1915), Irish-British astronomer ↑
Huggins helped pioneer the field of spectroscopy with her husband William Huggins, and was the first to discover that the nebulae inside the Orion Nebula is made of superheated oxygen gas, and is not solid, as was previously thought.
Sofia Kovalevskaya (1850-1891), Russian mathematician ↑
Kovalevskaya moved to Germany to complete her education, as women were not allowed to attend university in Russia. She first studied at the University of Heidelberg, under natural philosophers Hermann von Helmholtz, Gustav Kirchhoff, and Robert Bunsen.
Kovalevskaya gained her PhD in mathematics from the University of Gottingen in 1874, although she was not allowed to attend lectures at the university.
Sofia Kovalevskaya helped devise the Cauchy-Kovalevski theorem. Image credit: Cordula Tollmien/Public domain.
The former contained what is now known as the Cauchy-Kovalevski theorem, where Kovalevski is an alternative spelling for Kovalevskaya. Kovalevskaya was still not allowed to teach, even though she offered to do so for free.
In 1884, Kovalevskaya was appointed editor of the mathematics journal Acta Mathematica and in 1888, she won the Prix Bordin of the French Academy of Science for work that included the discovery of the 'Kovalevsky top', one of three types of rigid bodies in motion that are completely integrable. The following year, she was appointed a Professor at Stockholm University.
Kovalevskaya also wrote non-mathematical works, including a semi-autobiographical novel Nihilist Girl, which was published in 1890. She may also be the first known LGBQT woman to advance in mathematics, since it was known that she had a "romantic friendship" with Swedish author Anne Charlotte Edgren-Leffler, which lasted until Kovalevskaya's death.
Hertha Marks Ayrton (1854-1923), British mathematician and engineer ↑
Ayrton studied mathematics at the University of Cambridge, where she earned her degree in 1880, although at the time Cambridge did not grant degrees to women and so she was only given a 'certificate' in mathematics. The University of London upgraded this to a degree the following year.
Ayrton went on to explain why public lights had a tendency to flicker in a series of journal articles for the Electrician. This not only solved a practical problem, but also led to a deeper understanding of the physics of electrical engineering. Ayrton was elected the first female member of the Institution of Electrical Engineers (IEE) in 1899, and remained the only female member for the next 50 years.
Electrical engineer John Perry suggested Ayrton be accepted as a Fellow of the Royal Society in London, but the Council turned her application down on the basis that she was a married woman. The IEE presented her with the Hughes Medal in 1906 for her work on electrical engineering and her research into the motion of ripples in sand and water.
Ayrton's work on vortices inspired her to invent the Ayrton fan, which could be used to clear the air of poisonous gas, and was used in the trenches during World War I.
1857 - In Britain, the Matrimonial Causes Act made divorce possible for men and women.
Williamina Fleming (1857-1911), British-American astronomer ↑
Fleming was hired to do clerical work for Edward Charles Pickering, who was a Professor of Astronomy at Harvard University. While working in the observatory, Fleming showed an aptitude for astronomy and soon begun making discoveries of her own.
Fleming helped implement a system of stellar classification based on spectroscopy, which was improved by Annie Jump Cannon, and is still used today. She went on to catalogue over 10,000 stars and discover 59 nebulae, 310 variable stars, and 10 novae.
Fleming's most famous discovery is the Horsehead Nebula, which she co-discovered with Pickering's brother William Henry, although neither was acknowledged at the time. Fleming was made an honorary member of the Royal Astronomical Society in 1906.
Anna Winlock (1857-1904), American astronomer ↑
Winlock was an astronomer specialising in asteroids and the first of several women, after Williamina Fleming, to work as a 'computer' for Harvard Observatory under the direction of Edward Charles Pickering. These women processed the raw data given to them by the male astronomers.
Many suggest that Pickering was progressive for hiring women at a time when many universities wouldn't, although they were only paid half of what a man would have been paid.
Margaret Eliza Maltby (1860-1944), American physicist ↑
Maltby enrolled as student at the MIT Women's Laboratory, which was established by Ellen Swallow Richards, and was the first woman there to receive a degree, rather than 'certificate' for her work. After this, she enrolled at the University of Gottingen and became the first woman to obtain a PhD in physics from a German university.
In 1900, Maltby began teaching at Barnard College, a women's college in New York that was established in 1889. She later became a Professor of Physics. During her career, Maltby made advances in chemistry and physics, and allocated funds to support female researchers who were often not eligible to receive fellowships because of their sex.
Maltby also vigorously opposed the forced resignation of female researchers who chose to marry. The rules at MIT stated that: "the College cannot afford to have women on the staff to whom the college work is secondary; the College is not willing to stamp with approval a woman to whom self-elected home duties can be secondary". In 1906, Maltby was recognised as one of America's best scientists by the journal American Men of Science.
1861 - In Britain, the act of sexual intercourse between two men was no longer punishable by death. Sentences such as hard labour were given instead.
1863 - In the US, President Abraham Lincoln issued the Emancipation Proclamation.
Annie Jump Cannon (1863-1941), American astronomer ↑
Cannon gained a degree in physics from Wellesley College in Massachusetts in 1884, but could not find work in her field until a decade later, when she became the assistant to Professor Sarah Frances Whiting.
Whiting had been appointed as Wellesley College's first female Professor of Physics in 1876, shortly after the college's opening. While there, Cannon studied astronomy, specialising in spectroscopy. In 1896, she was hired as one of Edward Charles Pickering's 'computers'.
While at Harvard, Cannon devised the system of stellar classification that we use today, by combining the methods of fellow computers Antonia Maury and Williamina Fleming. This is known as the Harvard Classification Scheme.
Cannon also categorised over 230,000 stars, more than any other person, and discovered 300 variable stars and 5 novae. She was the first woman to receive an honorary doctorate from the University of Oxford, and the first woman to be elected an officer of the American Astronomical Society.
Cannon was also perhaps the first deaf woman to advance in astronomy, her deafness having occurred as a result of catching scarlet fever while she was studying for her first degree. Cannon now has a crater on the Moon named after her.
Marie Sklodowska-Curie (1867-1934), Polish-French chemist and physicist ↑
Curie began her first practical scientific training in 1890, in the chemical laboratory at the Museum of Industry and Agriculture, near Warsaw. The following year, she moved to France, where she first studied physics, completing her bachelor's degree at the University of Paris in 1893, and then mathematics, gaining her master's degree in 1894. That same year, she met her future husband and scientific collaborator, Pierre, who completed his PhD in 1895.
After completing her master's degree, Curie briefly moved back to Poland, where she was denied a place at the Jagiellonian University, which would not accept women at the time. Curie returned to Paris to begin her PhD in 1895.
Marie Sklodowska-Curie discovered two elements and suggested that atoms are divisible. Image credit: Wiki Commons/Public domain.
She married Pierre later that year, and gave birth to their first child, Irène, in 1897.
X-rays were discovered the year that Curie began her PhD, and her PhD supervisor, Antoine Henri Becquerel, discovered that uranium salts emit similar rays in 1896. Curie investigated these rays with a device known as a piezoelectric electrometer, which had been designed by Pierre and his brother Jacques. The electrometer showed that the uranium rays cause the air around a sample to conduct electricity, and that the level of conductivity depended on the mass of the sample. Curie suggested that these rays might be coming from inside the uranium atoms, challenging the idea that atoms are indivisible.
The uranium salts that Curie used were not pure. She used two types of ore: pitchblende and torbernite. Curie discovered that both were more radioactive than they should be if the only radioactive substance they contained was uranium, and pitchblende was the most radioactive. Curie believed that this was because pitchblende and torbernite contained other elements that were more radioactive than uranium, and began searching for other radioactive substances.
Curie discovered that thorium is also radioactive in April 1898, unaware that chemist Gerhard Schmidt had made the same discovery two years before. That year, Pierre stopped his own research and begun working on Curie's project.
Having been beaten to the discovery of the radioactivity of thorium, the Curies hurried to isolate the other elements in the uranium salts, grinding the ore themselves with pestle and mortars. By July of that year, they had discovered the element polonium, named for Curie's homeland of Poland, which did not exist as an independent country at the time. By December, they had discovered radium, named for the amount of radiation it produced, where radium is the Latin word for 'ray'. The Curies coined the term 'radioactivity' during this time.
By 1902, the Curies had ground down and separated over a tonne of pitchblende ore in order to isolate 0.1 grams of radium chloride. Curie was unable to isolate pure radium until 1910, and was never able to isolate polonium due to its short half-life.
Curie gained her PhD from the University of Paris in June 1903, becoming the first woman in France to be awarded a PhD. That month, Pierre was invited to give a speech on radioactivity at the Royal Institution of Great Britain, since she was a woman, Curie was merely asked to attend.
In December of that year, Curie became the first woman to win the Nobel Prize in Physics, which she shared with Becquerel and Pierre, for their research into radiation. The Nobel Prize Committee had not originally wanted to include Curie, but one member, Swedish mathematician Magnus Gösta Mittag-Leffler, told Pierre about this. Pierre complained and the rest of the Committee gave in. The Curies used the Prize money to hire a lab assistant.
Curie gave birth to their second child, Ève, in 1904, and Pierre died in a road accident in 1906. That year, Curie became the first female professor at the University of Paris. In 1909, she became head of the Curie Pavilion, created for her by the Pasteur Institute and the University of Paris. It was here that Curie first isolated radium, and defined the 'Curie' as a unit of radioactive decays per second.
In 1911, Curie attended the first Solvay Conference with physicists such as Max Planck, Ernest Rutherford, and Albert Einstein. Just over a month later, Curie became the first woman to be awarded the Nobel Prize in Chemistry, and the first person to win two Nobel Prizes. This time, Curie did not share the Prize, which was awarded specifically for her discovery of radium and polonium, and her research into them. Curie is still one of only two people to have won two Nobel Prizes in two different fields, the other being American chemist and peace activist Linus Pauling.
In 1912, the French government agreed to fund the Radium Institute, which was completed in 1914, the year World War I began. During World War I, Curie became Director of the Red Cross Radiology Service, assisted by her daughter Irène. This consisted of mobile field hospitals equipped with X-ray equipment.
After the War, Curie returned to the Institute, which became one of the four most successful radioactivity research laboratories in the world. Curie died in 1934, due to the effects of her long-term exposure to radiation.
Curie is perhaps the most well-known female scientist. She wrote a number of books, won numerous awards and medals, and has been honoured in many different ways. The Curies have an element named after them, curium, and three minerals between them, curite, sklodowskite, and cuprosklodowskite. Curie also has many institutions, an asteroid, and a crater on the Moon named after her, and there are museums dedicated to Curie in Warsaw and Paris.
Henrietta Swan Leavitt (1868-1921), American astronomer ↑
Leavitt graduated from Radcliffe College in Massachusetts in 1893 and, after a bout of illness that left her deaf, she began working as a 'computer' at the Harvard Observatory under Edward Charles Pickering. While cataloguing the brightness of stars, Leavitt noticed a correlation between the pulsation periods of certain types of stars, known as Cepheid variables, and their intrinsic luminosity.
The intrinsic luminosity of a star can be used to determine how bright it would be if it took the place of the Sun. Once this was known, scientists were able to determine how far away the star must be in order to be as faint as it's observed to be. Leavitt first published these results in 1908, and confirmed them in 1912.
Cepheids were soon used to measure the size of the Milky Way and the distance to the Andromeda nebula. This led to acceptance of the idea that Andromeda is in fact another galaxy, outside of the Milky Way. In 1929, physicist Edwin Hubble used this method to show that the universe is expanding, and hence originated in a big bang.
Leavitt was unable to make use of her discovery herself because women were not allowed to use telescopes of this calibre until the 1960s. Mathematician and member of the Nobel Prize Committee, Gösta Mittag-Leffler, tried to nominate Leavitt for the Nobel Prize in 1924, not realising she had died three years earlier (the Nobel Prize is not awarded posthumously). There is now an asteroid and a crater on the Moon named after her.
Annie Russell Maunder (1868-1947), British astronomer ↑
Maunder earned her degree at the University of Cambridge in 1889, graduating as the top mathematician in her college, although she did not actually receive her degree because the University did not give degrees to women at the time.
Maunder began working as a 'computer' for Greenwich Royal Observatory in 1891, where she worked on observations of the Sun. It was there that she met Walter Maunder, who she married in 1895. Annie Maunder lost her job due to the marriage, but continued to work with Walter in an unofficial capacity.
The Maunder's most famous work showed a direct correlation between the number of sunspots and the climate of the Earth. They showed that the Maunder Minimum - a period between about 1645 and 1715 when sunspots became exceedingly rare - resulted in what's now known as the 'Little Ice Age'.
Maunder travelled to India to photograph the Sun's outer solar corona in 1898, and became the first woman to be elected to the Royal Astronomical Society in 1916.
1870 - In Britain, married women could own property.
1876 - In Britain, universities opened to women.
Harriet Brooks (1876-1933), Canadian physicist ↑
Brooks gained a bachelor's degree in mathematics from McGill University in Quebec in 1898. She stayed on to study for her master's degree, becoming physicist Ernest Rutherford's first graduate student. Brooks became the first woman to receive a master's degree from the University in 1901.
After this, she carried on working under Rutherford, and briefly under Marie Sklodowska-Curie. Brooks discovered the 'recoil of the radioactive atom'. She was also one of the first people to discover radon and to try to determine its atomic weight. Rutherford described Brooks as being as apt as Curie; however, she lost her job after getting married in 1907.
1878 - In Britain, women who divorce on the grounds of abuse could claim custody of their children.
Lise Meitner (1878-1968), Austrian physicist and chemist ↑
Meitner became the second woman to obtain a PhD in physics at the University of Vienna in 1905. After this, she moved to Berlin to study under physicist Max Planck, soon becoming his assistant. During this time, she also worked with chemist Otto Hahn, researching beta radiation.
In 1912, Meitner and Hahn moved to the Kaiser-Wilhelm-Institut (KWI) near Berlin. The following year, Meitner rejected an offer to become an Associate Professor at the University of Prague, and was offered a permanent position at the KWI. During World War I, Meitner worked as a nurse, before returning to Berlin to continue her research in 1916.
In 1917, Meitner and Hahn discovered the first long-lived isotope of the element protactinium. In 1922, Meitner discovered the Auger emission process.
Lise Meitner was part of the group that first 'split the atom'. Image credit: Wiki Commons/Public domain.
The Auger effect describes how, when the inner-shell of an atom is filled by an electron, a photon or another electron is emitted. This effect is named after French physicist Pierre Auger who made the same discovery as Meitner independently, the following year.
Meitner became the first woman in Germany to become a full Professor of Physics in 1926, while at the University of Berlin. She began working with American physicist Leo Szilard in 1930. After the discovery of the neutron in 1932, physicists realised that it might be possible to create new elements by adding neutrons to the heaviest known element, uranium. A race to create the first new element ensued between Meitner and Hahn, and Ernest Rutherford, Irène Joliot-Curie, and Enrico Fermi.
Hitler came to power in 1933, and almost all Jewish scientists who were not Austrian citizens, or had not fought on the side of Germany during World War I, were removed from their posts. Meitner was Jewish but was also Austrian and so chose to stay, a decision she regretted.
Meitner escaped Nazi Germany for the Netherlands in July 1938 - with the help of Dutch physicists Dirk Coster and Adriaan Fokker - leaving all of her possessions behind.
Meitner travelled from the Netherlands to Sweden, to work at physicist Manne Siegbahn's laboratory in Stockholm, where she briefly worked with physicist Niels Bohr. Meitner reunited with Hahn in November of that year, in Copenhagen. There they discussed experiments that Hahn and fellow German chemist Fritz Strassmann could perform in Berlin. In December, Strassmann conducted the experiment that provided evidence for nuclear fission, but neither Strassmann nor Hahn recognised this. It was Meitner and her collaborator, and nephew, Austrian-British physicist Otto Robert Frisch, who analysed the results and showed that there was no other explanation.
Meitner and Frisch explained how the nucleus of an atom could be split into smaller parts, and why there are no stable elements in nature beyond uranium. By the end of 1938, Meitner was the first to realise that Einstein's theory of special relativity explained why a tremendous amount of energy was released during fission. Hahn and Strassman published their results in 1939.
Szilard had already suggested the possibility of a chain reaction, which could result in a massive explosion. The realisation that this knowledge was in German hands led to the formation of the Manhattan Project. Szilard, Frisch, and Hahn were all involved in the Manhattan Project. Meitner refused an offer to work on the project and stayed in Sweden.
After the War, Meitner criticised Hahn, Heisenberg, and other German scientists for staying in Nazi Germany for as long as they did, offering only passive resistance against the regime. In November 1945, it was announced that Hahn had been awarded the 1944 Nobel Prize in Chemistry for the discovery of nuclear fission.
Meitner was nominated to receive the Nobel Prize three times, she won a number of other awards and medals, and has a number of buildings named after her, as well as the element meitnerium, craters on the Moon and Venus, and an asteroid.
Ellen Gleditsch (1879-1968), Norwegian chemist ↑
Gleditsch began her career as an assistant to Marie Sklodowska-Curie, and became a pioneer of radiochemistry. Gleditsch was the first person to successfully establish the half-life of radium, and helped prove the existence of isotopes. She later became a Professor at the University of Oslo.
Emmy Noether (1882-1935), German mathematician ↑
Noether studied for her bachelor's degree in mathematics at the University of Erlangen between 1900 and 1902. Women were not officially allowed to study at German Universities at the time, and she had to ask each Professor for permission to take his course. In 1903, she transferred to the University of Gottingen where she attended lectures by mathematicians David Hilbert, Felix Klein, and Hermann Minkowski. Noether graduated in 1904, the same year that the University of Erlangen allowed women to enrol, and so she moved there to complete her PhD in 1907, working under Paul Gordan.
After completing her PhD, Noether stayed on at the University of Erlangen, unofficially and without pay, since the University did not yet employ female faculty members.
Emmy Noether proved the relationship between symmetries and conservation laws. Image credit: Wiki Commons/Public domain.
Noether published an extension of her thesis in 1910 and 1911. From 1913 to 1916, she extended Hilbert's methods and applied them to other mathematical objects.
In 1915, Hilbert and Klein persuaded Noether to return to the University of Gottingen, working freely while they tried to secure her an official post. This was not granted until 1919, and until then Noether's lectures were officially recorded as Hilbert's where Noether was recorded as the assistant.
Noether developed what would later be known as 'Noether's Theorem' while working at the University of Gottingen in 1915. Noether's Theorem proves the relationship between symmetries and conservation laws in physics. This had important consequences for quantum mechanics, and led to the formulations of several concepts in Einstein's theory of general relativity.
Noether began working on abstract algebra in 1920, making a number of important breakthroughs. The University of Gottingen began paying her a small salary in 1923.
Noether was dismissed from the University when Hitler came to power in 1933 because she was Jewish, although she continued teaching for free from her own home. Noether moved to the United States in 1934, working first at Bryn Mawr College in Pennsylvania, and then at the Institute for Advanced Study in Princeton.
Inge Lehmann (1888-1993), Danish seismologist ↑
Lehmann studied mathematics at the University of Copenhagen and the University of Cambridge, and went on to assist mathematician Niels Erik Nørlund in his seismological observatories in Denmark and Greenland.
In 1928, Lehmann became head of the Department of Seismology at the Geodetical Institute of Denmark. She was the first to explain the arrival times of P waves, and in 1936, she discovered that the Earth has a solid inner core beneath its liquid outer core.
Lehmann received many awards in her lifetime, including the Gold Medal of the Danish Royal Society of Science and Letters. She was elected a Fellow of the Royal Society in 1969, and received honouree doctorates from Columbia University and the University of Copenhagen. She now has an asteroid named after her.
Euphemia Lofton Haynes (1890-1980), American mathematician ↑
Haynes received her bachelor's degree in mathematics from Smith College in Massachusetts in 1914, and her master's degree from the University of Chicago in 1930. She gained her PhD from the Catholic University of America in Washington DC in 1943. This made her the first black American woman, and the ninth black American person, to receive a PhD in mathematics.
Haynes taught for almost 50 years, working as a Professor of Mathematics at the District of Columbia Teachers College and at Miner Teachers College, where she established the mathematics department. She was the first woman to chair the D.C. School Board, and was active in abolishing laws that discriminated against women and people of colour.
Edith Quimby (1891-1982), American physicist ↑
Quimby earned a degree in mathematics and physics in from Whitman College in Washington, and earned her master's degree from the University of California in 1916.
In 1919, Quimby began working at the Memorial Hospital for Cancer and Allied Diseases, where she researched radiation for medical benefits such as the treatment of cancer, and hence pioneered nuclear medicine.
Quimby became an Assistant Professor of Radiology at Cornell University Medical College in 1941. She became a full Professor in 1954, the same year she was elected president of the American Radium Society.
1893 - In New Zealand, women were allowed to vote.
1894 - In Britain, married women were allowed to vote in local elections.
Dorothy Maud Wrinch (1894-1976), British-American mathematician and chemist ↑
Wrinch completed a degree in mathematics at the University of Cambridge in 1916. She then continued for an extra year in order to study logic with mathematician Bertrand Russell. Wrinch went on to publish papers on mathematics and the philosophy of science. She also co-wrote a number of articles with mathematician Harold Jeffreys, which he described as forming "the basis of all [his] later work on scientific inference".
In the 1930s, Wrinch helped found the Biotheoretical Gathering, a group of academics from different disciplines who sought to discover how proteins worked in life forms. Wrinch then developed a model of protein structure, which she called the 'cyclol' structure. This was a precursor to the DNA double helix.
Marietta Blau (1894-1970), Austrian physicist ↑
Blau gained a PhD in physics from the University of Vienna in 1919. From 1923, she worked as an unpaid scientist at the Institute for Radium Research in Vienna. Blau went on to develop the first photographic plates that could accurately image high-energy nuclear particles, and showed how you could determine their energy from the tracks on the plate. These were used in cloud chambers, bubble chambers, and wire chambers, devices that were fundamental to the development of particle physics.
In 1937, Blau and her former student, fellow female physicist Hertha Wambacher, discovered star-like shapes in photographic plates that had been taken to an altitude of over 2 km. These were shown to be the tracks of cosmic rays.
Blau was of Jewish descent, and so was forced to leave Austria in 1938. Albert Einstein helped her obtain a job teaching physics in Mexico City, and she moved to the United States in 1944. Erwin Schrödinger nominated her for the 1950 Nobel Prize in Physics for her pioneering work on photographic plates, but she lost to Cecil Powell, who had been inspired by her work.
Blau returned to Austria in 1960, and worked for the Institute for Radium Research, without pay, until 1964, when she was appointed head of a group analysing the tracks of particles created in experiments at CERN.
Hertha Sponer (1895-1968), German physicist and chemist ↑
Sponer received her PhD from the University of Gottingen in 1921, and a fellowship to work at the University of California, Berkeley in 1925. While at Berkeley, Sponer collaborated with physicist Raymond Thayer Birge, and they developed what's now known as the Birge-Sponer method for measuring the strength of a chemical bond using spectroscopy.
By 1932, Sponer had significantly contributed to the application of quantum mechanics to molecular physics, published twenty papers, and become an Associate Professor of Physics. She lost her job when Hitler came to power, and moved to Oslo to teach as a Visiting Professor. In 1936, she moved to North Carolina and became a Professor at Duke University, where she remained until she retired in 1966.
Ida Noddack (1896-1978), German chemist and physicist ↑
Noddack obtained a PhD in chemistry from the Technical University of Berlin in 1919. She went on to correct Enrico Fermi's chemical proofs in his 1934 paper on radioactivity, and was arguably the first to describe nuclear fission.
In 1925, Noddack, her husband Walter, and fellow physicist Otto Berg claimed they had discovered two new elements: masurium (now known as technetium), named after an area of Poland famous for its thousands of lakes, and rhenium, named after the river Rhine.
The discovery of rhenium was accepted straight away, but their discovery of masurium would not be confirmed for another ten years. By then, its name had been changed to technetium, for the Greek word for 'artificial', since this element had too short a half-life to be found as a naturally occurring element on Earth, but could be created in a laboratory.
Noddack was nominated for the Nobel Prize in Chemistry three times, in 1933, when no prize was given, in 1935, when she lost to Irène and Frédéric Joliot-Curie, and in 1937, when she lost to Walter Norman Haworth and Paul Karrer.
Irène Joliot-Curie (1897-1956), French chemist ↑
Joliot-Curie was due to begin her bachelor's degree at the University of Paris when World War I began. At the age of 18, Joliot-Curie joined her mother Marie Sklodowska-Curie at the Red Cross Radiology Service, which at the time, consisted of 20 mobile field hospitals directed by Sklodowska-Curie.
After the War, Joliot-Curie returned to Paris to study at the Radium Institute, where she met her future husband and scientific collaborator Frédéric Joliot-Curie. Irène Joliot-Curie gained her PhD in nuclear physics in 1925, and married Frédéric the following year.
The Joliot-Curies began collaborating in 1928, in order to study atomic nuclei. They were the first to record evidence of the positron and the neutron, which were interpreted by Carl David Anderson and James Chadwick.
Frédéric completed his PhD in 1930 and in 1934, the Joliot-Curies showed that radioactive materials could be created artificially. They transformed boron into radioactive nitrogen, aluminium into radioactive phosphorus, and magnesium into radioactive silicon. This allowed people to quickly create cheap radioactive materials, which could be used in medicine. The Joliot-Curies won the 1935 Nobel Prize in Chemistry for this achievement, with Irène becoming the second woman to ever win the Prize.
In 1938, Irène Joliot-Curie and nuclear physicist Paul Savitch applied the same method the Joliot-Curies had used to create artificial radiation from elements like boron, to uranium. They created a new substance that was similar to the element lanthanum. This was the first step towards uranium fission, but their research was soon disrupted by World War II, which began in 1939.
During World War II, the Joliot-Curies joined the French Resistance, although Irène contacted tuberculosis and spent several years in Switzerland. In 1946, Irène Joliot-Curie became director of the Radium Institute. She helped construct the first French nuclear reactor in 1948.
In 1956, Irène Joliot-Curie died of leukaemia caused by exposure to radiation. She won a number of awards and medals, and now has a crater on Venus named after her.
Charlotte Moore Sitterly (1898-1990), American astronomer ↑
Sitterly was an astronomer who gained her first degree from Swarthmore College in Pennsylvania in 1920. She went on to assist Henry Norris Russell - known for developing the Hertzsprung-Russell diagram - at the Princeton University Observatory and the Mount Wilson Observatory.
While working at Princeton, Sitterly used spectroscopy to identify the chemical elements in the Sun. She briefly left Princeton to earn her PhD at the University of California, Berkeley, before returning.
Sitterly joined the National Bureau of Standards (NBS) in 1945, and soon published tables on atomic spectra and energy levels, which remained in use for many decades. She now has an asteroid named after her.
Mary Cartwright (1900-1998), British mathematician ↑
Cartwright graduated with a PhD in mathematics from the University of Oxford in 1928. In the 1930s, she developed Cartwright's theorem, which is used in signal processing. She began collaborating with mathematician John Edensor Littlewood in 1938, becoming the first to analyse a dynamical system with chaos theory.
Cecilia Payne-Gaposchkin (1900-1978), British-American astronomer ↑
Payne-Gaposchkin won a scholarship to the University of Cambridge in 1919, where she attended a lecture by physicist Arthur Eddington, who had proven Albert Einstein's theory of general relativity earlier that year.
Payne-Gaposchkin earned her degree but did not receive it, as Cambridge did not grant degrees to women until 1948. This prompted her to move to the United States in 1923, in order to work at the Harvard Observatory under its new director, Harlow Shapley. It was here that she earned her PhD in 1925. This was described by astronomer Otto Struve as "undoubtedly the most brilliant Ph.D. thesis ever written in astronomy".
Cecilia Payne-Gaposchkin showed that stars are mostly made of hydrogen and helium. Image credit: Acc. 90-105 - Science Service, Records, 1920s-1970s, Smithsonian Institution Archives/CC-NC-A.
Payne-Gaposchkin's PhD thesis related the spectral class of stars to their temperature, and showed that absorption lines vary because of different amounts of ionization at different temperatures, not because of different amounts of elements, as was previously thought. She used this information to correctly predict that common elements, like silicon and carbon, are found in the same relative amounts on the Sun as on Earth, but that the majority of the Sun's mass is made of helium and hydrogen, with much more of the latter.
Astronomer Henry Norris Russell derived the same result four years later, and is often given credit for the discovery, although he acknowledged her work in his paper. After completing her PhD, Payne-Gaposchkin went on to study variable stars in order to determine how stars change over time.
In 1954, astronomer Donald Menzel became Director of the Observatory. He attempted to improve the status of women at the University and, in 1956, made Payne-Gaposchkin the first female Professor in the faculty. She now has an asteroid named after her.
Kathleen Lonsdale (1903-1971), British physicist ↑
Lonsdale moved from Ireland to England when she was five years old, and later studied at Ilford County High School for Boys, since the Girls' school did not teach mathematics or science. She earned her bachelor's degree in physics from the University of London in 1922, and her master's degree from University College London in 1924.
Lonsdale then joined the crystallography research team at the Royal Institution of Great Britain, which was headed by physicist William Henry Bragg. Crystallography is the science that examines the arrangement of atoms in solids.
Lonsdale became a pioneer of X-ray crystallography. She used X-ray diffraction to determine the shape of molecules and in 1929, she showed that benzene is shaped like a flat ring. Two year later, she used Fourier spectral methods to determine the structure of hexachlorobenzene. She went on to work on the synthesis of diamonds.
Lonsdale became the first female Professor to gain tenure at University College London. In 1966, she was elected the first female president of the International Union of Crystallography, and she was elected the first female president of the British Association for the Advancement of Science (BAAS) the following year. She now has a crater on Venus named after her, as well as Lonsdaleite, also known as hexagonal diamond. Lonsdaleite is formed when meteorites containing graphite strike the Earth.
Katharine Way (1903-1995), American physicist ↑
Way gained her first degree from Columbia University in the United States in 1932, and earned her PhD at the University of North Carolina, where she was supervised by John Wheeler. She joined the Manhattan Project in 1942, working for Wheeler with physicist Alvin Weinberg.
Way used data that had been compiled by physicist Enrico Fermi in order to show that it's possible to create a self-sustaining nuclear chain reaction. Her calculations were used to construct Chicago Pile-1, the world's first nuclear reactor. She also worked with physicist Eugene Wigner to develop the Way-Wigner approximation for fission product decay.
Way co-edited the 1946 bestseller One World or None: a Report to the Public on the Full Meaning of the Atomic Bomb. This contained essays by physicists such as Niels Bohr, Albert Einstein, and Robert Oppenheimer. In 1949, she began to work for the National Bureau of Standards, where she helped establish the Nuclear Data Project. Way became a professor at Duke University in 1968.
Grace Hopper (1906-1992), American computer scientist ↑
Hopper graduated with a bachelor's degree in mathematics and physics from Vassar College in 1928, and a master's degree from Yale University in 1930. She stayed at Yale, earning her PhD in mathematics in 1934, and became Associate Professor of Mathematics at Vassar in 1941.
In 1943, Hopper left Vassar to join the United States Navy Reserve as one of the Women Accepted for Volunteer Emergency Service (WAVES).
Hopper trained at the Naval Reserve Midshipmen's School in Massachusetts, and graduated in 1944. She was then assigned to the Computation Project at Harvard University, as a Junior Lieutenant. Here, she worked on programming the IBM Automatic Sequence Controlled Calculator (ASCC), referred to as the Mark I.
Hopper is credited with coining the term 'debugging' in 1947, after a moth became stuck in a relay. The word 'bug' had previously been used to describe a technical error by Thomas Edison. Hopper turned down a full professorship at Vassar in order to continue working at the Harvard Computation Lab.
In 1949, Hopper became a senior mathematician for the Eckert-Mauchly Computer Corporation, as part of the team developing the second commercial computer produced in the United States, known as UNIVAC I. Hopper developed the first compiler in 1952. A compiler is a computer program that transforms source code written in one programming language into another.
Hopper became the Director of Automatic Programming in 1954, with her department producing some of the first compiler-based programming languages. They were largely responsible for the development of COBOL (COmmon Business-Oriented Language), one of the first modern programming languages.
Hopper became Director of the Navy Programming Languages Group in the Navy's Office of Information Systems Planning in 1967. She was promoted to Captain in 1973. That year, she became the first woman, and first American, to become a Distinguished Fellow of the British Computer Society.
Hopper then pioneered the use of standards for testing computer systems, working with early programs like FORTRAN and COBOL. These tests were adopted by the National Bureau of Standards in the 1980s. In 1983, she was promoted to Commodore, a position later named Rear Admiral, lower half.
Hopper retired in 1986, aged 79, and was awarded the Defence Distinguished Service Medal, the highest non-combat award given by the Department of Defence. She then worked as a Senior Consultant to Digital Equipment Corporation until her death in 1992. Hopper now has a US Navy warship, a supercomputer, a computer lab, a bridge, and a number of important awards and buildings named after her.
Maria Goeppert-Mayer (1906-1972), German-American physicist ↑
Mayer completed her PhD at the University of Gottingen in 1931, studying under physicists Max Born, James Franck, and Adolf Otto Reinhold Windaus. Her thesis showed that atoms can simultaneously absorb two photons, transferring this energy to the atom's electrons. This was not confirmed experimentally until the 1960s.
After completing her PhD, Mayer moved to the United States, taking many voluntary positions before being hired as a Senior Physicist at the Argonne National Laboratory in 1946. While there, she developed a mathematical model for the structure of nuclear shells, which explained how the number of particles in the nucleus is related to the atom's stability. Mayer suggested that the nucleus of an atom is a series of closed shells, and neutrons and protons undergo spin orbit coupling.
Mayer became a Professor of Physics at the University of California, San Diego in 1960. She won the 1963 Nobel Prize in Physics for her work on nuclear shells. This made her the second (and as of 2012, also the latest) woman to win the Nobel Prize in Physics.
The unit for the two-photon absorption cross section is named the Goeppert-Mayer unit, and Mayer also has a crater on Venus named after her.
Dorothy Crowfoot Hodgkin (1910-1994), British chemist ↑
Hodgkin studied for her bachelor's degree in chemistry at the University of Oxford, and earned her PhD at the University of Cambridge, where she was supervised by biologist John Desmond Bernal. It was here that she realised X-ray crystallography could be used to determine the structure of proteins (crystallography is the science that examines the arrangement of atoms in solids).
In 1934, Hodgkin began working at the University of Oxford as a tutor in chemistry, where she stayed until 1977. During this time, Hodgkin discovered the structure of many molecules, including penicillin, vitamin B12, insulin, and molecules that make up certain types of steroids.
In 1953, Hodgkin became one of the first people to measure the structure of DNA, confirming the double-helix model that had been developed by Rosalind Franklin, Francis Crick, and James Watson earlier that year.
Hodgkin won the 1964 Nobel Prize in Chemistry for her work on X-ray crystallography, making her the third woman to win the Nobel Prize in Chemistry, after Marie Sklodowska-Curie and Irène Joliot-Curie.
Chien-Shiung Wu (1912-1997), Chinese-American physicist ↑
Wu gained her bachelor's degree in physics from the National Central University in China in 1934. She then began postgraduate study at the Zhejiang University for two years, before becoming a researcher at the Institute of Physics of the Academia Sinica (Central Research Academy).
Wu moved to the United States to continue her postgraduate study in 1936. She joined the University of California, Berkeley, studying for her PhD under physicist Ernest Lawrence, known for the invention of the cyclotron particle accelerator.
Wu graduated in 1940, and then joined Smith College in Massachusetts, followed by Princeton University in New Jersey, and Columbia University in New York City, where she worked from 1944 until 1980.
Chien-Shiung Wu proved that parity does not apply to weak subatomic interactions. Image credit: Acc. 90-105 - Science Service, Records, 1920s-1970s, Smithsonian Institution Archives/CC-NC-A.
While at Columbia University, Wu worked on the Manhattan Project, helping to develop a process for separating uranium into isotopes by gaseous diffusion. She also helped to develop improved Geiger counters.
In 1956, physicists Tsung-Dao Lee and Chen Ning Yang showed that interactions involving the weak nuclear force do not follow the same symmetry as the other elementary forces. This symmetry is known as parity.
Lee and Yang designed several experiments for testing this theory, and Wu improved upon this design and carried out the experiment, proving Lee and Yang correct. These results were soon verified, and Lee and Yang were awarded the 1957 Nobel Prize in Physics for this discovery. Wu later conducted research into the cause of sickle-cell anaemia.
Wu published a reference book, Beta Decay, in 1965. She became the first female President of the American Physical Society in 1975, and received the first Wolf Prize in Physics in 1978. Wu won a number of awards and medals, and was the first living scientist to have an asteroid named after them.
1918 - In Britain, women over 30 were granted the right to vote and stand as an MP.
Leona Woods (1919-1986), American physicist ↑
Woods earned her bachelor's degree in chemistry from the University of Chicago in 1938, and studied for her PhD under Robert Mulliken, completing her thesis in 1943. After this, Woods worked for Enrico Fermi, as part of the group that constructed the first nuclear reactor for the Manhattan Project, Chicago Pile-1, and helped build the first atomic bomb. She was the youngest and only female member of the team.
After the World War II, Woods returned to the University of Chicago, becoming an Assistant Professor in 1953. Woods joined New York University in 1960, and became a full Professor in 1962. She later worked for the University of Colorado, and then the University of California, Los Angeles. It was here that she devised a method of using isotope ratios in tree rings to study changes in temperature and rainfall patterns. This allowed climate change to be studied in times before records were made.
Woods also wrote popular science books, including Creation of an Atmosphere for the Moon, which was published in 1969, the year the first people walked on the Moon's surface, and a number of books on environmental problems and climate change. These include Fifty environmental problems of timely importance, and Fifty more timely problems of the environment, both published in 1970. She also wrote the autobiographical The Uranium People, published in 1979.
1920 - In the US, women in all states were allowed to vote.
Rosalind Franklin (1920-1958), British chemist ↑
Franklin earned her bachelor's degree in chemistry at the University of Cambridge in 1941, although she didn't receive her degree, as the university didn't award women bachelor's degrees at the time. She went on to work for the British Coal Utilisation Research Association (BCURA). Here she predicted the performances of different types of coals for the production of products used in World War II.
Franklin put this knowledge to use in her PhD in chemistry, which she gained from the University of Cambridge in 1945. After this, she studied X-ray crystallography with Jacques Mering, and used this technique to study the structure of coal and graphite.
In 1951, Franklin began working under physicist John Randall in the Medical Research Council's (MRC) Biophysics Unit at King's College London. Here she used X-ray diffraction to study the structure of DNA with PhD student Raymond Gosling, a position previously occupied by physicist Maurice Wilkins. Franklin and Wilkins did not get on and so worked separately.
Franklin and Gosling discovered that DNA changes shape depending on the humidity. They named the dry, short, and fat form 'form A', and the wet, long, and thin form 'form B'. In 1952, Franklin produced evidence of the double helix structure of DNA, in what was known as Photo 51.
Watson had previously suggested collaborating with Franklin but she had refused. He had then spoken to Wilkins who, without Franklin's knowledge or permission, showed him Photo 51. This had inspired Crick and Watson to abandon their old model and adopt Franklin's.
Later that year, Franklin moved to Birkbeck College, part of the University of London. Here she studied the structure of the tobacco mosaic virus (TMV), a virus that infected tobacco and other plants, with chemist Aaron Klug. Together with chemist Donald Caspar, they showed that the DNA in the TMV virus is wound along the inner surface of the hollow virus. They then began to look at the structure of RNA in different types of viruses, including polio.
Franklin died of ovarian cancer in 1958, aged 37. The double helix model was not fully accepted at the time and she was not eligible to be nominated for the 1962 Nobel Prize in Physiology or Medicine, which was shared by Crick, Watson, and Wilkins, as the Nobel Prize is not awarded posthumously. Franklin now has a number of buildings named after her, as well as an asteroid.
Marie Maynard Daly (1921-2003), American chemist ↑
Daly earned her bachelor's degree in chemistry from the University of New York in 1942. She completed her PhD in chemistry at Columbia University in 1947, specialising in the chemicals that aid food digestion. This made her the first black woman to gain a PhD in chemistry in the United States. Daly went on to study the cell nucleus at the Rockefeller University in New York.
In 1955, Daly collaborated with Medical Doctor Quentin Deming at Columbia University, in order to study the cause of heart attacks. Daly and Deming showed that high cholesterol is a large contributing factor as it blocks arteries. Daly later looked at the effects of other nutrients on the arteries, including sugar, and became a pioneer in the study of the effects of cigarette smoke on the lungs.
1928 - In Britain, women were granted the same voting rights as men.
Vera Rubin (1928), American astronomer ↑
Rubin earned her bachelor's degree at Vassar College, and her master's at Cornell University, studying under physicists Richard Feynman and Hans Bethe, and completing her study in 1951. That same year, Rubin became the first to show that some galaxies are not simply moving outwards, as astronomer Edwin Hubble had suggested, but were rotating around an unknown source.
Rubin completed her PhD under physicist George Gamow at Georgetown University in Washington DC in 1954. In her thesis, she concluded that galaxies were not randomly distributed, but clumped together in clusters.
Rubin stayed on at Georgetown University as a research assistant, becoming an Assistant Professor in 1965. That same year, she became the first woman to be allowed to use a world-class telescope. She later worked as an astronomer for the Department of Terrestrial Magnetism (DMT) at the Carnegie Institution of Washington.
In the late 1960s and 1970s, Rubin and astronomer Kent Ford measured the rotational velocities of galaxies. It was expected that most of the mass of the galaxy would be located in the centre, which contained the most stars. This meant that the velocity of stars in each galaxy should be slower the further they are from the centre.
By 1980, Rubin and Ford had shown that this is false, and that stars in spiral galaxies, such as the Milky Way, orbit at roughly the same speed, irrespective of their distance from the centre of the galaxy. This means that either our understanding of gravity is wrong, or that the mass of the galaxy is not mostly contained in the centre, rather it is contained in the dark halo.
This mass does not shine like stars, and so was considered evidence of dark matter, a term coined by Fritz Zwicky, who had first suggested its existence in order to explain observations of the Coma galaxy cluster, in 1933.
Rubin's results suggested that 90% of the universe is composed of dark matter, and scientists still don't know exactly what this is. Rubin is currently a Senior Fellow at the Carnegie Institution of Washington and has an asteroid named after her.
1929 - In Canada, women were legally considered 'persons' for the first time.
Willie Hobbs Moore (1934-1994), American physicist ↑
Moore earned her bachelor's degree in electrical engineering from the University of Michigan in 1958, she stayed on to gain her master's degree in 1961, and her PhD in 1972, making her the first black woman to receive a PhD in Physics in the United States. Moore went on to work for the Bendix Aerospace Systems Division, and later became an executive at the Ford Motor Company.
Helen Edwards (1936), American physicist ↑
Edwards gained her bachelor's degree from Cornell University in 1957, she stayed on to receive her master's degree in 1963, and her PhD in 1966. She then became a Research Associate, working with the 10 GEV Electron Synchrotron particle accelerator at Cornell University. Edwards became Associate Head of the Booster Group at the Fermi National Accelerator Laboratory (Fermilab) in 1970.
Edwards became Lead Scientist in the design and construction of the Tevatron in the 1980s. This was the world's highest energy particle accelerator at the time, although it has since been surpassed by the Large Hadron Collider (LHC) at CERN. The Tevatron accelerated protons and antiprotons to energies of up to 1 TeV (1 trillion eV), and was the first high-energy particle accelerator to be completely based on superconducting magnets. It was completed in 1983, and used to discover the top quark in 1995.
Edwards was promoted to Head of the Accelerator Division in 1987, and Head and Associate Director of the Superconducting Division in 1989. She pushed the button to shut the Tevatron down in 2011, and is currently a Guest Scientist at Fermilab.
Valentina Tereshkova (1937), Russian cosmonaut and physicist ↑
Tereshkova was an amateur skydiver before she applied to train as a cosmonaut, and became the first woman, and the first civilian in space, piloting Vostok 6 in 1963.
Tereshkova was picked from over 400 applicants after intensive training and examinations.
This included weightless flights, isolation and centrifuge tests, pilot training in jet fighters, tests on rocket theory, and 120 parachute jumps.
Valentina Tereshkova was the first woman in space. Image credit: NASA/Public domain.
After several months, Tereshkova and three other candidates were commissioned as Junior Lieutenants in the Soviet Air Force.
Tereshkova orbited the earth 48 times during her three-day mission, logging more time in space than all the American astronauts who had flown before her combined. During this time, she took photographs of the atmosphere that were later used to identify aerosol layers.
Budget cuts meant that the female cosmonaut group was dissolved in 1969, the year that people first walked on the Moon.
Tereshkova continued studying engineering. She earned her bachelor's degree at the Zhukovsky Air Force Academy, and stayed on to earn her PhD in 1977. She is now retired and has an asteroid named after her call sign during her space flight, Chaika.
Ada Yonath (1939), Israeli chemist ↑
Yonath gained her bachelor's degree in chemistry from the Hebrew University of Jerusalem in 1962, and her PhD in X-ray crystallography from the Weizmann Institute of Science in 1968. After this, she moved to the United States and began working at the Carnegie Mellon University, joining the Massachusetts Institute of Technology (MIT) in 1970, where she established the only protein crystallography laboratory in Israel.
In 1979, Yonath became Group Leader, with biochemist Heinz-Günter Wittmann, at the Max Planck Institute for Molecular Genetics in Germany, where her research led to more efficient antibacterial drugs. In the 1980s, she split her time between the Max Planck Institute and the Weizmann Institute of Science.
In the mid-1980s, Yonath became a pioneer of cryo bio-crystallography. This is the application of crystallography - the science that examines the arrangement of atoms in solids - at cryogenic temperatures. Yonath used cryo bio-crystallography to study the 3D structure of ribosomes at the molecular level. Ribosomes are molecular 'machines', found in every living organism, that translate instructions written in the genetic code into proteins. Yonath's results ultimately explained the mechanics behind this process.
Yonath discovered the 3D structure of ribosomes in the late 1990s, publishing her results in 2000 and 2001. She shared the 2009 Nobel Prize in Chemistry with Thomas Steitz and Venkatraman Ramakrishnan for her studies on the structure and function of ribosomes. Yonath is the fourth and (as of 2012) the latest woman to win a Nobel Prize in Chemistry.
1941 - In Britain, the National Service Act allowed the conscription of all unmarried women between 20 and 30 years of age. This was later extended to include married women, and women up to the age of 43.
Helen Quinn (1943), American physicist ↑
Quinn received her bachelor's degree in physics from Stanford University in the United States in 1963, and stayed on to earn her master's degree in 1964, and her PhD in 1967. Quinn then worked at the German Synchrotron Laboratory and Harvard University, before returning to Stanford.
In 1974, while working at Harvard, Quinn co-authored the first paper to suggest how the strong, weak, and electromagnetic forces can merge in a grand unified theory, with physicists Howard Georgi and Steven Weinberg.
Quinn later worked with physicist Roberto Peccei and, in 1977, they published what is now known as the Peccei-Quinn theory. This is the best-known solution to the strong CP problem - the problem of why the strong force is symmetrical between particles and antimatter particles, and the weak force is not. It predicts the existence of a new particle, the axion, which is a candidate for dark matter.
Quinn also helped show that the behaviour of hadron particles could be predicted from the physics of quarks with physicists Enrico Poggio and Steven Weinberg. She has won a number of awards and medals, and is currently a Professor of Physics at the Stanford Linear Accelerator Center (SLAC).
Jocelyn Bell Burnell (1943), British astronomer ↑
Burnell gained her bachelor's degree from the University of Glasgow in 1965, and studied for her PhD under astronomer Antony Hewish at the University of Cambridge, graduating in 1969.
During her first two years at Cambridge, Burnell helped construct an 81.5 MHz radio telescope that was designed to track quasars. The telescope became operational in 1967, and it was Burnell's job to operate it and analyse the data produced, which took up about 30 metres worth of printer paper a day.
After a few weeks, Bell detected an anomaly, a source that was pulsating at regular, and extremely short intervals. Bell studied it further and looked for similar anomalies, and it was soon identified as a pulsating star - a pulsar.
Hewish shared the 1974 Nobel Prize in Physics for his role in the discovery of pulsars. Burnell did not, and although it was stated that this was because she was a graduate student and not because she was a woman, many astronomers expressed their anger at her exclusion, including astronomer Fred Hoyle.
After finishing her PhD, Burnell began working at the University of Southampton, and went on to work at University College London and the Royal Observatory in Edinburgh. In 1991, she became a Professor of Physics at the Open University and in 2001, she joined the University of Bath as the Dean of Science.
Burnell has since served two years as President of the Institute of Physics, and is currently a Visiting Professor at the University of Oxford, and a Fellow of Mansfield College. Burnell has won many awards and medals, and has written a number of books.
Sandra Moore Faber (1944), American astronomer ↑
Faber gained her bachelor's degree in physics from Swarthmore College in the United States in 1966, and her PhD in astronomy from Harvard University in 1972. In 1976, she published what's now known as the Faber-Jackson relation, with astronomer Robert Earl Jackson. This shows the relationship between the luminosity and orbital velocity of stars in elliptical galaxies, and allows astronomers to calculate their distance.
In the 1980s, Faber headed the team that discovered the Great Attractor, a gravitational anomaly in the space between galaxies within the Centaurus Supercluster. This anomaly has the mass of tens of thousands of galaxies, and it's still not known exactly what it is.
Faber also helped design the Keck Observatory in Hawaii, diagnosed the Hubble Space Telescope's optical flaw, and headed a team that used the Hubble Space Telescope to search for supermassive black holes at the centres of galaxies. Faber is currently a Professor at the Lick Observatory for the University of California, and co-editor of the journal Annual Review of Astronomy and Astrophysics.
1948 - In Britain, the National Health Service (NHS) gave everyone access to free healthcare.
1948 - The Universal Declaration of Human Rights was adopted by the United Nations (UN).
Sally Ride (1951-2012), American physicist and astronaut ↑
Ride gained her bachelor's degree in physics from Stanford University in 1973, and stayed on to gain her master's degree in 1975. She completed her PhD in physics in 1978, the same year that she joined NASA.
While at NASA, Ride helped develop the Space Shuttle's robotic arm. She was also the ground-based Capsule Communicator for the second and third Space Shuttle flights in 1981 and 1982.
Ride became the third woman in space, and the first American woman in space, in 1983 as a mission specialist on STS-7.
Sally Ride helped develop the Space Shuttle's robotic arm, and was the first American woman in space. Image credit: NASA/Public domain.
STS-7 was a 6-day mission with five crewmembers. It deployed two communications satellites, and conducted pharmaceutical experiments. Ride became the first woman in space to use the robotic arm that she had helped design, using it to retrieve a satellite.
Ride went back into space the following year, with STS 41-G, an 8-day mission that had seven crewmembers, two of whom were women. The second woman aboard was geologist Kathryn Sullivan, who became the first American woman to walk in space. Both of Ride's missions were aboard the Space Shuttle Challenger.
Ride was training for her third mission in 1986 when the Challenger disaster occurred. She served on the investigation panel into the disaster and was then assigned to NASA headquarters in Washington DC, where she founded NASA's Office of Exploration.
Ride left NASA in 1987 to work at Stanford University. She became a Professor of Physics at the University of California, San Diego and Director of the California Space Institute in 1989. Ride served on the investigation panel into the Space Shuttle Columbia disaster of 2003. She also co-wrote five science books for children. Ride won numerous awards and medals, and now has an area of the Moon named after her. Ride is still the youngest astronaut, having launched aged 32, and as of 2012, is the only publicly known LGBQT astronaut.
Carolyn Porco (1953), American planetary scientist ↑
Porco gained her bachelor's degree from the State University of New York at Stony Brook in 1974, and her PhD from the California Institute of Technology in 1983. For her PhD, she studied the rings of Saturn using data taken by the Voyager satellites in 1980 and 1981.
After completing her PhD, Porco took a position at the University of Arizona and became a member of NASA's Voyager Imaging Team. Porco led the Rings Working Group during Voyager 2's encounter with Neptune in 1989.
Porco was the first person to describe the detailed behaviour of the rings of Saturn, Uranus, and Neptune, as observed by Voyager 2, and helped with the design of several important photographs, including the famous 'pale blue dot' image. Porco became a Professor at the University of Arizona in 1991.
In 1990, Porco became leader of the Imaging Team for the Cassini-Huygens mission to Saturn and its moon Titan, which launched in 1997 and arrived in 2004. The mission is expected to last until 2017. Porco's team discovered several new rings of Saturn, seven new moons, and a moonlet. They were the first to see the hydrocarbon lakes on Titan, and jets of water erupting from Saturn's sixth largest moon Enceladus.
Porco is a member of the imaging team for the New Horizons mission to Pluto and the Kuiper Belt, which launched in 2006, and will reach Pluto in 2015. She is also an Adjunct Professor at the University of Colorado. Porco was an advisor for the 1997 film Contact, and the 2009 film Star Trek. She has won numerous awards and medals, written numerous popular science articles, and has an asteroid named after her.
1956 - In Britain, female teachers and civil servants were legally entitled to the same pay as men in the same role.
Lene Vestergaard Hau (1959), Danish physicist ↑
Hau gained a bachelor's degree in mathematics at the University of Aarhus in Denmark in 1984. She stayed on to gain a master's degree in physics in 1986, and a PhD in 1991, the same year she joined the Rowland Institute for Science in Massachusetts.
In 1999, Hau joined Harvard University as a Professor of Physics, where she became one of the first physicists to create a new state of matter known as a Bose-Einstein condensate.
In 2001, Hau became the first person to use a Bose-Einstein condensate to slow light until it came to a complete stop while still in a vacuum. In 2006, her team were the first to successfully transfer light into a matter wave and back again using Bose-Einstein condensates. This has proven useful in the development of quantum computers.
In 2009, Hau's team developed a detector that may be able to resolve fringes from the interference patterns of matter waves. She has won numerous awards and medals.
Fabiola Gianotti (1962), Italian physicist ↑
In 1999, Gianotti became Physics Coordinator for the ATLAS (A Toroidal LHC Apparatus) experiment, becoming Head of the experiment in 2009.
ATLAS is one of seven particle detector experiments conducted at the LHC, and involves about 3000 physicists in 38 countries. In 2012, Gianotti announced that data from the ATLAS experiment and the CMS (Compact Muon Solenoid) experiment at the LHC proved the existence of the Higgs boson. This was confirmed earlier this year.