Celebrating 17 Years on the Web
Find science on or your birthday

Today in Science History - Quickie Quiz
Who said: “I was going to record talking... the foil was put on; I then shouted 'Mary had a little lamb',... and the machine reproduced it perfectly.”
more quiz questions >>
JULY 31 – BIRTHS – Scientists born on July 31st
  Stephanie Kwolek
 Born 31 Jul 1923; died 18 Jun 2014 at age 90.   quotes
American chemist and inventor of Kevlar. Shortly after graduating with a bachelor's degree in chemistry (1946), she began a career at DuPont's textile fibers department in Buffalo, New York. Kwolek was assigned to search for a new, high-performance fiber that would be acid- and base-resistant and stable at high temperatures, suitable to replace steel in radial tyres. After extensive experimentation, she created a polymer solution which, when spun into a fibre, was five times stronger than steel and had half the density of fiberglass. It was named Kevlar. Today, this fibre is used to make bullet-proof jackets military helmets, aircraft parts, inflatable boats, gloves, rope, and building materials. Kwolek never pursued a Ph.D. degree. She was the fourth woman inducted into the National Inventors Hall of Fame (1995).
Women Inventors, by Jean F. Blashfield. - book suggestion.
  Primo Levi
 Born 31 Jul 1919; died 11 Apr 1987 at age 67.   quotes
An Italian novelist, short-story writer and poet, Primo Levi was also a chemist most of his professional life. As a memoirist, he is noted for his restrained and moving autobiographical account of and reflections on survival in the Nazi concentration camps. In his science work, The Periodic Table, he wrote: "...conquering matter is to understand it, and understanding matter is necessary to understanding the universe and ourselves." His gift of writing brought the subject to life. Chemistry, in turn, saved his life. Imprisoned as a Jew in Auschwitz, the young Italian chemist was granted a tenuous reprieve as a technician in the laboratory of an I. G. Farben rubber factory built by slave laborers on the camp's grounds. He died by suicide in 1987, after a long illness.
The Periodic Table, by Primo Levi. - book suggestion.
  Paul D. Boyer
 Born 31 Jul 1918.
American biochemist who, together with John E. Walker, received half the 1997 Nobel Prize for Chemistry for their work explaining the enzymatic process involved in the production of the energy-storage molecule adenosine triphosphate (ATP), which fuels the metabolic processes of the cells of all living things and how the enzyme ATP synthase catalyses the formation of ATP. Boyer and his co-workers proposed, on the basis of biochemical data, a mechanism for how ATP is formed from adenosine diphosphate (ADP) and inorganic phosphate. Walker and his co-workers have established the structure of the enzyme and verified the mechanism proposed by Boyer.
  Herbert E. Ives
 Born 31 Jul 1882; died 13 Nov 1953 at age 71.
Herbert Eugene Ives was an American physicist and inventor of transmission of mechanical video pictures. Research into a television process by the AT&T Co. at Bell Laboratories, New York was under the direction of Dr. Herbert E. Ives. On 7 Apr 1927, live images of Commerce Secretary Hoover were transmitted in the first successful long distance demonstration of television, sent from Washington D.C. to New York, over long distance wires. On 27 June 1929 the first public demonstration of color TV showed images are a bouquet of roses and an American flag using a mechanical system was used to transmit 50-line color television images between New York and Washington. A two-way video telephone was first demonstrated in 1930 by Ives in New York City.
  Baron Anton Freiherr von Eiselsberg
 Born 31 Jul 1860; died 1939 .
Austrian surgeon, teacher, and researcher who carried out important studies in the physiology of the thyroid gland (1891) and surgery of the central nervous system. Anton von Eiselsberg introduced neurosurgery to the First Surgical Clinic at the General Hospital in Vienna where he was the first to resect a cerebral tumor (1904). He also published The operative cure of acromegaly by removal of hypophysial tumor, (1908).
  Theobald Smith
Thumbnail -
 Born 31 Jul 1859; died 10 Dec 1934 at age 75.   quotes
American pathologist and microbiologist whose pioneering work in microbiology place him among America's best, if not the country's greatest bacteriologist. He made substantial, wide-ranging contributions, to the knowledge of parasitic organisms and their mode of trasmitting diseases. These have provided health and economic benefits for both humans and domestic animals. He is most remembered for his work on Texas cattle fever (1889-93, with F.L. Kilborne), finding the protozoan parasite carried by blood-sucking ticks that transmit infection. This was the first time an arthropod was shown to be a vector. Thus, he also stimulated other scientists to pursue more instances of insects spreading different infections, such as yellow fever and African sleeping sickness afflicting humans. A diptheria vaccine resulted from his reasearch in immunology.«
  Richard Dixon Oldham
 Born 31 Jul 1858; died 15 Jul 1936 at age 77.   quotes
Irish geologist and seismologist who discovered evidence for the existence of the Earth's liquid core (1906). In studying seismograms of great 1897 Indian Earthquake he identified P (primary) and S (secondary) waves. It is interesting that he did not get a clue to the presence of the core from the S waves, which are actually incapable of being transmitted through the liquid of the outer core. (The liquid core does not transmit the shear wave energy released during an earthquake.) Rather he noted the existence of a shadow zone in which P waves from an earthquake in the opposite hemisphere of the earth failed to appear.
  Guido Bodländer
 Born 31 Jul 1855; died 25 Dec 1904 at age 49.
German chemist who, with Richard Abegg, proposed an electrochemical theory of valency in a paper Die Elektronaffinität (Electron Affinity, 1899) to explain how certain atoms can combine based on the newly discovered electrons comprising the atom. It had several difficulties and was not generally accepted. Bodländer studied the electrolytical and optical properties of solutions; and the optical properties of crystals.« [Ref: Abegg and Bodländer, Zeit. Anorg. Chem. (1899), 20, 453.]
  Abram Stevens Hewitt
 Born 31 Jul 1822; died 18 Jan 1903 at age 80.
American engineer, industrialist, made first Bessemer steel in the US. He was also a philanthropist, and politician who in 1886 defeated Henry George and Theodore Roosevelt to become mayor of New York City. Hewitt was a partner in a company owning several iron works. At the Cheltenham meeting of the British Association for the Advancement of Science in the summer of 1856 he heard the presentation of Henry Bessemer on the production of steel without fuel. Within the same year, Hewitt arranged an experiment with that process at the furnace of Cooper and Hewitt, at Philipsburgh, in New Jersey, with successful results.
  George Baxter
Thumbnail -
 Born 31 Jul 1804; died Jan 1867 .
English engraver and printer who invented a process (patented 1835) of colour printing that made mass reproductions of paintings. Baxter used wood and metal colour blocks in conjunction with steel key plates and using oil inks. The subject was first engraved onto a steel key plate, impressions of this plate were taken, and colour blocks were cut for it - one for each different colour. The steel key plate printed a monochrome picture and then the colours would be built up by printing from the colour blocks using the relief process. Prints might require only 8 different blocks or as many as 20 different colours, each superimposed after being allowed to dry. Baxter died in Jan 1867 after being struck by a horse omnibus. [Image right: Detail from "Gems of the Great Exhibition, No. 2" showing statue of "The Unhappy Child" from the Belgian Deptartment, patented 26 Apr 1852.]
  John Ericsson
 Born 31 Jul 1803; died 8 Mar 1889 at age 85.
Swedish-American inventor and naval engineer, who became an American citizen in 1847. He was the inventor of the screw propeller, built the first armoured turret warship, the USS Monitor. At the age of 14, he participated in the building of the Göta Canal (1817). A locomotive of his design, The Novelty, participated in a competition with Stephenson's Rocket in 1829. Ericsson invented and patented (No.588, on 1 Feb 1836) a double rotation propeller. In Aug 1861, the American Congress authorized ironclad warships and one ship of the Monitor type designed by Ericsson was ordered. By Mar 1862 the Monitor was ready for sea. He also developed a torpedo boat, The Destroyer, and worked to design his sun-motor engine.   more
Man of the Monitor, The Story of John Ericsson, by Jean Lee Latham. - book suggestion.
  Friedrich Wöhler
 Born 31 Jul 1800; died 23 Sep 1882 at age 82.   quotes
German chemist who co-discovered vanadium. Having studied first medicine, then mineralogy, it was chemistry that became his primary interest. He found a method in 1827 for the production of metallic aluminum in the form of a grey powder by heating aluminum chloride with potassium. In 1828, he succeeded in the isolation of beryllium as a black-grey powder as well as of yttrium and (1856) crystalline silicon. He is most well-known for the synthesis of urea from ammonium cyanate (1828), which created an organic compound from an inorganic one, showing there was no absolute distinction between the two areas of chemical study. In 1862, he produced acetylene from calcium carbide. [Also known as Frederick Woehler.]   more
Wöhler's Outlines Of Organic Chemistry, by Friedrich Wöhler. - book suggestion.
  John Canton
 Born 31 Jul 1718; died 22 Mar 1772 at age 53.
British physicist and teacher, who educated himself about science, and for developing a new method of preparing artificial magnets, won election to the Royal Society (1749). In July 1752, he was the first Englishman to repeat French experiments verifying Franklin's hypothesis that lightning was just a huge electric spark, (as seen from charged Leyden jars). Following this, he studied the polarity of the charge on a cloud. He invented a portable electroscope to detect charge present in a system, and he remains well-known for electrostatic induction experiments. Canton proved that water is slightly compressible (1762). Noting compass needle irregularities during a prominent aurora borealis he made the first observations of magnetic storms (1756-9).

Nature bears long with those who wrong her. She is patient under abuse. But when abuse has gone too far, when the time of reckoning finally comes, she is equally slow to be appeased and to turn away her wrath. (1882) -- Nathaniel Egleston, who was writing then about deforestation, but speaks equally well about the danger of climate change today.
Carl Sagan Thumbnail Carl Sagan: In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion. (1987) ...(more by Sagan)

Albert Einstein: I used to wonder how it comes about that the electron is negative. Negative-positive—these are perfectly symmetric in physics. There is no reason whatever to prefer one to the other. Then why is the electron negative? I thought about this for a long time and at last all I could think was “It won the fight!” ...(more by Einstein)

Richard Feynman: It is the facts that matter, not the proofs. Physics can progress without the proofs, but we can't go on without the facts ... if the facts are right, then the proofs are a matter of playing around with the algebra correctly. ...(more by Feynman)
Quotations by:Albert EinsteinIsaac NewtonLord KelvinCharles DarwinSrinivasa RamanujanCarl SaganFlorence NightingaleThomas EdisonAristotleMarie CurieBenjamin FranklinWinston ChurchillGalileo GalileiSigmund FreudRobert BunsenLouis PasteurTheodore RooseveltAbraham LincolnRonald ReaganLeonardo DaVinciMichio KakuKarl PopperJohann GoetheRobert OppenheimerCharles Kettering  ... (more people)

Quotations about:Atomic  BombBiologyChemistryDeforestationEngineeringAnatomyAstronomyBacteriaBiochemistryBotanyConservationDinosaurEnvironmentFractalGeneticsGeologyHistory of ScienceInventionJupiterKnowledgeLoveMathematicsMeasurementMedicineNatural ResourceOrganic ChemistryPhysicsPhysicianQuantum TheoryResearchScience and ArtTeacherTechnologyUniverseVolcanoVirusWind PowerWomen ScientistsX-RaysYouthZoology  ... (more topics)
JULY 31 – DEATHS – Scientists died on July 31st
  Hendrik Christoffel Van de Hulst
 Died 31 Jul 2000 at age 81 (born 19 Nov 1918).
Dutch astronomer who predicted theoretically (1944) that in interstellar space the amount of neutral atomic hydrogen, which in its hyperfine transition radiates and absorbs at a wavelength of 21 cm, might be expected to occur at such high column densities as to provide a spectral line sufficiently strong as to be measurable. Shortly after the end of the war several groups set about to test this prediction. The 21-cm line of atomic hydrogen was detected in 1951, first at Harvard University followed within a few weeks by others. The discovery demonstrated that astronomical research, which at that time was limited to conventional light, could be complemented with observations at radio wavelengths, revealing a range of new physical processes.
  Pascual Jordan
Thumbnail - Pascual Jordan
 Died 31 Jul 1980 at age 77 (born 18 Oct 1902).
Ernst Pascual Jordan was a German physicist who in the late 1920s co-founded (with Max Born and later Werner Heisenberg) quantum mechanics using matrix methods, showing how light could be interpreted as composed of discrete quanta of energy. Later, (with Wolfgang Pauli and Eugene Wigner), while it was still in its early stages of development, he contributed to the quantum mechancs of electron-photon interactions, now called quantum electrodynamics. He also originated (concurrently with Robert Dicke) a theory of cosmology that proposed to make the universal constants of nature, (such as the universal gravitational constant G), variable over time. [Image: Heisenberg (L) with Jordan (R)]
  Gustav Lindenthal
 Died 31 Jul 1935 at age 85 (born 21 May 1850).
Austrian-born American civil engineer known for designing Hell Gate Bridge across New York City's East River.
  Francis Edgar Stanley
Thumbnail - Francis Edgar Stanley
 Died 31 Jul 1918 at age 69 (born 1 Jun 1849).   quotes
American inventor who, with his twin brother Freeman, were the most famous manufacturers of steam-driven automobiles. Francis previously had invented a photographic dry-plate process (1883), and as the Stanley Dry Plate Company the brothers had engaged in the manufacturing of the plates. They sold the company to Eastman Kodak in 1905, as their interest had turned to steam-powered automobiles. They began working on steam powered cars in 1897, and built thousands of them them until the 1920's as the Stanley Motor Company. At racing events, they often competed successfully against gasoline powered cars (1902-09). They set a world record in 1906 for fastest mile in 28.2 seconds (127 mph or 205 kph). [Image right: 1910 Stanley Model 71]
The Stanley Steamer: America's Legendary Steam Car, by Kit Foster. - book suggestion.
  Benoît Fourneyron
 Died 31 Jul 1867 at age 64 (born 31 Oct 1802).
French engineer and inventor of the water turbine. In 1827, age 25, Fourneyron, introduced a reaction turbine that channeled water through an enclosed chamber fitted with an inner ring of fixed guide blades. These guide blades deflected the water outward against the moving vanes of a "runner." The vanes of this outer runner were curved in the opposite direction from the fixed inner guide blades, reversing the direction of water flow within the device and creating a reactive force. Fourneyron's patent described his invention as "a wheel of universal and continuous pressure or hydraulic turbine." He died in Paris, known as " father of the turbine"
  Denis Diderot
 Died 31 Jul 1784 at age 70 (born 5 Oct 1713).   quotes
French encyclopedist.

Sitewide search within all Today In Science History pages:
Custom Quotations Search - custom search within only our quotations pages:
Visit our Science and Scientist Quotations index for more Science Quotes from archaeologists, biologists, chemists, geologists, inventors and inventions, mathematicians, physicists, pioneers in medicine, science events and technology.

Names index: | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |

Categories index: | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 1 | 2 | 3 | 4 |
JULY 31 – EVENTS – Science events on July 31st
  First unpowered flight across English Channel
Thumbnail -
  In 2003, Felix Baumgartner became the first man to cross the English Channel by unpowered flight. He jumped from a plane about 9,800-m (30,000-ft) above Dover, England and glided 36-km (22-mi) across the Channel in a 10-min flight wearing a special suit with carbon-fibre wings across his back. In sub-zero air, the 34-yr-old Austrian's flight began at about 220 mph, slowing to around 135 mph by the time he landed by parachute at Cap Blanc-Nez, near Calais, in France. He was equipped with oxygen, cameras and hi-tech data monitors to enable his journey to be tracked. His wing span of 1.8-m was about 10-cm longer than another he used a few weeks earlier to win a race against an aeroplane in the U.S. [Image right: Felix Baumgartner gliding above the English Channel.]
  Gene therapy
  In 1990, experiments in gene therapy by the insertion of new genes into body cells were approved for the first time by the Recombinant DNA Advisory Committee of the National Institutes of Health. These first real gene therapies for humans were for adenosine deaminase deficiency (a genetic disease that destroys the immune system) and for a form of cancer. Dr. McGarrity, chair of the committee noted that the protocols that they had voted upon were the first approvals for true gene therapy rather than simple gene insertion. Garrity added that this is a historic occasion in that now gene therapy can be added to the repertoire of vaccines, antibiotics, drugs, surgery, and radiation to fight disease. *
  Lunar auto
  In 1971, Dave Scott became the first person to drive a vehicle on the Moon - the battery-powered Lunar Rover (LRV) - as part of the Apollo 15 mission to the mountainous Hadley-Apennine region. This LRV, the first to be carried on an Apollo mission, built by Boeing, weighed 460 lb (209 kg) and folded into a space 5 ft by 20 in (1.5 m by 0.5 m). Each wheel was independently driven by ¼ horsepower (200 W) electric motor. The astronauts could travel further from their landing site and sample a wider variety of lunar materials. The car travelled 17.4 miles (28 km) and collected about 168 pounds (76 kg) of lunar materials to return to Earth. Shepard and Mitchell of the previous Apollo 14 mission walked about 2.5 miles (4 km), hauling their scientific gear in a two-wheeled cart .« [Image: Lunar Rover Vehicle driven by Dave Scott in the first lunar surface extravehicular activity at the Hadley-Apennine landing site.]
  Last cigarette commercial in GB
  In 1965, the last cigarette commercial appeared on British television.
  Moon pictures
  In 1964, the American space probe Ranger 7 transmitted the first close-up images of the moon's surface ever taken by a U.S. spacecraft, beginning the mapping of the surface in preparation for a future lunar landing. Ranger spacecraft were designed to fly straight down towards the Moon and send images back until the moment of impact. Ranger 7 carried six slow-scan vidicon TV cameras capable of transmitting high-resolution, close-up television pictures of the lunar surface. Seventeen minutes before impact it captured the first image, showing 360-km from top to bottom, including the large crater Alphonsus (108-km diam). The partial scan image taken immediately before impact had a resolution of 0.5 meters. A total of 4308 photographs of excellent quality were returned before Ranger 7 crashed in Mare Cognitum (Sea of Clouds), a mare terrain modified by crater rays.
  Los Angeles smog
  In 1954, a six year research program found that Los Angeles smog was caused by the chemical reaction of sunlight on auto and industrial emissions. The first eye-irritating “smog” in Los Angeles on 26 Jul 1943 - was a “gas attack”of haze, smoke and exhaust that reduced visibility to under three blocks. The Los Angeles Times launched an anti-smog campaign on 1 Dec 1946, and brought a smog expert to Los Angeles to study the problem. On 14 Oct 1947, the L.A. County Board of Supervisors established the nation's first air pollution control program by creating the L.A. County Air Pollution Control District. Dr Haagen-Smit later reported that ozone was the primary nuisance ingredient in smog. London experienced a killer Great Smog on 5 Dec 1952, which resulted in the Clean Air Act of 1956.« [Image: The first recorded photograph of LA smog, 26 July 1943]
Smogtown: The Lung-Burning History of Pollution in Los Angeles, by Chip Jacobs. - book suggestion.
  Dr Crippen apprehended by radio
  In 1910, a murderer was apprehended, after the first use of Marconi telegraph signals in a murder case. American-born Dr Hawley Crippen and his mistress, Ethel Le Neve, disguised as a boy, were arrested for the murder of his wife in England. Her remains were discovered 13 Jul 1910. She had been poisoned with hyoscine, an extract of the deadly plant henbane. An arrest warrant was issued 16 Jul 1910. Crippen was spotted mid-Atlantic as they sailed from Antwerp to Canada on the SS Montrose, the first ship to be equipped with radio-telegraph. On 22 Jul 1910, Captain Kendall alerted London Police of his “strong suspicions.” Crippen was later hanged in Pentonville Prison, London.
  Centennial of Chemistry
Thumbnail - Centennial of Chemistry
  In 1874, the Centennial of Chemistry in the U.S. was celebrated by chemists meeting at Northumberland, Pa. where Joseph Priestley was buried after spending the last years of his life in America. The chemists commemorated the 100th anniversary of Priestley's discovery of the element oxygen on 1 Aug 1774, regarded as the most important link in the chain of events which eventually led to the overthrow of the phlogistic hypothesis. The memorial exercises were planned to include an address by Professor Joseph Henry, an Essay on American Contributions to Chemistry by Benjamin Silliman, Jr., and a loan exhibition of Priestley's apparatus, books and manuscripts. The event was initiated by Henry Bolton.«   more
  Iron railway bridge collapse
  In 1849, an iron railway bridge near Mast Hope, Pennsylvania, collapsed as a stock train was crossing. The engineer heard a loud cracking, pulled the throttle wide open, and succeeded in getting the engine across in safety. However, the rest of the train fell into the deep ravine of the Westcolang Creek along with the wrecked bridge. A brakeman and two stockmen lost their lives. The New York and Erie Railroad had that year experimented by building three iron bridges, including the one that failed. In 1850, an article in the Scientific American magazine reported that the company, having lost confidence in iron bridges, would tear down the two remaining and replace them with wooden structures.«
  In 1849, Benjamin Chambers was issued a U.S. patent for the breech loading cannon (No. 6612). The advantage of breech loading was to speed up the reloading process, allowing troops to fire more rounds per minute. Prior to this technology, troops used musket loading guns and had to run to the front of the gun to reload - wasting time and risking lives. Breechloading guns required a mechanism able to withstand the strain of firing and still operate smoothly and quickly to allow the next round to be fired. This required not only a superior material but expert machining. Chambers' design used a breech piece with sectional screws to allow for speedy opening for "swabbing, depositing the load and readily it closing again."
  First U.S. Patent
  In 1790, the first U.S. patent was granted to Samuel Hopkins of Vermont for a process for making potash and pearl ashes. Potash was important as an ingredient in soap and fertilizer. The patent was granted for a term of 14 years and signed by President George Washington, who had the previous month signed the first U.S. patent statute into law on 10 April 1790. Hopkins did not get Patent with a serial No.1 as thousands of patents were issued before the Patent Office began to number them. Congress had passed the Patent Act on 10 Apr 1790. Two other patents were granted that year - one for a new candle-making process and the third for  flour-milling machinery of Oliver Evans (18 Dec 1790). The next year, 1791, Samuel Hopkins also was granted the first Canadian patent.«
The Patent Office Pony: A History of the Early Patent Office, by Kenneth W. Dobyns. - book suggestion.

who invites your feedback

- 100 -
Sophie Germain
Gertrude Elion
Ernest Rutherford
James Chadwick
Marcel Proust
William Harvey
Johann Goethe
John Keynes
Carl Gauss
Paul Feyerabend
- 90 -
Antoine Lavoisier
Lise Meitner
Charles Babbage
Ibn Khaldun
Ralph Emerson
Robert Bunsen
Frederick Banting
Andre Ampere
Winston Churchill
- 80 -
John Locke
Bronislaw Malinowski
Thomas Huxley
Alessandro Volta
Erwin Schrodinger
Wilhelm Roentgen
Louis Pasteur
Bertrand Russell
Jean Lamarck
- 70 -
Samuel Morse
John Wheeler
Nicolaus Copernicus
Robert Fulton
Pierre Laplace
Humphry Davy
Thomas Edison
Lord Kelvin
Theodore Roosevelt
Carolus Linnaeus
- 60 -
Francis Galton
Linus Pauling
Immanuel Kant
Martin Fischer
Robert Boyle
Karl Popper
Paul Dirac
James Watson
William Shakespeare
- 50 -
Stephen Hawking
Niels Bohr
Nikola Tesla
Rachel Carson
Max Planck
Henry Adams
Richard Dawkins
Werner Heisenberg
Alfred Wegener
John Dalton
- 40 -
Pierre Fermat
Edward Wilson
Johannes Kepler
Gustave Eiffel
Giordano Bruno
JJ Thomson
Thomas Kuhn
Leonardo DaVinci
David Hume
- 30 -
Andreas Vesalius
Rudolf Virchow
Richard Feynman
James Hutton
Alexander Fleming
Emile Durkheim
Benjamin Franklin
Robert Oppenheimer
Robert Hooke
Charles Kettering
- 20 -
Carl Sagan
James Maxwell
Marie Curie
Rene Descartes
Francis Crick
Michael Faraday
Srinivasa Ramanujan
Francis Bacon
Galileo Galilei
- 10 -
John Watson
Rosalind Franklin
Michio Kaku
Isaac Asimov
Charles Darwin
Sigmund Freud
Albert Einstein
Florence Nightingale
Isaac Newton

Thank you for sharing.
Today in Science History
Sign up for Newsletter
with quiz, quotes and more.