Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
1940 in science
open-in-new
<h2 id="biochemistry">Biochemistry</h2> <ul><li>August 24 – <a href="/facts/Howard_Florey/DEoR72FC">Howard Florey</a> and a team including <a href="/facts/Ernst_Chain/VC1EwmT0">Ernst Chain</a>, <a href="/facts/Arthur_Duncan_Gardner/2DmAEfkS">Arthur Duncan Gardner</a>, <a href="/facts/Norman_Heatley/gKvV50CT">Norman Heatley</a>, M. Jennings, J. Orr-Ewing and G. Sanders at the <a href="/facts/Sir_William_Dunn_School_of_Pathology/9kn51oPI">Sir William Dunn School of Pathology</a>, <a href="/facts/University_of_Oxford/ExVVQL6V">University of Oxford</a>, publish their laboratory results showing the <i><a href="/facts/In_vivo/kWcWyl6f">in vivo</a></i> bactericidal action of <a href="/facts/Penicillin/Abo8VQ3p">penicillin</a>. They have also purified the drug.<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a><a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> On December 25 they seed their first batch of culture with spores of penicillin to grow it in medicinal quantity.</li> <li>The <a href="/facts/Antibiotic/sF1kIfxg">antibiotic</a> <a href="/facts/Dactinomycin/HvkQHVDc">dactinomycin</a> (actinomycin D) is first isolated by <a href="/facts/Selman_Waksman/sq4CBkQ5">Selman Waksman</a> and <a href="/facts/H._Boyd_Woodruff/2mvv5T5K">H. Boyd Woodruff</a> at <a href="/facts/Rutgers_University/dC8074a9">Rutgers University</a>.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a></li></ul> <h2 id="biology">Biology</h2> <ul><li>February 2 – The first <a href="/facts/Transposon/WbVMhuWR">transposons</a> are discovered in <a href="/facts/Maize/lJ6c5xMH">maize</a> (<i>Zea mays</i>, aka corn) by <a href="/facts/Barbara_McClintock/aupcEqKv">Barbara McClintock</a>.</li> <li>March 11 – <a href="/facts/Ed_Ricketts/RppLoCyU">Ed Ricketts</a>, <a href="/facts/John_Steinbeck/A1URmFIc">John Steinbeck</a> and six others leave <a href="/facts/Monterey,_California/ssUz4gN8">Monterey</a> for the <a href="/facts/Gulf_of_California/6Da8barh">Gulf of California</a> on a marine invertebrate collecting expedition.</li></ul> <h2 id="chemistry">Chemistry</h2> <ul><li>February 27 – The <a href="/facts/Radioactive/Ya6FVjt4">radioactive</a> <a href="/facts/Isotope/KD9B1y6o">isotope</a> <a href="/facts/Carbon-14/Ut8SBNNa">carbon-14</a> is discovered by <a href="/facts/Martin_Kamen/QFegAuA9">Martin Kamen</a> and <a href="/facts/Sam_Ruben/70mDamCy">Sam Ruben</a> at the <a href="/facts/University_of_California,_Berkeley/MXVEjklr">University of California, Berkeley</a>.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a></li> <li>May 15 – Women's <a href="/facts/Stocking/53cpRTU6">stockings</a> made of <a href="/facts/Nylon/hBvG9bCw">nylon</a> are first placed on sale across the United States.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a></li> <li>December 14 – <a href="/facts/Plutonium/4bUw9zH3">Plutonium</a> is first synthesized by a team led by <a href="/facts/Glenn_T._Seaborg/w1a3mume">Glenn T. Seaborg</a> and <a href="/facts/Edwin_McMillan/XQWS1IkY">Edwin McMillan</a> at the University of California, Berkeley by bombarding <a href="/facts/Uranium-238/QhcHm6q8">uranium-238</a> with <a href="/facts/Deuteron/Bv4wfCkw">deuterons</a>.</li> <li>The radioactive <a href="/facts/Chemical_element/0jducgWD">element</a> <a href="/facts/Astatine/AlbHPBK5">Astatine</a> is synthesized by <a href="/facts/Dale_R._Corson/Klyuh7zN">Dale R. Corson</a>, <a href="/facts/Kenneth_Ross_MacKenzie/CDWHa2Qs">Kenneth Ross MacKenzie</a> and <a href="/facts/Emilio_Segr%C3%A8/yqe8NKp3">Emilio Segrè</a> at the University of California, Berkeley.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a></li> <li><a href="/facts/Neptunium/pwp7Yvds">Neptunium</a>, the first <a href="/facts/Transuranium_element/a12PwdAw">transuranic</a> element, is synthesized by <a href="/facts/Edwin_McMillan/XQWS1IkY">Edwin McMillan</a> and <a href="/facts/Philip_H._Abelson/vwN9SaGK">Philip H. Abelson</a> at the University of California, Berkeley.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a></li> <li><a href="/facts/Louis_Plack_Hammett/1659s4aL">Louis Plack Hammett</a> coins the term <i><a href="/facts/Physical_organic_chemistry/qQSFoCoS">Physical organic chemistry</a></i> when he uses it as the title of a textbook published in New York.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a></li> <li><a href="/facts/Robert_McCance/AHR8K30c">Robert McCance</a> and <a href="/facts/Elsie_Widdowson/XXAShlP6">Elsie Widdowson</a> published the standard text <i>The Chemical Composition of Foods</i>.<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a></li></ul> <h2 id="computer-science">Computer science</h2> <ul><li>January 8 – In the <a href="/facts/History_of_computing_hardware/83xXSmuW">history of computing hardware</a>, <a href="/facts/Bell_Labs/fKP5Gk0H">Bell Labs</a>' Complex Number Computer, a <a href="/facts/Relay/NQcb9usW">relay</a>-based calculator for <a href="/facts/Complex_numbers/2w7mqI7e">complex numbers</a>, is completed under the direction of <a href="/facts/George_Stibitz/M6pUBsqx">George Stibitz</a> in New York City.<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a></li> <li>May–August – <a href="/facts/Alan_Turing/klov9b6g">Alan Turing</a> and <a href="/facts/Gordon_Welchman/94NHoqRx">Gordon Welchman</a> at the United Kingdom <a href="/facts/Government_Code_and_Cypher_School/XCMkfqWE">Government Code and Cypher School</a>, <a href="/facts/Bletchley_Park/ID0B04WB">Bletchley Park</a>, design the British <a href="/facts/Bombe/PR64Llq7">Bombes</a> to help <a href="/facts/Cryptanalysis_of_the_Enigma/RJB0W0S0">decrypt</a> <a href="/facts/Wehrmacht/cVGQH8JW">Wehrmacht</a> <a href="/facts/Enigma_machine/FSMJwbCL">Enigma machine</a> signals.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a></li> <li>September 9 – George Stibitz first demonstrates remote operation of a computer, using a modified <a href="/facts/Teleprinter/pn5SQKTf">teletype</a> working over telegraph lines between an <a href="/facts/American_Mathematical_Society/fr5gotCt">American Mathematical Society</a> conference at <a href="/facts/Dartmouth_College/JLk2nNaN">Dartmouth College</a> in New Hampshire and the Complex Number Computer in New York.<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a><a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a><a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a></li></ul> <h2 id="exploration">Exploration</h2> <ul><li>December – <a href="/facts/Finn_Ronne/t3cv4zED">Finn Ronne</a> and <a href="/facts/Carl_R._Eklund/LSsGHYLp">Carl Eklund</a> of the <a href="/facts/United_States_Antarctic_Service/E9g0E5rh">United States Antarctic Service</a> determine that <a href="/facts/Alexander_Island/KdPNRTKv">Alexander I Land</a> is an island.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a><a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a></li></ul> <h2 id="mathematics">Mathematics</h2> <ul><li><a href="/facts/Friedrich_Wilhelm_Levi/4W0PrfPh">Friedrich Wilhelm Levi</a> introduces the <a href="/facts/Levi_graph/pMnp7zkv">Levi graph</a> in a series of lectures on <a href="/facts/Finite_geometry/GL0nnEk8">finite geometry</a> at the <a href="/facts/University_of_Calcutta/CjjFrJnT">University of Calcutta</a>.<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a></li></ul> <h2 id="medicine">Medicine</h2> <ul><li>At <a href="/facts/Johns_Hopkins_Hospital/SDFhJozp">Johns Hopkins Hospital</a> in the United States, Dr. Austin T. Moore (1899–1963) performs the first metallic <a href="/facts/Hip_replacement/YcdY8GGC">hip replacement</a> surgery.</li> <li>German optometrist <a href="/facts/Heinrich_W%C3%B6hlk/BudJxKW5">Heinrich Wöhlk</a> produces fully plastic <a href="/facts/Contact_lens/0nzxq5Rm">contact lenses</a>.</li></ul> <h2 id="metallurgy">Metallurgy</h2> <ul><li><a href="/facts/William_Justin_Kroll/Tgzam8kA">William Justin Kroll</a> devises the <a href="/facts/Kroll_process/xzTkfDCQ">Kroll process</a>.</li></ul> <h2 id="physics">Physics</h2> <ul><li>January 5 – <a href="/facts/FM_radio/TpKl3FJv">FM radio</a> demonstrated to the <a href="/facts/Federal_Communications_Commission/Ueghz8W0">FCC</a> for the first time.</li> <li>March – <a href="/facts/Frisch%E2%80%93Peierls_memorandum/hy72RRtq">Frisch–Peierls memorandum</a>: <a href="/facts/Otto_Frisch/dyLPH66s">Otto Frisch</a> and <a href="/facts/Rudolf_Peierls/La4r1ISU">Rudolf Peierls</a>, at this time working at the <a href="/facts/University_of_Birmingham/b2YEFk2X">University of Birmingham</a> in England, calculate that an <a href="/facts/Atomic_bomb/QVdBcMdm">atomic bomb</a> could be produced using very much less enriched <a href="/facts/Uranium/n2sGWBzU">uranium</a> than has previously been supposed, making it a practical proposition.<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a></li> <li>April 10 – <a href="/facts/MAUD_Committee/4vv2CPM0">MAUD Committee</a> first convened in Britain to consider the feasibility of an atomic bomb.</li> <li><a href="/facts/Cavity_magnetron/8qd9pfsj">Cavity magnetron</a> invented by <a href="/facts/John_Randall_(physicist)/STtE751y">John Randall</a> and <a href="/facts/Harry_Boot/PIwERQ4Q">Harry Boot</a>.</li> <li><a href="/facts/Spontaneous_fission/0QuJoVKI">Spontaneous fission</a> first observed by <a href="/facts/Georgy_Flyorov/qhcQHs2q">Georgy Flyorov</a> and <a href="/facts/Konstantin_Petrzhak/ouUMxd1H">Konstantin Petrzhak</a>.</li></ul> <h2 id="technology">Technology</h2> <ul><li>May 26 – First free flight of <a href="/facts/Igor_Sikorsky/pSr0lV7v">Igor Sikorsky</a>'s <a href="/facts/Vought-Sikorsky_VS-300/G0cXuDc2">Vought-Sikorsky VS-300</a> <a href="/facts/Helicopter/chQF7H55">helicopter</a>, in the United States.</li> <li>September 21 – <a href="/facts/American_Bantam/D5XCYkJw">American Bantam</a> deliver the first prototype BRC Quarter-Ton General Purpose Vehicle – the <a href="/facts/Four-wheel_drive/5sFHvumf">four-wheel drive</a> <a href="/facts/Jeep/6f5snxWn">Jeep</a>, designed by <a href="/facts/Karl_Probst/SzaS6LKH">Karl Probst</a>.<a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a></li> <li>November 7 – The new <a href="/facts/Tacoma_Narrows_Bridge_(1940)/qHJsPjTm">Tacoma Narrows Bridge</a> collapses due to <a href="/facts/Aeroelastic_flutter/xEL9ae5M">aeroelastic flutter</a>.</li> <li><a href="/facts/Donald_Leslie/t24cgdqr">Donald Leslie</a> demonstrates the <a href="/facts/Leslie_speaker/oWXlCukc">Leslie speaker</a>, intended as an adjunct to the <a href="/facts/Hammond_organ/1Xr2Ia2c">Hammond organ</a>.</li></ul> <h2 id="other-events">Other events</h2> <ul><li>September–November – The <a href="/facts/Tizard_Mission/u9qwYqjA">Tizard Mission</a>, a British technical and scientific mission, exchanges information on wartime scientific advances with the United States, including <a href="/facts/Radar/jk9BTbFA">radar</a> (in particular a greatly improved <a href="/facts/Cavity_magnetron/8qd9pfsj">cavity magnetron</a>), <a href="/facts/Frank_Whittle/sQysmK64">Frank Whittle</a>'s <a href="/facts/Jet_engine/CJjFpeqt">jet engine</a>, the <a href="/facts/Frisch%E2%80%93Peierls_memorandum/hy72RRtq">Frisch–Peierls memorandum</a> on feasibility of an atomic bomb and work of the '<a href="/facts/Tube_Alloys/SEvxMHJ5">Tube Alloys</a>' project on production of <a href="/facts/Enriched_uranium/vSb2Tcsb">enriched uranium</a>.</li></ul> <h2 id="births">Births</h2> <ul><li>January 8 <ul><li><a href="/facts/Mark_Bretscher/YATAAJEy">Mark Bretscher</a>, English biologist and academic</li> <li><a href="/facts/Brian_Josephson/GG07CsRp">Brian Josephson</a>, Welsh-born theoretical physicist and winner of the <a href="/facts/Nobel_Prize_in_Physics/o6w1nCbr">Nobel Prize in Physics</a>.</li></ul></li> <li>April 1 – <a href="/facts/Wangari_Maathai/6joUk5HR">Wangari Maathai</a>, née Muta (died <a href="/facts/2011_in_science/wT16UWvG">2011</a>), <a href="/facts/Kenya/Y9Ko9pQu">Kenyan</a> <a href="/facts/Biologist/yJJGXyKR">biologist</a> and winner of the <a href="/facts/Nobel_Peace_Prize/2wVhmLrX">Nobel Peace Prize</a>.</li> <li>April 18 – <a href="/facts/Joseph_L._Goldstein/fbEtMlDS">Joseph L. Goldstein</a>, American <a href="/facts/Biochemist/gAWNAY5v">biochemist</a> and winner of the <a href="/facts/Nobel_Prize_in_Physiology_or_Medicine/rlnpJX84">Nobel Prize in Physiology or Medicine</a>.</li> <li>May 17 – <a href="/facts/Alan_Kay/opDYqrcm">Alan Kay</a>, American computer scientist and winner of the <a href="/facts/Turing_Award/HbEEp0GF">Turing Award</a>.</li> <li>June 1 – <a href="/facts/Kip_Thorne/o6wkjTtP">Kip Thorne</a>, American gravitational physicist and winner of the <a href="/facts/Nobel_Prize_in_Physics/o6w1nCbr">Nobel Prize in Physics</a>.</li> <li>June 5 – <a href="/facts/Dickson_Despommier/UGLGbMA7">Dickson Despommier</a>, American <a href="/facts/Microbiologist/cqEyJwNK">microbiologist</a>, <a href="/facts/Ecologist/YE8upuJU">ecologist</a> and Professor of <a href="/facts/Public_health/4563Kre9">Public health</a> in Environmental Health Sciences at <a href="/facts/Columbia_University/Hlf1gw53">Columbia University</a>.</li> <li>June 22 – <a href="/facts/Daniel_Quillen/E4Nak15V">Daniel Quillen</a> (died 2011), American <a href="/facts/Mathematician/eaFSR8Fx">mathematician</a>.</li> <li>July 15 – <a href="/facts/Stephen_Jacobsen/QHCe9eLp">Stephen Jacobsen</a> (died <a href="/facts/2016_in_science/xaChyHmT">2016</a>), American <a href="/facts/Bioengineer/N8WPz0P7">bioengineer</a> and <a href="/facts/Roboticist/wkmvodJz">roboticist</a>.</li> <li>July 30 – <a href="/facts/Clive_Sinclair/t5eqanJQ">Clive Sinclair</a> (died <a href="/facts/2021_in_science/jWGfKMyf">2021</a>), English inventor.</li> <li>September 12 – <a href="/facts/Joachim_Frank/F5qAdMR1">Joachim Frank</a>, German-born <a href="/facts/Biophysicist/l9u5gqCy">biophysicist</a> and winner of the <a href="/facts/Nobel_Prize_in_Chemistry/8Nb8Ajjy">Nobel Prize in Chemistry</a>.</li> <li>September 26 – <a href="/facts/Louise_Johnson/k4oE20gH">Louise Johnson</a> (died <a href="/facts/2012_in_science/LJKMAdSd">2012</a>), British <a href="/facts/Biochemist/gAWNAY5v">biochemist</a> and protein <a href="/facts/Crystallography/9B5toeqG">crystallographer</a>.</li> <li>November 20 – <a href="/facts/Arieh_Warshel/GFdpNtAN">Arieh Warshel</a>, <a href="/facts/Israel/dEe3IcaY">Israeli</a>-born winner of the <a href="/facts/Nobel_Prize_in_Chemistry/8Nb8Ajjy">Nobel Prize in Chemistry</a>.</li> <li>November 26 – <a href="/facts/Enrico_Bombieri/MU6xU5vr">Enrico Bombieri</a>, Italian-born mathematician.</li> <li><a href="/facts/Judith_Pipher/FfLjtzS6">Judith Pipher</a>, American <a href="/facts/Astrophysicist/krFPRWLA">astrophysicist</a>.</li> <li>December 24 – <a href="/facts/Anthony_Fauci/QFebcwYs">Anthony Fauci</a>, American physician-scientist and immunologist.</li></ul> <h2 id="deaths">Deaths</h2> <ul><li>March 9 – <a href="/facts/Robert_Gunther/QV1lzkoH">Robert Gunther</a> (born <a href="/facts/1869_in_science/CYwoS0jj">1869</a>), English historian of science.</li> <li>April 13 – <a href="/facts/Pierre_Marie/fgXtENsu">Pierre Marie</a> (born <a href="/facts/1853_in_science/R7q2BBVn">1853</a>), French <a href="/facts/Neurologist/TXYEMSYI">neurologist</a>.</li> <li>April 29 – <a href="/facts/Edgar_Buckingham/BslxMrdB">Edgar Buckingham</a> (born <a href="/facts/1867_in_science/W9300Kyo">1867</a>), American physicist.</li> <li>June 17 – <a href="/facts/Arthur_Harden/tYYdraTP">Arthur Harden</a> (born <a href="/facts/1865_in_science/WUHc8xS1">1865</a>), English <a href="/facts/Biochemist/gAWNAY5v">biochemist</a> and Nobel laureate in chemistry.</li> <li>June 21 – <a href="/facts/John_T._Thompson/KLAsHhpG">John T. Thompson</a> (born <a href="/facts/1860_in_science/RDhtEhvt">1860</a>), American inventor.</li> <li>July 31 – <a href="/facts/Louis_Charles_Christopher_Krieger/loSQLxlj">Louis Charles Christopher Krieger</a> (born <a href="/facts/1873_in_science/Cz0weAdA">1873</a>), American <a href="/facts/Mycologist/rzC12BLF">mycologist</a>.</li> <li>August 30 – <a href="/facts/J._J._Thomson/Y4jyndJF">J. J. Thomson</a> (born <a href="/facts/1856_in_science/5jhUepAI">1856</a>), English physicist and Nobel laureate in physics.</li> <li>November 8 – <a href="/facts/Arthur_Vierendeel/vu43VTxU">Arthur Vierendeel</a> (born <a href="/facts/1852_in_science/BSfIEwWG">1852</a>), <a href="/facts/Belgians/xSmHFHch">Belgian</a> <a href="/facts/Civil_engineer/RjIFIjNe">civil engineer</a>.</li> <li>November 17 – <a href="/facts/Raymond_Pearl/PCuN2uBU">Raymond Pearl</a> (born <a href="/facts/1879_in_science/6aYnyD1n">1879</a>), American <a href="/facts/Biologist/yJJGXyKR">biologist</a>.</li> <li>December 16 – <a href="/facts/Eug%C3%A8ne_Dubois/aDarVA1I">Eugène Dubois</a> (born <a href="/facts/1858_in_science/bxUykk1b">1858</a>), <a href="/facts/Netherlands/y8xn5stT">Dutch</a> <a href="/facts/Paleoanthropology/Umjg0sUn">paleoanthropologist</a>.</li> <li>December 17 – <a href="/facts/Alicia_Boole_Stott/FoqXBA5T">Alicia Boole Stott</a> (born <a href="/facts/1860_in_science/RDhtEhvt">1860</a>) <a href="/facts/British_people/xn7cqlzV">British</a> mathematician.</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Drews, Jürgen (March 2000). "Drug Discovery: a Historical Perspective". Science. 287 (5460): 1960–4. Bibcode:2000Sci...287.1960D. doi:10.1126/science.287.5460.1960. PMID 10720314. S2CID 1827304. <a href="/wiki/Science_(journal)" target="_blank">/wiki/Science_(journal)</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Robertson, Patrick (1974). The Shell Book of Firsts. London: Ebury Press. p. 124. <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Waksman, S. A.; Woodruff, H. B. (1940). "Bacteriostatic and bacteriocidal substances produced by soil actinomycetes". Proceedings of the Society for Experimental Biology and Medicine. 45: 609–614. doi:10.3181/00379727-45-11768. S2CID 84774334. <a href="/wiki/Proceedings_of_the_Society_for_Experimental_Biology_and_Medicine" target="_blank">/wiki/Proceedings_of_the_Society_for_Experimental_Biology_and_Medicine</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Kamen, Martin D. (1963). "Early History of Carbon-14: Discovery of this supremely important tracer was expected in the physical sense but not in the chemical sense". Science. 140 (3567): 584–590. Bibcode:1963Sci...140..584K. doi:10.1126/science.140.3567.584. JSTOR 1710512. PMID 17737092. <a href="/wiki/Science_(journal)" target="_blank">/wiki/Science_(journal)</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Trossarelli, L. (2010). "the history of nylon". Club Alpino Italiano, Centro Studi Materiali e Tecniche. Archived from the original on 2012-04-25. Retrieved 2012-02-28. <a href="http://www.caimateriali.org/index.php?id=32" target="_blank">http://www.caimateriali.org/index.php?id=32</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Corson, D. R.; MacKenzie, K. R.; Segrè, E. (1940). "Artificially Radioactive Element 85". Physical Review. 58 (8): 672–678. Bibcode:1940PhRv...58..672C. doi:10.1103/PhysRev.58.672. <a href="/wiki/Physical_Review" target="_blank">/wiki/Physical_Review</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Mcmillan, Edwin; Abelson, Philip Hauge (1940). "Radioactive Element 93". Physical Review. 57 (12): 1185–6. Bibcode:1940PhRv...57.1185M. doi:10.1103/PhysRev.57.1185.2. <a href="https://doi.org/10.1103%2FPhysRev.57.1185.2" target="_blank">https://doi.org/10.1103%2FPhysRev.57.1185.2</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Hammond, George S. (1997). "Physical organic chemistry after 50 years: It has changed, but is it still there?" (PDF). Pure and Applied Chemistry. 69 (9). IUPAC: 1919–22. doi:10.1351/pac199769091919. S2CID 53723796. Retrieved 2014-01-22. <a href="/wiki/George_S._Hammond" target="_blank">/wiki/George_S._Hammond</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Whitehead, Roger (2004). "Widdowson, Elsie May (1906–2000)". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/74313. Retrieved 2011-08-10. (Subscription or UK public library membership required.) <a href="http://www.oxforddnb.com/view/article/74313" target="_blank">http://www.oxforddnb.com/view/article/74313</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>US patent 2668661, "Complex Computer", issued 1954-02-09, assigned to American Telephone & Telegraph <a href="https://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US2668661" target="_blank">https://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US2668661</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>Smith, Michael (2007). Station X: the Codebreakers of Bletchley Park. Pan Grand Strategy Series (rev. ed.). London: Pan Macmillan. ISBN 978-0-330-41929-1. <a href="978-0-330-41929-1" target="_blank">978-0-330-41929-1</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>Ritchie, David (1986). "George Stibitz and the Bell Computers". The Computer Pioneers. New York: Simon and Schuster. p. 39. ISBN 067152397X. <a href="067152397X" target="_blank">067152397X</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>Metropolis, Nicholas (2014). History of Computing in the Twentieth Century. Elsevier. p. 481. ISBN 9781483296685. <a href="9781483296685" target="_blank">9781483296685</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>Dalakov, Georgi. "Relay computers of George Stibitz". History of Computers: Hardware, Software, Internet. Retrieved 2015-03-30. <a href="http://history-computer.com/ModernComputer/Relays/Stibitz.html" target="_blank">http://history-computer.com/ModernComputer/Relays/Stibitz.html</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>U.S. Geological Survey Geographic Names Information System: 1940 in science <a href="https://web.archive.org/web/2020/https://geonames.usgs.gov/apex/f?p=gnispq:5:::NO::P5_ANTAR_ID:236" target="_blank">https://web.archive.org/web/2020/https://geonames.usgs.gov/apex/f?p=gnispq:5:::NO::P5_ANTAR_ID:236</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></p></li> <li id="fn:16"><p>Siple, Paul (1963). "Obituary: Carl R. Eklund, 1909-1962" (PDF). Arctic. 16 (2). Arctic Institute of North America: 147–148. doi:10.14430/arctic3531. Retrieved 2013-01-19. <a href="/wiki/Paul_Siple" target="_blank">/wiki/Paul_Siple</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></p></li> <li id="fn:17"><p>Levi, F. W. (1942). Finite Geometrical Systems. University of Calcutta. MR 0006834. <a href="/wiki/MR_(identifier)" target="_blank">/wiki/MR_(identifier)</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> <li id="fn:18"><p>Gowing, Margaret (1964). Britain and Atomic Energy, 1935–1945. London: Macmillan Publishing. pp. 40–43. OCLC 3195209. <a href="/wiki/Margaret_Gowing" target="_blank">/wiki/Margaret_Gowing</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></p></li> <li id="fn:19"><p>Auto Editors of Consumer Guide. "1906-1939 Jeep: Jeep Makes History". HowStuffWorks. Archived from the original on 2012-05-01. Retrieved 2012-05-31. <a href="https://web.archive.org/web/20120501212215/http://auto.howstuffworks.com/1906-1939-jeep4.htm" target="_blank">https://web.archive.org/web/20120501212215/http://auto.howstuffworks.com/1906-1939-jeep4.htm</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></p></li> </ol>