Wednesday, 18 February 2026

On This Day in Math - February 18

  

Leon Battista Alberti, De pictura and Elementa *Museo Galileo

The power of mathematics rests on its evasion of all unnecessary thought and on its wonderful saving of mental operations.
~Ernst Mach

The 49th day of the year; lots of numbers are squareful (divisible by a square number) but 49 is the smallest number so that it, and both its neighbors are squareful. (Many interesting questions arise for students.. what's next, can there be four in a row?, etc)

And Prof. William D Banks of the University of Missouri has recently proved that every integer in base ten is the sum of 49 or less palindromes. (August 2015) (Building on Prof. Banks groundbreaking work, by February 22, 2016 JAVIER CILLERUELO AND FLORIAN LUCA had proved that for any base > 4   EVERY POSITIVE INTEGER IS A SUM OF THREE PALINDROMES )


1 / 49 = 0.0204081632 6530612244 8979591836 7346938775 51 and then repeats the same 42 digits.  It's better than it looks.  Write down all the powers of two, and then index them two to the right and add.




 

The 49th Mersenne prime is discovered. On Jan 19th, 2016 The GIMPS program announced a new "largest known" prime, 274,207,281 -1. called M74,207,281 for short, the number has 22,338,618 digits.


EVENTS
3102 B.C. The Kaliyuga begins according to the Indian mathematician Aryabhata (born A.D. 476). He believed all astronomical phenomena were periodic, with period 4,320,000= 20 × 603 years, and that all the planets had mean longitude zero on this date. [College Mathematics Journal, 16 (1985), p. 169.] *VFR

1670 “Joannes Georgius Pelshower [Regimontanus Borussus] giving me a visit, and desiring an example of the like, I did that night propose to myself in the dark without help to my memory a number in 53 places: 2468135791011121411131516182017192122242628302325272931 of which I extracted the square root in 27 places: 157103016871482805817152171 proxim´e; which numbers I did not commit to paper till he gave me another visit, March following, when I did from memory dictate them to him.” So wrote John Wallis. [American Journal of Psychology, 4(1891), 38] *VFR
Wallis made significant contributions to trigonometry, calculus, geometry, and the analysis of infinite series. In his Opera Mathematica I (1695) he introduced the term "continued fraction".  He was one of the finest cryptographers of the period.
Wallis has been credited as the originator of the number line "for negative quantities" and "for operational purposes." This is based on a passage in his 1685 treatise on algebra in which he introduced a number line to illustrate the legitimacy of negative quantities.









1673: Robert Hooke writes in his Journal: "Bought Copernicus tower hill 2sh " *‏@HookesLondon Thony Christie points out that current first editions run about \( 2,500,000 \) GB Pounds.

1727 Leonhard Euler defends his De Sono essay in a public disputation at the law auditorium at Basal. His paper had been submitted as his "habilitationsschrift", part of his application for the Physics Professorship at Basal. Fortunately, he did not get the position, and soon departed for a position at Petersburg Academy of Science in Russia. Among other competitors overlooked for the position was Jakob Hermann. *Ronald S. Calinger; Leonhard Euler: Mathematical Genius in the Enlightenment


1772 the Royal Danish Academy of Sciences and Letters presented Alexander Wilson with a gold medal for his work on sunspots. Wilson was a Scottish surgeon, type-founder, astronomer, mathematician and meteorologist and the first scientist to record the use of kites in meteorological investigations. Wilson noted that sunspots viewed near the edge of the Sun's visible disk appear depressed below the solar surface, a phenomenon referred to as the Wilson effect. When the Royal Danish Academy of Sciences and Letters announced a prize to be awarded for the best essay on the nature of solar spots, Wilson submitted an entry which won. *Wik  Regius Professor of Practical Astronomy at the University of Glasgow.



1879 “I will do the same for the young women that I do for the young men. I shall take pleasure in giving gratuitous instruction to any person whom I find competent to receive it. I give no elementary instruction, but only in the higher mathematics.” Benjamin Peirce to Arthur V. Gilman, president of Harvard. [Scripta Mathematica, 11(1945), 259
*VFR




1879 J. J. Sylvester, in a lecture at the Peabody Institute in Baltimore, read “Rosalind”, a mock-sentimental poem of four hundred lines all ending in “ind”. For the first few lines of this dreadful poem, see Osiris, 1(1936), p. 106. *VFR Encyclopedia.com says that Sylvester was the author of this poem, and another which had two hundred lines rhyming with “Winn.” These were products of his later residence in Baltimore. Sylvester had perhaps a better appreciation of music.

In 1913, chemist Frederick Soddy introduced the term "isotope". Soddy was an English chemist and physicist who received the Nobel Prize for Chemistry in 1921 for investigating radioactive substances. He suggested that different elements produced in different radioactive transformations were capable of occupying the same place on the Periodic Table, and on 18 Feb 1913 he named such species "isotopes" from Greek words meaning "same place." He is credited, along with others, with the discovery of the element protactinium in 1917. *TIS He also wrote the mathematical poem, The Kiss Precise, which includes a solution to Descartes Circle Problem. the poem begins:
For pairs of lips to kiss maybe
Involves no trigonometry.
'Tis not so when four circles kiss
Each one the other three.
To bring this off the four must be
As three in one or one in three.
If one in three, beyond a doubt
Each gets three kisses from without.
If three in one, then is that one
Thrice kissed internally.
The complete link is here





1930 Clyde Tombaugh (1906–1997) discovered Pluto on photographic plates under the direction of V M Slipher at the Lowell Observatory at Flagstaff, Az. For 45 minutes, before he showed his superiors, he was the only person in the world who knew it existed. When he later went to college he was not allowed to take Astronomy I, the instructor thinking it unsuitable for the discoverer of a planet. (On August 24th of 2006 the International Astronomical Union decided to rescind Pluto’s status as a planet and reclassify it as another entity called a “dwarf planet”. ) *FFF, pg 537

And from @MAAnow " Clyde Tombaugh proved the existence of what would become Pluto, but the woman whose calculations made that possible has been largely forgotten by history. Meet Elizabeth Williams, the mathematician behind our favorite tiny (non?)planet. Williams' role in the Planet X project was that of head human computer, performing mathematical calculations on where Lowell should search for an unknown object and its size based on the differences in the orbits of Neptune and Uranus. Her calculations led to predictions for the location of the unknown planet, :


2006 The game of Connect Four was first solved by James D. Allen (Oct 1, 1988), and independently by Victor Allis (Oct 16, 1988). First player can force a win. Strongly solved by John Tromp's 8-ply database (Feb 4, 1995). It was weakly solved for all boardsizes where width+height is at most 15 (Feb 18, 2006). *Wik






BIRTHS

1201 Muhammad ibn Muhammad ibn al-Hasan al-Tusi (18 Feb 1201; 26 Jun 1274 at age 73) Persian philosopher, scientist, mathematician and astronomer who made outstanding contributions in his era. When The Mongol invasion, started by Genghis Khan, reached him in 1256, he escaped likely death by joining the victorious Mongols as a scientific adviser. He used an observatory built at Maragheh (finished 1262), assisted by Chinese astronomers. It had various instruments such as a 4 meter wall quadrant made from copper and an azimuth quadrant which was Tusi's own invention. Using accurately plotted planetary movements, he modified Ptolemy's model of the planetary system based on mechanical principles. The observatory and its library became a center for a wide range of work in science, mathematics and philosophy. He was known by the title Tusi from his place of birth (Tus)*TIS
Iranian stamp for the 700th anniversary of his death


1404 Leon Battista Alberti (18 Feb 1404; 25 Apr 1472 at age 68) Italian artist and geometrist who “wrote the book,” the first general treatise Della Pictura (1434) on the the laws of perspective, establishing the science of projective geometry. Alberti also worked on maps (again involving his skill at geometrical mappings) and he collaborated with Toscanelli who supplied Columbus with the maps for his first voyage. He also wrote the first book on cryptography which contains the first example of a frequency table. *TIS
. This noted architect took up the study of mathematics for relaxation. He contributed to the study of perspective. *VFR





1677 Jacques Cassini (18 Feb 1677; 16 Apr 1756 at age 79) French astronomer whose direct measurement of the proper motions of the stars (1738) disproved the ancient belief in the unchanging sphere of the stars. He also studied the moons of Jupiter and Saturn and the structure of Saturn's rings. His two major treatises on these subject appeared in 1740: Elements of Astronomy and Astronomical Tables of the Sun, Moon, Planets, Fixed Stars, and Satellites of Jupiter and Saturn. He also wrote about electricity, barometers, the recoil of firearms, and mirrors. He was the son of astronomer, mathematician and engineer Giovanni Cassini (1625-1712) with whom he made numerous geodesic observations. Eventually, he took over his father's duties as head of the Paris Observatory.*TIS Cassini was born at the Paris Observatory and died at Thury, near Clermont. Admitted at the age of seventeen to membership of the French Academy of Sciences, he was elected in 1696 a fellow of the Royal Society of London, and became maître des comptes in 1706. *Wik



1745 Count Alessandro Giuseppe Antonio Anastasio Volta (18 Feb 1745; 5 Mar 1827 at age 82) Italian physicist who invented the electric battery (1800), which for the first time enabled the reliable, sustained supply of current. His voltaic pile used plates of two dissimilar metals and an electrolyte, a number of alternated zinc and silver disks, each separated with porous brine-soaked cardboard. Previously, only discharge of static electricity had been available, so his device opened a new door to new uses of electricity. Shortly thereafter, William Nicholson decomposed water by electrolysis. That same process later enabled Humphry Davy to isolate potassium and other metals. Volta also invented the electrophorus, the condenser and the electroscope. He made important contributions to meteorology. His study of gases included the discovery of methane. The volt, a unit of electrical measurement, is named after him.*TIS
Volta battery at the Tempio Voltiano museum, Como
*Wik






1832 Octave Chanute(18 Feb 1832, 23 Nov 1910) U.S. aeronaut whose work and interests profoundly influenced Orville and Wilbur Wright and the invention of the airplane. Octave Chanute was a successful engineer who took up the invention of the airplane as a hobby following his early retirement. He designed and built the Hannibal Bridge with Joseph Tomlinson and George S. Morison. In 1869, this bridge established Kansas City, Missouri as the dominant city in the region, as the first bridge to cross the Missouri River there. He designed many other bridges during his railroad career, including the Illinois River rail bridge at Chillicothe, Illinois, the Genesee River Gorge rail bridge near Portageville, New York (now in Letchworth State Park), the Sibley Railroad Bridge across the Missouri River at Sibley, Missouri, the Fort Madison Toll Bridge at Fort Madison, Iowa, and the Kinzua Bridge in Pennsylvania.
Knowing how railroad bridges were strengthened, Chanute experimented with box kites using the same basic strengthening method, which he then incorporated into wing design of gliders. Through thousands of letters, he drew geographically isolated pioneers into an informal international community. He organized sessions of aeronautical papers for the professional engineering societies that he led; attracted fresh talent and new ideas into the field through his lectures; and produced important publications. *TIS The town of Chanute, Kansas is named after him, as well as the former Chanute Air Force Base near Rantoul, Illinois, which was decommissioned in 1993. The former Base, now turned to peacetime endeavors, includes the Octave Chanute Aerospace Museum, detailing the history of aviation and of Chanute Air Force base. He was buried in Springdale Cemetery, Peoria, Illinois. *Wik
Chanute's 12 wing glider, Katydid.


Chanute's 1896 biplane hang glider is a trailblazing design adapted by the Wright brothers, who "contrived a system consisting of two large surfaces on the Chanute double-deck plan".




1838 Ernst Mach (18 Feb 1838; 19 Feb 1916 at age 77) Austrian physicist and philosopher who established important principles of optics, mechanics, and wave dynamics. His early physical works were devoted to electric discharge and induction. Between 1860 and 1862 he studied in depth the Doppler Effect by optical and acoustic experiments. He introduced the "Mach number" for the ratio of speed of object to speed of sound is named for him. When supersonic planes travel today, their speed is measured in terms that keep Mach's name alive. His lifetime interest, however, was in psychology and human perception. He supported the view that all knowledge is a conceptual organization of the data of sensory experience (or observation). *TIS
Ernst Mach's historic 1887 photograph (shadowgraph) of a bow shockwave around a supersonic bullet.




1844 Jacob Lueroth (18 Feb 1844 in Mannheim, Germany - 14 Sept 1910 in Munich, Germany) Lüroth was taught by Hesse and Clebsch and continued to develop their work on geometry and invariants. He published results in the areas of analytic geometry, linear geometry and continued the directions of his teachers in his publications on invariant theory. In 1869 Lüroth discovered the "Lüroth quartic". This came out of an investigation he was carrying out into when a ternary quartic form could be represented as the sum of five fourth powers of linear forms.
Some of his work on rational curves, published in Mathematische Annalen in 1876, was extended to surfaces by Castelnuovo in 1895. In 1883 Lüroth published his method on constructing a Riemann surface for a given algebraic curve.
Lüroth also worked on the big problem of the topological invariance of dimension. He made some useful progress but this difficult problem was not completely solved until the work of Brouwer in 1911.
Among his other work, Lüroth undertook editing. He was an editor of the complete works of Hesse and of Grassmann. He also has some fine results on logic, a topic he worked on in collaboration with his friend Ernst Schröder.
Von Staudt's ideas of geometry interested Lüroth and he further developed von Staudt's complex geometry. He published Grundriss der Mechanik in 1881. This mechanics book makes heavy use of the vector calculus. *sau




1922 Ferdinand Wittenbauer (18 February 1857 in Maribor – 16 February 1922 in Graz) was an Austrian mechanical engineer and writer. He is known for introducing graphic methods in dynamics.

Ferdinand Wittenbauer was born on 18 February 1857 in Maribor as third child to Ferdinand Wittenbauer, a military doctor. His parents died early. He then lived in Graz with his uncle and attended Realschule, where he was always top of his class. He did his Matura at the early age of fifteen and later studied at the School of Engineering at Technische Hochschule Graz.  In 1879, he graduated from the Technische Hochschule with honours.  From 1883 to 1884 he undertook a study trip through Germany visiting the universities of Berlin and Freiburg im Breisgau. In 1887, he was appointed to the chair Reine und Technische Mechanik und Theoretische Maschinenlehre which relates to mechanics and machine science at the Technische Hochschule Graz. He succeeded Franz Stark who was appointed professor at the Deutsche Technische Hochschule in Prague.[ From 1894 to 1896 and from 1903 to 1905, Wittenbauer served as dean to the faculty of mechanical engineering, from 1911 to 1912 as rector to his alma mater.


Ferdinand Wittenbauer married Hermine née Weiß in 1882. His wife died in 1914. Their only son Ferdinand was born in 1886, became an engineer as well and died by suicide in September 1922. Ferdinand Wittenbauer died on 16 February 1922 in Graz due to the consequences of a stroke he suffered earlier that year.

At the beginning of his scientific career, Wittenbauer worked on kinematic geometry. His main contribution lay in applying graphic methods of kinematic geometry to dynamics. In 1904, he started publishing treatises which were preliminary works for his almost 800-page book on Graphische Dynamik (Graphical Dynamics), which he completed only shortly before his death. In 1905, Wittenbauer first published his internationally acclaimed and still valid method for a graphic determination of the flywheel moment of inertia.

You may come across posts that mention Wittenbaur's parallelogram, without ever commenting on why he chose such an unusual way to form a parallelogram, a pretty trivial process.  His method was to take any quadrilateral and by trisecting each side, and then construction of a parallelogram with sides parallel to the diagonals of the original quadrilateral.  The center of gravity of a random quadrilateral is harder to arrive at than the center of gravity of a parallelogram. But by creating a parallelogram with the same center of gravity as the original quadrilateral it made the centroid (centre of mass) easy. 

Ferdinand Wittenbauer also discovered an easy method to calculate the centroid (centre of mass) of any quadrangle, known as Wittenbauer's  Theorem or Wittenbauer's Parallelogram. 

In addition, Wittenbauer is known for his Aufgaben aus der technischen Mechanik, a collection of exercises in technical mechanics including solutions published in three volumes. Co-author was mathematician and engineer Theodor Pöschl (son to Jakob Pöschl, Nikola Tesla’s teacher). Finished in 1911, it served as very first and then most prominent set of problems in the fields of mechanics in the German-speaking area for some decades. It was translated into several languages, in 1965 a Spanish edition still appeared. *Wik * PB

Draw an arbitrary quadrilateral and divide each of its sides into three equal parts. Draw a line through adjacent points of trisection on either side of each vertex and you'll have a parallelogram. *Futility Closet





1871 George Udny Yule (18 Feb 1871 in Morham (near Haddington), Scotland - 26 June 1951 in Cambridge, Cambridgeshire, England) graduated in Engineering from University College London and then studied in Bonn. He worked with Karl Pearson on the statistics of regression and correlation. He took a post with an examinations board before being appointed to a Cambridge fellowship. He is best known for his book: Introduction to the Theory of Statistics.*SAU





DEATHS

901 Al-Sabi Thabit ibn Qurra al-Harrani (born c. 836, 18 Feb 901) was a Mesopotamian scholar and mathematician who greatly contributed to preparing the way for such important mathematical discoveries as the extension of the concept of number to (positive) real numbers, integral calculus, theorems in spherical trigonometry, analytic geometry, and non-euclidean geometry. In astronomy he was one of the first reformers of the Ptolemaic system, writing Concerning the Motion of the Eighth Sphere. He believed (wrongly) that the motion of the equinoxes oscillates. Including observations of the Sun, eight complete treatises by Thabit on astronomy have survived. In mechanics he was a founder of statics. He wrote The Book on the Beam Balance in which he finds the conditions for the equilibrium of a heavy beam. *TIS



1851 Karl Gustav Jacob Jacobi (10 Dec 1804; 18 Feb 1851) German mathematician who, with the independent work of Niels Henrik Abel of Norway, founded the theory of elliptic functions. He also worked on Abelian functions and discovered the hyperelliptic functions. Jacobi applied his work in elliptic functions to number theory. He also investigated mathematical analysis and geometry. Jacobi carried out important research in partial differential equations of the first order and applied them to the differential equations of dynamics. His work on determinants is important in dynamics and quantum mechanics and he studied the functional determinant now called the Jacobian. *TIS He died from smallpox, in his 47th year.*VFR



1856 Baron Wilhelm von Biela (19 Mar 1782, 18 Feb 1856 at age 73) Austrian astronomer who was known for his measurement (1826) of a previously known comet as having an orbital period of 6.6 years. Subsequently, known as Biela's Comet, it was observed to break in two (1846), and in 1852 the fragments returned as widely separated twin comets that were not seen again. However, in 1872 and 1885, bright meteor showers (known as Andromedids, or Bielids) were observed when the Earth crossed the path of the comet's known orbit. This observation provided the first concrete evidence for the idea that some meteors are composed of fragments of disintegrated comets.*TIS
Biela's Comet in February 1846, soon after it split into two pieces, and the biela meteor showers as seen on Nov 27, 1872





1877 Charles Henry Davis (16 Jan 1807; 18 Feb 1877) U.S. naval officer and scientist who published several hydrographic studies, was a superintendent of the Naval Observatory (1865–67, 1874–77) and worked to further scientific progress. Between his naval duties at sea, he studied mathematics at Harvard. He made the first comprehensive survey of the coasts of Massachusetts, Rhode Island, and Maine, including the intricate Nantucket shoals area. He helped establish and then supervised the preparation of the American Nautical Almanac (1849) for several years. Davis was a co-founder of the National Academy of Sciences (1863), and wrote several scientific books.*TIS




1899 (Marius) Sophus Lie (17 Dec 1842; 18 Feb 1899) was a Norwegian mathematician who made significant contributions to the theories of algebraic invariants, continuous groups of transformations and differential equations. Lie groups and Lie algebras are named after him. Lie was in Paris at the outbreak of the French-German war of 1870. Lie left France, deciding to go to Italy. On the way however he was arrested as a German spy and his mathematics notes were assumed to be coded messages. Only after the intervention of French mathematician, Gaston Darboux, was Lie released and he decided to return to Christiania, Norway, where he had originally studied mathematics to continue his work. *TIS




1900 Eugenio Beltrami (November 16, 1835, Cremona – February 18, 1900, Rome) was an Italian mathematician notable for his work concerning differential geometry and mathematical physics. His work was noted especially for clarity of exposition. He was the first to prove consistency of non-Euclidean geometry by modeling it on a surface of constant curvature, the pseudosphere, and in the interior of an n-dimensional unit sphere, the so-called Beltrami–Klein model. He also developed singular value decomposition for matrices, which has been subsequently rediscovered several times. Beltrami's use of differential calculus for problems of mathematical physics indirectly influenced development of tensor calculus by Gregorio Ricci-Curbastro and Tullio Levi-Civita.*Wik
Beltrami studied elasticity, wave theory, optics, thermodynamics, and potential theory, and was among the first to explore the concepts of hyperspace and time as a fourth dimension. His investigations in the conduction of heat led to linear partial differential equations. Some of Beltrami's last work was on a mechanical interpretation of Maxwell's equations. *TIS



1944 Charles Benedict Davenport (1 Jun 1866, 18 Feb 1944 at age 77) American zoologist who contributed substantially to the study of eugenics (the improvement of populations through breeding) and heredity and who pioneered the use of statistical techniques in biological research. Partly as a result of breeding experiments with chickens and canaries, he was one of the first, soon after 1902, to recognize the validity of the newly discovered Mendelian theory of heredity. In Heredity in Relation to Eugenics (1911), he compiled evidence concerning the inheritance of human traits, on the basis of which he argued that the application of genetic principles would improve the human race. These data were at the heart of his lifelong promotion of eugenics, though he muddled science with social philosophy. *TIS




1957 Henry Norris Russell (25 Oct 1877; 18 Feb 1957) American astronomer and astrophysicist who showed the relationship between a star's brightness and its spectral type, in what is usually called the Hertzsprung-Russell diagram, and who also devised a means of computing the distances of binary stars. As student, professor, observatory director, and active professor emeritus, Russell spent six decades at Princeton University. From 1921, he visited Mt. Wilson Observatory annually. He analyzed light from eclipsing binary stars to determine stellar masses. Russell measured parallaxes and popularized the distinction between giant stars and "dwarfs" while developing an early theory of stellar evolution. Russell was a dominant force in American astronomy as a teacher, writer, and advisor. *TIS




1967 Julius Robert Oppenheimer (22 Apr 1904, 18 Feb 1967 at age 62) was an American theoretical physicist and science administrator, noted as director of the Los Alamos laboratory during development of the atomic bomb (1943-45) and as director of the Institute for Advanced Study, Princeton (1947-66). Accusations as to his loyalty and reliability as a security risk led to a government hearing that resulted the loss of his security clearance and of his position as adviser to the highest echelons of the U.S. government. The case became a cause célèbre in the world of science because of its implications concerning political and moral issues relating to the role of scientists in government. *TIS


1995 Walter Samuel McAfee (September 2, 1914 – February 18, 1995) was an American scientist and astronomer, notable for participating in the world's first lunar radar echo experiments with Project Diana.

McAfee was born in Ore City, Texas to African-American parents Luther F. McAfee and Susie A. Johnson; he was the second of their nine children. When McAfee was three months old, the family moved to Marshall, Texas, where McAfee would grow up and attend undergraduate school. He graduated high school in Marshall in 1930, and later noted that his high school physics and chemistry teacher, Freeman Prince Hodge, was a great influence of his.[4] Following the completion of his master's degree, McAfee took a job in 1939 teaching science and mathematics in Columbus, Ohio. In 1941, he married Viola Winston, who taught French at the same junior high school in Columbus, Ohio where McAfee taught. McAfee and Winston had two daughters.[5] McAfee died at his home in South Belmar, New Jersey, on February 18, 1995.

McAfee attended Wiley College, where his mother studied, graduating with a B.S. in mathematics in 1934. Following his undergraduate work, McAfee attended Ohio State University and earned his M.S. in physics in 1937. After his work on Project Diana with the United States Army Signal Corps Engineering Laboratories, McAfee returned to school, receiving the Rosenwald Fellowship to continue his doctoral studies at Cornell University. In 1949, McAfee was awarded his PhD in Physics for his work on nuclear collisions under Hans Bethe.

In 1956 President Dwight D. Eisenhower presented him with one of the first Secretary of the Army Research and Study Fellowships. The fellowship enabled McAfee to spend two years studying radio astronomy at Harvard University.

McAfee left his teaching position in Columbus when he was hired by the Army Signal Corps to work at the Electronics Research Command at Fort Monmouth, New Jersey, in May 1942.[8] It was here that he participated in Project Diana, completing the first calculations showing that radar signals could be successfully bounced from a ground-based antenna to the Moon and back; this prediction was verified experimentally in 1946.

During his time at Fort Monmouth, he lectured in physics and electronics at Monmouth College (now Monmouth University) from 1958 to 1975, and served as a trustee at Brookdale Community College. McAfee also served on the Curriculum Advisory Council of the electronics engineering department at Monmouth and was recognized with an honorary doctorate of science in 1985.

In 1961, McAfee received the first U.S. Army Research and Development Achievement Award. He was eventually promoted to GS-16, making him the first African-American person to achieve this "super grade" civil service position.[7] After his death, a building at Fort Monmouth was renamed the McAfee Center, marking the first time a civilian was so honored at the site.[9] A research building at Aberdeen Proving Ground was named in his honor (2011), and he was inducted into the United States Army Materiel Command's Hall of Fame (2015), becoming the first African American to receive that honor.[5] Wiley College inducted McAfee into its Science Hall of Fame. *Wik






Credits :
*CHM=Computer History Museum
*FFF=Kane, Famous First Facts
*NSEC= NASA Solar Eclipse Calendar
*RMAT= The Renaissance Mathematicus, Thony Christie
*SAU=St Andrews Univ. Math History
*TIA = Today in Astronomy
*TIS= Today in Science History
*VFR = V Frederick Rickey, USMA
*Wik = Wikipedia
*WM = Women of Mathematics, Grinstein & Campbell



Tuesday, 17 February 2026

Notes on the History of the Factorial

 I recently came across a nice blog from Paul Hartzer who blogs at Hero's Garden (apparently no longer open) about Kramp's work with factorials. It prompted me to share my more general notes on the early history of factorials.


I have a curiosity about the etymology and history of mathematical terms as well, so I have included some notes on the etymology of factorial at the bottom.

In his book on The Art of Computer Programming, Donald Knuth points to an example of the factorial (in particular 8!) in the Hebrew book of creation.  NOTE (a comment corrects my poor writing here to point out that, "There is more than one volume, not just one book written by D. E. Knuth with the title "The Art of Computer Programming." There are four volumes. It is volume 2, subtitled "Seminumerical Algorithms", that mentions the Sefer Yetsirah ('Hebrew book of creation') as having an example of the factorial."  Thank you)


The first use of a multiplication of long strings of successive digits for a specific problem may have been by Euler in solving the questions of derangements. "The Game of Recontre (coincidence), also called the game of treize (thirteen), involves shuffling 13 numbered cards, then dealing them one at a time, counting aloud to 13. If the nth card is dealt when the player says the number 'n,' the dealer wins (this is known in combinatorics as a derangement of 13 objects.). Euler calculated the probability that the dealer will win.

It should be noted that this problem was solved earlier, by P.R. de Montmort, in 1713, though his work was unknown to Euler."
In an article entitled, "Calcul de la probabilité dans le jeu de rencontre" published in 1753, Euler wrote.


which is translated by Richard J. Pulskamp as "The number of cases \(1^. 2^. 3^. 4 \dotsb m\) being put for brevity =M." Cajori points out that this was probably not intended to be a general notation, but a temporary expedient.

In 1772 A T Vandermonde used [P]n to represent the product of the n factors p(p-1)(p-2)... (p-n+1). With such a notation [P]p would represent what we would now write as p!, but I can imagine this becoming, over time, just [p] (De Morgan would do just such a thing in his 1838 essays on probability). Vandermonde seems to have been the first to consider [p]0 (or 0!) and determined it was (as we now do) equal to one. Vandermonde's notation included a method for skipping numbers, so that [p/3]n would indicate p(p-3)(p-6)... (p-3(n-1)). It even allowed for negative exponents.

Vandermonde's symbol for [P]n would today represent what is generally called the "falling factorial." The common symbols seem to be [n]k or Donald Knuth's suggestion of \( n^{\underline{k}} \). Similar symbols exist for a "rising factorial", (n) (n+1) (n+2)...(n+k-1). Knuth's pleasing mnemonic version \( n^{\overline{k}} \) and (n)k which is common in working with hypergeometric series and is called the Pochammer symbol, although he never seemed to have used it for that, and used it for the combination of n things taken k at a time \( \binom{n}{k} \). I think either approach could be easily extended to using \ (n/s) as the base with the "s" representing the "skip rate". 

Because the use of 5!! is sometimes used as 5x3x1, and confused with (5!)! = 120!, I am trying to repurpose a change in   Vandermonde's notation. \( ( n!)_{a,b} \)  could be used with both rising and falling factorials with a as the skip rate and b as the number of skips.  A plus or minus on the a would indicate rising or falling factorials.  Thus \( (9!)_{-2})\) would replace what some write as 9!! and no b term needed as it descends to the smallest positive, in this case 1.  If we wanted the descending factorial 14 x 10 x 6 we write \( (14!)_{-4,3}\) to indicate descending by four for three terms. A + in the same would indicate 14 x 18 x 22.  (A similar alternative would be to eliminate the plus and minus and use subscripts for declining factorials, and superscripts for the rising factorial.  So 14! means what it always meant.  14 x 18 x 22 would be \((14!)^{4,3}\).  14 x 10 x 6  could be written \((14!)_{4,3}\).  The confusing symbol 9!! for 9x7x5x3x1 would be \((9!)_{2}\).

The word factorial is reported to be the creation of Louis François   Arbogast (1759-1803). The symbol now commonly used for factorial seems to have been created by Christian Kramp in 1808 according to a note I found in Lectures on fundamental concepts of algebra and geometry (1911), by John Wesley Young with a note on "The growth of algebraic symbolism" by Ulysses Grant Mitchell. It was in the Note by Mitchell (pg 239) that I found the credit for the symbol to Kramp. Kramp had previously used the word "facultes" for the process, but deferred in favor of Arbogast's term instead. Here is a translation from Jeff Miller's page, "I've named them facultes. Arbogast has proposed the denomination factorial, clearer and more French. I've recognized the advantage of this new term, and adopting its philosophy I congratulate myself of paying homage to the memory of my friend". Both Kramp and Arbogast were working with sequences of products. (Kramp's more general notation allowed for "the product of the factors of an arithmetic progression, that is,\(a(a+r)(a+2r)\dotsb(a+nr−r)\), I think the notation \(a^{n|r}\) is well described in the post mentioned above by Hartzer).  

Well after my first writing, Ben Gross of Ben Gross@bhgross144 posted an image of the cover page of Kramp's Élémens d'arithmétique universelle (1808), featuring the first use of n! to represent a factorial. I have captured these images from his twitter feed.



In his Dictionary of Curious and Interesting Numbers, David Wells tells the following story: "Augustus de Morgan ... was most upset when the " ! " made its way to England. He wrote: 'Among the worst of barbarisms is that of introducing symbols which are quite new in mathematical, but perfectly understood in common, language. Writers have borrowed from the Germans the abbreviation n! ... which gives their pages the appearance of expressing admiration that 2, 3, 4, etc should be found in mathematical results.'" 

Another early symbol (shown below) was also used. Here is the description of its origin from the web page of Jeff Miller,
An early factorial symbol, was suggested by Rev. Thomas Jarrett (1805-1882) in 1827. It occurs in a paper "On Algebraic Notation" that was printed in 1830 in the Transactions of the Cambridge Philosophical Society and it appears in 1831 in An Essay on Algebraic Development containing the Principal Expansions in Common Algebra, in the Differential and Integral Calculus and in the Calculus of Finite Differences (Cajori vol. 2, pages 69, 75).

I later found a copy of the 1830 paper on Google Books, and here is the way Jarrett presented the notation:

The symbol persisted and both symbols were in use for some time. Cajori suggests that the Jarrett |n symbol was little used until picked up by I. Toddhunter in his texts around 1860, and it was the use of his texts in America that may have influenced its use in the USA where it was more popular than the current symbol until around WWI.
The image below is from the 1889 textbook, A College Algebra by J.M. Taylor of Colgate.


A second image shows that the symbol was still in use even after the textbooks had adopted the "n!" symbol. This image is a note on the top a page on combinations in the 1922 text College Algebra by Walter Burton Ford of the University of Michigan. The book uses the exclamation point notation, but the hand written reminder is in the notation of Jarrett (and perhaps the teacher of Ms. Mabel M Walker whose signature is in the front of the book).




I recently found even a later date of the use of the Jarrett symbol. In the Mathematics Teacher for February of 1946 the symbol is used in an article by C. V. Newsome and John F. Randolph in illustrating Newton's power series for Sin(x). The fact that it is done with no comment indicates it must have still been commonly used.
I also came across an Arabic use of a very similar symbol,  that is apparently still current. A note from an AP calculus teacher in February of 2009 indicated that a transfer student from Egypt uses something like this symbol currently.

A variation of Vandermonde's [p/3]n which allow the symbol to be extended to the idea of multiplying every other number, or every third, etc. What is today called the double factorial, triple factorial etc.  The earliest use I can find of either the "!!" notation or the term double factorial is by B. E. Meserve, in 1948 (Double Factorials, American Mathematical Monthly, 55 (1948)) His usage indicates he is using a well understood term, and symbol so I suspect there is earlier usage.  For example the use of a double factorial, as in 7!! means multiply 7*5*3*1; and 7!!! would be 7*4*1 (every third multiple). This seems to be little or no improvement to my mind from the notation Vandermonde used for the same purpose. It is important not to confuse these symbols with (7!)! which is the factorial of 7! or 5040!.

I received a comment to this post from Maurizio Codogno who had an even later use of Jarrett's symbol for factorial. He writes, "I found the L notation for the factorial in the book The Math Entertainer,(by Philip Heafford) which is dated 1959 (I have the 1983 reprint) He even shared a digital copy from the book.
This may seem a big number of arrangements. It is the product of 6 x 5 x 4 x 3 x 2 x 1. Another way of writing this product is \( \lfloor6 \), or, as it is often printed, 6!. It is called factorial 6.
I am now wondering if the notation is still in use in some part of the globe. (Asked and answered, a note in the comments says "jarret's symbol is still used to this day in Arabic mathematics the L for factorial We never use the exclamation mark(!)")

A good approximation to n! for large values of n is given by Stirling's Formula, which probably ought to be named for De Moivre. \( n! \approx \sqrt{2\pi n} (\frac{n}{e})^n\)
The Factorial can also be generalized to the real and complex numbers using the Gamma Function 


There is also a subfactorial term and symbol in math. I am still searching for links to early uses, variations, etc. What little I knew a few years ago (and today) is here. Would love to have your input.
Unfortunately the same symbol, !n, often used for the subfactorial, was applied in 1971 by D. Kurepa for the sum of factorials,\( !n=\sum _{k=0}^{n-1} k! \) so !5 would be 4! + 3! + 2! + 1! + 0! = 24 + 6 + 2 + 1 + 1=34 .
Amazingly these two seemingly unconnected sequences are related. For clarity if we call the subfactorial seqeunce S(n) and the factorial sum sequence F(n) then it can be shown that \( F(n) \equiv (-1)^{k-1} S(n-1)\) Mod n.

There are other variations on the factorial. The primorial is the product of all the primes less than or equal to n, and is usually expressed as n#, so 5# = 5*3*2. They are useful to prime hunters, and the term was created by the very successful prime finder, Harvey Dubner. I would love to have a source for it's use, or the creation of the symbol.

There is an alternating factorial which is the sum of the terms of a factorial sequence alternately added and subtracted. For example af(5) = 5!- 4! + 3! - 2! + 1!. The only symbol I have seen is af(n), but I think something like \( (n\pm)! \) would be somewhat elegant. Go forth and use it. Donald Knuth, are you reading this?
There is also a superfactorial,defined  by J. A. Sloane and Simon Plouffe,  the product of the factorials from 1 to n, \(\prod\limits_{k=1}^n k! \).  I have seen the symbol of a heart suggested, so 3 (heart-shape) would be 1!*2!*3!. Unfortunately, mathematics has more ideas than terms it seems, and the term superfactorial has been used by Pickover for a tower of powers of n! that is n! high, so 1$ (his symbol I believe, is 1, but 2! $ = \( 2!^{2!}\) or 4 .  3$ is 6^6^6 or a little over 2 billion if I multiplied correctly.  I've never seen anyone use the Pickover symbol or term.

There is even a hyperfactorial, although I have never seen it in use. H(n) = \(\prod\limits_{k=1}^n k^k \) These get big in a hurry. (If you have information on the origin and uses of any of these, please advise.) 

The term factorial is drawn from the more common math (and English) term factor. The roots of both these words are in the word fact and its Latin root facere, to do. To know the facts, is to know what has been done. The person who does something is then called the factor. In business a factor was once a common term for one who buys or sells for another. Today the word agent is more common. Colonial businesses often employed a person to do various menial tasks, as a factotum, literally one who does everything (today we might call them a "gopher"). Things that were necessary in order to "do something" became factors in the event, and today you may hear a coach say, "Defense was the most important factor in our victory."
Factors then became the parts of the whole, and a factory was where they were put together to make a final product. These words run over into the mathematical meanings. The factors are the numbers that are put together (by multiplication) to make the product. Because the product is made up by putting together parts, it is called a composite number.
The word "measure" has often been used in much the same way we now use the word factor. In his Universal Arithmetick Newton distinguishes three kinds of numbers, "integer, fracted, and surd", and defines an integer as "what is measured by Unity." Frederick Emerson's North American Arithmetic(1850)says "One number is said to MEASURE another, when it divides it without leaving any remainder." (pg 18) Later it states," A number which divides two or more numbers without a remainder is called their COMMON MEASURE." This is after the definition of factor on page 12, and immediately precedes "A square number is the product of two equal factors" on page 19.

Other English words from the "to do" meaning of fact include facility (the ability to do), faction (a group working to do the same thing), facilitate (make easy to do) and faculty.

On This Day in Math - February 17

Statue of Quetelet in Brussels



Inductive inference is the only process known to us by which essentially new knowledge comes into the world.
~Sir Ronald Aylmer Fisher

The 48th day of the year; 48 is the smallest number with exactly ten divisors. (This is an interesting sequence, and students might search for others. Finding the smallest number with twelve divisors will be easier than finding the one with eleven.)

48 is also the smallest even number that can be expressed as a sum of two primes in 5 different ways:

If n is greater than or equal to 48, then there exists a prime between n and 9n/8 This is an improvement on a conjecture known as Bertrand's Postulate. In spite of the name, many students remember it by the little rhyme, "Chebyshev said it, but I'll say it again; There's always a prime between n and 2n ." Mathematicians have lowered the 2n down to something like n+n.6 for sufficiently large numbers.

48 is the smallest betrothed (quasi-amicable) number. 48 and 75 are a betrothed pair since the sum of the proper divisors of 48 is 75+1 = 76 and the sum of the proper divisors of 75 is 48+1=49. (There is only a single other pair of betrothed numbers that can be a year day)

And 48 x 48 = 2304 but 48 x 84 = 4032.

In 1719 Paul Halcke observed that the product of the aliquot divisors of 48 is equal to the fourth power of 48. 1*2*3*4*6*8*12*16*24= 5,308,416= 484.   48 and 80 are the only two year dates for which this is true.


Always the bridesmaid.... 48 is the leg of ten different Pythagorean triangles, but is never the hypotenuse.  (Not all primitive)

EVENTS
1600 The Inquisition brought Giordano Bruno to the Campo dei Fiori in Rome’s center where they chained him to an iron stake and burned him alive for his beliefs that the earth rotated on its axis. *Amir Aczel, Pendulum, pg 9 (Aczel gives this date as the 19th but this date seems wrong. Thony Christie noted that " Bruno was executed on 17th Feb and not for his cosmology but for his heretical theology." Thanks... several other sources agree with Feb 17th date))


1753 One of the earliest ideas for the electronic telegraph was suggested on this day in Scots Magazine.  The suggestion of C. M. (never identified more specifically) proposed a set of 26 wires extended horizontally between two places.  They would signal each other through an electrostatic generator to energize a wire from one place and a letter under the wire would be attracted to show which letter was being sent.  *The Book of Scientific Anecdotes.
In 1806, Ralph Wedgwood submitted a telegraph based on frictional electricity to the Admiralty, but was told that the semaphore was sufficient for the country. In a pamphlet he suggested the establishment of a telegraph system with public offices in different centres. Francis Ronalds, in 1816, brought a similar telegraph of his invention to the notice of the Admiralty, and was politely informed that 'telegraphs of any kind are now wholly unnecessary.' *Whiteflies org
Ronald's telegraph:



In 1857, the City of New York passed a charter to enable Peter Cooper to found a scientific institution in the city. He established the Cooper Union for the Advancement of Science and Art for the express purpose of improving the working classes by providing free education. Courses included algebra, geometry, calculus, chemistry, physics, mechanics, architectural and mechanical drawing. It also provided a School of Design for Women, a Musical Department, and a Free Library and Reading Room with all the periodicals of the day. By 1868, an article in the New York Times stated there were nearly 1500 students attached to the institution, and the classes, which included night classes, were universally full. *TIS
Peter Cooper was not a man who engaged in empty rhetoric. He made his school free for the working classes. He took the revolutionary step of opening the school to women as well as men. There was no color bar at Cooper Union. Cooper demanded only a willingness to learn and a commitment to excellence, and in this he manifestly succeeded. *History at Cooper Union Edu




In 1869, Dmitri Mendeleev cancelled a planned visit to a factory and stayed at home working on the problem of how to arrange the chemical elements in a systematic way. To begin, he wrote each element and its chief properties on a separate card and arranged these in various patterns. Eventually he achieved a layout that suited him and copied it down on paper. Later that same day he decided a better arrangement by properties was possible and made a copy of that, which had similar elements grouped in vertical columns, unlike his first table, which grouped them horizontally. These historic documents still exist, and mark the beginning of the form of the Periodic Table as commonly used today. (The date is given by the Julian calendar in use in Russia at the time. The Gregorian date is March 1) *TIS



1994 A small satellite named Dactyl was found which orbits the asteroid Ida. This was the first discovery of a satellite orbiting and asteroid. Dactyl was discovered in images taken by the Galileo spacecraft during its flyby in 1993. Dactyl was found on 17 February 1994 by Galileo mission member Ann Harch, while examining delayed image downloads from the spacecraft.
It was named by the International Astronomical Union in 1994, for the mythological dactyls who inhabited Mount Ida on the island of Crete. It is only 1.4 kilometres (4,600 ft) in diameter. *Wik



In 1996, world chess champion Gary Kasparov defeated Deep Blue, IBM's chess-playing computer, by winning a six-game match 4-2, in a regulation-style match held in Philadelphia, as part of the ACM Computer Science Conference. Deep Blue is an improved version of the older Deep Thought, augmented by parallel special-purpose hardware. Deep Blue uses a selectively deepening search strategy, using improvements of the alpha-beta search strategy, with powerful evaluation functions. Transposition tables help avoid unnecessarily calculating the same position more than once. Two powerful databases further augment Deep Blue's play. *TIS On May 11, 1997, the machine won a six-game match by two wins to one with three draws against world champion Garry Kasparov, the first time the grandmaster ever lost a six-game match in championship play. *Wik


BIRTHS
*Wik
1201 Khawaja Muhammad ibn Muhammad ibn Hasan Tūsī (17 February 1201; Ṭūs, Khorasan – 25 June 1274; Baghdad), better known as Nasīr al-Dīn Tūsī was a Persian polymath and prolific writer: An architect, astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, and theologian
Tusi convinced Hulegu Khan to construct an observatory for establishing accurate astronomical tables for better astrological predictions. Beginning in 1259, the Rasad Khaneh observatory was constructed in Azarbaijan, west of Maragheh, the capital of the Ilkhanate Empire.
Based on the observations in this for the time being most advanced observatory, Tusi made very accurate tables of planetary movements as depicted in his book Zij-i ilkhani (Ilkhanic Tables). This book contains astronomical tables for calculating the positions
of the planets and the names of the stars. His model for the planetary system is believed to be the most advanced of his time, and was used extensively until the development of the heliocentric model in the time of Nicolaus Copernicus.
For his planetary models, he invented a geometrical technique called a Tusi-couple, which generates linear motion from the sum of two circular motions. He used this technique to replace Ptolemy's problematic equant for many planets, but was unable to find a solution to Mercury. The Tusi couple was later employed in Ibn al-Shatir's geocentric model and Nicolaus Copernicus' heliocentric Copernican model.
Al-Tusi was the first to write a work on trigonometry independently of astronomy. In his Treatise on the Quadrilateral he gave an extensive exposition of spherical trigonometry, distinct from astronomy. It was in the works of Al-Tusi that trigonometry achieved the status of an independent branch of pure mathematics distinct from astronomy, to which it had been linked for so long. He was also the first to list the six distinct cases of a right triangle in spherical trigonometry.
In his On the Sector Figure, appears the famous law of sines for plane triangles.

\( \frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C} \)

He also stated the law of sines for spherical triangles,discovered the law of tangents for spherical triangles, and provided proofs for these laws. *Wik

1723 Tobias Mayer (17 Feb 1723; 20 Feb 1762 at age 38) German astronomer who developed lunar tables that greatly assisted navigators in determining longitude at sea. Mayer also discovered the libration (or apparent wobbling) of the Moon. Mayer began calculating lunar and solar tables in 1753 and in 1755 he sent them to the British government.
 These tables were good enough to determine longitude at sea with an accuracy of half a degree. Mayer's method of determining longitude by lunar distances and a formula for correcting errors in longitude due to atmospheric refraction were published in 1770 after his death. The Board of Longitude sent Mayer's widow a payment of 3000 pounds as an award for the tables. *TIS Leonhard Euler described him as 'undoubtedly the greatest astronomer in Europe'. More notes on Meyer can be found on this blog at the Board of Longitude Project from the Royal Museums at Greenwich.
In 1758, Mayer attempted to define the number of colors that the eye can distinguish with accuracy. His color triangle was first published in 1775 by the Göttinger physicist Georg Christoph Lichtenberg — more than 12 years after Mayer’s death.

Diagram of comet orbits in the solar system, showing that the tails always point away from the Sun, engraving, in Mathematischer Atlas, by Tobias Mayer, plate 21, 1745 (Linda Hall Library)




1765 Sir James Ivory (17 February 1765 – 21 September 1842) was a Scottish mathematician born in Dundee. He was essentially a self-trained mathematician, and was not only deeply versed in ancient and modern geometry, but also had a full knowledge of the analytical methods and discoveries of the continental mathematicians.
His earliest memoir, dealing with an analytical expression for the rectification of the ellipse, is published in the Transactions of the Royal Society of Edinburgh (1796); and this and his later papers on Cubic Equations (1799) and Kepler's Problem (1802) evince great facility in the handling of algebraic formulas. In 1804 after the dissolution of the flax-spinning company of which he was manager, he obtained one of the mathematical chairs in the Royal Military College at Marlow (afterwards removed to Sandhurst); and until the year 1816, when failing health obliged him to resign, he discharged his professional duties with remarkable success.*Wik It has been suggested that Ivory may have suffered from schizophrenia (*ALEX D. D. CRAIK) of some type throughout his life.

Ivory, because of his mental problems, tended to quarrel with his fellow mathematicians. His relations with Wallace deteriorated with arguments over Ivory's Attraction article to Encyclopaedia Britannica. Ivory's article on Capillary action for the same publication led to an argument with Thomas Young. Many other cases were simply caused by Ivory suffering from a quite incorrect belief that he was being persecuted by others. In fact he never joined the Royal Astronomical Society, despite his interests in astronomy, since he believed that members of that Society were systematically working against him. As De Morgan wrote that Ivory was of
... thoroughly sound judgement in every other respect seemed to be under a complete chain of delusions about the conduct of others to himself. But the paradox is this: - I never could learn that Ivory, passing his life under the impression that secret and unprovoked enemies were at work upon his character, ever originated a charge, imputed a bad motive, or allowed himself an uncourteous expression.
*SAU



1874 Thomas J. Watson Sr. is born. A shrewd businessman, Watson started his career as a cash register salesman, eventually taking the helm of IBM and directing it to world leadership in punch card equipment sales. Watson died in 1956 and control of IBM passed on to his son, Thomas Watson, Jr. who brought IBM into the electronic age and, after several bold financial risks, to dominance in the computer industry.*CHM

1888 Otto Stern (17 Feb 1888; 17 Aug 1969 at age 81) German-American scientist and winner of the Nobel Prize for Physics in 1943 for his development of the molecular beam as a tool for studying the characteristics of molecules and for his measurement of the magnetic moment of the proton. *TIS



1890 Ronald Aylmer Fisher FRS (17 February 1890 – 29 July 1962) was an English statistician, evolutionary biologist, eugenicist and geneticist. Among other things, Fisher is well known for his contributions to statistics by creating Fisher's exact test and Fisher's equation. Anders Hald called him "a genius who almost single-handedly created the foundations for modern statistical science" while Richard Dawkins called him "the greatest of Darwin's successors". In 2010 Dawkins named him "the greatest biologist since Darwin". Fisher was opposed to the conclusions of Richard Doll and A.B. Hill that smoking caused lung cancer. He compared the correlations in their papers to a correlation between the import of apples and the rise of divorce in order to show that correlation does not imply causation.
To quote Yates and Mather, "It has been suggested that the fact that Fisher was employed as consultant by the tobacco firms in this controversy casts doubt on the value of his arguments. This is to misjudge the man. He was not above
accepting financial reward for his labours, but the reason for his interest was undoubtedly his dislike and mistrust of puritanical tendencies of all kinds; and perhaps also the personal solace he had always found in tobacco."
After retiring from Cambridge University in 1957 he spent some time as a senior research fellow at the CSIRO in Adelaide, Australia. He died of colon cancer there in 1962.
He was awarded the Linnean Society of London's prestigious Darwin–Wallace Medal in 1958.
Fisher's important contributions to both genetics and statistics are emphasized by the remark of L.J. Savage, "I occasionally meet geneticists who ask me whether it is true that the great geneticist R.A. Fisher was also an important statistician"*Wik The stained glass window is from the Greatroom at Caius College.
For the first fifty years after Fisher’s death, his defense of eugenics was not held against him.  But the modern climate is not so forgiving of misguided beliefs, and Fisher is increasingly taken to task for his advocacy of eugenics.  At Gonville and Caius College, his window was removed in 2020. A laboratory at University College, London that had been named for Fisher was renamed last year as well. 




1891 Abraham Halevi (Adolf) Fraenkel (February 17, 1891, Munich, Germany – October 15, 1965, Jerusalem, Israel) known as Abraham Fraenkel, was an Israeli mathematician born in Germany. He was an early Zionist and the first Dean of Mathematics at the Hebrew University of Jerusalem. He is known for his contributions to axiomatic set theory, especially his addition to Ernst Zermelo's axioms which resulted in Zermelo–Fraenkel axioms.*Wik



1905 Rózsa Péter (orig.: Politzer) (17 February 1905–16 February 1977) was a Hungarian mathematician. She is best known for her work with recursion theory.
Péter was born in Budapest, Hungary, as Rózsa Politzer (Hungarian: Politzer Rózsa). She attended Eötvös Loránd University, where she received her PhD in 1935. After the passage of the Jewish Laws of 1939 in Hungary, she was forbidden to teach because of her Jewish origin. After the war she published her key work, Recursive Functions.
She taught at Eötvös Loránd University from 1955 until her retirement in 1975. She was a corresponding member of the Hungarian Academy of Sciences (1973).*Wik In 1951 she wrote the first monograph on recursive function theory.



1918 Jacqueline Lelong-Ferrand (17 February 1918, Alès, France – 26 April 2014, Sceaux, France) was a French mathematician who worked on conformal representation theory, potential theory, and Riemannian manifolds. She taught at universities in Caen, Lille, and Paris.

Ferrand was born in Alès, the daughter of a classics teacher, and went to secondary school in Nîmes. In 1936 the École Normale Supérieure began admitting women, and she was one of the first to apply and be admitted. In 1939 she and Roger Apéry placed first in the mathematics agrégation; she began teaching at a girls' school in Sèvres, while continuing to do mathematics research under the supervision of Arnaud Denjoy, publishing three papers in 1941 and defending a doctoral thesis in 1942. In 1943 she won the Girbal-Baral Prize of the French Academy of Sciences, and obtained a faculty position at the University of Bordeaux. She moved to the University of Caen in 1945, was given a chair at the University of Lille in 1948, and in 1956 moved to the University of Paris as a full professor. She retired in 1984.

Ferrand had nearly 100 mathematical publications, including ten books, and was active in mathematical research into her late 70s. One of her accomplishments, in 1971, was to prove the compactness of the group of conformal mappings of a non-spherical compact Riemannian manifold, resolving a conjecture of André Lichnerowicz, and on the basis of this work she became an invited speaker at the 1974 International Congress of Mathematicians in Vancouver.




1950 Viktor Aleksandrovich Gorbunov (17 Feb 1950 in Russia - 29 Jan 1999 in Novosibirsk, Russia) He published his first paper in 1973 being a joint work with A I Budkin entitled Implicative classes of algebras (Russian). The implicative class of algebras is a generalisation of quasivarieties. The structural characteristics of the implicative class are studied in this paper. A second join paper with Budkin On the theory of quasivarieties of algebraic systems (Russian) appeared in 1975. In the same year he published Filters of lattices of quasivarieties of algebraic systems (Russian), this time written with V P Belkin. In fact he had written six papers before his doctoral thesis On the Theory of Quasivarieties of Algebraic Systems was submitted. He received the degree in 1978. Gorbunov continued working at Novosibirsk State University, being promoted to professor. He also worked as a researcher in the Mathematics Institute of the Siberian Branch of the Russian Academy of Sciences. *SAU




DEATHS

1600 Giordano Bruno (born 1548 - 17 Feb 1600)Italian philosopher, astronomer, mathematician and occultist whose theories anticipated modern science. The most notable of these were his theories of the infinite universe and the multiplicity of worlds, in which he rejected the traditional geocentric (or Earth-centred) astronomy and intuitively went beyond the Copernican heliocentric (sun-centred) theory, which still maintained a finite universe with a sphere of fixed stars. Although one of the most important philosophers of the Italian Renaissance, Bruno's various passionate utterings led to opposition. In 1592, after a trial he was kept imprisoned for eight years and interrogated periodically. When, in the end, he refused to recant, he was burned at the stake in Rome for heresy.*TIS Professor Rickey of USMA disagrees about Bruno's "failure to recant." "It is a nineteenth century myth that he refused to recant his view that the earth moves." *VFR



1680 Jan Swammerdam (February 12, 1637, Amsterdam – February 17, 1680) was a Dutch biologist and microscopist. His work on insects demonstrated that the various phases during the life of an insect—egg, larva, pupa, and adult—are different forms of the same animal. As part of his anatomical research, he carried out experiments on muscle contraction. In 1658, he was the first to observe and describe red blood cells. He was one of the first people to use the microscope in dissections, and his techniques remained useful for hundreds of years.*Wik



1865 George Phillips Bond (20 May 1825, 17 Feb 1865 at age 39) American astronomer who made the first photograph of a double star, discovered a number of comets, and with his father discovered Hyperion, the eighth moon of Saturn. *TIS




1867 Alexander Dallas Bache (19 Jul 1806, 17 Feb 1867 at age 60) was an American physicist who was Ben Franklin's great grandson and trained at West Point. Bache became the second Superintendent of the Coast Survey (1844-65). He made an ingenious estimate of ocean depth (1856) by studying records of a tidal wave that had taken 12 hours to cross the Pacific. Knowing that wave speeds depend on depth, he calculated a 2.2- mile average depth for the Pacific (which is within 15% of the presently accepted value). Bache created the National Academy of Sciences, securing greater government involvement in science. Through the Franklin Institute he instituted boiler tests to promote safety for steamboats. *TIS



1874 (Lambert) Adolphe (Jacques) Quetelet (22 Feb 1796, 17 Feb 1874 at age 78) was a Belgian mathematician, astronomer, statistician, and sociologist known for his pioneering application of statistics and the theory of probability to social phenomena, especially crime. At an observatory in Brussels that he established in 1833 at the request of the Belgian government, he worked on statistical, geophysical, and meteorological data, studied meteor showers and established methods for the comparison and evaluation of the data. In Sur l'homme et le developpement de ses facultés, essai d'une physique sociale (1835) Quetelet presented his conception of the average man as the central value about which measurements of a human trait are grouped according to the normal curve. *TIS Quetelet created the Body Mass Index in a paper in 1832.  It was known as the Quetelet Index until it was termed the Body Mass Index in 1972 by Ancel Keys.
Statue of Quetelet in Bruxelles



1875 Friedrich Wilhelm August Argelander (22 Mar 1799, 17 Feb 1875 at age 75)
German astronomer who established the study of variable stars as an independent branch of astronomy and is renowned for his great catalog listing the positions and brightness of 324,188 stars of the northern hemisphere above the ninth magnitude. He studied at the University of Königsberg, Prussia, where he was a pupil and later the successor of Friedrich Wilhelm Bessel. In 1837, Argelander published the first major investigation of the Sun's motion through space. In 1844 he began studies of variable stars.*TIS



1947 Ettore Bortolotti (6 March 1866 in Bologna, Kingdom of Sardinia (now Italy) - 17 Feb 1947 in Bologna, Italy) Italian mathematician who worked in various areas in analysis. He was interested in the history of mathematics. *SAU

1974 Heinrich Franz Friedrich Tietze contributed to the foundations of general topology and developed important work on subdivisions of cell complexes. The bulk of this work was carried out after he took up the chair at Munich in 1925.*SAU

2012 Nicolaas Govert "Dick" de Bruijn (9 July 1918 – 17 February 2012) was a Dutch mathematician, affiliated as professor emeritus with the Eindhoven University of Technology. He received his Ph.D. in 1943 from Vrije Universiteit Amsterdam.
De Bruijn covered many areas of mathematics. He is especially noted for the discovery of the De Bruijn sequence. He is also partly responsible for the De Bruijn–Newman constant, the De Bruijn–Erdős theorem (in both incidence geometry and graph theory) and the BEST theorem. He wrote one of the standard books in advanced asymptotic analysis (De Bruijn, 1958). De Bruijn also worked on the theory of Penrose tilings. In the late sixties, he designed the Automath language for representing mathematical proofs, so that they could be verified automatically (see automated theorem checking). Lately, he has been working on models for the human brain.*Wik




2017 Father Magnus J. Wenninger OSB (born Park Falls, Wisconsin, October 31, 1919, 17 Feb, 2017 ) is a mathematician who works on constructing polyhedron models, and wrote the first book on their construction. *Wik
It was while studying at Columbia University Teachers College that he became interested in polyhedra after seeing models in display cases along the walls. He read Mathematical Models by H Martyn Cundy and A P Rollett, and then The Fifty-nine Icosahedra by H S M Coxeter, P Du Val, H T Flather and J F Petrie. After reading this book he began to make models of all the fifty-nine icosahedra and many of the uniform polyhedra. In 1966 the National Council of Teachers of Mathematics published Father Magnus's Polyhedron Models for the Classroom. The original booklet contained 40 pages but the revised edition, published in 1975, had 80 pages. Father Magnus writes in the Introduction:-
This booklet, first published in 1966, went through its sixth printing in 1973, making up a total of 35000 printed copies. That fact alone attests to the continuing interest in this work on the part of teachers and students alike. *SAU





Credits :
*CHM=Computer History Museum
*FFF=Kane, Famous First Facts
*NSEC= NASA Solar Eclipse Calendar
*RMAT= The Renaissance Mathematicus, Thony Christie
*SAU=St Andrews Univ. Math History
*TIA = Today in Astronomy
*TIS= Today in Science History
*VFR = V Frederick Rickey, USMA
*Wik = Wikipedia
*WM = Women of Mathematics, Grinstein & Campbell