Monday, 3 September 2018

On This Day in Math - September 3


If it's just turning the crank it's algebra,
but if it's got an idea in it, it's topology.
~Solomon Lefschetz

The 246th day of the year; 246 is a sphenic (wedge) composite since it is the product of three distinct prime factors, 246 = 2x3x41. (what would be the next sphenic number?)

246 is also equal to the sum  9C2 + 9C4 + 9C6 (9 choose 2,4,6)

246 = 233 + 13 (13th Fibonacci number plus 13) *Derek Orr@Derektionary

246 is the smallest number whose complete factorization contains the first four digits (and no others) 246 = 2*3*41


Algebra Fact @AlgebraFact points out that: "Tao, et all, have proved that there are infinitely many primes 246 apart." On the way to proving, hopefully, that there are an infinity of twin primes.


EVENTS

1752 The dates 3 to 13 September did not exist in England in 1752 due to the conversion to the Gregorian calendar. Poor Richard’s Almanac for 1752 carried the catchy heading, “September hath XIX days.” Much of Europe made the change in 1582, and since 1600 was a leap year under the Gregorian but not the Julian calendar, England had to omit eleven days, not ten. *VFR England and the American Colonies dropped the Roman era Julian Calendar, which had become 10 days out of synchrony with the solar cycle, and adopted the Gregorian Calendar. People rioted in the streets thinking the government stole 11 days of their lives. Instituted by Pope Gregory XIII in 1582, the calendar has 365 days with an extra day every four years (the leap year) except in years divisible by 100 but not divisible by 400. Thus, the calendar year has an average length of 365.2422 days. It moved the day's date up from September 3rd to September 14th. Some other countries, including Russia, did not change until the twentieth century.*TIS

1806 Francois Arago and Jean-Baptiste Biot leave Paris for Spain to finish the measurement of the Paris Meridian.  Arago had been picked to head the completion of the task while a 19yr old student at the Ecole Polytechnique.  He was nominated by his professor, Dennis Poisson and appointed on Feb 2, 1805 to finish the work began by Mechain and Delambre.  *Amir D Aczel, Pendulum, pg 75-78

1806 F. Nichols sends a copy of his printing of Playfair's Geometry to Thomas Jefferson.
"Sir,—
I desire you to accept a copy of Playfair’s Geometry, which I reprinted last winter.
The corrections of grammatical inaccuracies, &. mentioned in the Advertisement, occur after Book I. There are few corrections in Book I.
The book is pretty correctly printed. The principal typographical errors appear at the end of the volume.
Some improvements will be made in another edition, if indeed another edition should ever be wanted.
Playfair’s Geometry is adopted at Cambridge in Massachusetts, Newhaven in Connecticut, & in a few private places of education. I have been informed that it will be introduced into other colleges.
It is a circumstance unfriendly to the reception of a new elementary work of science, designed for the use of students, that some teachers are unwilling to introduce any book into their seminaries, which they have not read at school or college.
I am, with respect, Sir, Your obedient Servant,
F. Nichols."
Jefferson would reply with thanks on 19 Sept.  *Natl. Archives
(advertising in the Apr. 7, 1795, issue of the Massachusetts Mercury as "Francis Nichols, late professor of mathematics in the new college at Manchester"; author and bookseller at Philadelphia, 1802-14; member of the American Philosophical Society; bookseller at New York City, 1817-20)*Library of Congress

1821 A Hurricane made landfall on this day in New York City and moved north into Connecticut. It would confuse and inspire William Redfield, and become the first hurricane tracked from beginning to end. While reviewing the storm damage on horseback across Connecticut Redfield noticed that trees in the northern parts of the state fell in the opposite direction from those he had witnessed further south. His interest led him to make a careful study of newspaper reports, letters and ships log an document the storm from beginning to end. He concluded, "This storm was exhibited in the form of a great whirlwind." Redfield was the first to give evidence to support that hurricanes are large circular vortexes. His study of this and other storms led to the classic meteorology paper, "On The Prevailing Storms of the Atlantic Coast." John Farrar had made similar observations describing the hurricanes as “a moving vortex and not the rushing forward of a great body of the atmosphere”, after the Great September Gale of 1815..*Wik

1822 A wagon train containing three tons of books arrived at Allegheny College in Meadville, PA. They came from one of the finest private libraries in America, that of James Winthrop. He was a descendant of John Winthrop, first governor of the Massachussettts Bay Colony. His father was Professor of Mathematics and Natural Philosophy at Harvard and so the collection contained a number of important mathematical works. Winthrop was upset that Harvard had not given him an honorary degree and so he gave the books to Allegheny. [Allegheney College Alumni Bulletin, June 1933.] *VFR

In 2000, NASA data showed the hole at just under 11 million square miles - the biggest it had ever been. Record low temperatures in the stratosphere are believed to have helped the expansion of the ozone hole during the southern hemisphere’s spring season. Antarctic ozone depletion starts in July, when sunlight triggers chemical reactions in cold air trapped over the South Pole during the Antarctic winter. It intensifies during August and September before tailing off as temperatures rise in late November of early December. Depletion of the ozone layer over Antarctica and the Arctic is being monitored because ozone protects Earth from harmful ultraviolet radiation. By 9 Sep 2000, the hole had grown over Chile, exposing a populated city for the first time. Image, compiled from NASA's Total Ozone Mapping Spectrometer instrument onboard the Earth Probe satellite, reveals how the ozone hole (in deep blue) has extended as far as southern Chile. *TIS

2009 Saturn's rings cross the plane of the Earth's orbit. This was the first such crossing since May 22, 1995, and another will not occur until March 23, 2025. *Wik (Wonder if/when Earth will intersect rings? What would that look like?



BIRTHS

1780 Heinrich Christian Schumacher (September 3, 1780 – December 28, 1850)
Schumacher was a German astronomer. He was director of the Mannheim observatory from 1813 to 1815, and then became professor of astronomy in Copenhagen. From 1817 he directed the triangulation of Holstein, to which a few years later was added a complete geodetic survey of Denmark (finished after his death). For the sake of the survey an observatory was established at Altona, and Schumacher resided there permanently, chiefly occupied with the publication of Ephemerides (11 parts, 1822–1832) and of the journal Astronomische Nachrichten (founded by himself in 1821 and still being published), of which he edited thirty-one volumes. *TIA

1814 James Joseph,(Sylvester) (3 Sep 1814; 15 Mar 1897) youngest child of Abraham Joseph, born in London. The eldest son, an actuary, eventually migrated to the U.S. where, for unknown reasons, he took the surname Sylvester. The rest of the family soon followed suit, so that is how James Joseph Sylvester got his name. *VFR British mathematician who, with Arthur Cayley, founded the theory of algebraic invariants, algebraic-equation coefficients that are unaltered when the coordinate axes are translated or rotated. Beginning in 1833, he studied at St John's College, Cambridge. However, at this time signing a religious oath to the Church of England was required to graduate. Being Jewish, he refused and so he did not graduate. He taught physics at the University of London (1838-41), one of the few places which did not bar him because of his religion. Sylvester did important work on matrix theory, in particular, to study higher dimensional geometry. In 1851 he discovered the discriminant of a cubic equation. Earlier in his life, he tutored Florence Nightingale.*TIS (This idea of Sylvester tutoring Nightingale, to the best of my knowledge, originates from the Herbert Baker obituary. Karen Hunger Parshall, among others, has questioned the accuracy of this statement.)
He was instrumental in shaping graduate study and American mathematics in the later half of the 19th century as a professor at the Johns Hopkins University and as founder of the American Journal of Mathematics. *Wik
James Joseph Sylvester died, at age 83, after earlier suffering a paralytic stroke while working at his mathematics. *VFR
I came across a nice story about Sylvester on the wonderful "Cut-the-Knot" blog of Alexander Bogomolny. He writes, "Sylvester was one the greatest British mathematicians of the 19th century. He was known for his absentmindedness and poor memory; on one occasion he even denied the truth of one of his own theorems. "

1869 Austrian chemist Fritz Pregl (3 September 1869 – 13 December 1930) Pegl began research on bile acids in 1904. With only tiny yields to study, he pioneered micro analytical techniques and designed a new balance capable of weighing 20 grams to an accuracy of 0.001 milligrams. Pregl was awarded the Nobel Prize in Chemistry 1923 for his efforts *RSC.org
In 1950, the department of the University of Graz where Fritz Pregl had worked was named the Institute of Medical Chemistry and Pregl Laboratory. Streets in Graz, Innsbruck, Vienna and Klagenfurt were named after him. In Slovenia, Pregl Awards have been bestowed annually since 2007 by the National Institute of Chemistry for the research work and for outstanding doctorates. Slovenian pupils are conferred Pregl Recognition Awards, whereas secondary school students are conferred Pregl Citations for excellent results in national competitions in chemistry. A square in Ljubljana is named after Pregl. The Fritz Pregl Prize has been awarded annually since 1931 in chemistry by the Austrian Academy of Sciences from the funds left at its disposal by Pregl. *Wik

1874 Fredrik (Carl Mülertz) Størmer (3 Sep 1874; died 13 Aug 1957) was a geophysicist and mathematician who developed a mathematical theory of auroral phenomena. An aurora is the light emitted by energetic protons and electrons at the top of Earth's atmosphere when they come in contact with solar wind particles. He also contributed both important photographic observations and mathematical data to the understanding of the polar aurora, of stratospheric and mesospheric clouds, and of the structure of the ionosphere. The discovery of the Van Allen Radiation Belts by James Van Allen confirmed with surprising accuracy Størmer's theoretical analysis of solar charged particle trajectories in Earth's magnetic field.*TIS

1884 Solomon Lefshetz (3 September 1884 – 5 October 1972) born in Moscow. He invented the phrase “algebraic topology.” See A Century of Mathematics in America, Part I, 1988, p. 171. *VFR mathematician who did fundamental work on algebraic topology, its applications to algebraic geometry, and the theory of non-linear ordinary differential equations.*Wik

1905 Carl David Anderson (3 Sep 1905; 11 Jan 1991)American physicist who, with Victor Francis Hess of Austria, won the Nobel Prize for Physics in 1936 for his discovery of the positron, or positive electron, the first known particle of antimatter. He examined the photographs of cosmic rays taken as they passed through a Wilson cloud chamber in a strong magnetic field. Besides the curved paths of negative electrons, he found also paths deviating in the opposite direction, corresponding to positively charged particles - yet having the the same mass as an electron! Previously, Dirac had predicted such particles by theoretical solution to electromagnetic field equations. *TIS

1970 Stanislav Konstantinovich Smirnov (3 September 1970 - ) is a Russian mathematician currently working at the University of Geneva, who was awarded the Fields Medal in 2010. His research focuses on the fields of complex analysis, dynamical systems and probability theory. *Wik


DEATHS

1595 Federico Commandino (1509 – September 5, 1575) died on this day. “In the sixteenth century, Western mathematics emerged swiftly from a millennial decline. This rapid ascent was assisted by Apollonius, Archimedes, Aristarchus, Euclid, Eutocius, Hero, Pappus, Ptolemy, and Serenus—as published by Commandino,” *VFR He translated the works of ancient mathematicians and was responsible for the publication of the works of Archimedes. He also translated the works of Aristarchus of Samos (On the masses and distances of the Sun and the Moon), Pappus of Alexandria (Mathematical collection), Hero of Alexandria (Pneumatics), and Euclid (Elements). Among his pupils was Guidobaldo del Monte. Commandino maintained a correspondence with the astronomer Francesco Maurolico.
The proposition known as Commandino's theorem** first appears in his work on centers of gravity, Liber de centro gravitatis solidorum in 1565. *Wik
**The four medians of a tetrahedron concur in a point which divides each tetrahedron median in the ratio 1:3, the longer segment being on the side of the vertex of the tetrahedron. Student's should compare this to the property of the medians of a triangle which concur at a point that divides the meadian in a 1:2 ratio.

1910 Wilhelm Winkler (29 June 1884 in Prague, Bohemia (Austro-Hungarian Empire, now Czech Republic - 3 Sept 1984 in Vienna, Austria) After attending the trading high school in Gera, Winkler worked as a merchant in Eisenberg, following in the footsteps of his grandfather. In 1875 he gave up this trade and devoted his time entirely to astronomy. Advised by Carl Bruhns, director of the Leipzig University Observatory, he established an observatory on his estate in Gohlis near Leipzig. From 1878 Winkler regularly observed sunspots; other fields of his observational interests were comets, occultations of stars by the Moon, and Jupiter's satellites. *Uni Bonn Web page

1967 William P Milne (22 May 1881 in Longside, Aberdeenshire, Scotland - 3 Sept 1967 in Glack, Aberdeenshire, Scotland) studied at Aberdeen and Cambridge universities. He taught at Clifton College and then became Professor of Mathematics at Leeds. He published papers in Geometry including many in the Proceedings of the EMS. *SAU (Not to be confused with the William J Milne who, as President of the New York State Normal School in Albany, wrote many popular textbooks in arithmetic, algebra and geometry for high school use)

1992 Barbara McClintock (16 Jun 1902, 3 Sep 1992) American scientist regarded as one of the most important figures in the history of genetics. In the 1940s and 1950s McClintock's work on the cytogenetics of maize led her to theorize that genes are transposable - they can move around - on and between chromosomes. McClintock drew this inference by observing changing patterns of coloration in maize kernels over generations of controlled crosses. The idea that genes could move did not seem to fit with what was then known about genes, but improved molecular techniques of the late 1970s and early 1980s allowed other scientists to confirm her discovery. She was awarded the 1983 Nobel Prize in Physiology or Medicine, the first American woman to win an unshared Nobel Prize. *TIS

1995 Bent Christiansen From his Obituary: "Bent was a legend in mathematics education in Denmark and the Nordic countries. His impact on the development of the teaching and learning of mathematics in primary and lower secondary education can hardly be over-estimated. He wrote textbooks and books on mathematics education, especially the very influential 'Goals and means in basic mathematics education' ('Mål og midler I den elementære matematikundervisning', 1967). He gave innumerable in-service courses and invited lectures at meetings and conferences. Naturally, he also served on hosts of national committees, including the Danish National Sub-Commission of ICMI (1961-1972). All this earned him a reputation as a charismatic, enthusiastic and extremely energetic mentor for generations of mathematics teachers, teacher trainers and colleagues."

247 = 50123 - 49876


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

Sunday, 2 September 2018

On This Day in Math - September 2



The importance of the "New Mathematics" lies mainly in the fact that it has taught us the difference between the disc and the circle.

D MacHale, Comic Sections (Dublin 1993)
(I realize that a whole generation has grown up who have no idea what "New Mathematics" means, my apologies to them for a dated quote)

The 245th day of the year; 245 is the fifth StellaOctangula number. The sum of the 5th octahedral number (85) and eight of the fourth tetrahedral numbers (20). 245 =85 + 8 (20)

245 is also the sum of three consecutive squares, \(245 = 8^2 + 9^2 + 10^2 \)

There are 245 odd entries in the first 33 rows of the Arithmetic Triangle.

245 is also the 46th prime plus 46, 199+46=245




EVENTS

1666 Five days previously Wren had visited Old St. Paul's Cathedral to determine the reconstruction needs for the decaying old building.    During the night of Sep 2, and for the next five days, the Great Fire of London will burn out about 7/8 of the city of London and greatly alter Wren's work at St Paul's.  [The Great Fire of is supposed to have started in the house of King Charles II's baker on Pudding Lane near London Bridge.*@History Magazine]
 Image from Wikipedia,

In 1752, today was the last day of the Julian calendar in Great Britain and the British colonies; the Gregorian Calendar designed to correct the extra leap year day problem went into effect the next day with tomorrow being September 14, hence 11 days were dropped. Most other countries made the adjustment in 1582. *TIS

1808 Gauss writes Wolfgang Bolyai: “It is not knowledge, but the act of learning, not possession but the act of getting there, which grants the greatest enjoyment.” * Mathematical Circles Squared,Howard Eves, pg 113

1905 While a student at Kumbakonam he was so obsessed with his math studies that he failed all his other classes. It seems after a conflict at home, he ran away, causing his mother to send a missing-person letter to the newspaper:

1958 The National Defense Education act was passed in response to Sputnik (4 October 1957). $840 million was appropriated to improve the teaching of mathematics, science, and foreign languages. *VFR

1997 After its Deep Blue chess-playing computer defeated human world chess champion Gary Kasparov​ in a closely watched match in May, the pioneering computer company decided to make the machine even faster and stronger. On September 2, IBM announced that its RS/6000 SP model, a parallel supercomputer, was now 58 percent faster thanks to a new microprocessor and some software refinements. Kasparov was not available for comment.*CHM




BIRTHS

1841 Paul Matthieu Hermann Laurent born (2 September 1841 Luxembourg City – 19 February 1908 Paris, France). He developed statistical formulas for the calculation of actuarial tables and studied heat conduction. *VFR (Laurent series expansions for complex functions were not named after him)

1850 Alfred Pringsheim born (2 September 1850 – 25 June 1941), a German mathematician who worked on real and complex functions. *SAU Pringsheim's theorem concerns the convergence of a power series with non-negative real coefficients. Pringsheim and Ivan Śleszyński, working separately, proved what is now called the Śleszyński–Pringsheim theorem on convergence of certain continued fractions.*Wik

1856 Wilhelm Franz Meyer born (2 September 1856 in Magdeburg; 11 April 1934 in Königsberg . Meyer studied algebraic geometry, algebraic curves and invariant theory.*SAU He was a Founding member of the German Mathematical Society. *Wik

1877 Frederick Soddy (2 September 1877 – 22 September 1956) was an English radiochemist and monetary economist who explained, with Ernest Rutherford, that radioactivity is due to the transmutation of elements, now known to involve nuclear reactions. He also proved the existence of isotopes of certain radioactive elements. He received the Nobel Prize for Chemistry in 1921, and named after him is small crater on the far side of the Moon and the radioactive Uranium mineral, Soddyite.He rediscovered the Descartes' theorem in 1936 and published it as a poem. The kissing circles in this problem are sometimes known as Soddy circles.
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.
The entire poem is found here, along with a story about how, In a strange "chain reaction" of ideas, Soddy played a part in the US developing an atomic bomb. *(Assorted notes)

1878 (René-)Maurice Fréchet (2 Sep 1878; 4 June 1973) was a French mathematician known chiefly for his contribution to real analysis. He is credited with being the founder of the theory of abstract spaces, which generalized the traditional mathematical definition of space as a locus for the comparison of figures; in Fréchet's terms, space is defined as a set of points and the set of relations. In his dissertation of 1906, he investigated functionals on a metric space and formulated the abstract notion of compactness. In 1907, he discovered an integral representation theorem for functionals on the space of quadratic Lebesgue integrable functions. He also made important contributions to statistics, probability and calculus. *TIS

1891 Ivan Matveyevich Vinogradov (2 Sep 1891[OS? SAU gives 14 Sep], 20 Mar 1983)Soviet mathematician known for his contributions to the analytical theory of numbers, including a partial solution of the Goldbach conjecture proving that every sufficiently large odd integer can be expressed as the sum of three odd primes. He described his methods in his most celebrated piece of work Some Theorems Concerning the Theory of Prime Numbers (1937)*TIS

1892 Frank Wilcoxon, (2 September 1892 - 18 November 1965) whose name should be familiar to anyone who has used classic nonparametric (distribution-free) tests, was born in County Cork, Ireland, to American parents. He spent much of his early life in the Hudson River Valley region of New York, and in 1924 received a doctorate in inorganic chemistry from Cornell. Thus, much of his early work was in research related to chemistry, with his interest in statistics resulting from reading Fisher's well-known book Statistical Methods for Research Workers (which I
recall reading somewhere was for some time the most cited book in all of science). During the 1940s Dr. Wilcoxon was perhaps most instrumental in the growth of the fledgling field of nonparametric or distribution-free statistics, introducing his signed-rank test for paired samples and his famous two-sample rank-sum test as an alternative to Student's unpaired two-sample t-test, each of which carry Wilcoxon's name in its appellation. (Wilcoxon's 1945 paper introducing these two tests
was titled "Individual Comparisons by Ranking Methods".)
For a good description of how outliers led the chemist Wilcoxon to develop these tests, read Chapter 16, "Doing Away With Parameters", in David Salsburg's book The Lady Tasting Tea, in which Salsburg writes in a footnote that "the nonparametric approach was not fully understood to be such a drastic revolution until Wilcoxon's work in this field" *David Bee

1909 Deane Montgomery (2 Sept 1909 - 15 March 1992 in Chapel Hill, North Carolina, USA) was a mathematician specializing in topology who was one of the contributors to the final resolution of Hilbert's fifth problem in the 1950s. He served as President of the American Mathematical Society from 1961 to 1962.
Born in the small town of Weaver, Minnesota, he received his B.S. from Hamline University in St. Paul, MN and his Masters and Ph.D. from the University of Iowa in 1933; his dissertation advisor was Edward Chittenden.
In 1941 Montgomery was awarded a Guggenheim Fellowship. In 1988, he was awarded the American Mathematical Society Leroy P. Steele Prize for Lifetime Achievement.*Wik

1923 René Thom (September 2, 1923 – October 25, 2002) is known for his development of catastrophe theory, a mathematical treatment of continuous action producing a discontinuous result. *SAU
Born in Montbeliard, France. In 1958 he received a Fields Medal for his 1954 creation of cobordism in algebraic topology. His classification of manifolds used homotopy theory in a fundamental way and this work became an important example of general cohomology theory. *VFR Thom is also known for his later work developing the catastrophe theory (1972), a mathematical treatment of continuous action producing a discontinuous result. Thom's theory is an attempt to describe, in a way that is impossible using differential calculus, those situations in which gradually changing forces lead to so-called catastrophes, or abrupt changes. The theory has widespread application in the physical and biological sciences and in the social sciences, but eventually fell from favour.*TIS

1925 Roy Jay Glauber (born September 1, 1925) is an American theoretical physicist. He is the Mallinckrodt Professor of Physics at Harvard University and Adjunct Professor of Optical Sciences at the University of Arizona. Born in New York City, he was awarded one half of the 2005 Nobel Prize in Physics "for his contribution to the quantum theory of optical coherence", with the other half shared by John L. Hall and Theodor W. Hänsch.
In this work, published in 1963, he created a model for photodetection and explained the fundamental characteristics of different types of light, such as laser light (see coherent state) and light from light bulbs (see blackbody). His theories are widely used in the field of quantum optics. *Wik

1948 Christa McAuliffe (2 Sep 1948; died 28 Jan 1986) Astronaut, first teacher in space, who died on
the Challenger Space Shuttle when 73 seconds into its 10th launch, Challenger (STS-51L) exploded in midair, killing its crew of seven. Space shuttle flights were suspended until 1988. An independent U.S. commission blamed the disaster on unusually cold temperatures that morning and the failure of the O-rings, a set of gaskets in the rocket boosters. *TIS





DEATHS

1764 Nathaniel Bliss (28 November 1700 – 2 September 1764) was an English mathematician and astronomer who went on to become Astronomer Royal. He succeeded Edmond Halley as professor of geometry at Oxford University in 1742 and was elected a Fellow of the Royal Society the same year. He succeeded James Bradley to become the fourth Astronomer Royal in 1762, but held the post for too short a period to make a significant impact (1762-1764).*Wik

1768 Antoine Deparcieux (October 28, 1703 – September 2, 1768) was a French mathematician who is best known for an early work on annuities and mortality.*SAU In 1746, he published Essai sur les probabilités de la durée de la vie humaine (An Essay on the Probabilities of the Duration of Human Life). Deparcieux analyzed in detail empirical observations. As a mathematician and physicist, he can be considered, after Halley and Struyck, one of the founders of the estimation of longevity and all the issues surrounding that concept. *Wik

1832 Franz Xaver von Zach (4 June 1754, 2 Sep 1832) German-Hungarian astronomer patronized by Duke Ernst of Saxe-Gotha-Altenburg. Director of observatory near Gotha (1787-1806). There he organized in 1798 the first congress of astronomers with Josef Lalande (1732-1807) as celebrated guest. In last years of the 18th century he formed a group of 24 astronomers chosen from throughout Europe to track down a "missing" planet between the orbits of Mars and Jupiter, where they instead discovered the asteroids. His greatest contribution was in the organizational area, for he maintained an enormous correspondence with all the astronomers of his time, and edited 28 volumes of Monatliche Korrespondenz zur Beforderung der Erd- und Himmelskunde (1800-13).*TIS

1865 Sir William Rowan Hamilton (4 Aug 1805, 2 Sep 1865) Irish mathematician in the fields of optics, geometrics, and classical mechanics. By age 12, Hamilton had already learned fourteen languages when he met the American, Zerah Colburn, who could perform amazing mental arithmetical feats, and they joined in competitions. It appears that losing to Colburn sparked Hamilton's interest in mathematics. At 15, he began studied the works of LaPlace and Newton so by age 17 had become the greatest living mathematician. He contributed to the development of optics, dynamics, and algebra. His invention of the calculus of quaternions enabled a three-dimensional algebra or geometry which provided a basis for the later development of quantum mechanics. *TIS

2002 Sheila Edmonds was one of the last of the old-style Cambridge dons who devoted their lives to teaching and to their colleges.
Sheila had an excellent undergraduate career ending up a `Wrangler', as students who are placed first class in the examinations for the Mathematical Tripos are called - though this did not result in a Cambridge BA degree because women were ineligible until 1947. The following year, she was awarded a distinction in the notoriously demanding Part III of the Tripos. In a speech she gave at her 80th birthday dinner, she acknowledged that a key to her success was the thorough mathematical training she received from her Director of Studies at Newnham, Margaret Grimshaw, who was 11 years her senior and another of the old-style dons. *Newnham College web page


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

Saturday, 1 September 2018

Pythagoras and Matrices

I first learned about Barning trees in 2008.  Over the years people much brighter than I am, chipped in to tell me more.  This is a consolidation of posts since then that I hope will be readable and informative.  I find the ideas here fascinating.  Hope you enjoy


You can click on any image to expand it and make it sharper

It’s been a good weekend for Geometry for me. Several notes from folks telling me about geometry stuff I never knew… While I’m waiting on permission from the author of one, I wanted to tell you about the other.. The graph (tree) below shows a set of Primitive Pythagorean triples… All the ones with hypotenuse less than 100. Primitive Pythagorean triples are right triangles that have all sides as integers and none of them have a common factor.

What was new (to me) was that any one of them (and all the others not shown here) can be found as transformations of (4,3,5) using only three transformations. Let me make that clearer. If you think of a primitive Pythagorean triple as a point in three-space, then any other primitive Pythagorean triple is a point in three space that is just a transformation of this one… but there are only three transformations needed to get ALL of them. The tree shows which ones are generated by which ones, but you need to crank out the calculator and do some of these to see how neat it really is.
This type of graph is called a Barning-Tree because it seems to have first been discovered by F. J. M. Barning, “On Pythagorean and quasi-Pythagorean triangles and a generation process with the help of unimodular matrices, (Dutch) Math. Centrum Amsterdam Afd. Zuivere Wisk, ZW-011 (1963) 37 pp..
If you take the three matrices below, and write any of the primitive triples as a column vector, then multiplying by any of the matrices will give you another unique triple.. they never duplicate one, and they don’t leave any out (OK, I’m taking that on faith as I haven’t proven it for myself yet). I think that is kind of wild, and am totally impressed with people who can notice stuff like that.
Here are the three transformations

On This Day in Math - September 1




"Life is good for only two things, discovering mathematics and teaching mathematics"
Siméon Poisson


The 244th day of the year; 244 is the smallest number (besides 2) that can be written as the sum of 2 squares or the sum of two 5th powers. *What's Special about this number

244 is anti-perfect. The proper divisors are 1, 2, 4, 61, and 122, & adding their reversal is 1 + 2 + 4 + 16 + 221 = 244. *Jim Wilder ‏@wilderlab (244 is the smallest multi-digit anti-perfect number; There is one more year day which is anti-perfect.... don't just sit there, go find it!)

244 is also the sum of three cubes, \( 244 = 1^3 + 3^3 + 6^3 \)



EVENTS
1488 The Plimpton Library has a copy of Anianus, Computus Manualis combined with Boethius, Arithmetica, which is probably the first book on mathematics printed in Strasburg. It DIDN'T happen on this date but I include it here because it has the first known printing of the little mnemonic that begins, “Thirty days bath September,”
*historyofscience.com

1672 Hooke's diary records " Calculated lengths of Glasses." from Hooke's Journal *Robert Hooke ‏@HookesLondon This was done using Hookes "musical cylinder" or string phone. In July 1664 Hooke produced an experiment to show the number of vibrations of an extended String, made in a determinate time, requested to give a certain Tone or Note, by which it was found that "a Wire making two hundred seventy two vibrations in one second of time sounded G Sol Re Vt. in the Scale of all Musick". Hooke had found that middle C had 272 beats a second, and on 1st September 1672 Hooke noted the he had invented an easy way for "a musical cylinder with pewter tips pinched between cylindrick rings". *Daniel P McVeigh, "An Early History of the Telephone 1664-1865"

1698 The last Russian year to begin on September 1. January 1, 1699 began a new year. *VFR but still on the Julian Calendar. Russia would not switch to the Gregorian calendar until 24 January 1918 when the Council of People's Commissars issued a Decree that Wednesday, 31 January 1918 was to be followed by Thursday, 14 February 1918, thus dropping 13 days from the calendar. *Wik

1742 a letter from Euler to Niklaus I Bernoulli on pentagonal number theorem. Euler also notes in this letter that the coefficients of the terms in the series
1 + 1n + 2n
2 + 3n
3 + 5n
4 + 7n
5 + 11n
6 + 15n
7 + 22n
8 + 30n
9 + 42n
10 + 56n
11 + etc.
give the number of different ways in which the exponent of the term can be made by addition, i.e. that it is the generating function for the (unrestricted) partition function. Euler then writes: “This series moreover arises from division, if unity were divided by \((1 − n)(1 − n^2)(1 − n^3)(1 − n^4)(1 − n^5 )\) etc., which product if expanded gives this expression \( 1 − n − n^2 + n^5 + n^7 − n^{12} − n^{15} + n^{22} + n^{26} − n^{35} − etc\) . where the precise way in which the exponents proceed I have not been able to penetrate, although by induction(Euler means experimentation and extrapolation of a pattern, not the proof by induction we use today) I have concluded for no other exponents to occur, unless they are contained in the formula (3xx ± x)/2; and this is such that the powers of n have the + sign if the exponents arise with an even number substituted for x”. *Jordan Bell, Euler and the Pentagonal Number Theorem

1849 On the night of September 1, 1849, the nearly full Moon appeared over the town of Canandaigua, New York. At 10:30 P.M., Samuel D. Humphrey slid a highly polished, silver-plated copper sheet measuring 2¾x1¾ inches into his camera, which was pointed at the Moon. After developing the plate with mercury vapor, he sent his daguerreotype to Harvard College. This is believed to be the oldest existing photo of the moon.
Many sources (Wikipedia, for instance) claim this is actually the first known photo of the moon was taken on March 23, 1840 (see my page for that date) by John W. Draper of New York City. Draper is credited with making a clearer daguerreotype of the (full) Moon in March 1840, and he sent a letter with a copy of the image to John Herschel. Others believe his original photo was destroyed in a fire. This may be due to some confusion about a photo taken the previous year by Daguerre, which burned in his laboratory fire.  *PB notes

1854 It was on this day that John Snow became aware of the cholera epidemic, and began his studies leading to the isolation of the Broad Street Pump. "Early on the morning of September 1st, 1854, in the Berwick Street district of St. James's, Westminster, where I had spent some hours of the preceding day without hearing any mention of cholera-and where, in former epidemics, the mortality from that disease had been inconsiderable-I was asked to visit a house in which lay, already collapsed, four persons who had been seized with cholera during the night; and, on leaving this house, whichever way I turned, I came upon similar scenes. At noon, when I met my brother curate and the Scripture-reader for a short time in the vestry of St. Luke's, Berwick Street, I learned that they had each been occupied all the morning in the same way as myself. The rest of the day was spent in the same manner; and, as an indication of the severity of the outbreak, I record that, of all the cholera patients visited by me on that day, only one recovered." *The John Snow Archives, For those who are unfamiliar with the case, a beautiful book:


1859 First recorded observation of a solar flare. Richard Christopher Carrington English astronomer was the first to map the motions of sunspots and thus discover from them that the Sun rotates faster at the equator than near the poles (equatorial acceleration). He observed that the sunspots were not attached to any solid object, and also discovered the movement of sunspot zones toward the Sun's equator as the solar cycle progresses. On 1 Sep 1859, Carrington was the first to record the observation of a solar flare. *TIS Richard Hodgson, another English amateur astronomer, independently made the observations of the same solar flare. *Wik He reported his Description of a Singular Appearance seen in the Sun in the Monthly Notices of the Royal Astronomical Society (1860), "While engaged in the ... observation of ... solar spots ... two patches of intensely bright and white light broke out. ... I therefore noted down the time, ... and seeing the outburst to be very rapidly on the increase ... I hastily ran to call some one to witness ... and on returning within 60 seconds, was mortified to find that it was already much changed and enfeebled. Very shortly afterwards the last trace was gone. In this lapse of 5 minutes, the two patches of light traversed a space of about 35,000 miles."*TIS

1861 (Sept ?) Sir Charles Bright and Mr. Latimer Clark proposed the names of ohm, volt, and farad for the practical units based on the centimetre-gramme-second absolute system, Sir William Thomson gave a cordial support; and on his initiative was formed the famous Committee of Electrical Standards of the British Association, which year by year has done so much to carry to perfection the standard and the methods of electrical measurement. *IEC History This seems to have been the first time a unit of measure was named for a famous scientist.

In 1869, Cleveland Abbe began a weather reporting system in Cincinnati, Ohio and published a weather bulletin which contained his first weather forecast on September 1, 1869. In the United States, on October 21, 1743, Benjamin Franklin had tracked a hurricane for the first time. It was the first recorded instance in which the progressive movement of a storm system was recognized. A photo gallery of the development of the US Weather Bureau is available here:
In 1847, the first weather warnings were issued via telegraph. In 1870, the National Weather Service was born. *Weather.about.com

1902 The French film pioneer George Méliès presented the very first science fiction movie to the stunning public of the Paris Olympia theater. *Yovisto 



1916 The first (late) summer meeting of the MAA was held at MIT, September 1-2, 1916. *MAA

1920 The central limit theorem didn't get it's name until 1920 even though the first version of the theorem was published in 1733. *Probability Fact ‏@ProbFact,
The first version of this theorem was postulated by Abraham de Moivre who used the normal distribution to approximate the distribution of the number of heads resulting from many tosses of a fair coin. The actual term "central limit theorem" (in German: "zentraler Grenzwertsatz") was first used by George Pólya in 1920 in the title of a paper, "Über den zentralen Grenzwertsatz der Wahrscheinlichkeitsrechnung und das Momentenproblem", in Mathematische Zeitschrift. (9/1/1920) Pólya referred to the theorem as "central" due to its importance in probability theory. According to Le Cam, the French school of probability interprets the word central in the sense that "it describes the behaviour of the centre of the distribution as opposed to its tails". *Wik

1922 British chemist and physicist Francis W. Aston was awarded the Nobel Prize in Chemistry. He developed the mass spectrometer, a device that separates molecular fragments of different mass and measures them with remarkable accuracy. Using the spectrometer, Aston discovered that neon had two isotopes, \(^{20} \)Ne and \(^{21} \)Ne, and was awarded the 1922 Nobel Prize for this work. *RSC.org

1936 The first meeting of the Association for Symbolic Logic was held in Cambridge, Massachusetts. Rudolf Carnap presented an invited address, “Truth in Mathematics and Logic,” to an audience of three hundred. *VFR

1939 Robert Oppenheimer wrote a seminal paper on black holes that went mostly overlooked and is still relatively un-noted because it was published on the same day that WWII began with German invasion of Poland.

1939 World War II began, as German troops marched into Poland.

1963 The scientific community learned about rotating black holes in general relativity #OTD in 1963, when Roy Kerr's groundbreaking paper appeared in Physical Review Letters. hat tip @RobertMcNees

1964 The Ryukyu Islands issued a stamp commemorating the opening of the Ryukyu Islands–Japan microwave system for telephone and telegraph messages. Pictured is a parabolic antenna, one of the many applications of the reflective properties of the conics. [Scott #123] *VFR

1967 Harvey Friedman was appointed Assistant Professor of Mathematics at Stanford University, just three weeks before his nineteenth birthday. This is the youngest at which anyone has begun a university career. He is now a distinguished logician at The Ohio State University. (Guinness) See September 23, 1948, September 30, 1717, and November 19, 1982. *VFR

In 1997, the discovery of a new sub-atomic particle was announced, called the "exotic meson." Scientists speculated that the exotic meson might comprise four quarks, unlike all other known particles, which have three. The research team included physicists at Brookhaven National Laboratory, Upton, N.Y., and other facilities in the U.S. and Russia.*TIS

1994 U.S. Library of Congress starts "Virtual Library" project.The LOC holds the first of several meetings to plan a project to convert its materials to digital form so they will be accessible via computer networks to students and researchers around the world. The "virtual library" project could also save rare materials that are degrading or have been vandalized, as well as saving space for the library, whose belongings fill up 575 miles of shelving. At the time of the initial meeting -- at which librarians and technical experts from several major computer companies discussed strategy and funding -- the library hoped to have its most vulnerable materials digitized by the year 2000. *CHM

2008 John D. Barrow is appointed Gresham Professor of Geometry. He had previously held the Gresham chair in Astronomy, (2003-2007). *Wik



BIRTHS

1659 Joseph Saurin (September 1, 1659 at Courtaison – December 29, 1737 at Paris) . In the early seventeenth century he defended the calculus against the criticisms of Michael Rolle. *VFR He became friends with de L'Hôpital, Malebranche and Varignon but, by 1702, he was in dispute with Rolle over the calculus. This came about because of his role as mathematics editor of the Journal des Sçavants. He appealed to the Académie Royal des Sciences but, although Saurin was correct, they had no wish to come out against Rolle who was a member. Perhaps to be diplomatic, Saurin was elected to the Académie Royal des Sciences in 1707. *SAU In the Paris Académie Royale des Sciences in July of 1700, Michel Rolle voiced opposition to the use of infinitesimal magnitudes.Rolle was not alone in this project, for he allied himself with several mathematical conservatives, including the Abbé Jean Gallois and the Abbé Thomas Gouye, both of whom venerated the Greek standards of rigor and had significant reservations about the use of infinitesimal methods. Rolle's criticisms were later published in the memoir Du nouveau systême de l'infini, which he opened by declaring that
We have always regarded geometry as an exact science, and also as the source of the exactness which is spread throughout all the other parts of mathematics. We see among its principles only true axioms: all the theorems and all the problems proposed here are either solidly demonstrated or capable of a solid demonstration. And if it should happen that any false or less certain principles slip in, they should be at once banished from this science.
But it seems that this character of exactitude no longer reigns in geometry, ever since we became entangled in the new system of the infinitely small. For myself, I do not see that it has produced any new truth, and it seems to me that it often leads to error.
*Leibniz on the Foundations of the Calculus:
The Question of the Reality of Infinitesimal Magnitudes, Douglas M. Jesseph

1826 Alfred Ely Beach (1 Sep 1826; 1 Jan 1896) American inventor and publisher, whose Scientific American helped stimulate 19th-century technological innovations and became one of the world's most prestigious science magazines. Beach himself invented a tunneling shield and built the pneumatic tube subway (1870). In 1856 he won First Prize and a gold medal at New York's Crystal Palace Exhibition. Beach had invented a typewriter for the blind. It resembled the modern typewriter in the arrangement of its keys and typebars, but embossed its letters on a narrow paper strip instead of a sheet. *TIS Beach purchased SA while the paper was still a small weekly journal with a circulation less than 300. It was bought for $800 in July 1846 by 20-year-old Beach as editor, and Orson Desaix Munn.

1835 William Stanley Jevons,(1 September 1835 – 13 August 1882) Political economist. He did early work in symbolic logic and built an early logic machine, the first that could solve complicated problems faster than they could be solved by hand.*VFR Irving Fisher described his book The Theory of Political Economy (1871) as beginning the mathematical method in economics. It made the case that economics as a science concerned with quantities is necessarily mathematical. In so doing, it expounded upon the "final" (marginal) utility theory of value. Jevons had written in his Principles of Science, p. 123, "Can the reader say what two numbers multiplied together will produce the number 8616460799 ? I think it unlikely that anyone but myself will ever know." This became known as Jevons' Number and was factored by Derrick Norman Lehmer in 1903. (Reader, try your hand.)
In economics, the Jevons paradox (sometimes Jevons effect) is the proposition that technological progress that increases the efficiency with which a resource is used tends to increase (rather than decrease) the rate of consumption of that resource. *Wik

1902 Dirk Brouwer (1 Sep 1902; 31 Jan 1966) Dutch-born U.S. astronomer and geophysicist known for his achievements in celestial mechanics, especially for his pioneering application of high-speed digital computers for astronomical computations. While still a student he determined the mass of Titan from its influence on other Saturnian moons. Brouwer developed general methods for finding orbits and computing errors and applied these methods to comets, asteroids, and planets. He computed the orbits of the first artificial satellites and from them obtained increased knowledge of the figure of the earth. His book, Methods of Celestial Mechanics, taught a generation of celestial mechanicians. He also redetermined astronomical constants.*TIS




DEATHS

1648 Marin Mersenne died (8 September 1588 – 1 September 1648).Often called the center of the scientific world in the early 17th century for his communication with and between many of the most prominent scientific minds of the period. He also performed extensive experiments to determine the acceleration of falling objects by comparing them with the swing of pendulums, reported in his Cogitata Physico-Mathematica in 1644. He was the first to measure the length of the seconds pendulum, that is a pendulum whose swing takes one second, and the first to observe that a pendulum's swings are not isochronous as Galileo thought, but that large swings take longer than small swings. *Wik

1687 Henry More (October 12, 1614 – September 1, 1687) was an English philosopher of science whose ideas may have influenced Newton. One other thing about Henry More which we should discuss is his relation to Newton. Newton was born close to Grantham and attended the Free School in Grantham. In fact he had lodgings in Grantham for seven years with a Mr Clark, the brother of a teacher at the Free School. More, who was about 30 years older than Newton, often returned to his home town of Grantham and when he did so he lived with one of the two Clark brothers. Therefore when More was a major figure at Cambridge he must have got to know the young pupil Newton. We certainly know that there was contact between Newton and More up till the time More was around 70 years of age.
Did More's ideas of space influence Newton? It is impossible to say with any certainty, but we can certainly note that Newton's idea of absolute space and time was crucial to his physics and that this notion of space is closely related to that put forward by More in his arguments against Descartes. Also in terms of gravity, for Descartes it was necessary to have an interaction through matter between the bodies. For Newton gravity was a force which acted through empty space and although he does not appear to have identified space with God as More did, nevertheless the spiritual aspect of space supported Newton's gravitational theories. *SAU

1716 Heinrich Meissner (April 20th 1644 in Hamburg - September 1 1716 Hamburg) was a co-founder of the Hamburg Masters and computing Mathematical Society in Hamburg. This is the oldest existing mathematical society in the world.
From 1688 until shortly before his death he was "writing, arithmetic and upper-master" of the parish school of St. Jacobi .
Meissner founded (Jan 2, 1690) along with Valentin Heins 'art-accounting practicing Society ", which became Hamburg Mathematical Society .
Meissner published a whole series of books and magazines. Worth mentioning are especially the key star and Algebrae, a textbook on algebra in the German language, and the Teutsche Euclid, a translation of the first two books in the "Elements" of Euclid with extensive annotations. *Wik

1908 Aleksandr Nikolayevich Korkin (3 March [O.S. 19 February] 1837–September 1, 1908) was a Russian mathematician. He made contribution to the development of partial differential equations. After Chebyshev, Korkin was the most important initiator of the formation of the Saint Petersburg Mathematical School*Wik

1982 Haskell Brooks Curry (12 Sep 1900, 1 Sep 1982)American mathematician who was a pioneer of modern mathematical logic. His research in the foundations of mathematics led him to the development of combinatorial logic. Later, this seminal work found significant application in computer science, especially in the design of programming languages. Curry worked on the first electronic computer, called ENIAC, during WW II. He also formulated a logical calculus using inferential rules. In 1942, he published Curry's paradox, which occurs in naive set theory or naive logics, and allows the derivation of an arbitrary sentence from a self-referring sentence and some apparently innocuous logical deduction rules. *TIS

1982 Ludwig Georg Elias Moses Bieberbach​ (4 December 1886, 1 September 1982 wrote a habilitation thesis in 1911 about groups of Euclidean motions – identifying conditions under which the group must have a translational subgroup whose vectors span the Euclidean space – that helped solve Hilbert's 18th problem. He worked on complex analysis and its applications to other areas in mathematics. He is known for his work on dynamics in several complex variables, where he obtained results similar to Fatou's. In 1916 he formulated the Bieberbach conjecture, stating a necessary condition for a holomorphic function to map the open unit disc injectively into the complex plane in terms of the function's Taylor series.*Wik

1988 Luis Walter Alvarez (June 13, 1911 – September 1, 1988) was an American experimental physicist, inventor, and professor who was awarded the Nobel Prize in Physics in 1968. The American Journal of Physics commented, "Luis Alvarez was one of the most brilliant and productive experimental physicists of the twentieth century.
In 1940 Alvarez joined the MIT Radiation Laboratory, where he contributed to a number of World War II radar projects, from early improvements to Identification Friend or Foe (IFF) radar beacons, now called transponders, to a system known as VIXEN for preventing enemy submarines from realizing that they had been found by the new airborne microwave radars. The radar system for which Alvarez is best known and which has played a major role in aviation, most particularly in the post war Berlin airlift, was Ground Controlled Approach (GCA). Alvarez spent a few months at the University of Chicago working on nuclear reactors for Enrico Fermi before coming to Los Alamos to work for Robert Oppenheimer on the Manhattan project. Alvarez worked on the design of explosive lenses, and the development of exploding-bridgewire detonators. As a member of Project Alberta, he observed the Trinity nuclear test from a B-29 Superfortress, and later the bombing of Hiroshima from the B-29 The Great Artiste.
After the war Alvarez was involved in the design of a liquid hydrogen bubble chamber that allowed his team to take millions of photographs of particle interactions, develop complex computer systems to measure and analyze these interactions, and discover entire families of new particles and resonance states. This work resulted in his being awarded the Nobel Prize in 1968. He was involved in a project to x-ray the Egyptian pyramids to search for unknown chambers. With his son, geologist Walter Alvarez, he developed the Alvarez hypothesis which proposes that the extinction event that wiped out the dinosaurs was the result of an asteroid impact. *Wik

1982 Haskell Brooks Curry (12 Sep 1900; 1 Sep 1982)American mathematician who was a pioneer of modern mathematical logic. His research in the foundations of mathematics led him to the development of combinatory logic. Later, this seminal work found significant application in computer science, especially in the design of programming languages. Curry worked on the first electronic computer, called ENIAC, during WW II. He also formulated a logical calculus using inferential rules. In 1942, he published Curry's paradox, which occurs in naive set theory or naive logics, and allows the derivation of an arbitrary sentence from a self-referring sentence and some apparently innocuous logical deduction rules.*TIS

2006 Warren J. Mitofsky, (17 September 1934 - 1 September 2006)While working at the Census Bureau in the 1960s, he and a colleague, Joseph Waksberg, began to devise a random-digit dialing (RDD) system that now bears both their names.
Mr. Mitofsky went to work at CBS News in 1967. Not long afterwards, he organized the first "exit poll" in a Kentucky gubernatorial election, with his first national exit poll being in 1972. He directed the CBS News Election and Survey Unit until 1990, leading, in 1975, to the joint effort with the NYTimes, the CBS News/New York
Times Poll (which The Times calls the New York Times/CBS News Poll),
which he directed until 1990.
Since 2003, Mitofsky, considered the "Father of Exit Polling" by many, led election-night analysis for the News Election Pool, providing exit-poll results and projections. (Mitofsky disliked the term "exit poll"; he preferred "Election Day survey".)
In exit polls on Election Day in 2004, Mitofsky's early exit polls found Senator John Kerry leading over President Bush, which led some in the news media to prepare for Senator Kerry becoming President Kerry. But such was too premature, as Mitofsky readily acknowledged, later discovering that the pro-Kerry exit-poll lead was caused by Republicans refusing to participate at a greater rate than Democrats in the exit polls. [Guess this shows the importance of not ignoring nonresponse.]
However, despite all this, Mitofsky will probably be best remembered by many for his efficient method of sampling telephone numbers using random-digit dialing (RDD), which is now known as the Mitofsky-Waksberg Method. In 1970, Mitofsky wrote an unpublished CBS News memorandum titled "Sampling of Telephone Households" that helped make his name a household word in public-opinion polling. Eight years later, Joseph Waksberg published an analogous paper, "Sampling Methods for Random Digit Dialing", in the prestigious Journal of the American Statistical Association (JASA), thus resulting in the Mitofsky-Waksberg Method appellation.
The Mitofsky-Waksberg Method of RDD is a cluster-sampling method
for sampling residential telephone numbers that greatly increases
the percentage of calls that do reach residential households. *David Bee


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