## Tuesday 30 July 2024

### On This Day in Math - July 30

I have created a new universe from nothing.

~Janos Bolyai

The 211th Day of the Year
The 211th day of the year; 211 is a primorial prime,(a prime that is one more, or one less than a primorial  can you find the next larger (or smaller) primorial prime?

211 is also the sum of three consecutive primes (67 + 71 + 73)...

There are 211 primes on a 24-hour digital clock. (00:00 - 23:59) *Derek Orr @ Derektionary

211 is the 4th** Euclid number: 1 + product of the first n primes.(after Euclid's method of proving the primes are infinite. most Euclid numbers, unlike 211, are not themselves prime, but are divisible by a prime different than any of the primes in the product n#) (**some would call it the fifth since Euclid seemed to consider 1 as a unit as similar to the primes.)

211 is a prime lucky number, and there are 211 lucky primes less than 10^4 (or 10 ^(2+1+1))*Prime Curios

211 is the concatenation of the smallest one digit prime and the smallest two digit prime, 2, 11.

211 = 3^5 - 2^5, two consecutive fifth powers, it is only the second, following 31, and is the last year date with the property.

Hardy wrote a New Year Resolution in a card to Ramujan to get 211, none out, in a cricket test match at the oval.

A Lazy Caterer number, A Pizza can be cut into 211 pieces with 20 straight cuts.

211 is a repunit in base 14 (111)14^2 + 14 + 1

211 is also SMTP status code for system status.*Wik

211 is an odd number, so it is the difference of two consecutive squares, 106^2 - 105^2 = 211

211 is the first of fifteen consecutive odd numbers that sum to the cube of 15, 3375

211 is a prime of the form 4k+3. According to Gauss' reciprocity law, if two numbers, p and q are in this sequence then there exists a solution to only one of x^2 = p (mod q) or x^2 = q (mod p). 3 is another number in the sequence. Can you find an x^2 so that one of these congruences is true?

And one more from *Prime Curios. If you've ever heard the expression "a month of Sundays," for something that takes a really long time that's 31 Sundays, starting on a Sunday and going for 30 more weeks to end on a Sunday, or 211 days, Sunday to Sunday.

EVENTS

1738 Euler sends a letter to John Bernoulli with the solution to a question from Danial Bernoulli regarding isoperimetric curves, particularly the  one for which the integral of rm gave a maximum or minimum.

It was Johann Bernoulli who tutored Euler in mathematics when he was young, and who started Euler on his path to scientific greatness. Their collected correspondence covered 38 letters.

1859 Bernhard Reimann is appointed full professor at Gottingen, succeeding his two former teachers, Gauss and Dirichlet. He also is allowed to occupy Gauss' apartments at the observatory. *John Derbyshire, Prime Obsession, pg 135

In 1898, Corn Flakes were invented by William Kellogg. At Battle Creek Sanitarium, Sanitarium superintendent, Dr. John Harvey Kellogg and Will Keith Kellogg, his younger brother and business manager, invented many grain-based foods, including a coffee substitute, a type of granola, and peanut butter to provide patients a strict nutritious diet. In 1894 they unintentionally invented a flaked cereal process based on wheat. By 1898, W.K. Kellogg had developed the first flaked corn cereal. Patients enjoyed the cereals and wanted more to take home. In 1906, the Battle Creek Toaster Corn Flake Company was founded by W.K. Kellogg.*TIS

1907 The Axiom of Choice is usually given as created by Zermelo in 1908, presumably because that was the year it appeared in Mathematische Annalen, but the date on the actual paper is "Chesières, 30 July 1907.". The paper contains, "AXIOM VI. (Axiom of choice). If T is a set whose elements all are sets that are different from 0 and mutually disjoint, its union "union of T" includes at least one subset S1 having one and only one element in common with each element of T." [The original German read "Axiom der Auswahl".]
Ernst Zermelo used the Axiom of Choice to prove that every set can be well-ordered on a paper of 1904, but did not use the name "Axiom of Choice". *Jeff Miler, Earliest Known Uses of Some of the Words of Mathematics

1918 Richard Courant sat down with Ferdinand Springer and signed a contract for the series of books now famous as the “Yellow Series.” *Constance Reid, Courant in Gottingen and New York, p. 72

1971 Apollo 15 mission became the fourth mission to land on the moon when the Falcon lunar lander touched down. This mission allowed the astronauts to spend more time on the surface of the moon. The lander stayed three days on the surface and the crew conducted over 18 hours of outside work. They also were aided for the first time by a lunar rover vehicle.*Science Today

1983 The Sumida River Festival in Tokyo celebrated its 250th anniversary, as the oldest, grandest fireworks festival in Japan. The festival spent \$400,000 on the hanabi—literally “fire flowers”— alone: 17,500 shells in an hour and 20 minutes, none bigger than four-and-a-half inches in diameter. How many shells is that per minute? [New York Times, July 17, 1983, sect. 10, p. 37]

Every last Saturday in July, colorful fireworks are launched from both sides of the Sumida River. The spectacle is best seen from close to the river, although it can get very crowded, and best spots are often taken hours in advance. Still, the festive atmosphere, with people dressing up in yukata and picnicking in the streets and parks, is worth it.

1985  Julia Robinson died of leukemia. After receiving her Ph.D. in 1948 under the direction of Alfred Tarski, she began work on Hilbert’s tenth problem, the problem which occupied most of her professional life.
Robinson was awarded a doctorate in 1948 and that same year started work on Hilbert's Tenth Problem: find an effective way to determine whether a Diophantine equation is soluble. Along with Martin Davis and Hilary Putman she gave a fundamental result which contributed to the solution to Hilbert's Tenth Problem, making what became known as the Robinson hypothesis. She also did important work on that problem with Matijasevic after he gave the complete solution in 1970. *SAU

BIRTHS

1857 Thorstein Bunde Veblen, (July 30, 1857 – August 3, 1929) was an American economist and sociologist, and a leader of the so-called institutional economics movement. Besides his technical work he was a popular and witty critic of capitalism, as shown by his best known book The Theory of the Leisure Class (1899).

1859 Henry Louis Smith (July 30, 1859–February 17, 1951) was the ninth president of Davidson College and the first president to not be an ordained Presbyterian minister.

American physicist and administrator who is credited with making the first X-ray photograph in the U.S. on about 12 Jan 1896, while he was a professor of physics and astronomy at Davidson College, North Carolina. Shortly after Röntgen's announcement of his discovery of X-rays, Smith copied the technique. Smith made an X-ray photograph of a bullet he had shot into the hand of a cadaver, that was  published in the Charlotte Observer (27 Feb 1896). Shortly thereafter, he made the first clinical use of X-rays to locate a thimble stuck in a young girl's throat, enabling its surgical removal. Smith became the college president in 1901 and oversaw adding a new science building. He established an electric light plant. Near the end of WW I, his idea to inform the German population of President Wilson's peace plans was adopted. Millions of messages carried by gas-filled balloons were released from France into the winds over Germany. *TiS

 *Wik

1863 Henry Ford (July 30, 1863 – April 7, 1947) American inventor and car manufacturer, born in Dearborn, Mich. Ford first experimented with internal combustion engines while he was an engineer with the Edison Illuminating Company. He completed his first useful gas motor on 24 Dec 1893. The Quadricycle, he designed made its first road test on 4 Jun 1896. In 1903 the Ford Motor Company was incorporated. By 1908, Ford was manufacturing the low cost, reliable Model T, while continuing to revolutionize his industry. Ford introduced precision manufactured parts designed to be standardized and interchangeable parts. In 1913, production was increased using a continuous moving assembly line. By 1918, half of all cars in America were Model T's.*TIS

1878 Joel Stebbins (July 30, 1878 – March 16, 1966) was an American astronomer who pioneered photoelectric photometry in astronomy.
He earned his Ph.D at the University of California. He was director of University of Illinois observatory from 1903 to 1922 and the Washburn Observatory at the University of Wisconsin-Madison from 1922 to 1948. After 1948, Stebbins continued his research at Lick Observatory until his final retirement in 1958.
Stebbins brought photoelectric photometry from its infancy in the early 1900s to a mature technique by the 1950s, when it succeeded photography as the primary method of photometry. Stebbins used the new technique to investigate eclipsing binaries, the reddening of starlight by interstellar dust, colors of galaxies, and variable stars.

Rumford Prize of the American Academy of Arts and Sciences (1913)
Henry Draper Medal of the National Academy of Sciences (1915)
Bruce Medal of the Astronomical Society of the Pacific (1941)
Gold Medal of the Royal Astronomical Society (1950)
Henry Norris Russell Lectureship of the American Astronomical Society (1956)

The Lunar crater Stebbins and the asteroid 2300 Stebbins are named in his honor. *TIA

Joel Stebbins, then a graduate student, at Lick Observatory about 1902 posing next to the 36-inch refractor.

1887 Felix Andries Vening Meinesz (The Hague July 30, 1887 - Amersfoort August 10, 1966) was a Dutch geophysicist and geodesist who was known for his measurements of gravity at sea for which he devised the Vening Meinesz pendulum apparatus with comparable accuracy as on land. Starting in 1923 he conducted several global gravity surveys on voyages on submarines, particularly to and in the Indonesian Archipelago. He detected strong gravity anomaly belts running parallel to the Indonesian deep sea trenches. He explained these Meinesz belts as sites of downbuckling of the Earth's crust. He introduced the concept of regional isostasy taking flexure of an elastic crust into account. He also contributed to physical geodesy: The Vening Meinesz formula connects the deviation of the vertical from the plumbline to gravity anomalies. *TIS

Vening Meinesz with his gravimeter

 *Wik

1888 Vladimir Zworykin (July 29 [O.S. July 17] 1888 – July 29, 1982) was born in Russia. After emigrating to Pittsburgh, Zworykin took a job at Westinghouse Electric Corp., where in 1923 he filed a patent for the iconoscope, the first television transmission tube and a technology that was to become of interest to early computer designers. With a later invention, the kinescope, Zworykin was able to create the first all-electric television system. Zworykin took the technology to RCA in 1929, where he continued his work and earned the title "father of television.*CMH

2021  Marion Walter (July 30, 1928 – May 9, 2021) was an internationally-known mathematics educator and professor of mathematics at the University of Oregon in Eugene, Oregon.

Marion Ilse Walter was born in Berlin and escaped the Nazis on the Kindertransport to England. She emigrated to the United States in 1948 and after earning her doctorate, founded the Mathematics Department at Simmons College. She published over 40 journal articles, several children's books, and the popular book The Art of Problem Posing.

There is a theorem named after her, called Marion Walter's Theorem or just Marion's Theorem as it is affectionately known.

This theorem, first stated by Walter in 1994, is the following:

Let  ABC be any triangle. Trisect each side, so that AB has C1 and C2  as the two trisection points and similarly for the other two sides. Draw the lines A  A1,  A A2, and similarly lines B B1 , B B2 , C C1, C C2.

These lines define an hexagonal region in the middle of triangleABC. Then the area of the hexagonal region is 1/10 the area of ABC.

1934 Donald Samuel Ornstein (born July 30, 1934, New York) is an American mathematician working in the area of ergodic theory. He received a Ph.D. from the University of Chicago in 1957 under the guidance of Irving Kaplansky. During his career at Stanford University he supervised the Ph. D. thesis of twenty three students, including David H. Bailey, Bob Burton, Doug Lind, Ami Radunskaya, Dan Rudolph, and Jeff Steif.

He is most famous for his work on the isomorphism of Bernoulli shifts, for which he won the 1974 Bôcher Prize. He has been a member of the National Academy of Sciences since 1981. In 2012 he became a fellow of the American Mathematical Society. *Wik

DEATHS

1762 William Braikenridge (1700; 30 July 1762 in London, England) was an English clergyman who worked on geometry and discovered independently many of the same results as Maclaurin.*SAU

In geometry the Braikenridge–Maclaurin theorem was independently discovered by Colin Maclaurin. It occasioned a priority dispute after Braikenridge published it in 1733; Stella Mills writes that, while Braikenridge may have wished to establish priority, Maclaurin rather felt slighted by the implication that he did not know theorems in the Exercitatio that he had taught for a number of years. *Wik

In geometry, the Braikenridge–Maclaurin theorem, named for 18th-century British mathematicians William Braikenridge and Colin Maclaurin, is the converse to Pascal's theorem. It states that if the three intersection points of the three pairs of lines through opposite sides of a hexagon lie on a line L, then the six vertices of the hexagon lie on a conic C; the conic may be degenerate, as in Pappus's hexagon theorem.

1832 French chemist John Antoine Chaptal He authored the first book on industrial chemistry, and coined the name "nitrogen". Chaptal also helped improve the technology used to manufacture sulfuric acid, saltpetre for gunpowder, beetroot sugar and wine, amongst other things. *RSC.Org

1978 Rufus Bowen (23 February 1947 - 30 July 1978) worked on dynamical systems. Rufus died of a cerebral hemorrhage at the age of 31. *SAU

In 1970, Bowen completed his doctorate in Mathematics at Berkeley under Stephen Smale, and joined the faculty as assistant professor in that year. At this time he began calling himself Rufus, the nickname he had been given because of his red hair and beard.  He was an invited speaker at the 1974 International Mathematical Conference in Vancouver, British Columbia.He was promoted to full professorship in 1977.
Bowen's mature work dealt with dynamical systems theory, a field which Smale, Bowen's dissertation advisor, explored and broadened in the 1960s.

1985 Julia Robinson (December 8, 1919 – July 30, 1985) died of leukemia. After receiving her Ph.D. in 1948 under the direction of Alfred Tarski, she began work on Hilbert’s tenth problem, the problem which occupied most of her professional life.*VFR She also worked on computability, decision problems and non-standard models of arithmetic. *SAU Her sister was Constance Reid who wrote biographies of several mathematicians and several popular math books.

Julia Robinson's Job Description:

Monday: Try to prove theorem

Tuesday: Try to prove theorem

Wednesday: Try to prove theorem

Thursday: Try to prove theorem

Friday: Theorem false

Elizabeth Scott in a tribute to Robinson,

1993 Jeremiah Certaine (6 June 1920, 30 July 1993) was an African American mathematician who was awarded a Ph.D. by Harvard University for a thesis on algebra in 1945. He taught at Howard University for a few years but for most of his career he was an applied mathematician for Nuclear Development Associates and the United Nuclear Corporation.

Certaine was awarded a B.A. by Temple University in 1940 and was accepted to continue studying mathematics at Temple University for a Master's Degree which he was awarded in 1941, After the award of his Master's Degree, Certaine went to Harvard University where he began research advised by Garrett Birkhoff. In 1942-43 he was a member of the Harvard Math Club and presented the paper Groups as algebras of a single operation at one of its meetings.

In 1945 Certaine was awarded a Ph.D. from Harvard University for his 69-page thesis Lattice-Ordered Groupoids and Some Related Problems. *SAU

2002 Dr. Lyle B. Borst, (Nov 24, 1912 - July 30, 2002) was a nuclear physicist who helped build Brookhaven National Laboratory's nuclear reactor and was an early member of the Manhattan Project.
In 1950, Dr. Borst led the construction of the Brookhaven Graphite Research Reactor, which was the largest and most powerful reactor in the country and the first to be built solely for research and other peacetime uses of atomic energy.
Within the first nine months of operating the reactor, Dr. Borst announced that it had produced a new type of radioactive iodine, which is used in treating thyroid cancer.
In 1952, based on studies of new types of atomic nuclei created in the reactor, Dr. Borst helped explain the mystery behind giant stars, known as supernovae, that burst with the energy of billions of atomic bombs and flare for several years with the brilliance of several million suns.
Dr. Borst found that beryllium 7, an isotope of beryllium that does not occur naturally on earth, is formed in supernovae by the fusion of two helium nuclei. The fusion takes place after the star has used up its hydrogen supply. This reaction absorbs huge quantities of energy, causing the star to collapse in the greatest cosmic explosion known. *NY Times obit.

2016 András Hajnal (May 13, 1931 - July 30, 2016 ) is an emeritus professor of mathematics at Rutgers University and a member of the Hungarian Academy of Sciences known for his work in set theory and combinatorics. Hajnal is the author of over 150 publications. Among the many co-authors of Paul Erdős, he has the second largest number of joint papers, 56. With Peter Hamburger, he wrote a textbook, Set Theory

In 1992, Hajnal was awarded the Officer's Cross of the Order of the Republic of Hungary. In 1999, a conference in honor of his 70th birthday was held at DIMACS, and a second conference honoring the 70th birthdays of both Hajnal and Vera Sós was held in 2001 in Budapest. Hajnal became a fellow of the American Mathematical Society in 2012.*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