## Saturday, 16 May 2015

### On This Day in Math - May 16

To isolate mathematics from the practical demands of the sciences
is to invite the sterility of a cow shut away from the bulls.

Pafnuty Chebyshev
Quoted in G Simmons, Calculus Gems (New York 1992)

The 136th day of the year; 136 is the sum of the cubes of the digits of the sum of the cubes of its digits. (13 + 33 + 63 = 244 and 23 + 43 + 43 = 136) *Tanya Khovanova, Number Gossip (Only one other number pair share this relation. Can you find them?)
The sum of all prime factors of 136 is equal to the reversal of $\pi(136)$. $\pi(n)$ is the number of primes less than n (so $\pi(136)=32$ and the sum of the prime factors of 136 is 2+2+2+17 =23)

EVENTS

1571 Johannes Kepler was conceived at 4:37 a.m. on his parents’ wedding night, according to his computations for his own horoscope. His actual date of birth is more certain, Dec 17th of the same year. He was born in Weil der Stadt, about 20 km west of Stuttgart, There is a museum in the Marketplatz that claims to be his birthplace, but the building seems to only date to about 1648.

1667 "...in the course of attempting to conceive of the physical laws that would explain how the Moon revolved around the Earth, Newton happened to be sittting near the apple tree in the garden at Woolsthorpe when he saw an apple drop to the ground. At that moment, he realized that the same central pull of the Earth applied to both objects. *Brody & Brody, The Science Class You Wish You Had
On April 15, 1726, writer William Stukeley held a conversation with Isaac Newton in Kensington during which Newton recalled “when formerly, the notion of gravitation came into his mind.” Later, Stukeley writing in his Memoirs of Sir Isaac Newton's Life, recorded that Newton said, “It was occasioned by the fall of an apple, as he sat in contemplative mood. Why should that apple always descend perpendicularly to the ground, thought he to himself. Why should it not go sideways or upwards, but constantly to the earth's centre.” *TIS The story was also related to John Conduitt who was Newton's assistant at the Royal mint, and the husband of Newton's niece. The idea that the apple hit Newton on the head seems to date from the early 20th Century. A copy of the page of Stukeley's manuscript where he tells this story is available on-line at the Royal Society.

1678  Hooke records in his diary that he has been performing experiments on mercury barometers at the Great Fire memorial on Fish St.  "It descended at the top by about 1/3 of an inch." *Lisa Jardine, Ingenious Pursuits pg 78

1695 Leibniz, in a letter to Johann Bernoulli, tells of his discovery of the multinomial theorem, “a wonderful rule for the coefficients of powers not only of the binomial x + y, but also of the trinomial x + y + z, in fact, of any polynomial.” [Smith, Source Book, p. 229]*VFR
This allows us to find terms of the expansion of, say, (x+y+z)6 and show that the term with x3y2z will have a coefficient of

1713 John Machin was appointed as Professor of Astronomy at Gresham College, London. He succeed Dr Torriano and went on to hold the chair until his death 38 years later. *SAU

1800 Gauss records in his diary “On about these days (May 16) we most elegantly resolved the problem of the chronology of the Easter Feast.” [Gray, Expositiones Mathematicae, 2(1984), 97–130] *VFR

1866, root beer was invented by Charles Elmer Hires.*TIS    I'll drink to that!

1910 Halley's comet was big news during its visible period in New York City. Beginning with the Saturday edition of May 14 and continuing on through the Sunday edition of May 22, the comet was given top billing in the New York Times. This was the period when the comet was at the height of its brilliance and activity and the coverage clearly reflected this.
May 16: European and American astronomers agree Earth will not suffer from passing through comet’s tail. *Joseph M. Laufer, Halley's Comet Society - USA

1940 Dr. H. J. Spinden reported the decipherment of Mayan relics in Mexico indicate a civilization 1250 years in advance of Europe in astronomy and mathematics.

1960 "VoilÁ. that Was It! The Laser was Born!" words Hughes Research Laboratories' physicist Dr. Theodore Maiman used in recounting the historic moment he and fellow researchers Drs. Irnee D'Haenens and Charles Asawa's synthetic ruby laser produced light pulses that steadily increased in brightness as the simple, yet revolutionary, device was powered up. "The output trace started to shoot up in peak intensity and the initial decay time rapidly decreased," he recalled. *Hughes Research Lab Web page.

BIRTHS

1718 Maria Gaetana Agnesi
(May 16, 1718 – January 9, 1799)  Her Istituzioni analitiche of 1748 was an important calculus text. Her name is most often associated with the cubic curve called the Witch of Agnesi, which gets its name by mistranslation. Her sister Maria Teresa was a noted composer.*VFR
For stat's students, I point out that the “witch” is also the same curve as Gossett’s t-distribution with only one degree of freedom. Find more on the history of the name “witch”. After the death of her father in 1752, Agnesi entirely devoted herself and spent her money to do charitable work. She died in total poverty in the poorhouse of which she had been the director. The MAA Digital Library has images of several pages from here Istituzioni analitiche, including her illustration of the construction of "The Witch".  There is also a image of page 381 on which she clearly writes la versiera.

1804  Elizabeth Palmer Peabody, (May 16, 1804 – January 3, 1894)the educator who opened the first English-language kindergarten in the United States. Long before most educators, Peabody embraced the premise that children's play has intrinsic developmental and educational value. *Library of Congress

1821 Pafnuty Lvovich Chebyshev (16  May 1821 (4 May OS) - 8 Dec 1894) Russian mathematician who founded the St. Petersburg mathematical school (sometimes called the Chebyshev school), who is remembered primarily for his work on the theory of prime numbers, including the determination of the number of primes not exceeding a given number. He wrote about many subjects, including the theory of congruences in 1849, probability theory, quadratic forms, orthogonal functions, the theory of integrals, the construction of maps, and the calculation of geometric volumes. Chebyshev was also interested in mechanics and studied the problems involved in converting rotary motion into rectilinear motion by mechanical coupling. The Chebyshev parallel motion is three linked bars approximating rectilinear motion. *TIS
(I always loved the little jingle by Nathan Fine, "Chebyshev said, and I say it again. There is always a prime between n and 2n.")
For an amusing article on how to spell Tschebyscheﬀ, see The Thread (Birkhauser Boston) by Philip J. Davis, or an article with the same title in the Two-Year College Mathematics Journal, 14(1983), 98–104. *VFR

1934 Roy P(atrick) Kerr (16 May 1934 - )is a New Zealander mathematician who solved (1963) Einstein's field equations of general relativity to describe rotating black holes, thus providing a major contribution to the field of astrophysics. He deduced a unique two-parameter family of solutions which describes the space-time around black holes in July 1963. The two parameters are the mass of the black hole and the angular momentum of the black hole. (The static solution, with zero angular momentum, was discovered by Karl Schwarzschild in Dec 1915.) Rotating black holes are often called Kerr Black Holes. He showed that there is a vortex-like region outside the event horizon, called the ergo-region, that drags space and time around with the rotating black hole.*TIS

DEATHS
1830 Baron Jean-Baptiste-Joseph Fourier (21 Mar 1768; 16 May 1830 at age 62) French mathematician, Egyptologist and administrator who exerted strong influence on mathematical physics through his Théorie analytique de la chaleur (1822; The Analytical Theory of Heat). He introduced an infinite mathematical series to aid in solving conduction equations. This analysis technique allows the function of any variable to be expanded into a series of sines of multiples of the variable, which is now known as the Fourier series. His equations spawned many new areas of study in mathematics and physics, including the branch of optics named for him, have subsequently been applied other natural phenomena such as tides, weather and sunspots.*TIS His work on heat was termed by Maxwell, “a great mathematical poem.” He traveled to Egypt with Napoleon and became convinced that desert heat was ideal for good health. Consequently, he wore many layers of garments and lived in rooms of unbearably high heat. This hastened his death, by heart disease, so that he died, thoroughly cooked. [Eves, History of Mathematics, 362] *VFR

He introduced an infinite mathematical series to aid in solving conduction equations. This analysis technique allows the function of any variable to be expanded into a series of sines of multiples of the variable, which is now known as the Fourier series. His equations spawned many new areas of study in mathematics and physics, including the branch of optics named for him, have subsequently been applied other natural phenomena such as tides, weather and sunspots.*TIS Fourier was buried in the Pere Lachaise Cemetery in Paris in a tomb decorated with an Egyptian motif.

1935 Hector Munro Macdonald (19 Jan 1865 in Edinburgh, Scotland - 16 May 1935 in Aberdeen, Scotland) Macdonald graduated from Aberdeen and Cambridge Universities. He stayed on at Cambridge and won the Adams prize. He returned to Aberdeen as Professor. He did important work on electromagnetic waves. *SAU

1983 Edouard Zeckendorf (2 May 1901 in Liège, Belgium - 16 May 1983 in Liège, Belgium)

Eduourd Zeckendorf was an amateur mathematician whose name is given to the property that every positive integer can be represented uniquely as the sum of non-consecutive Fibonacci numbers, the sequence defined by
F1 = F2 = 1 and Fn = Fn-1 + Fn-2 for n greater than 2.
This is called Zeckendorf's theorem, and the subsequence of Fibonacci numbers which add up to a given integer is called its Zeckendorf representation. (Because F1= F2, we need to exclude F1 from the representation to give uniqueness.) For example,
71 = 55 + 13 + 3,
1111 = 987 + 89 + 34 + 1.
Zeckendorf qualified as a medical doctor, became an officer in the Belgium army in 1925 and subsequently also qualified as a dentist. Following the surrender of the Belgium army in May 1940 Zeckendorf was interned as a prisoner of war until 1945. He subsequently published several mathematical papers, nearly all of them in the Bulletin de la Société Royale des Sciences de Liège, mainly on elementary number theory.
*SAU
Since this is the 137th day of the year; I add that 137 = 89+34+13+1

1995 Raymond Arthur Lyttleton(May 7, 1911 – May 16, 1995) English mathematician and theoretical astronomer who researched stellar evolution and composition. In 1939, with Fred Hoyle, he demonstrated the large scale existance of interstellar hydrogen, refuting the existing belief of that space was devoid of interstellar gas. Together, in the early 1940's, they applied nuclear physics to explain how energy is generated by stars. In his own mongoraph (1953) Lyttleton described stability of rotating liquid masses, which he extended later to explain that the Earth had a liquid core resulting from a phase change associated with a combination of intense pressure and temperature. With Hermann Bondi, in 1959, he proposed the electrostatic theory of the expanding universe. He authored various astronomy books. *TIS

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