Alexander Bogomolny (January 4, 1948 July 7, 2018) was a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

-born

Israeli-American , native_name_lang = , image = , caption = , population = 110,000–150,000 , popplace = New York metropolitan area, Los Angeles metropolitan area, Miami metropolitan area, and other large metropolitan a ...

mathematician. He was

Professor Emeritus ''Emeritus'' (; female: ''emerita'') is an adjective used to designate a retired chair, professor, pastor, bishop, pope, director, president, prime minister, rabbi, emperor, or other person who has been "permitted to retain as an honorary title ...

of Mathematics at the

University of Iowa The University of Iowa (UI, U of I, UIowa, or simply Iowa) is a public research university in Iowa City, Iowa, United States. Founded in 1847, it is the oldest and largest university in the state. The University of Iowa is organized into 12 co ...

, and formerly research fellow at the

Moscow Institute of Electronics and Mathematics Moscow Institute of Electronics and Mathematics, MIEM (russian: Московский институт электроники и математики НИУ ВШЭ, МИЭМ; also occasionally referred to as ''Moscow Institute of Electronic Enginee ...

, senior instructor at

Hebrew University The Hebrew University of Jerusalem (HUJI; he, הַאוּנִיבֶרְסִיטָה הַעִבְרִית בִּירוּשָׁלַיִם) is a public university, public research university based in Jerusalem, Israel. Co-founded by Albert Einstein ...

and software consultant at

Ben Gurion University Ben-Gurion University of the Negev (BGU) ( he, אוניברסיטת בן-גוריון בנגב, ''Universitat Ben-Guriyon baNegev'') is a public research university in Beersheba, Israel. Ben-Gurion University of the Negev has five campuses: the ...

. He wrote extensively about

arithmetic Arithmetic () is an elementary part of mathematics that consists of the study of the properties of the traditional operations on numbers— addition, subtraction, multiplication, division, exponentiation, and extraction of roots. In the 19th ...

probability Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, ...

algebra Algebra () is one of the broad areas of mathematics. Roughly speaking, algebra is the study of mathematical symbols and the rules for manipulating these symbols in formulas; it is a unifying thread of almost all of mathematics. Elementary ...

geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...

trigonometry Trigonometry () is a branch of mathematics that studies relationships between side lengths and angles of triangles. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies. ...

and mathematical games. He was known for his contribution to heuristics and mathematics education, creating and maintaining the mathematically themed educational website ''Cut-the-Knot'' for the Mathematical Association of America (MAA) Online. He was a pioneer in mathematical education on the internet, having started ''Cut-the-Knot'' in October 1996.Interview with Alexander Bogomolny
MathTango, March 2, 2014

Education and academic career

Bogomolny attended

Moscow Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 million ...

school No. 444, for gifted children, then entered Moscow State University, where he graduated with a master's degree in

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

in 1971. From 1971 to 1974 he was a junior research fellow at the

Moscow Institute of Electronic Machine Building Moscow Institute of Electronics and Mathematics, MIEM (russian: Московский институт электроники и математики НИУ ВШЭ, МИЭМ; also occasionally referred to as ''Moscow Institute of Electronic Enginee ...

(MIEM). He emigrated to Israel and became a senior programmer at Lake Kinneret Research Laboratory in Tiberias, Israel (19741977) and a software consultant at

in Negev, Be’er Sheva, Israel (19761977). From 1976 to 1983 he was a senior instructor and researcher at

Jerusalem Jerusalem (; he, יְרוּשָׁלַיִם ; ar, القُدس ) (combining the Biblical and common usage Arabic names); grc, Ἱερουσαλήμ/Ἰεροσόλυμα, Hierousalḗm/Hierosóluma; hy, Երուսաղեմ, Erusałēm. i ...

. He received his Ph.D. in mathematics at Hebrew University in 1981. His dissertation is titled, ''A New Numerical Solution for the Stamp Problem'' and his thesis advisor was Gregory I. Eskin. From 1981 to 1982 he was also a visiting professor at

Ohio State University The Ohio State University, commonly called Ohio State or OSU, is a public land-grant research university in Columbus, Ohio. A member of the University System of Ohio, it has been ranked by major institutional rankings among the best pub ...

, where he taught mathematics. From 1982 to 1987 he was professor of mathematics at the

. From August 1987 to August 1991 he was vice president of software development at CompuDoc, Inc.Linked in: Alexander Bogomolny
software developer at CTK Software Development

Cut-the-Knot

Cut-the-Knot (CTK) was a free, advertisement-funded educational

website A website (also written as a web site) is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. Examples of notable websites are Google, Facebook, Amazon, and W ...

which Bogomolny maintained from 1996 to 2018. It was devoted to popular exposition of various topics in

. The site was designed for teachers, children and parents, and anyone else curious about mathematics, with an eye to educating, encouraging interest, and provoking curiosity. Its name is a reference to the legend of

Alexander the Great Alexander III of Macedon ( grc, Ἀλέξανδρος, Alexandros; 20/21 July 356 BC – 10/11 June 323 BC), commonly known as Alexander the Great, was a king of the ancient Greek kingdom of Macedon. He succeeded his father Philip II to ...

's solution to the Gordian knot. CTK won more than 20 awards from scientific and educational publications, including a ''

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it ...

'' Web Award in 2003, the ''

Encyclopædia Britannica The (Latin for "British Encyclopædia") is a general knowledge English-language encyclopaedia. It is published by Encyclopædia Britannica, Inc.; the company has existed since the 18th century, although it has changed ownership various t ...

''s Internet Guide Award, and ''

Science Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence ...

''s NetWatch award. The site contained extensive analysis of many of the classic problems in recreational mathematics including the Apollonian gasket,

Napoleon's theorem In geometry, Napoleon's theorem states that if equilateral triangles are constructed on the sides of any triangle, either all outward or all inward, the lines connecting the centres of those equilateral triangles themselves form an equilateral ...

, logarithmic spirals, the "Futurama Theorem" from the episode "

The Prisoner of Benda "The Prisoner of Benda" is the 10th episode of the sixth season of the animated sitcom ''Futurama''. It aired on Comedy Central on August 19, 2010. In the episode, Professor Farnsworth and Amy build a machine that allows them to switch minds so ...

", the Pitot theorem, and

the monkey and the coconuts The monkey and the coconuts is a mathematical puzzle in the field of Diophantine analysis that originated in a magazine fictional short story involving five sailors and a monkey on a desert island who divide up a pile of coconuts; the problem is ...

problem. Once CTK published 122 proofs of the Pythagorean theorem. He wrote a manifesto for CTK in which he said that "Judging Mathematics by its pragmatic value is like judging symphony by the weight of its score." He described the site as "a resource that would help learn, if not math itself, then, at least, ways to appreciate its beauty," and he wondered why it is acceptable among otherwise well-educated people "to confess a dislike and misunderstanding of Mathematics as a whole." Many mathematical ideas were originally illustrated by Java applets, but most of them got later replaced by

GeoGebra GeoGebra (a portmanteau of ''geometry'' and ''algebra'') is an interactive geometry, algebra, statistics and calculus application, intended for learning and teaching mathematics and science from primary school to university level. GeoGebra is ...

applications, which were also used for material added later. CTK wiki (powered by

PmWiki PmWiki is wiki softwareWikiMatrix / PmWiki Features - Compare Them All
Wiki ...

) extends the main site with additional mathematical content, especially that with more complicated formulae than available on the main site.

Book

* ''Cut the Knot: Probability Riddles.'' Champaign, IL: Wolfram Media, 2020. Published after Bogomolny's death, with a foreword by his friend

Nassim Nicholas Taleb Nassim Nicholas Taleb (; alternatively ''Nessim ''or'' Nissim''; born 12 September 1960) is a Lebanese-American essayist, mathematical statistician, former option trader, risk analyst, and aphorist whose work concerns problems of randomness ...

, this book of probability riddles is curated to challenge the mind and expand mathematical and logical thinking skills. First housed on cut-the-knot.org, these puzzles and their solutions represent the efforts of great minds around the world. Bogomolny presented these selected riddles by topical progression.

Personal life

Bogomolny had to leave

academia An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary education, secondary or tertiary education, tertiary higher education, higher learning (and generally also research or honorary membershi ...

because he had an uncorrectable hearing problem and was practically deaf in latter years.Obituary of Alexander Bogomolny
By Gary Ernest Davis in Crikey Math, July 13, 2018

Tribute

Bogomolny's older son David chronicled his yearlong recitation of kaddish in honor of his father, originally on

The Times of Israel ''The Times of Israel'' is an Israeli multi-language online newspaper that was launched in 2012. It was co-founded by Israeli journalist David Horovitz, who is also the founding editor, and American billionaire investor Seth Klarman.

blogs, in a series titled, "The skeptic's kaddish for the atheist", consisting of traditional Jewish sources, religious text analysis, modern interpretations and expressions of kaddish, philosophy, theology, eschatology, creative writing, and the personal reflections; memories; and experiences of a son in mourning.

References

External links

*
Math of all types: The problems of Alexander Bogomolny

Cut-the-Knot official website
{{DEFAULTSORT:Bogomolny 1948 births 2018 deaths Mathematics popularizers Recreational mathematicians 20th-century American mathematicians Soviet mathematicians Israeli emigrants to the United States Israeli people of Russian-Jewish descent Israeli American Mathematics websites Science blogs Moscow State University alumni University of Iowa faculty 21st-century American mathematicians Einstein Institute of Mathematics alumni Scientists from Moscow