Cantore mathematics is a complicated arithmetic leaving the metric to the venue for the opening to introduce the understanding of how Albert Einstein found MC2 at E. To engage that only by name "Albert Einstein" I broaden the Fibonacci to encompass the seashell found as a sand dollar at Ocean beach when I was a child, this is important as the 'Conch shell' is mentioned in the conical design of his sequence called the Fibonacci Number (sequence) of the Fibonacci. Fibonacci himself is also known as Leonardo Bonacci, Leonardo of Pisa, or Leonardo Bigollo Pisano was an Italian mathematician from the Republic of Pisa, considered to be "the most talented Western mathematician of the Middle Ages": See below.
These simple numbers in designed are in representation and demonstrate nothing more to cantore mathematics than the sand dollar as I was born and raised in San Francisco, California and the downtown of my city represents by number and address the sand dollar in multiply the sight to thought and never represent that as a discount to the work. As that is done the Band of Holes in Peru of more than to the last post is of demonstration to a possible volcanic chain due to the design and local story to the mystery of "ley lines" (Nazca Lines) that can only be seen from the air. These basic foundation would by design introduce the same as the planet to planet representing the interest of just the magma to planet introducing the meteor as the projection to the landing of the Fibonacci by both gravity and temperature.
reference: Scuba diving at Lake Tahoe
Logarithmic spiral
A logarithmic spiral, equiangular spiral, or growth spiral is a self-similar spiral curve that often appears in nature. The first to describe a logarithmic spiral was Albrecht Dürer (1525) who called it an "eternal line" ("ewige lini").[1] More than a century later, the curve was discussed by Descartes (1638), and later extensively investigated by Jacob Bernoulli, who called it Spira mirabilis, "the marvelous spiral".
The logarithmic spiral can be distinguished from the Archimedean spiral by the fact that the distances between the turnings of a logarithmic spiral increase in geometric progression, while in an Archimedean spiral these distances are constant.
Definition
In polar coordinates the logarithmic spiral can be written as[2]
or
with being the base of natural logarithms, and being real constants.
In Cartesian coordinates
The logarithmic spiral with the polar equation
can be represented in Cartesian coordinates by
In the complex plane :
Spira mirabilis and Jacob Bernoulli
Spira mirabilis, Latin for "miraculous spiral", is another name for the logarithmic spiral. Although this curve had already been named by other mathematicians, the specific name ("miraculous" or "marvelous" spiral) was given to this curve by Jacob Bernoulli, because he was fascinated by one of its unique mathematical properties: the size of the spiral increases but its shape is unaltered with each successive curve, a property known as self-similarity. Possibly as a result of this unique property, the spira mirabilis has evolved in nature, appearing in certain growing forms such as nautilus shells and sunflower heads. Jacob Bernoulli wanted such a spiral engraved on his headstone along with the phrase "Eadem mutata resurgo" ("Although changed, I shall arise the same."), but, by error, an Archimedean spiral was placed there instead.[3][4]
Properties
The logarithmic spiral has the following properties (see Spiral):
- Polar slope:
- with polar slope angle (see diagram).
- (In case of angle would be 0 and the curve a circle with radius .)
- Curvature:
- Arc length:
- Especially: , if .
- This property was first realized by Evangelista Torricelli even before calculus had been invented.[5]
- Sector area:
- Inversion: Circle inversion () maps the logarithmic spiral onto the logarithmic spiral
- Rotating, scaling: Rotating the spiral by angle yields the spiral , which is the original spiral uniformly scaled (at the origin) by .
- Scaling by gives the same curve.
- Self-similarity: A result of the previous property:
- A scaled logarithmic spiral is congruent (by rotation) to the original curve.
- Example: The diagram shows spirals with slope angle and . Hence they are all scaled copies of the red one. But they can also be generated by rotating the red one by angles resp.. All spirals have no points in common (see property on complex exponential function).
- Relation to other curves: Logarithmic spirals are congruent to their own involutes, evolutes, and the pedal curves based on their centers.
- Complex exponential function: The exponential function exactly maps all lines not parallel with the real or imaginary axis in the complex plane, to all logarithmic spirals in the complex plane with centre at :
- The polar slope angle of the logarithmic spiral is the angle between the line and the imaginary axis.
Special cases and approximations
The golden spiral is a logarithmic spiral that grows outward by a factor of the golden ratio for every 90 degrees of rotation (polar slope angle about 17.03239 degrees). It can be approximated by a "Fibonacci spiral", made of a sequence of quarter circles with radii proportional to Fibonacci numbers.
In nature
In several natural phenomena one may find curves that are close to being logarithmic spirals. Here follow some examples and reasons:
- The approach of a hawk to its prey in classical pursuit, assuming the prey travels in a straight line. Their sharpest view is at an angle to their direction of flight; this angle is the same as the spiral's pitch.[6]
- The approach of an insect to a light source. They are used to having the light source at a constant angle to their flight path. Usually the sun (or moon for nocturnal species) is the only light source and flying that way will result in a practically straight line.[7]
- The arms of spiral galaxies.[8] Our own galaxy, the Milky Way, has several spiral arms, each of which is roughly a logarithmic spiral with pitch of about 12 degrees.[9]
- The nerves of the cornea (this is, corneal nerves of the subepithelial layer terminate near superficial epithelial layer of the cornea in a logarithmic spiral pattern).[10]
- The bands of tropical cyclones, such as hurricanes.[11]
- Many biological structures including the shells of mollusks.[12] In these cases, the reason may be construction from expanding similar shapes, as is the case for polygonal figures.
- Logarithmic spiral beaches can form as the result of wave refraction and diffraction by the coast. Half Moon Bay (California) is an example of such a type of beach.[13]
In engineering applications
- Logarithmic spiral antennas are frequency-independent antennas, that is, antennas whose radiation pattern, impedance and polarization remain largely unmodified over a wide bandwidth.[15]
- When manufacturing mechanisms by subtractive fabrication machines (such as laser cutters), there can be a loss of precision when the mechanism is fabricated on a different machine due to the difference of material removed (that is, the kerf) by each machine in the cutting process. To adjust for this variation of kerf, the self-similar property of the logarithmic spiral has been used to design a kerf cancelling mechanism for laser cutters.[16]
- Logarithmic spiral bevel gears are a type of spiral bevel gear whose gear tooth centerline is a logarithmic spiral. A logarithmic spiral has the advantage of providing equal angles between the tooth centerline and the radial lines, which gives the meshing transmission more stability.[17]
See also
References
- Jiang, Jianfeng; Luo, Qingsheng; Wang, Liting; Qiao, Lijun; Li, Minghao (2020). "Review on logarithmic spiral bevel gear". Journal of the Brazilian Society of Mechanical Sciences and Engineering. 42 (8): 400. doi:10.1007/s40430-020-02488-y. ISSN 1678-5878.
- Weisstein, Eric W. "Logarithmic Spiral". MathWorld.
- Jim Wilson, Equiangular Spiral (or Logarithmic Spiral) and Its Related Curves, University of Georgia (1999)
- Alexander Bogomolny, Spira Mirabilis - Wonderful Spiral, at cut-the-knot
External links
Wikimedia Commons has media related to Logarithmic spirals. |
- Spira mirabilis history and math
- NASA Astronomy Picture of the Day: Hurricane Isabel vs. the Whirlpool Galaxy (25 September 2003)
- NASA Astronomy Picture of the Day: Typhoon Rammasun vs. the Pinwheel Galaxy (17 May 2008)
- SpiralZoom.com, an educational website about the science of pattern formation, spirals in nature, and spirals in the mythic imagination.
- Online exploration using JSXGraph (JavaScript)
- YouTube lecture on Zeno's mice problem and logarithmic spirals
Languages
Fibonacci
Fibonacci | |
---|---|
Born | c. 1170 |
Died | c. 1250 (aged 79–80) Pisa, Republic of Pisa |
Other names | Leonardo Fibonacci, Leonardo Bonacci, Leonardo Pisano |
Occupation | Mathematician |
Known for |
|
Parent(s) | Guglielmo "Bonacci" (father) |
Fibonacci (/ˌfɪbəˈnɑːtʃi/;[3] also US: /ˌfiːb-/,[4][5] Italian: [fiboˈnattʃi]; c. 1170 – c. 1240–50),[6] also known as Leonardo Bonacci, Leonardo of Pisa, or Leonardo Bigollo Pisano ('Leonardo the Traveller from Pisa'[7]), was an Italian mathematician from the Republic of Pisa, considered to be "the most talented Western mathematician of the Middle Ages".[8]
The name he is commonly called, Fibonacci, was made up in 1838 by the Franco-Italian historian Guillaume Libri[9][10] and is short for filius Bonacci ('son of Bonacci').[11][b] However, even earlier in 1506 a notary of the Holy Roman Empire, Perizolo mentions Leonardo as "Lionardo Fibonacci".[12]
Fibonacci popularized the Hindu–Arabic numeral system in the Western world primarily through his composition in 1202 of Liber Abaci (Book of Calculation).[13][14] He also introduced Europe to the sequence of Fibonacci numbers, which he used as an example in Liber Abaci.[15]
Biography
Fibonacci was born around 1170 to Guglielmo, an Italian merchant and customs official.[7] Guglielmo directed a trading post in Bugia, the capital of the Hammadid empire.[16] Fibonacci travelled with him as a young boy, and it was in Bugia (Algeria) where he was educated that he learned about the Hindu–Arabic numeral system.[17][6]
Fibonacci travelled around the Mediterranean coast, meeting with many merchants and learning about their systems of doing arithmetic.[18] He soon realised the many advantages of the Hindu-Arabic system, which, unlike the Roman numerals used at the time, allowed easy calculation using a place-value system. In 1202, he completed the Liber Abaci (Book of Abacus or The Book of Calculation),[19] which popularized Hindu–Arabic numerals in Europe.[6]
Fibonacci was a guest of Emperor Frederick II, who enjoyed mathematics and science. In 1240, the Republic of Pisa honored Fibonacci (referred to as Leonardo Bigollo)[20] by granting him a salary in a decree that recognized him for the services that he had given to the city as an advisor on matters of accounting and instruction to citizens.[21] [22]
Fibonacci is thought to have died between 1240[23] and 1250,[24] in Pisa.
Liber Abaci
In the Liber Abaci (1202), Fibonacci introduced the so-called modus Indorum (method of the Indians), today known as the Hindu–Arabic numeral system.[25][26] The manuscript advocated numeration with ten digits including a zero and positional notation. The book showed the practical use and value of this by applying the numerals to commercial bookkeeping, converting weights and measures, calculation of interest, money-changing, and other applications. The book was well-received throughout educated Europe and had a profound impact on European thought. Replacing Roman numerals, its ancient Egyptian multiplication method, and using an abacus for calculations, was an advance in making business calculations easier and faster, which assisted the growth of banking and accounting in Europe.[27][28]
The original 1202 manuscript is not known to exist.[29] In a 1228 copy of the manuscript, the first section introduces the numeral system and compares it with others, such as Roman numerals, and methods to convert numbers to it. The second section explains uses in business, for example converting different currencies, and calculating profit and interest, which were important to the growing banking industry. The book also discusses irrational numbers and prime numbers.[29][27][28]
Fibonacci sequence
Liber Abaci posed and solved a problem involving the growth of a population of rabbits based on idealized assumptions. The solution, generation by generation, was a sequence of numbers later known as Fibonacci numbers. Although Fibonacci's Liber Abaci contains the earliest known description of the sequence outside of India, the sequence had been described by Indian mathematicians as early as the sixth century.[30][31][32][33]
In the Fibonacci sequence, each number is the sum of the previous two numbers. Fibonacci omitted the "0" and first "1" included today and began the sequence with 1, 2, 3, ... . He carried the calculation up to the thirteenth place, the value 233, though another manuscript carries it to the next place, the value 377.[34][35] Fibonacci did not speak about the golden ratio as the limit of the ratio of consecutive numbers in this sequence.
Legacy
In the 19th century, a statue of Fibonacci was set in Pisa. Today it is located in the western gallery of the Camposanto, historical cemetery on the Piazza dei Miracoli.[1][36]
There are many mathematical concepts named after Fibonacci because of a connection to the Fibonacci numbers. Examples include the Brahmagupta–Fibonacci identity, the Fibonacci search technique, and the Pisano period. Beyond mathematics, namesakes of Fibonacci include the asteroid 6765 Fibonacci and the art rock band The Fibonaccis.
Works
- Liber Abaci (1202), a book on calculations (English translation by Laurence Sigler, 2002)[25]
- Practica Geometriae (1220), a compendium of techniques in surveying, the measurement and partition of areas and volumes, and other topics in practical geometry (English translation by Barnabas Hughes, Springer, 2008).
- Flos (1225), solutions to problems posed by Johannes of Palermo
- Liber quadratorum ("The Book of Squares") on Diophantine equations, dedicated to Emperor Frederick II. See in particular congruum and the Brahmagupta–Fibonacci identity.
- Di minor guisa (on commercial arithmetic; lost)
- Commentary on Book X of Euclid's Elements (lost)
See also
Notes
- The etymology of Bonacci is "good-natured", so the full name means "son from a good-natured [family]".[7]
References
- Devlin, Keith (2010). "The Man of Numbers: In Search of Leonardo Fibonacci" (PDF). Mathematical Association of America. pp. 21–28.
Further reading
- Devlin, Keith (2012). The Man of Numbers: Fibonacci's Arithmetic Revolution. Walker Books. ISBN 978-0802779083.
- Goetzmann, William N. and Rouwenhorst, K.Geert (2005). The Origins of Value: The Financial Innovations That Created Modern Capital Markets. Oxford University Press Inc., US, ISBN 0-19-517571-9.
- Goetzmann, William N., Fibonacci and the Financial Revolution (October 23, 2003), Yale School of Management International Center for Finance Working Paper No. 03–28
- Grimm, R. E., "The Autobiography of Leonardo Pisano", Fibonacci Quarterly, Vol. 11, No. 1, February 1973, pp. 99–104.
- Horadam, A. F. "Eight hundred years young," The Australian Mathematics Teacher 31 (1975) 123–134.
- Gavin, J., Schärlig, A., extracts of Liber Abaci online and analyzed on BibNum [click 'à télécharger' for English analysis]
External links
Wikisource has the text of the 1911 Encyclopædia Britannica article "Leonardo of Pisa". |
- "Fibonacci, Leonardo, or Leonardo of Pisa." Complete Dictionary of Scientific Biography. 2008. Encyclopedia.com. (April 20, 2015). [1]
- Fibonacci at Convergence
- O'Connor, John J.; Robertson, Edmund F., "Leonardo Pisano Fibonacci", MacTutor History of Mathematics archive, University of St Andrews
- Fibonacci (2 vol., 1857 & 1862) Il liber abaci and Practica Geometriae – digital facsimile from the Linda Hall Library
- Fibonacci, Liber abbaci Bibliotheca Augustana
Languages
The basic meanings of "bigollo" appear to be "bilingual" or "traveller". A. F. Horadam contends a connotation of "bigollo" is "absent-minded" (see first footnote of "Eight hundred years young"), which is also one of the connotations of the English word "wandering". The translation "the wanderer" in the quote above tries to combine the various connotations of the word "bigollo" in a single English word.
Virahanka Fibonacci.
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