المرجع الالكتروني للمعلوماتية
المرجع الألكتروني للمعلوماتية

الرياضيات
عدد المواضيع في هذا القسم 9761 موضوعاً
تاريخ الرياضيات
الرياضيات المتقطعة
الجبر
الهندسة
المعادلات التفاضلية و التكاملية
التحليل
علماء الرياضيات

Untitled Document
أبحث عن شيء أخر
ماشية اللحم في الولايات المتحدة الأمريكية
2024-11-05
أوجه الاستعانة بالخبير
2024-11-05
زكاة البقر
2024-11-05
الحالات التي لا يقبل فيها الإثبات بشهادة الشهود
2024-11-05
إجراءات المعاينة
2024-11-05
آثار القرائن القضائية
2024-11-05

النفي
25-4-2018
الحسن بن محمد بن سماعة
29-8-2016
تقادم الدفع الشكلي الجزائي
2023-09-02
القيم العظمى والصغرى : EXTREMA – MAXIMA AND MINIMA
10-11-2021
Fatty Acid Saturation
7-10-2021
طريق تسخير القلوب
18-8-2020

Oscar Chisini  
  
28   05:29 مساءً   date: 13-6-2017
Author : C F Manara
Book or Source : Oscar Chisini, Rend. Sem. Mat. Fis. Milano 37
Page and Part : ...


Read More
Date: 16-6-2017 35
Date: 9-6-2017 23
Date: 9-6-2017 122

Born: 14 March 1889 in Bergamo, Italy

Died: 10 April 1967 in Milan, Italy


Oscar Chisini was the third son of a noble Venetian family. His father, who held a degree in law, was a professional soldier and as his family accompanied him along the path of his career. The young Oscar received a classical education, first in Ravenna and then in Bologna. This was to leave its mark on him, as we know from Carlo Felice Manara [1] that Professor Chisini enjoyed quoting long passages from Dante's Divina Commedia.

Later, enrolled as an engineering student at the University of Bologna, Oscar Chisini met Federigo Enriques in a meeting that was to change his life. Indeed, Enriques immediately recognised his talent, led him to obtain a degree in mathematics in 1912, and engaged him as assistant and coauthor in the writing of the treatise Lezioni sulla teoria geometrica delle equazioni e delle funzioni algebriche (Lessons on the geometric theory of equations and algebraic functions). The four volumes of this monograph, started in 1915 and finished in 1934, were conceived in what Chisini called a peripatetic way, that is walking under the porches of Bologna with Enriques possibly stopping to write on the flooring with the tip of his umbrella. This could be related with the origin of Chisini's idea that:-

Geometry teaches you how to carry out the correct reasoning on the wrong picture.

The four volumes appeared in 1915, 1918, 1924 and 1934 and were reprinted as two books, of two volumes each, in 1985. Du Val, reviewing Chisini's 1960 paper Singolarità delle curve algebriche piane: Schemi rappresentativi e questioni connesse, writes:-

This is a sort of mature meditation on the theory of the singularities of a plane curve, classically laid down by Enriques and [Chisini], over half a century ago.

The Great War marked a break in Chisini's academic career, as he volunteered in the alpine artillery. On the other hand, it gave him an opportunity to display his versatility by applying mathematics to solve technical military problems. In particular, he invented a telemeter that was patented. After the war, he first became a professor in Cagliari in 1923, then in 1925 he moved to Milan where he remained until he retired in 1959. At the time of his death, he was professor emeritus and also a member of the Accademia dei Lincei.

According to Eugenio Giuseppe Togliatti [2], the activity of Oscar Chisini in the mathematical sciences was threefold: scientific research in the field of algebraic geometry, high level original reconstruction of mathematical theories, and active involvement in the teaching of mathematics at secondary school level. It was the latter that led him to reflect on the notion of mean, eventually giving an original definition that was first appreciated by Bruno de Finetti and then became a point of reference in statistics. Also as part of his work on mathematical education he was associated over a period of 46 years with the journal Periodico di Matematiche and wrote many articles and books on various aspects of elementary mathematics. For example he published in this journal: Sul principio di continuità (1956) which is an expository lecture on the principle of continuity in algebraic geometry, beginning with the ideas of Kepler; La superficie cubica(1957) which gives a clear and original treatment of the principal properties of cubic surfaces, presenting it as a preliminary introduction to the study of algebraic geometry; and Isoperimetri (1960) which contains elementary thoughts on the plane isoperimetric problem.

As an algebraic geometry researcher, Oscar Chisini is to be considered part of the so-called Italian school, featuring among others Luigi Cremona, Corrado Segre, Guido Castelnuovo, Francesco Severi, Beniamino Segre and, of course, Federigo Enriques. Extended bibliographies of Chisini's works are given by Carlo Felice Manara [1] and Eugenio Giuseppe Togliatti [2].

Carlo Felice Manara [3] identifies three main traits of the intellectual personality of Oscar Chisini: the liveliness of his imagination, his ability to deal with generality by means of special cases, and a radical critical spirit that allowed him to avoid the pitfalls of this kind of reasoning. Manara writes [3]:-

... the uncommon qualities of his mind, both in the creative process and in criticism, are well apparent in his work.

Overall, Chisini expressed a dynamic vision of science in which history and mistakes are to play a prominent role. For example, he believed that theorems should be presented as raw minerals rather than polished gems. 


 

Articles:

  1. C F Manara, Oscar Chisini, Rend. Sem. Mat. Fis. Milano 37 (1967),13-31.
  2. E G Togliatti, Oscar Chisini, Discorso commemorativo pronunciato nella seduta ordinaria del 19 aprile 1969 : Accademia Nazionale dei Lincei, Celebrazioni Lince No 26 (Accademia Nazionale dei Lincei, Rome, 1969).
  3. C F Manara, Ricordo di Oscar Chisini, Atti del Convegno di Geometria, Milano e Gargnano, Rend. Sem. Mat. Fis. Milano 57 (1987), 11-29.

 




الجبر أحد الفروع الرئيسية في الرياضيات، حيث إن التمكن من الرياضيات يعتمد على الفهم السليم للجبر. ويستخدم المهندسون والعلماء الجبر يومياً، وتعول المشاريع التجارية والصناعية على الجبر لحل الكثير من المعضلات التي تتعرض لها. ونظراً لأهمية الجبر في الحياة العصرية فإنه يدرّس في المدارس والجامعات في جميع أنحاء العالم. ويُعجب الكثير من الدارسين للجبر بقدرته وفائدته الكبيرتين، إذ باستخدام الجبر يمكن للمرء أن يحل كثيرًا من المسائل التي يتعذر حلها باستخدام الحساب فقط.وجاء اسمه من كتاب عالم الرياضيات والفلك والرحالة محمد بن موسى الخورازمي.


يعتبر علم المثلثات Trigonometry علماً عربياً ، فرياضيو العرب فضلوا علم المثلثات عن علم الفلك كأنهما علمين متداخلين ، ونظموه تنظيماً فيه لكثير من الدقة ، وقد كان اليونان يستعملون وتر CORDE ضعف القوسي قياس الزوايا ، فاستعاض رياضيو العرب عن الوتر بالجيب SINUS فأنت هذه الاستعاضة إلى تسهيل كثير من الاعمال الرياضية.

تعتبر المعادلات التفاضلية خير وسيلة لوصف معظم المـسائل الهندسـية والرياضـية والعلمية على حد سواء، إذ يتضح ذلك جليا في وصف عمليات انتقال الحرارة، جريان الموائـع، الحركة الموجية، الدوائر الإلكترونية فضلاً عن استخدامها في مسائل الهياكل الإنشائية والوصف الرياضي للتفاعلات الكيميائية.
ففي في الرياضيات, يطلق اسم المعادلات التفاضلية على المعادلات التي تحوي مشتقات و تفاضلات لبعض الدوال الرياضية و تظهر فيها بشكل متغيرات المعادلة . و يكون الهدف من حل هذه المعادلات هو إيجاد هذه الدوال الرياضية التي تحقق مشتقات هذه المعادلات.