Thứ sáu ngày 13 dưới góc nhìn toán học và văn hóa

TTO - Ở một số nước phương Tây, người ta cho rằng thứ sáu ngày 13 là ngày rủi ro. Tuy nhiên, báo Le Figaro (Pháp) số ra ngày 11-3-2009 cho biết số người mua lô tô tại Pháp vào thứ sáu ngày 13 cao gấp 3 lần so với những ngày khác.

Vậy thứ sáu ngày 13 có đặc điểm gì về mặt toán học và văn hóa? Nó là ngày tốt hay xấu?



Kiệt tác Bữa tiệc cuối cùng của Léonardo da Vinci (Leonardo da Vinci: The Last Supper)



Bằng lý thuyết đồng dư, toán học chứng minh được một năm bất kỳ có ít nhất một thứ sáu ngày 13 và nhiều nhất ba thứ sáu ngày 13. Hơn nữa, một năm có ba thứ sáu ngày 13 khi và chỉ khi ngày đầu năm là thứ năm (đối với năm không nhuận) hoặc chủ nhật (đối với năm nhuận). Đó là trường hợp của năm 2009: có ba thứ sáu ngày 13 rơi vào tháng hai, tháng ba và tháng mười một. Sự kiện này đã xảy ra vào năm 1998 và sẽ lặp lại vào các năm 2015, 2026.

Những năm sắp đến, 2010 và 2011 chỉ có một thứ sáu ngày 13 mỗi năm. Năm 2012 có ba thứ sáu ngày 13 rơi vào tháng giêng, tháng tư và tháng bảy. Bộ ba “giêng, tư, bảy” này ít gặp hơn so với bộ ba “hai, ba, mười một”. Năm 2013 có hai thứ sáu ngày 13 rơi vào tháng 9 và tháng 12. Tổng cộng có 21 thứ sáu ngày 13 từ 2009 - 2019.

Cũng bằng toán học, ta tính được khoảng cách giữa hai ngày thứ sáu 13 gần nhất chỉ có thể là 27, 90, 181, 244, 272, 335 hoặc 426 ngày. Như vậy, hai thứ sáu ngày 13 gần nhất có thể cách nhau hơn một năm. Đó chính là trường hợp 13-8-1999 và 13-10-2000.

Theo Kinh Thánh, Chúa Jésus bị đóng đinh trên thập tự giá vào thứ sáu. Hơn nữa, bữa ăn cuối cùng của Chúa với các môn đồ có đúng 13 người. Việc này thường được xem là nguồn gốc việc kiêng sợ thứ sáu ngày 13.

Ở Ý, số 17 được gắn với sự rủi ro chứ không phải số 13. Còn ở Trung Quốc, con số này là 4 vì được phát âm gần giống với “tử” nghĩa là chết. Ở châu Mỹ Latin, ngày kiêng cữ lại là thứ ba 13.

Về mặt thống kê, hiện chưa có dữ liệu đáng tin cậy nào để gán cho thứ sáu ngày 13 với “may mắn” hay “rủi ro” theo một nghĩa nào đó. Chẳng hạn, xác suất trúng lô tô ở Pháp vào thứ sáu ngày 13 cũng giống với những ngày khác và xấp xỉ với 1/14.000.000. Xác suất nhỏ bé này không có nghĩa là bạn không thể trúng lô tô và không hề ngăn cản người chơi lô tô nuôi hi vọng!

http://www.gloversvilleschools.org/kings/teachers/tdavis/featured-artist.htm

http://www.thenagain.info/WebChron/WestCiv/DaVinci.html

http://imagesbible.com/ANGLAIS/ANG_FICHES/Ang_Baptism_Jesus.htm

Leonardo da Vinci
1452-1519
On April 15, 1452 , in the small town Tuscan of Vinci near Florence, one of the most widely known painters of all time, Leonardo da Vinci, was born. He was born illegitimate to a peasant woman known only as Caterina and a fairly well-to-do notary, Piero da Vinci. He was raised in his fathers house at Vinci. He began to study under the Florentine artist Andrea del Verrochio, with whom he continued his studies for a good ten years. It is evident that he possessed a special gift from the start of his art career. It is said that his talent was so impressive that Verrochio gave up painting forever.


In nearly three decades, from shortly before 1500 until around 1525, we see a brief but glorious time in the history of art known as the "High Renaissance." Though many artists worked in this era, unquestionably da Vinci was among the greatest. He has been called the "Renaissance man". He is well known for many genres of art including: painting, sculpting, architectural design, engineering, and his fascinating representations of the human body. Additionally, he was handsome, persuasive in conversation, and a fine musician.

His first large painting was, The Adoration of Magi. Other works ascribed to his youth are Benois Madonna, Ginevra de Benci, and Saint Jerome. The two pictured on this page, and probably the most widely recognized, are The Last Supper and the Mona Lisa.



Leonardo da Vinci: The Last Supper

During the years 1495 to 1497, da Vinci created The Last Supper while in Milan. It is a mural painted on a wall of the Monastery of Santa Maria delle Grazie, depicting the final gathering of Jesus Christ and his disciples. He created it using oils on dry plaster, a technique which has proven to be unsound.

The next painting, created during 1503-1506, is one of the most celebrated portraits ever painted, the Mona Lisa; also known as La Gioconda presumably after the name of the woman's husband. This painting has been the object of special fascination ever since it was created. It could be due, in part, to the choice of techniques and the captivation of the mysterious smile that adorns the woman's face.

The techniques used in the Mona Lisa are known as sfumato and chiaroscuro. Sfumato (deriving from the Latin word for "smoke") , describes the smoky atmospheric effects from the transitions between colors. It is evident in the delicate gauzy robe and in her enigmatic smile. The other technique, chiaroscuro, refers to the modeling and defining of forms through the contrast of light and shadow. The sensitive hands on the sitter, portrayed with luminous modulation of light and shade, are a prime example of the above technique. Also, his landscape background was among the first to introduce atmospheric prospective.


Leonardo da Vinci: Mona Lisa

Leonardo da Vinci died on May 2, 1519, while residing in the city of Amboise, where he was the court painter for King Francis I. The king had provided da Vinci with comfortable lodgings. da Vinci lived his life unmarried and with very few close attachments. His obsession with creating art consumed him entirely. In his Treatise on Painting, made up of the writings on his notebook pages and published after his death, he advised his followers to follow his method: "You should be yourself when you take a walk for recreation, in watching and taking notes of the attitudes and actions of men as they talk and dispute, or laugh or come to blows with one another.....noting these down with rapid strokes, in a little pocket book which you should always carry with you....for there is such an infinite number of forms and actions that memory is incapable of preserving them."


Sources:

Earls, Jane. Renaissance Art: A Topical Dictionary (Greenwood Press, Inc. Connecticut. 1987). Pages 60, 113, 142, 161, 163-64, 198, 224, 263-64.

Gilbert, Rita. Living With Art (McGraw Hill, Inc. St. Louis 1995) Pages 398-401.

Pioch, Nicolas. "Leonardo de Vinci." WebMuseum, Paris . 20 May 1996. <http://www.southern.com/wm/paint/auth/vinci> (2 February 1999).

Turner, Jane, eds. The Dictionary of Art , (Grove Dictionaries Inc. New York; 1996). Pages 180-198.


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Featured Artist
Leonardo DaVinci

In 1452, Leonardo Da Vinci was born in an Italian town called Vinci. He lived in a time period called the Renaissance, when everyone was interested in art. Even though Da Vinci was a great artist, he became famous because of all the other things he could do. He was a sculptor, a scientist, an inventor, an architect, a musician, and a mathematician. When he was twenty, he helped his teacher finish a painting called The Baptism of Christ. When he was thirty, he moved to Milan. That is where he painted most of his pictures. DaVinci's paintings were done in the Realist style

The Baptism of Christ:
http://images.google.com/images?q=The%20Baptism%20of%20Christ&oe=UTF-8&um=1&ie=UTF-8&sa=N&hl=en&tab=wi
http://gardenofpraise.com/bibl37s.htm

Do you recognize any of these pictures from the art room?

http://www.gloversvilleschools.org/kings/teachers/tdavis/featured-artist.htm



http://www.leonardo-da-vinci-biography.com/the-last-supper.html

http://www.leonardo-da-vinci-biography.com/leonardo-da-vinci-painting.html

http://www.leonardo-da-vinci-biography.com/index.html

Biography of Leonardo da Vinci
Leonardo da Vinci was born April 15, 1452 and died May 2, 1519. In his 67 years of life he was able to become a master in a wide range of subject's other then becoming one of the Greatest Painters in History. Some of his many talents include becoming an established Inventor, Sculptor, Mathematician, architect designer, writer, musician and of course a Great Painter for which he is most famous for. This self described Renaissance Man is still to this day regarded as one of the most diversely talented person to ever walk on the face of this Earth.

First Period of Leonardo da Vinci
Leonardo was raised my his Mother and moved to Florence, Italy in 1466 where he first started working under Verroccio and quickly made friends with Lorenzo de Credi, Botticelli and Ghirlandaio who were already famous Artists during at this time period. Verroccio was so impressed with Leonado da Vinci's impressive painting skills at such an early age, he let his new apprentice paint the now famous Angel along with a few landscape scenes in Verrocchio's 'Baptism of Christ' Masterpiece Painting. After six successful years working under Verroccio, Leonardo finally was able to register with the Painter's Guild in 1477. One of his most famous paintings during this period is ironically the unfinished 'Adoration of the Magi' painting that was still commissioned by the Monks of San Donato a Scopeto.

Middle Period of Leonardo da Vinci
After Leonardo da vince compled his apprenticeship in Florence, Leonardo moved to Milan in 1482 to the court of Ludovico Sforza which he remained for the next 16 years. During this period he was the court artist which he remained for several of those years. This is also the time when he was known for painting the Famous Artworks of Trattato della pittura and one of the two famous Paintings of Madonna of the Rocks. In 1488 Leonardo da Vinci became interested in Art Culture and drew up his first plans for the tambour and dome for the cathedral within the court of Milan. The township was so impressed with Leonardo da vinci's drawings and ideas, he was hired in 1490 as the consulting engineer to over-see the restoration of both the Cathedral at Paris and the Cathedral at Piacenza.

In 1495 Leonardo began work on the very famous painting Fresno of the Last Supper and it wasn't completed until 1498. unfortunately even though this painting still exists, it has been badly damaged over the years. In 1999 the fresno of the last supper underwent extensive restoration but not even that was enough to bright back the brilliant colors that only Leonardo da Vinci could paint. After a brief stint when Leonardo entered the service of Cesare Borgia as a Military Engineer, Leonardo returned to Milan in 1506 and was engaged by Charles d'Amboise coming from no other then the French King Louis X11. During this time period he was able to put many of his skills he had already mastered including his architect skills, engineering and the various scientific experiments in botany, geology, hydraulics, mechanics and mathematics.

last Period of Leonardo da Vinci
in 1513 Leonardo headed to Rome, Italy where his good friend and the new elected medici Pope known as Leo-x and his brother Giuliano now resided. The Artist's competition was very fierce within the Vatican where he now competed with the likes of Michelangelo and Raphael. Leonardo did various engineering and architectural projects throughout the Cathedral as we'll found time to work on some of his most valuable paintings. The famous painting St. John the baptist (louvre) was one such painting done during this time. Of course it goes without saying the the Most famous Painting in the World, The Mona Lisa painting, was also painted in this this period. Around 1515, Leonardo moved to the Castle of Cloux which is outside of Amboise, and lived the remainder of his life surrounded by his Life's Work which he continued to his last days here on earth.

Leonardo da Vinci is arguably the Most Famous painter of All Time as we'll as Painted The Most Famous Painting Ever!

http://www.artpaintings.info/articles/3455/Leonardo-da-Vinci-Paintings