Monday, October 20, 2008

The Astrolabe: World’s Oldest Scientific Instrument

Throughout the ages all cultures have had some sort of fascination with the sky and/or the celestial bodies. As this fascination grew people began to develop astronomical tools to help them study the sun, moon, stars, and other planets. The astrolabe, often referred to as the oldest scientific instrument in the world, has been used to measure/predict the location, height, and position of extraterrestrial bodies, to determine the time of day, and to navigate ships.

Around the 2nd century BC the astrolabe was developed in ancient Greece to determine the altitude of objects in space. However the instructions for this tool's construction were supposedly lost in the fire at the Library in Alexandria. During the approaching Dark Ages astronomical information was further lost to the western world as the Christian churches banned such knowledge. The preservation of astrolabe technology is credited to the Islamic cultures, as they collected as many reaming Greek astrolabes as possible; thus preserving and improving the uses of the astrolabe. In 12 AD, as Islam migrated though southern Europe, the astrolabe was reintroduced to Western World.

Create Your Own Astrolabe:

This simple astrolabe can be used to determine the altitude (angular height) of almost any tall object you wish.

List of Equipment:

  • A copy of the Astrolabe Illustration
  • Glue
  • Cardboard or Poster Board
  • Scissors
  • 1 Straw
  • 1' of String (approximately)
  • 1 Metal Washer
  • A hole-punch
  • Tape
Step 1: Print a copy of the Astrolabe Illustration

Step 2: Glue copy to poster board or cardboard and cut out with scissors.

Step 3: Using hole-punch make a notch where each degree line meets the curved edge of the astrolabe.

Step 4: Cut straw to fit edge marked "attach straw along this edge" and tape into place.
Note: tape the straw above the astrolabe and not to the surface of the illustration.
Step 5: Carefully poke a hole though the dot located in the upper right of the illustration.

Step 6: Pass string though hole and secure to the back of the illustration.
Note: can either tie a knot in the string or tape to the back of the astrolabe.

Step 7: Tie metal washer to hanging end of sting to function as a weight.

How to use:
Step 1: Look thought straw and aim at any tall structure

Step 2: Read altitude in degrees from the side of the astrolabe.
Note: This will be where the sting hangs across the degree scale.

For more information/references:

"The Islamic Astrolabe: An Indicator of the Role of Islamic Astronomy During the Middle Ages," By Diana Strode

"At Home Astronomy" Presented by The Center for Science Education @ Space Sciences Laboratory UC Berkeley.

Thursday, October 2, 2008

Mary vs. Madonna: A Comparison of two Renaissance Artists

Having pursued a life as a painter in the art world of 13th century Europe, which was still highly influenced by the traditional Byzantine style, Cimabue came to be known as a revolutionary pre-renaissance artist. In his painting "Madonna Enthroned with Angels and Prophets (see to the left)" the viewer can see subtle differences between Cimabue's style and the standard Byzantine technique. These departures make this painting stand out from other late medieval works.

The artist retains the traditional Byzantine portrayal of the human face (down turned lips, almond eyes, and a rather elongated nose, face and hands); however, the features are softened and the viewer is no longer confronted directly by the faces of the fourteen figures in the painting. Instead each figure casts a sidelong glance while tilting its head in one direction or the other. These glances are essential to this work of art. As the viewer's eyes move down the piece, the angels, Madonna, and Christ child are all looking out at the spectator, but once the viewer's eyes reach the prophets at the bottom, his or her eyes follow their uplifted gaze back to the face of the Madonna. An invisible triangle is formed between the gaze of the prophets and the face of Mary, which both keeps the viewer's eyes within the confines of the picture, and emphasizes the subject of the piece. Yet it is at the bottom, or predella, of Cimabue's piece that all the truly innovative changes occur. Not only is the predella where we see the upward gazing prophets, but it is where we find one of the first attempts at suggesting a three-dimensional space on a two-dimensional surface. This can be seen above the two center prophets where the concave arch which seems to recede from the viewer. Because of these subtle changes, the art of Cimabue is often considered the end of Byzantine period as well as the inspiration for one of the most influential early Renaissance artists, Giotto.

The influence of Cimabue on Giotto can best be seen when comparing "Madonna Enthroned with Angels and Prophets" to Giotto's piece "Madonna Enthroned (see to the right)," which was created twenty-five years later. Both artists place the subject, Madonna and Child, in the upper center of the piece while supporting them with architectural structures and surrounding them with figures. In both paintings there are an equal number of figures, and the location of these figures is symmetrical around the subject (Cimabue includes fourteen figures total, six on either side of Madonna and Child. Giotto includes sixteen figures total, seven on either side of Mary and Christ). The basic composition between these two pieces seems identical; however, Giotto made some very important modifications. All sixteen figures are softer and more natural than in previous works. Baby Jesus is portrayed looking more like an actual baby with baby fat, as opposed to being portrayed as a small scale man as seen in medieval art. The faces of the figures are not as compartmentalized, and form and volume are now defined by the use of light and shadow. To make his subject more powerful, all the figures have their eyes fixed on the subject; it is only Mary and the Christ child that look out of the piece. The viewer follows the gaze of the surrounding angels and finds their eyes constantly drawn back to the face of the Madonna who is sitting back in her architectural throne, a convincing attempt at rendering a three dimensional space.

Developments and changes such as those
seen in these two paintings are what continue to keep art developing. Giotto was influenced by the adjustments Cimabue made in his art, and many renaissance artists were inspired by Giotto, just as artists today are still inspired by the art of those who came before them.

Wednesday, October 1, 2008

The Cry of the Brazen Bull

From approximately 570 b.c.–554 b.c. the tyrannous ruler Phalaris held control of Acragas (now Agrigentum), Sicily. Although Phalaris was known for his excessive cruelty it was the inventor, Perillus of Athens, who suggested the advent of the brazen bull (pictured left); the execution/torture device who's implementation made Phalaris most infamous.

The bull was essentially a hollow brass casting (as Perillus was a brass-founder) with a door in its side, into which criminals were placed. Once the criminal was within the belly of the bull the door was shut, locked, and a fire was started just under the bull's abdomen. The fire would grow and gain heat until the victim within was basically cooked to death. Yet Perillus did not leave his invention at that; a series of tubes from inside the bull transformed the convict's dying screams into a replication of the sounds one might hear from an angered bull. Consequently, when it came time to test the bull's ability to produce sound, Phalaris ordered that Perillus be thrown into the death machine of his own creation. Rumor has it that Phalaris also died within the belly of the bull when he was overthrown by Telemachus. Yet the bull claimed saints and sinners alike. One of the most famous people to lose their life within the brazen bull was the Christian martyr St. Eustathius.

According to legend, after his conversion to Christianity, St. Eustathius (pictured below) won a battle for the Roman Empire; which was the makings of a wealthy and glorious return to Rome. However, upon his return the Emperor Hadrian invited Eustathius to join him in the Temple of Apollo, where they would give thanks to the gods for St. Eustathius' military victory. Eustathius declined Hadrian's offer as Christianity forbids the worshiping of false idols. Because of his refusal Eustathius and his family were sentenced to be burned within the brazen bull (anywhere from 118-126 a.d.). Yet when the brass door was opened following their execution, the bodies of St. Eustathius and his wife and two sons remained unscathed.

Like the story St. Eustathius the actual implication of the brazen bull has become a legend unto itself. There is no actual documentation of the bull's construction or existence. In fact, some of the earliest accounts of the brazen bull can be found in a poem by the ancient Greek poet Pindar (522 b.c.-443b.c.) in his poem Pythian 1: For Hieron of Aetna, winner of the of the chariot race:

"…My friend, do not be taken in by unworthy use of wealth,
for the award of posthumous fame is the only testimonies
that story tellers and poets can give to the lives of the dead.
Croesus' generous virtues do not fade,
but he who burn men in his brazen bull, Phalaris,
is dogged by and evil report throughout the world,
and no lyres in men's halls welcome him to soft embrace…"

However, in 146 b.c. a brazen bull was found among the spoils at Carthage (the city with which Phalaris strengthened trade). With the discovery of this bull, the general belief became that Phalaris' torture device had been shipped to Carthage around 406 b.c. when Himilco took rule of Acragas. Yet other sources still claimed that the original brazen bull remained in Sicily. The reports from Timaeus, an ancient Greek historian from Sicily, claimed that the bull found at Carthage was not from Acragas. He stated that the original bull was cast into the sea by the people of Acragas following the death of Phalaris.

Sources for the article/for more information:
"Classica Et Rabbinica I: the Bull of Phalaris and the Tophet." Bohak, Gideon. Journal for the Study of Judaism in the Persian, Hellenistic, and Roman period. yr:2000 vol:31 iss:1 pg:203-216

"Phalaris' Bull in Timaeus ." Walbank, F.W. The Classical Review. Vol. 59, No. 2 (Dec., 1945), pp. 39-42

"St. Eustathius." Walter, Christopher. The warrior saints in Byzantine art and tradition. pp. 163-164

"Pythian 1: For Hieron of Aetna, winner of the of the chariot race." Pindar, Anthony Verity, and Stephen Instone. The Complete Odes. pp. 45