November 6, 2011 ALP Monthly Meeting Report
by James Kevin Ty , Jett Aguilar and Christopher Louie Lu
 

Last October 9, members of the Astronomical League of the Philippines (ALP) attended their monthly meeting at Rizal Technological University in Boni Avenue , Mandaluyong City despite hard rain  in some areas of Manila.   Members who attended were ALP President James Kevin Ty , Charito Ty and son Kendrick Cole KC Ty ,  VP Jett Aguilar, Secretary Edgar Ang, Christopher Louie Lu , Norman Marigza, Ronald Sison, and Vincent Gella and Dr. Jesus Rodrigo Torres.

Meeting started at around 2:30pm with ALP Special Events chairman Christopher Louie Lu who touched on November Celestial Events  as well as Part 2 of his Ancient Astronomy.

Throughout the centuries, Astronomy has achieved so much knowledge from exploration and discovery.  With the use of modern and high tech instruments we can see, touch and smell things that are way beyond our reach and still we know so little of  the unexplored universe.  But this seem to be not a problem to our ancient forebears who, without the use of modern equipment, tried to understand not just the natural world they lived in but the universe as well.

During the 4^th to the 2^nd millenias BCE, intellectual achievements were made by different civilizations and cultures.  It was era of the Sumerians, Babylonians, Egyptians, Chinese and Indians intellect that flourished and expanded the known world.  But on the 1^st millenia BCE,  it was no question that it was the Greeks who conquered this era in intellectual achievements.  Though many famous Greek thinkers and Philosophers has made their mark and contributed a great deal in the field of mathematics, literature, art and science, I would like to concentrate on the Greek intellectuals who made great contributions in the field of astronomy.

1. Thales – (c. 629 – 555 BCE) Known as the 1^st Philosopher and Scientist

-        He was the first to try to answer questions such as “What is the Universe?” or “What is life?” without invoking the supernatural

2. Pythagoras – (c. 580 – 500 BCE) He is known as the 1^st real mathematician.

-        He linked numbers (arithmetic) to shapes (geometry) and ultimately to nature an astronomy.

-        He proposed that the spheres carrying the Sun, Moon, planets & stars around the Earth are harmonious & could be represented by numbers.

3. Plato – (c. 427 – 347 BCE) He believed that the natural world is a imperfect representation of   the true Universe and so the only way to learn more of the Universe is by logic & reason, rather than by observations.

-        He also stated that the sphere is the perfect geometric shape and that all astronomical bodies must be spherical and their motions circular.

-        Built & founded his school in 368 BCE, naming it “the Academy”.

4. Aristotle – (c. 384 – 322 BCE) A pupil of Plato, he tutored Alexander the Great.

-        His model of the Universe will go unchallenged for the next 2000 years.

-        He recorded the first known views of motion & gravity.

-        Considering the motions of the heavenly bodies, he believed that the laws governing them are different from the laws here on Earth. Where, here on Earth, everything is to remain stationary, the motions of the heavenly bodies were permanent and endless. This meant that heavenly bodies move in circular motion and at constant speeds.

5.      Aristarchus – (c.310 – 230 BCE)  He was from Samos & a great scholar in Alexander

•         -    Though he was not the first to ask the questions - “How far is the Moon?, How far is the Sun?, How far are the stars?”,  he was the first to use geometrical methods to answer them.

-        His methods was geometrically correct but his precision was limited in accuracy.

-        He concluded that the Earth was 3x larger than the Moon. (Actually, its 4x larger)

-        He also estimated the distance of the Earth to the Moon in 25 Earth-diameters. (Actually, its 30x Earth-diameters)

-        He concluded that the Sun is 20x distant and 20x larger than the Moon or 7x larger    than the Earth.

-        He was able to determined that the Sun was much farther away from the Earth than the Moon was. And that it was much larger than the Earth, which was itself larger than the Moon.

-        Following his passion for determining astronomical distances, he realized that his model gave him a method of measuring the distance to the stars.

            6. Eratosthanes – (c. 275 – 195 BCE) Born in Athens but was to spent most of his life in                        Alexandria.

                   -    Greatest and remarkable achievement was to measure the size of the Earth.

                   -    He thus calculated the Earth circumference to 40,000 km (the actual circumference is                             39,940 km)

            7. Hipparchus – (c. 194 - 120 BCE) Born in Nicea but spent most of his life on the island of                              Rhodes and in the city of Alexandria.

                   -    He is said to be the first really great observational astronomer.

                   -    Hipparchus mapped the positions of 1080 stars over a 30 year period and gave                                                 estimates of their brightness; he did the same for the five planets: Mercury, Venus, Mars,                        Jupiter and Saturn.

                   -    One of his great achievements was the detection of the precession of the Earth’s axis.

                   -    He also sought to bring to geography the precision of astronomy by using his stellar                                observations to locate places on Earth.

                   -    He determine the distance to the Moon and arrived at a remarkably accurate value of 30                                   Earth diameters.  Using the measurement of the Earth’s diameter by Eratosthenes, he                             derived the Earth-Moon distance to be 382,000 kilometers.

            8. Claudius Ptolemy – (c. 100 - 170 CE) He was a Roman citizen of Egypt who wrote in Greek.

                   -    He lived in Egypt under Roman rule, and is believed to have been born in the town of                             Ptolemais Hermiou in the Thebaid.

                   -    His greatest work in astronomy was known by its Arabic name “The Almagest”; The                            Greatest.

                   -    The Almagest consisted of 13 books.  Eight books were essentially a description of the                                     achievements of Greek astronomy before him, but the last five books represented his  own major contribution to astronomy.

Afterwards, ALP VP Jett Aguilar then presented his very interesting and  educational lecture  on Jupiter observation.  He started out by touching on the basic planetary information on the largest planet on our solar system.  He then discuss on the recent discoveries and excellent planetary imaging made by amateur astronomers like our very own ALPers Christopher Go  & John Nassr  as well as  Anthony Wesley and Damian Peach.

He then proceeded to discussed on the cloud belts and zones of Jupiter and also tackle on the 3 Systems being used to compute when a certain object in Jupiter can be observed.  Also discussed by Jett are the Jovian main satellites namely Io, Europa, Ganymede and Callisto. 

Lastly, he also shared his own early Jupiter images and how it had improved over the years through dedication and perseverance that other amateur astronomers can follow.

ALPer Christopher Louie Lu started out his lecture on the highlights of the November sky.	ALPer Christopher Louie Lu then continue his second part of his Ancient Astronomy lecture series.
ALP VP Jett Aguilar gave a very interesting and educational lecture on Jupiter observation.	ALPers pose in front of the various beautiful astro wallpapers inside the RTU Astronomy Center.