A GENERAL OVERVIEW OF ASTRONOMY

Anıl ATALAN - Istanbul University, Institute of Science, Department of Astronomy and Space Sciences, Istanbul

Summary: Since the first time human beings began to think, they have been in the process of understanding the physical world they live in. For this purpose he tried to understand the celestial bodies he saw and aimed to place these objects in a system. In this process, the foundation of today's astronomy has been laid down first and these bases are based primarily on ancient myths and metaphysical items.
To understand this process, the description of astronomy and cosmology and how it evolved throughout history forms the basis of this work.

1 . Definitions: What is Astronomy, Cosmology and Cosmogony?

Astronomy, astronomy, is one of the oldest sciences of human history. From the very first moment that he had a human self, he wondered about his surroundings and tried to restrain his curiosity. The interest in the Sun and other celestial objects, the most obvious objects in the environment, has also led to the birth of this science.
If we look at the origin of the definition, astronomy is derived from the ancient Greek words astro and nomos, which means the law of the stars. In the sense we use today, astronomy is a science that traverses all observable events, such as astronomical orbiting objects, and events outside the Earth's atmosphere, such as stars, planets, comets, polar lights, and galaxies. Astronomy examines the distribution, movement, chemical composition, evolution, physical properties and interactions of each kind of substance found in the environment.
If we look at the archaeological finds, people have known about the characteristic cycles of equinoxes since the neolithic age and their effects on the seasons. When we look at mythical stories, it is easy to understand that the naming of constellations was made thousands of years ago.
The fact that astronomers take their present state has come about thanks to the scientific tools and advanced mathematical methods discovered at the end of the Middle Ages. Thanks to these developments astronomy and astrology, which are almost inseparable from each other for thousands of years from the beginning, are separated.

If cosmology, the universe, is science, it examines the universe as a whole. The universe has been studied from the different aspects of human history, such as science, philosophy, occultism, and theology, but in modern times cosmology is generally used for physics-based cosmology. Astronomy and astrophysics as well as statistics, biology and chemistry are widely used in cosmology studies. The reason for this is to provide the perspective necessary to understand the universe, to obtain information and to make calculations.

If we mention the naming of cosmology; It comes from Greek words of cosmos and logia, and it means knowledge of order. The Cosmologia Generalis, first published by Chiristian Wollf in 1731, was used in the name of the work.

In order to understand where cosmology comes from, it is first necessary to know cosmogony. Cosmogony is formed by the combination of the Greek cosmos and gonos words and means the birth of the universe.
Man has always struggled to understand how the universe is formed. From ancient Mesopotamia to Asian and American civilizations legends have emerged in every region. For this reason, there are myths of creation on the basis of every civilization. These myths aim to answer the question of how the universe was created by the principle of causality by observing and interpreting the objective world.

In the light of these definitions; we can conclude that the cosmology is seeking to see how the cosmology is more stationary (physical), and that the cosmogony is for the purpose of basing the first formation in the world on certain mythological reasons.

2 . Astronomy in Antiquity

Before talking about astronomy and cosmology in Islam, it is necessary to give brief information about the accumulation of knowledge that has been created until the end of the betting period.

The birth of the astronomer dates back to history. Since the early ages the events in the sky have attracted people's attention and have made efforts to understand these events. However, this was very difficult due to the living conditions of the first humans, and the accumulation of knowledge was not so advanced as to be able to grasp these celestial events that attracted attention. He had to understand the forces of nature in order to make life easier and secure. This is the real reason why the first person is astronomical. It would be appropriate to study the first-generation astronomy born of human necessity in two distinct ways. The second is the practical astronomy based on physical phenomena.

The source of the tradition-bound astronomy is the fear and exaltation that the first man has about the power of nature. Man produced his own mythology in this process. This mythology is rooted in animals and plants nearby. He eventually positioned these beings in the celestial bodies and began to worship them. For this reason astronomy can be regarded as a magic or religious ceremony in the early ages.
Team stars have also emerged at the end of such a process. When the Earth's rotation around the sun is centered, the sun is perceived as turning around the earth. This movement, seen among the stars of the sun, is followed by 12 sets of stars. These are the Zodiac team stars we call our zodiac signs. The Greek word 'zoon' comes from the word living. The names of the zodiac signs on the zodiac include live creatures such as crab, fish and so on. They take from inanimate objects such as scales, buckets, as they are from animals. Finally, it must be noted that there are extensions in a set of stars called zodiacal lines in the zodiac line, but they are often ignored, as can be noticed on the sky atlases we use today.

If we look at the bases of the physics-based astronomy, it is based on the need for time measurement and the need for reinforcement. Since the early ages, the Sun, Moon and 5 celestial bodies (Mercury, Venus, Mars, Jupiter and Saturn) in the sky could be observed. The naming of the days of the week was made for the first time by the Babylonians on the basis of these celestial bodies. However, it is also an area of ​​use of the physics-based astronomer that it is understood that the winter season has come in ancient Egypt due to the birth of the Sirius star and that the Nile river has been overthrown.

3 . Islamic Astronomy

When we look at the astronomy against Arabic, it is referred to as 'ilm al-delegation' or 'ilm al-felek' and is defined as a mathematical science. In this way, astrology is separated from 'astrology en-nucum', the science of making sense out of the stars.

We can not talk about the existence of a scientific astronomer in the Arabs that will look back on the turn of Islam, but they have a vast knowledge of the stars as a result of the tradition of verbal transmission. This accumulation can be seen as an extension of the Keldani astronomy.

If the Chaldean name would look where it came from; The Chaldean name was first used by the Kaldi Dynasty, 6th century has emerged. Kaldilerin country in the culture of Helen Keldan Kaldea is called. This country covered the southernmost part of Mesopotamia, the coasts of Kuwait and the Gulf of Basra. For this reason, it is probable that the previous Mesopotamian cultures had continued their astronomical accumulation and transferred their accumulation to arabic civilization. As a small detail, 'Keldani' is a star scientist or hawk in the Bible. This meaning can be seen as a reason for the closeness of the Chaldean culture to astronomy.

Looking at early pre-Islamic arabic poetry, more than 300 star names have passed. The name of many stars used today is arabic. The 'Aldebaran' on the Taurus team star means follow, and it is one of the most obvious examples to give to the stars. According to Hommel, the sources of these star names are Akadca and Sumer.

When we came to the Islamic period, the calculation of the time bound to the celestial objects was added to fulfill the necessities of religion for the needs of astronomy. For this reason, the development of astronomy is accelerated. This development has also been supported by translation activities. For example, M.S. Latin-origin works written in the 2nd century AD 8th century. when it came to Arabic, people like al-Kindi, who gave new works by taking advantage of these works, came out.

Muslim scholars have received a lot of information from antiquities that have been turned into Arabic, which will be the basis for that day's astronomers. These include the thoughts of the Greeks on the globality of their place, the view that the world is in the midst of the universe, and that the whole universe is constantly returning with the sky. However, Some views, such as the systematic idea of ​​the solar-centric system of Aristarkos, who lived around 120, seemed to have not reached the Arab-Islamic astronomers, but the views of Aryabhata, the founder of the Indian astronomer and Indo-Arab number system living in the 4th century, had been learned at the latest with Biruni .

But it was necessary to make a breakthrough in observational astronomy to test the knowledge and views of Muslim astronomers. For this reason, the observatory culture was developed.

4 . Observatorys

Observatory or observatory; are the institutions established to observe the events that occur in the sky, to observe the movements of the stars and planets.

When asked about the possible existence of the observatory culture before Islam, Zinner answered:
'As was the case with the Babylonians, observations did not exist at all or existed for a very short time, and in Greece there was no requirement to observe all the events of the sky for hundreds of years. It was the activity in which individual individuals in question had to be careful not to observe this or that sky thing in the direction of their passion. As far as Eudoxos is concerned, it is said to be influenced by the Egyptians and close to Heliopolis and then an observatory in Knidos. An equatorial ring in the square hall in Alexandria was visible for hundreds of years and used in lessons. But an observatory can not make sense of them. Hipparkos could make his observations with portable tools. For Ptolema's observations, the presence of a fixed instrument and a rasathanen is unacceptable.

From here it is possible that we can get out of the end, until the birth of Islam, societies did not need an institution like observatory. Astronomers have yet to develop enough to require fixed and large-scale tools to reduce the amount of error in their observations. The absence of an observatory, of course, does not prevent the presence of ziggurat, pyramid or stonehenge in societies for astronomical events or on the basis of astronomical events.

According to the information in our hand, the Abbasi caliphs al-Mahdi and al-Me'un were very much interested in astronomical activities. This importance has led to the establishment of the observatory established in Baghdad Şemmasiyya in the last years of al-Me'mun period and the observatory established on the Kasiyun hill in the north of Damascus.
However, there is the impression that even al-Me'mun, who participated in the observations and was instrumental in the construction of the instruments, did not have an opinion of the observatory for a long time. Increasing work, the increase in the number of astronomers participating in these studies, the necessity of maintaining the dimensions of the instruments, their protection, and their observations made it necessary to prepare observations.
As a remarkable point in the founding of the two observations, the book has a religious structure in the previous periods in the structure of the two observatories. Şemmasiyya is an old synagogue, Kasiyun is an old monastery.

In the following period, observations were institutionally developed and now become a necessity. As a result of this obligation, an order was issued by the ruler Hulagu in Meraga, the capital of the West Mongol Empire, to establish a new observatory on Nasireddin et-Tusi. According to some narrations, the idea of ​​establishing an observatory is based on the cryptic Mönghe of Hulagu, but this idea is more likely to have passed from the Tusi to the Emperor.
Although the construction of the observatory was begun in 1259, the end date is not known precisely. However, it is thought that Hulagu started to work at about 1270 a few years after his death.
One of the most important activities of the Meraga observatory is the preparation of a new astronomy chart called Zic-i Ilhani. This chart also contains the latitude and longitude grades that are arranged alongside the observation results.
Apart from Zic-i Ilhani, one of the most important achievements of the Meraga observatory is the preparation and use of advanced astronomical instruments. So much so that in the coming period Tycho Brahe was the pioneer of the tools he used in his observatory.

5 . Scientists Contributing to Islamic Astronomy

At this point of the study, it is necessary to mention the scholars who contributed to the Islamic Astronomy. Because of their efforts astronomy has taken important steps towards becoming a science and finally we have come to the point where we are today.

For example, Abraham al-Fazari (seventy-sixty-nine or 806) is the first known Muslim to do violence. Then a century later Hamid b. Ali and Ali b. Moses was best known as the best masters. We also know that al-Siczi, as Biruni says, is doing an usturlab according to the model of the solar centered universe, which is suitable for today's system approach.

Fixed b. Kurra has written the first known book of the solar time, using the knowledge he has developed in these subjects, as well as the contributions he made to mathematics and geometry.

Abu'-Vefa al-Buzcani is the mirror of spherical geometry according to Carra Vaux, though not much is mentioned in his name.

The book, which is very important for the Islamic astronomy of Ptolemy, is the first to turn the apple tree into arabic. Rabban al-Tabaridir.

Fergani is called the brightest astronomer of the 9th century, but it has been a great influence all over the world for the next 3 centuries thanks to works translated into Latin when the 12th century came.

Ibn al-Haytham, the pioneer name of optical science, broadened the scope of his observations and saw that the intensity of the atmosphere influenced the light's fall to earth. He wrote a very important essay for the elmecist, and he talked about how the astronomer should become. It is also believed that the camera of the needle-hole makes it possible for Ibn Sina to perform the first venus crossing observation.

Abdurrahman al-Sufi brought a constellation about the constellations that was unprecedented until modern times.

Abu Ubeyd wrote a thesis entitled About Arrangement of Al-Jurassic Spheres and referred to the problem of ekuant with this thesis.

Muhyiddin al-Muhammad b. In November 'Astronomy Problems', he referred to the problem of the Ptolemy astronomy. The important point is to present the solution in this criticism.

Ali Kuşçu has written a commentary on Elmecisti as well as Uluğbey zicine. Mercury dealt with the issue of equations and found one of the best theses on this subject.

In addition to making astronomy tools, Müeyyeduddin al-Urdu wrote Kitab al-Hey'ya yil and tried to model for Mercury.

As an alternative to Bitruci Ptolemy, who lived in the 12th century, he designed an arrangement free from eccentricities.

Alaeddin ibn Shatir designed astronomical instruments just like Urdi and he signed the work that compiles Greek astronomy. In his works he lifted the eccentric from the whole place, saving the models from the bulky stuff that the excess of shapes is. In the following period, it laid the foundations of a great splasher and was used by the Copernicus in the solar centered model.

As can be seen from the last example given, the Islamic Astronomy has successfully absorbed the astronomical predecessors born with natural needs and has developed and shaped them according to their own needs. Then this new astronomy reached the West and continued to develop there, making important contributions to the science of astronomy today.

6 . References

1. Mehmet BULGEN 'The Cosmological Dimensions of Kelâm İlmin and Present Cosmology', M.Ü. Journal of Theology Faculty 39 (2010/2)

2. Science and Technology in Islam, volume: 2

3. M.E. Special 'Planet Transitions in History and 2012 Venus Transition', UAK 2012

4. George Saliba, 'Islamic Science and the Formation of European Renaissance', Mahya Yayıncılık, 2012

5. Ahmad Isa, 'Contribution of Muslims to Renaissance', Mahya Publishing, 2012

6. Friday Vural, 'Isik Rises from the East - Famous Turkish and Muslim Scientists', Panama Publishing, 2013

7. Y. Tzvi Langermann, 'Arabic Cosmology'