Astronomy:

Introduction:

Astronomy is a scientific science that examines celestial objects and phenomena (from the Ancient Greek "o" (astronoma), "science that investigates the laws of the stars"). In order to describe their creation and evolution, it makes use of mathematics, physics, and chemistry. Planets, moons, stars, nebulae, galaxies, and comets are among the interesting celestial bodies. Supernova explosions, gamma ray bursts, quasar, blazar, pulsar, and cosmic microwave background radiation are examples of relevant phenomena. Astronomy is the study of everything that comes from outside the atmosphere of the Earth. Astronomical cosmology is the study of the cosmos as a whole.

 

Astronomy

One of the first natural sciences was astronomy. Methodical observations of the night sky were conducted by the earliest civilizations in recorded history. The Babylonians, Greeks, Indians, Egyptians, Chinese, Maya, and other prehistoric indigenous groups from the Americas are among them. Astronomy used to encompass a variety of fields, including astrometry, celestial navigation, observational astronomy, and calendar making. Today, it's common to claim that astrophysics and professional astronomy are the same thing.

 

The two main subfields of professional astronomy are observational and theoretical. Data gathering from observations of celestial objects is the main goal of observational astronomy. Then, using fundamental physics concepts, this data is examined. The goal of theoretical astronomy is to create analytical or computational models that may be used to describe celestial objects and events. These two disciplines are complementary. Observations are used to validate theoretical conclusions, whereas theoretical astronomy aims to explain observational data.

 

One of the few fields of science where amateurs are actively involved is astronomy. This is specifically accurate while learning about and watching fleeting events. The discovery of new comets is just one of the significant discoveries made possible by amateur astronomers.

 

History:

 

Astronomy in the past has only ever involved observing and predicting the motions of objects that are visible to the unaided eye. Early societies assembled large artefacts in some places that may have served an astronomical function. These observatories might be used for ceremonial purposes as well as for determining the seasons, which is crucial for knowing when to produce crops and for estimating the length of the year.

 

Early star studies were done with the naked eye, before instruments like the telescope were created. Astronomical observatories were built as civilizations advanced, most notably in Mesopotamia, Greece, Persia, India, China, Egypt, and Central America. This contributed to the emergence of concepts about the nature of the universe. The majority of early astronomy included charting the locations of the planets and stars, a field of study now known as astrometry.Early theories concerning planet motions and the philosophical exploration of the Sun, Moon, and Earth's role in the universe both derived from these findings. The Sun, the Moon, and the stars were thought to revolve around the Earth, which was positioned at the centre of the cosmos. The Ptolemaic system, after Ptolemy, is also known as the geocentric model of the cosmos.

 

The beginning of mathematical and scientific astronomy, which was practised by the Babylonians and established the groundwork for later astronomical traditions that emerged in several other civilizations, was a particularly significant early development. Lunar eclipses were found to occur in a repeating cycle known as a saros by the Babylonians.

 

Astronomy

After the Babylonians, the Hellenistic civilization and ancient Greece made great astronomical advancements. Greek astronomy has been distinguished by its pursuit of a logical, physical explanation for celestial phenomena from the beginning. Aristarchus of Samos calculated the sizes and distances of the Moon and Sun in the third century BC. He also postulated the heliocentric model of the solar system, in which the Earth and planets revolved around the Sun.Hipparchus created the oldest known astronomy instruments, such as the astrolabe, in the second century BC. He also discovered precession and computed the size and distance of the Moon. A detailed catalogue of 1020 stars was also produced by Hipparchus, and Greek astronomy is where the majority of the constellations in the northern hemisphere originate. The Antikythera mechanism, a first-generation analogue computer built to determine the Sun, Moon, and planet positions for a given date, operated between 150 and 80 BC. Until the invention of mechanical astronomical clocks in Europe in the 14th century, such technological monuments of complexity had vanished.

 

Many significant astronomers lived in mediaeval Europe. Richard of Wallingford (1292–1336) made significant contributions to astronomy and horology, including the development of the first astronomical clock, the Rectangulus, which allowed for the measurement of angles between planets and other astronomical bodies, and an equatorium called the Albion, which could be used for astronomical calculations like calculating the longitudes of the moon, the sun, and other planetary bodies as well as forecasting eclipses.In order to demonstrate that planets could move without the aid of angels, Jean Buridan (1300–1361) and Nicole Oresme (1320–1382) first addressed evidence for the Earth's rotation. Buridan also created the theory of impetus, which is the forerunner of the contemporary scientific theory of inertia. Astronomical advancements made by Regiomontanus (1436–1476) and Georg von Peuerbach (1423–1461) were crucial to Copernicus's creation of the heliocentric paradigm decades later.

 

In the Islamic world and other regions of the world, astronomy flourished. By the beginning of the ninth century, the first astronomical observatories had begun to appear throughout the Muslim world as a result. The Persian Muslim astronomer Abd al-Rahman al-Sufi wrote about the Andromeda Galaxy, the biggest galaxy in the Local Group, in his Book of Fixed Stars in 964. Chinese astronomers and the Egyptian Arabic scientist Ali ibn Ridwan both spotted the SN 1006 supernova, the greatest apparent magnitude star explosion in recorded history, in the year 1006. Al-Battani, Thebit, Abd al-Rahman al-Sufi, Biruni, Ab Ishq Ibrhm al-Zarql, Al-Birjandi, and the astronomers of the Maragheh and Samarkand observatories are some of the well-known Islamic (primarily Persian and Arab) astronomers who made major contributions to science.Back then, astronomers gave stars several Arabic names that are still used today.

 

Additionally, it's thought that Timbuktu and Great Zimbabwe's ruins may have formerly been home to astronomical observatories. Astronomers in post-classical West Africa studied the motion of the stars and its relationship to the seasons, drawing detailed maps of the skies and models of the orbits of other planets using intricate mathematical calculations. Mahmud Kati, a Songhai historian, wrote about a meteor shower in August 1583. Contrary to what Europeans traditionally assumed, there were astronomical observations made in sub-Saharan Africa throughout the pre-colonial Middle Ages.

 

Over a period of more than six centuries (from the rediscovery of old knowledge in the late Middle Ages to the Age of Enlightenment), the Roman Catholic Church provided astronomy research with more financial and social support than most other organisations combined. Finding the Easter date was one of the Church's goals.

 

Nicolaus Copernicus proposed a heliocentric theory of the solar system during the Renaissance. Galileo Galilei maintained his theories, while Johannes Kepler built on them. The movement of the planets around the Sun was first accurately explained using a system created by Kepler. Kepler tried to develop a hypothesis to explain the laws he recorded, but he was unsuccessful. The definitive theory to explain why the planets move was developed by Isaac Newton using his laws of gravitation and celestial dynamics. Additionally, Newton created the reflecting telescope.

 

New discoveries were made as the telescope's size and quality improved. John Flamsteed, an English astronomer, catalogued approximately 3000 stars. Nicolas Louis de Lacaille created more thorough star lists. Astronomer William Herschel created a thorough inventory of nebulosity and clusters, and in 1781 he made the first discovery of a planet—Uranus.

 

More precise predictions concerning the motions of the Moon and planets were made in the 18th and 19th centuries as a result of Leonhard Euler, Alexis Claude Clairaut, and Jean le Rond d'Alembert's research of the three-body problem. The masses of the planets and moons can be inferred from their perturbations thanks to work that Joseph-Louis Lagrange and Pierre Simon Laplace furthered.

 

New technologies, such as the spectroscope and photography, led to significant advancements in astronomy. In 1814–1815, Joseph von Fraunhofer found 600 bands in the spectrum of the Sun, which Gustav Kirchhoff attributed to the presence of several elements in 1859. It was established that stars had a wide range of temperatures, masses, and diameters yet were comparable to the Sun here on Earth.

 

It wasn't until the 20th century that the Milky Way galaxy and "external" galaxies were both proven to exist as separate groups of stars. The universe's expansion was discovered as a result of the observed recession of those galaxies. Theories based on theoretical astronomy have been used to explain phenomena like quasars, pulsars, blazars, and radio galaxies by postulating the presence of things like black holes and neutron stars. The 20th century saw significant advancements in physical cosmology.

 

The Big Bang hypothesis model was developed in the early 1900s, with strong support from the cosmic microwave background radiation, Hubble's law, and the cosmological abundances of elements. Measurements in portions of the electromagnetic spectrum ordinarily covered or obscured by the atmosphere have been made possible by space telescopes.  It was disclosed in February 2016 that gravitational wave evidence had been found by the LIGO project in September of the previous year.