On that time, we had no idea about that falling object. On that time, our limit was only Earth as we used to consider that Earth is the centre and every star or planet which we see up above the sky rotates around it even sun too. But what changed our perspective? What made humans to say, no, this isn't true? What we read or being taught is not true? There's something else happening which we aren't aware of.
All the answers to every questions are given and proven by science. Science not only helped us to develop our thinkings but it changed the Though science has various branches, but the one which we'll talk about in this video is astronomy. The branch which gave answer to all the space related phenomena happening around the Universe. But the question is what is astronomy and why is it so important and considered as one of the most groundbreaking branches of science? How did astronomy evolve and what is its entire history?
Astronomy, the branch of Science which deals with the study of every celestial objects including planets, stars, galaxies etc. and their formation. This branch of science is regarded as one of the oldest branches of Science. The word ASTRONOMY has been derived from the Greek Word “Astronomos” where the meaning of word “Astro” is star while “Nomos” means specified area of knowledge. Let's check out its history:-
Astronomy is one of the oldest branch of science(if not the oldest) and has been practiced since a time when humans first observed the stars and wondered about their significance in the night sky. Early civilization studied astronomy as a mixture of deep observations of the positions and movements of the celestial bodies in the night sky, religious significance and astrology. Ancient civilizations like Harappans, Chinese, Mayans etc started to use astronomy in tracking time(usually by watching the movement of Sun), orienting their cities and they also started to predict the future.
The Ancient Greeks who were the first to name the planets and stars and plotted their respective positions in sky. While various Europeans broke their shackles of Dark ages and travelled to various part of the World and shares their knowledge with the people of other continents. Astronomers in the middle east initially translated the Greek books of astronomy into Arabic which not only preserved but also expanded humanity's knowledge of the sky.
For several centuries, people believed that Earth is the centre of whole Universe. Every planet, every star and every celestial body revolve around the Earth. The cosmological model of astronomy where we assume that Earth is placed at a centre and all other object rotates around them, then this cosmological model is known as Geocentric model. This model of astronomy was first proposed by the Alexandrian astronomer and mathematician Plotemy back in 150 CE. This model of astronomy dominated for over 1400 years until the Polish astronomer Nicolaus Copernicus proposed the Heliocentric model of the Universe which states that Earth is not the centre of the Universe, but along with Earth and other planets of solar system actually revolve around the Sun. However, this model didn't consider Sun as the centre of Universe.
Evolution of Modern Astronomy:-
Copernicus's heliocentric model was so revolutionary on that time as it broke the shackles of Plotemy's geocentric model of the Universe which had dominated astronomy for over 1400 years. Copernicus was lucky enough as because people didn't believe his theory and he received hate from everywhere but his theory got its support when Johannes Kepler proposed his “Three laws of Planatery motion” which for the very first time described the actual way the planets move around the Solar System. Kepler's theory also considered Sun as the centre of the Solar System not the Earth and hence Copernicus's heliocentric model of the Universe finally came into play. And this theory lead to the birth of modern astronomy.
The invention of telescope in 1608 by Hans Lippershey, made astronomy subject much more interesting. Through telescope, a person can see an object which is millions miles away from us. The person who used the telescope for the very first time was Galileo Galilei, he was also the first person who look at the celestial bodies for the time and discovered the brightest four moons of the planet Jupiter. This also proved that not everything in the solar system revolve around the Sun but there are objects which also revolve around the planets too.
Modern astronomy:-
Astronomy as a subject hasn't been the same as Galileo's time but it has made various strides. Now, we not only know that planets revolve around the Sun, but we also know that Sun also revolve around our milky way galaxy. We have now discovered planets which are located outside of our Solar System. The first planet which we discovered outside the Solar System in 1991, and since then we have discovered over 4000+ exoplanets all around the Universe. Several scientists have won Nobel Prize in Physics in this field.
Now, we know that our Universe is 13.7 billion light years wide which once was our Earth only. We know now that there are billions of billions of planets, stars, galaxies and many other celestial object in the Universe. Now, we have very advance telescopes which can observe objects far far away from us.
Hubble Space Telescopes, the telescope which showed the various nature of the Universe. It expanded our knowledge of astronomy to a scale which people back in 18th or 19th century could never dream of. It has left several questions for us which we're going to have when the next generation telescope James Webb Space Telescope will start operating which is currently on its way to its destination point.
Importance of astronomy:-
Astronomy can be considered as one the most important branches of Science as the future of humanity completely dependent on our knowledge of Astronomy. There are several things present outside Earth which can easily destroy Earth within a second. By studying astronomy, we know now about few of those like an asteroid impact would easily destroy life on Earth but since we have knowledge about asteroids and the technology through which we would easily observe them heading towards Earth, we can deflect its direction by using our technology. This is one of the examples of why astronomy is important and how it can save Earth from interstellar threats.
Astronomy would also help us to find our new home since Earth has very limited resources and population is growing very rapidly, therefore, the time is not so far away when Earth will run out of its resources and we'll need a new home to survive. Due to this fact, study of other planets is too important as we can't take humans to any planets whose gravity, atmosphere, surface etc is different from Earth. To call a planet our new home, that planet should be very identical to our planet and we can only find that planet only when we'll have huge knowledge of astronomy.
At last, it won't be wrong enough to say that the future of humanity or Earth is completely reliable on the future of astronomy. Better the future of astronomy, the better future we humans will have.