The inventor of the telescope might be someone else, but it is through Galileo Galilei, considered the father of modern science, that it served its right purpose. Hence, he became the first to use a telescope to observe the celestial objects hovering in space. The story is brought to you by Obuli Chandran.

Narrator: Obuli Chandran


Hey there everyone, this is Aasif and you are listening to Hello Educator.


Today’s episode of Hello Educator is from Mango Science Radio and the story is from Obuli Chandran. Obuli’s stories mostly revolve around physics, space, and astronomy. Today’s story is titled ‘The Sun or The Earth’. I hope you enjoy today’s episode. 

00:42  Hi Mango Science Radio listeners. Obuli Chandran here. Hope you’re all doing good during this lockdown. I hope the situation returns to normalcy very soon, at least in a month or so. Today, I’m going to talk about a very interesting historical fact. Since I’m interested in astronomy and space science, my stories would be around it mostly. Of course, I’ll try to include stories from other domains as well but this story is about Galileo. I’m not going to talk about the entire history of Galileo and what he has done but I’m going to talk about one particular thing that is very important for science.

01:23  Galileo was one of the very first persons, in fact, according to the records that we have, he was the first person to observe celestial objects through a telescope. And it was nothing short of a revolution because when he observed things like, for example, Venus. He could observe the phases of Venus. Like how our moon goes through different phases from Full Moon to New Moon, waning gibbous, waxing gibbous, crescent moon and different things, Venus also exhibited similar phases and no one had ever seen it before until him because it was not possible to observe the phases using the naked eye. Even if you see in the night sky these days, if you look up in the evening after sunset, about half an hour after sunset the sky is dark enough, you will see a very bright point of light.

02:16  That is the planet Venus, it is just like a bright point of light. You cannot tell whether it is half Venus or crescent Venus or waxing crescent, you cannot tell anything. You don’t even know if it has phases but Galileo was the first person to observe this through a telescope. Also, of the several other objects that he observed through the telescope, he also observed Jupiter. And guess what? He found four other small dots that are orbiting Jupiter. The first observation of objects moving around another object in space. People thought until then everything was orbiting the Earth, including the Sun. So that is what we call as the geocentric theory of the solar system, the geocentric model.

02:59  During his time, Galileo’s, it was the most widely accepted model of the solar system. Today we know it is wrong, today we know the sun is the centre of our solar system and we call it the heliocentric theory but back then, it was very well established. According to the evidence or the thought processes that they had back then, the Earth was the centre. Maybe 30 – 40 or about 50 – 60 years before Galileo’s time, there was this scientist Nicolaus Copernicus who proposed the heliocentric model. His books stirred up a lot of controversy.

03:37  When Galileo tried to observe the celestial objects through his telescope, he also favoured or promoted the idea of Nicolaus Copernicus that the Sun could be the centre of the solar system. In fact, they didn’t even know the solar system was the entire universe or what the solar system is. They thought the entire universe was what they saw in the sky and the entire universe was orbiting the Earth. Nicolaus Copernicus said no, Earth is just one of the objects that is moving around the Sun and everything in this universe orbits the Sun, that was his model. When Galileo observed it and he favoured it he was very strongly convinced. Particularly the phases of Venus revealed that such patterns could be exhibited by Venus only if it moves around the Sun, and the Sun has to be at the centre. Of course, when no one thought anything else could orbit any other object there was this Jupiter and its observations of the moons.

04:35  Now this was staunchly opposed by the church and state back then because it went directly against the religious beliefs that were held at that time. This was looked at like going against the faith and Nicolaus Copernicus was also admonished. When Galileo wrote his book, in 1610 or 1613, called as ‘The Starry Messenger’, he favoured Nicolaus Copernicus explicitly and that is when people got at him. They warned him, issued a very severe warning that if you do not retract these words or if you do not get these words back and accept that geocentric model is the right model then you would be facing serious troubles from the church because whatever that is being proposed by Galileo and also by Nicolaus Copernicus before him, went directly against the views of the Holy Scripture back then.

05:38  So I think Galileo did not take the troubles of the church back then, he sort of accepted the warning and did not go much about promoting the heliocentric model until at least for the next 15-20 years but he was very convinced, he was very sure that this model has to be wrong. In 1633, he wrote another book related to astronomy where he did not explicitly support the Copernicus view but he was sort of supporting the Copernicus view. Of course, that book also became very popular and the church was very scared. They didn’t want this book to be popular. That was when he was tried at court by the church and he was accused of going against the faith and was put under house arrest. I’m sure you would all know about Galileo being put under house arrest and until his death in 1642 he was placed under house arrest for at least seven to eight years.

06:48  The reason I’m telling you this is that it looks very ridiculous that Galileo had to suffer through this for proposing something that is correct. If we had someone proposing a similar thing in our times today, something that’s extremely radical, something extremely revolutionary with evidence of course, shouldn’t we celebrate him or shouldn’t we at least look to hear what he has to say? And that was what was happening to Galileo back then, he was not even listened to. Forget listened to, he, in fact, invited a couple of them to even look through the telescope, please look through a telescope this is what the telescope is telling, this is the reality out there. But, people even refused to look through the telescope. They said no, this is just against the faith and this is plain wrong.

07:44  Today, we are way better in terms of, you know, being open-minded and allowing ideas to flourish and allow anybody to come up with theories and go through the scientific process and then reject it or accept it. But back then this freedom was not even there. Imagine someone like Galileo had to endure this. I feel very sorry for him. He’s someone who should have been celebrated. I think Einstein was more lucky in the sense he was born in the early 20th century so he was lucky he did not have to face a very similar issue or problem. Then again what a contribution Galileo has done. So this is what I wanted to share.

Whenever you hear of stories, when you hear of ideas, you just keep your mind open. So, you have to be trained to be sceptical and at the same time, you should be learning to embrace empirical evidence. So that is what science is all about. I’ll catch you again with some other story next time or about somebody else, so until then see you. Bye. 

We sincerely hope that you really liked this episode. We upload one science story every day and if you are a science enthusiast and you would like to contribute to Mango Science Radio, please WhatsApp us at 9952243541 and you can also share your feedback via an audio message or Whatsapp that would really be helpful. Thank you again, thank you so much for listening to Hello Educator. I will see you tomorrow.

Music by Karthikeyan KC