Hello, friends! About 500 years ago, Kurukshetra was a major pilgrimage center, Once, there was a huge fair on the day of a solar eclipse. Guru Nanak and his friend Bhai Mardana had gone to the fair. Back then, the belief that during a solar eclipse people shouldn't eat was quite prevalent. While Guru Nanak was at the fair, he was offered deer meat to eat. Deer's meat was offered as food. Since Guru Nanak did not discriminate between food, he accepted the offer. This meat was being roasted. But when the other revelers in the fair saw this, they were shocked to see someone cooking during a solar eclipse. And not even normal food, meat! Some people were very offended. People started threatening him. Some even said that they'd kill Guru Nanak. What happened next? I'll tell you later. 




"Solar Eclipse happens when the Moon's shadow falls somewhere on the surface of the Earth. And a Lunar Eclipse is the opposite. When the Earth's shadow falls on the Moon." "People thought that some deity was angry or the king would die." "To witness a total solar eclipse, is to experience fear. At least a little." "Throughout history, human affairs have been shaped by the suddenness and eerieness of a Solar Eclipse." Friends, if you paid attention in science class at school, you'd know the basic reason of solar and lunar eclipses. But there are some things that aren't explained properly in school, which then creates some confusion. We know that the moon revolves around Earth. And the Earth revolves around the Sun. And the Sun? Does it remain still at its place? No! Sun revolves around the centre of the Milky Way Galaxy. In fact, along with the Sun, our entire Solar System revolves around the Milky Way Galaxy. You might wonder why Earth revolves around the Sun. 

The reason for this is that 99.8% of the mass of our Solar System, is in the Sun. Due to this mass, the Sun has an extremely strong gravitational force. This gravitational pull acts on all planets. But why then does the Earth not ram into the Sun due to this force? The reason is the inherent speed of the Earth. And the Earth's speed is sideways as compared to that of the Sun. So the Earth is under the influence of sideways momentum. The speed is actually 67,000 miles per hour. 30 kilometres every second. But this remains balanced due to this sideways momentum. Without this, the Earth would have collided with the Sun. In the same way, there is a Supermassive Black Hole at the centre of the Milky Way, with a huge gravitational pull, due to which the Sun is revolving around the Milky Way Galaxy. I talked about this in the video on Black Holes. 

Next, you may wonder why does the Moon revolve around the Earth? And why not around the Sun? But think about this once, The moon isn't revolving only around the Earth. Since the Earth is revolving around the Sun, The Moon is revolving the Sun too. The only difference is that it has a spiral orbital path. So in the midst of these revolutions, sometimes, the three objects get into a straight line. If in this straight line, the Earth is the one in the middle, Earth's shadow falls on the moon, and we call it a lunar eclipse. But if in this straight line, the moon is between the Sun and Earth, from our perspective on the Earth, the Sun gets hidden behind the Moon, and we call it a solar eclipse. Most of the diagrams of Solar and Lunar Eclipses that you are shown in schools, are like this. But these diagrams create some confusion. The confusion that even though the Moon completes a revolution around the Earth each month, given the frequency, there should be solar and lunar eclipses every month. Isn't that interesting? So why don't we get Solar and Lunar eclipses every month? The reason is equally interesting, and the problem is our 2-dimensional drawings. 

If you look at things from a 3-dimension perspective, you will understand what's actually happening. The plane of the Earth's orbit around the Sun, and that of the Moon's orbit around the Earth are different. Let's understand this with an example. Here, I have a garlic, let's considered this the Earth. This small tomato, that'll play the Moon, And this big orange that'll be our Sun. In the drawings, you are shown the Earth revolving around the Sun like this. And the Moon revolving around the Earth like this. But in reality, the Moon isn't revolving in this plane. The revolution is on a tilted plane, around a tilted axis like this. Can you understand what I'm trying to say? There is a tilt in the plane. It means that the plane of the Earth is horizontal, And the plane of Moon's orbit is tilted like this. And the intersection of both planes are limited to only 2 points. One of them here, and the other here. When either of these points come in front of the Earth, in a straight line, we get to witness a solar or a lunar eclipse. Look at a proper animation of this, while demonstrating this, I had exaggerated the tilt. In reality, the tilt is only by 5°. Thanks to Jared Owen for this animation, It's tilted by about 5°. 

This means that most of the time the Moon passes above or below the Sun, as seen from the Earth. We can map out two invisible points in space in which the Moon's orbit crosses the ecliptic. We call these the lunar nodes. When they line up with the Sun, Moon and Earth, that's when a Solar Eclipse or a Lunar Eclipse will occur. In this, you can see that it's quite rare that these two points can be in a straight line between the Earth and the Sun. This is why Solar and Lunar Eclipses are quite rare. 

Here, I'd like to request the teachers, to try to explain these eclipses in 3-dimensions the next time onwards. The students will understand this better. Many people have a misconception that the night of the new moon is a lunar eclipse. That's incorrect. Some nights are simply No Moon nights. Where the moon isn't visible at all, And such nights are almost a monthly occurrence. We call them Amavasya in Hindi. Once again, the reason for this difference is the tilt of the Moon's orbit. We know that light is emitted from the Sun only, Earth and Moon emit no light. At any point in time, Sun's light reaches half the Earth that is known as a day. Similarly, half the Moon is alight with sunlight at all times. Apart from these revolutions, the Earth rotates around its axis as well. This turns day into night, and night into day. During day, we cannot see the Moon and the stars simply because the sunlight is too bright. But if you noticed closely, sometimes you can see the Moon even during the day. But what's the reason for the changing phases of the Moon? Sometimes full moon, half moon, and even no moon. You can understand this in this animation. 

You'll see that the speed of the Earth's rotation faster than the speed of the Moon's revolution. How much of the Moon will be visible depends upon the Moon's placement in its orbit. Let me take my tomato and garlic, Imagine that our Sun, our orange is there, that's the source of light, Since the light is coming from there, this half of the Earth will be alight. And this half will be in darkness. This is the night and that's the day. And suppose that the moon is in this position. This part of the moon will be in light, and this will be in darkness. If you are here on Earth, you will see half the moon illuminated and the other half in darkness. A half moon. Had the moon been here, this whole face would be illuminated by the sunlight, and from our perspective here, we see the entire illuminated face of it. A Full Moon. So literally, when the Earth is in the middle, we see the Full Moon. But if there was no tilt to the Moon's orbit, the Moon would've been on the same plane as the Earth, and we would've gotten a lunar eclipse every month. But because of the tilt, the sunlight falls on the entire face, and from the Earth below the level of the Moon, we get to see it as a disk. But on the night of the no moon, the moon gets in front of the Earth, and the sunlight lights up this part of the moon. And the face that we can see from the Earth, is engulfed in darkness. We see it from here. 

The whole game is basically about the tilt of the moon's orbit. It is the same logic as when you are watching a movie in the cinema hall, the projector is behind you, even then you can see the unobstructed view of the film on the screen because the projector is kept above the level of your head. But if you stand up or go closer to the projector, the view will be obstructed. Another mindblowing thing here, in this video, I've been talking about the moon going around the Earth. Even in schools, we've been taught the same thing. But in reality, the orbit of the moon isn't a perfect circle. It is an elliptical orbit. An orbit where at times the moon is closer to the Earth, and at times it is farther. The Earth isn't at the exact centre of the Moon's orbit. So friends, this can cause two types of solar eclipses, The Annular Solar Eclipse, Also known as the Ring of Fire eclipse, In this solar eclipse, the Moon's orbit is farther from the Earth. 

Because of this, we can see the outer boundary of the Sun. It seems like a ring of fire. And the other is the Total Solar Eclipse. When the Moon hides the Sun entirely. This can happen when the Moon is closer to the Earth. When the orbit of the moon is closer to the Earth, this total solar eclipse happens then. And the Sun is hidden behind the Moon completely. If you like these space-related topics, I'd recommend this audiobook for you on KUKU FM, Stephen Hawkin's The Theory of Everything. It is a book summary. Written by a world-famous physicist. There's a huge Diwali Sale on KUKU FM, Not only is there a 50% off on their annual subscription, but also gifts worth ₹1 Million, such as car, gold coin, vouchers, you can get the chance to win all these. This offer is valid till 25th October only. You need to use the coupon code DIWALI50, And you'll get 50% off on their subscription. The annual plan will cost you only ₹199. And you will automatically be enrolled in a lucky draw. The total worth of these gifts is up to ₹ 1 Million! So let's be prosperous this Diwali. And now let's get back to the topic. This was the science of the eclipses. 

Now, let's talk about the history and cultural impact of eclipses. For the longest time in history, the eclipses have fascinated humans. In some scribes found in China from the year 1200 BC, it was written, "The Sun has been eaten." Even before this, on 5,000 years old stone carvings found in Ireland, believed to be the first visual representation of an eclipse, Some people tried to draw an eclipse on stones. Today, we know the science behind the eclipses, but it was an Indian mathematician, 23-year-old Aryabhatta was the one to figure out in 499 AD, that the reason for the eclipses are the shadows of the moon and the earth. In a village in Bihar, he made an observatory in a Sun Temple to prove this. Before Aryabhatt, the common knowledge among people, was that during an eclipse the Sun was being swallowed by some demon. The story goes like this. The Gods and Demons came together to churn the sea, to get the elixir. When the pot of elixir emerged, Lord Vishnu took Mohini's avatar, and the elixir was being given only to the Gods. 

At this time, a demon named Swarbhanu, was sitting among the Gods, so could drink the elixir. As soon as Lord Vishnu discovered this, he decapitated Swarbhanu. The head was known as Rahu since then, and the Body was Ketu. And according to this mythology, Rahu and Ketu "eat" the Sun. This story is mentioned in the Rig Veda: Mandal 5, Hymn 40, Shlok 5-9. Similarly, this can be found in Buddhist religious texts as well where they claim that Rahu gobbled up the Sun. Not just these, similar stories can be found in almost all cultures, in all countries and in ancient civilisations. In China, it was believed that a celestial dragon eats the Sun and Moon. According to the mythology of a tribe of Native Americans, a black squirrel ate the Sun. In Vietnam, a frog ate the Sun. In the Andes region of South America, a lion or puma ate the Sun. 

In ancient Greek mythology, Zeus was the one blamed. In the Mayan legends of Mexico, demons that looked like snakes and insects were blamed. In the African countries of Togo and Benin, believed that because humans were enraged with each other and fighting each other, the Sun and Moon disappeared. The eclipses were major events, that would terrify people. In those eras, people were very scared of eclipses. Because they had no explanation for this. It was easy to find patterns in other phenomenons, The sun would rise and set every day. The phases of the moon were repeated every month, but the pattern of the eclipses was so random that they seemed to happen suddenly without any notice. Because of this fear, these superstitions and myths regarding these were formed. Look at this famous photo by Edward Curtis. This shows the native Kwakiutl Tribe of North America, dancing during an eclipse. People would light a fire, make loud noises, to scare away the demon who had engulfed the Sun. In some places people would shoot arrows, to kill the imaginary demon. 

Even today, there are places in South America and Asia where people bang on pots and plates, because they believe it would drive away the monster causing the Solar Eclipse. If we fast forward to the year 1500, such superstitions were very common during Guru Nanak's life. If we get back to the story from the beginning of the video, some people were threatening to kill Guru Nanak. When he had meat during the eclipse. So when the angry mob went to Guru Nanak, Guru Nanak told them that the eclipses were simply celestial phenomena. 

That happened because of the shadows of the earth and the moon. He said that the mob may kill him if they so wish, but since they consider it wrong to kill the animal, that it was wrong to kill and eat the deer during the eclipse, and the mob was about to kill a human. He asked them if it shouldn't be a worse crime? This calmed the mob a bit. This led to a debate between Guru Nanak and a conservative man. Friends, this is where Guru Nanak composed his famous poem, "Fools squabble over meat, Unaware of the reasons to do so." This poem can be found in the Guru Granth Sahib, page 1289. This poem is still very relevant today. 

I will put a link to it in the description below, so that you can go read it. Friends, surprisingly, thousands of years ago, Aryabhatt explained this, Guru Nanak explained this, after that, NASA took humans to the moon, even so, today in 2022, people make up and believe these superstitions. Look at the articles published by the media. "Solar eclipse is going to cause dangerous events, These 3 horoscopes are in danger" Wait, let me check out which horoscopes are these. Oops, that's Libra, even I'm a Libra.

Let's see their prediction about me. "Since the solar eclipse will be when Libra is in power, these people have to be very careful. There can be a danger. They may get hurt, stressed, they should stay alert about their work." Aren't these astrological predictions comedic? According to them, I 'might' get into an accident tomorrow. Interestingly, people who believe these predictions, would believe in these no matter what happens to them. Suppose a superstitious man read the prediction, he'd try to be careful. If nothing happens to him tomorrow, he would be thankful for having read the prediction that kept him safe. Thanks to the astrological prediction. But then if something wrong does happen to him tomorrow, he'd claim that it was foretold by the astrological prediction. Since he got into an accident, the prediction was correct. Irrespective of whether something happens or not, superstitious people will always think that the predictions are correct. 

I made a detailed video on Astrology 3 years ago with Karan Singh, this one, if you haven't watched it yet, it's an interesting video you can go watch it too, I'll put the link to that in the description below. Apart from these predictions, some people believe that one shouldn't go out during an eclipse. They claim that especially pregnant women shouldn't go out. Because apparently there are some harmful radiation from the Sun a special kind of harmful radiation. But try to apply some logic, the path of the planetary bodies and orbit that I showed you now, does it make sense that the sun will emit a special kind of harmful radiation? Simply because of the moon's shadow? The moon is always revolving around the Earth, but from our perspective, at one point in time, the shadow falls on us, does that mean special radiation is released? To be clear, this doesn't even affect the Sun. 

The Sun isn't a person who'll get offended that the moon came between them and the Earth, so they'll emit a new radiation. Friends, the same thing is applicable to other superstitions. One shouldn't eat during an eclipse. Some conman says that the food gets stale faster during the eclipse, and to demonstrate it, the conman runs a fake experiment. he brings a bowl of food, holds a rosary over it, and then will show how the rosary moves over the food. And then he'll make the rosary move the other way to claim that the food has gone stale. How can I debunk something this ridiculous? All I can say is this. "No 'part' of it is wrong, this is entirely wrong." Apart from this, some people believe in the superstition that new work shouldn't be started. Why? Does the Sun tell you that since Ramesh put in a new job application, the Sun will then interfere with it? This reminds me of a quote by Swami Vivekananda, "If a star disturbs my life, then it is worthless.

You will see that astrology and mystical stuff is a sign of a weak mind. So whenever you start falling for these, get checked out by a good doctor, and eat good food." Apart from these, people are advised not to look directly at the Sun, during a solar eclipse. Friends, this is advice is actually correct. And there's a scientific reason for this. You'd remember conducting an experiment in school, where you put a piece of paper under a lens, the sun's rays get converged due to the lens, and it starts burning the paper. The thing is, our eyes have a similar lens, friends. If we look at the sun directly, the ultraviolet rays fall on our eyes, they converge and damage the retina of our eyes. This is known as Solar Retinopathy. The same thing happens when you point your camera at the sun, without any filter. The lens of the camera focuses the rays on the sensor. This can destroy the sensors of the older cameras. So the logic that one shouldn't look at a solar eclipse with one's naked eyes, is always applicable. 

Never look at the Sun with your naked eyes. But this special advisory is issued only during the eclipse, because normally no one looks at the Sun when it's bright and shining. A solar eclipse is a major event, when everyone wants to see the sun. There are some safe ways to see the solar eclipse. First, you can use solar filters, known as eclipse glasses, they are made especially for solar eclipses. Use the ones that are compliant with International Safety Standards. You can see the eclipse through them. Second, you can see it through a telescope equipped with a solar filter. That's a good method. The third option suggested by the experts, is to use the welding glasses with a sufficiently high number, shade 12 or above, it is then okay to see the solar eclipse through those welding glasses. And finally, if you do not want to use any glasses, you can see the eclipse through pinhole projection. Go in the shade of a tree, the leaves of the trees create small pinholes, so when the shadow of those leaves falls on the ground, you can see the solar eclipse happening in the shadow. The eclipse tomorrow will be a partial solar eclipse. 

You won't see the sun disappear entirely, the moon will partially cover the sun like this. Overall, solar eclipses are rare events, enjoy them. I found these events very exciting ever since I was a child. To see the sun get covered during the day. And the superstitions that are still prevalent today, don't fall for these baseless, superstitions. If anyone in your family believes in these, share this video with them. So that they might use logic the next time. If you like this video, do watch the one on Astrology by clicking here. You will find out more mindblowing facts in that. Thank you very much!