Why the 2024 Solar Eclipse is Such a Big Deal

- Hello, smart people, this is Joe. The sun is huge, 10 times the size of anything else in the

solar

system. Uh oh. (upbeat music) And 100 times the size of the earth. But Earth is part of a lucky cosmic coincidence. Our moon is 400 times smaller than the sun, but it is almost exactly 400 times closer to us. This means that to us here on Earth, they appear almost exactly the same size in the sky. Due to this coincidence, from time to time, our small moon, although 400 times smaller than the sun, crosses in front of it and blocks its light from reaching Earth.

A

solar

eclipse

. On April 8, that will happen right here. The shadow of the moon will pass right over where I am standing. You don't want to miss this. The United States won't see another total solar

eclipse

for another 20 years. This is a once-in-a-generation opportunity to see one of the most mind-blowing events in the solar system. Today I will tell you everything you need to know to make the most of this eclipse or any eclipse you have the opportunity to see in the future. We are talking about how to choose the right place to be in the maximum shadow of the moon.

I'll give you some ideas on what to bring, tell you everything there is to see before, during and after an eclipse, and all the amazing things you can learn from an eclipse, whether you're a scientist or just a scientist. someone who wants to sit back and feel the awe of witnessing an incredible cosmic event. (upbeat music) First things first. If you need convincing that it's worth seeing, well, first consider how special an eclipse is. Eclipses occur because the moon's orbit comes between us and the sun, but the moon orbits between the earth and the sun once a month, whenever there is a new moon.

So why don't we have an eclipse every month? This is because the Moon's orbit is tilted a few degrees relative to the Earth's orbital plane. Eclipses only occur when the Moon's inclined orbit aligns perfectly with the Earth's orbital plane between us and the Sun, allowing the Moon to cast its shadow on our planet. Between two and five solar eclipses occur somewhere on Earth each year, but on average, any given location on Earth only receives one total eclipse every few hundred years. Simply put, if you have the chance to see an eclipse, you won't want to miss it.

The first thing you should do is choose the right place. You will want to be on the path of totality. Totality is the moment during an eclipse when the moon's shadow completely covers the sun, and there is only a small strip of land where you can see that. That's the path of totality on April 8 across this swath of North America. Now, outside the strip, the moon will partially cover the sun, but you won't see all of it. And the closer it is to the center line, the longer the totality will last. There are tons of maps and apps to help you choose a location.

I've included links to several in the description so you can find a good place to view them. The time, however, depends entirely on you, I can't do anything about it. I'm just a scientist on YouTube, folks. Still, you'll want to figure out exactly what times totality will occur where you live so you don't have to do it on eclipse day when you're freaking out about all the wonder. And to make the most of the eclipse, consider an app like this solar eclipse timer, which accurately times every key moment you should watch instead. They're not sponsoring this video or anything, but it's a cool app that really works.

I'll leave you a link in the description, but I want to pause for a second and just acknowledge that the fact that we can calculate this is absolutely crazy. Eclipses are incredibly difficult to predict. Ancient people like the Babylonians, Chinese, and Mayans had advanced mathematics and astronomy good enough to construct some of the most accurate calendars in human history. But none of them can predict exactly when and where solar eclipses would occur. And that's not surprising because it is one of the most complicated problems in orbital physics. Predicting the exact positions of the Earth, Sun and Moon in the future requires taking into account every little tug of every object with gravity in the solar system.

We're not just solving three bodies in space, it's a million-plus body problem. Together, these tilted and oscillating orbits are the literal definition of mathematical chaos. It wasn't until 1715 that anyone came even remotely close to predicting the time and location of a solar eclipse. When astronomer Edmund Haley used giant tables filled with the future positions of celestial bodies to manually calculate the timing of an eclipse over London. He only had four minutes left. He must have forgotten to bring all three. Today, NASA takes into account about 38,000 different overlapping orbital patterns, processing the data with supercomputers, allowing us to plan our eclipse viewing down to the second.

But even with all that fancy computer wizardry, NASA can only accurately predict eclipses in the next thousand years. It is a problem that is impossible to solve mathematically. We just hope to get closer. So remember that while you're planning your eclipse day down to the minute or second, the fact that we can do it at all is amazing at all. Does he seem relaxed, natural? It's good, awesome. Well, the next step, once you've figured out where you'll be and what time totality is, think about how you want to see it. This is where I have to remind you.

Never, ever, look directly at the sun. I just want to say that one more time. Never, ever, look directly at the sun. Not if you're wearing sunglasses, not if it's 99% covered. Definitely not through a telescope or binoculars. Just don't do it. The first thing I would recommend is getting some cool eclipse glasses. I bought them from a large online retailer named after a river in South America, but you can pick them up at different places in person or online. Just do your homework and make sure you get the real thing. However, if you don't have eclipse glasses, there are still some really cool ways to view the eclipse.

This one is really simple and easy to do. It is a pinhole camera projector. All you have to do is make a very small, smooth hole in a piece of paper and hold it over a bright surface in the sun. Or you can be a little more sophisticated and make yourself a small pinhole camera. Simply take a box like this, trace the bottom on a white sheet of paper, cut it out, and place it inside the bottom of the box. At the other end, cut two notches in the lid and cover one of them with aluminum foil.

Make a small hole there, then stand with your back to the sun, looking through the other hole, and you'll see the entire eclipse projected onto the bottom of that pinhole camera. So why does this work? Well, sunlight always shoots in all directions, but because this hole is so small, only a few rays of light make it through, traveling in a straight line. That means that the rays from the left side of the sun passed through the hole and hit the ground on the right side and vice versa. And what you end up getting is a little image of the sun in flip flops in front of you.

During the eclipse, when the moon moves over the sun, you will see this circle turn into a crescent and get smaller and smaller. So this is a safe way to view the eclipse without looking at the sun. You can see the same effect using anything with small holes like a sieve, or even light filtering through tree leaves. You can even overlap your fingers this way, leaving small holes between them. Watching an eclipse is amazing even if you don't understand everything that happens during it. But if you know a little about what's happening and what to expect, there's a lot to see, and most of it goes by very quickly.

So the last thing you want to plan ahead is what you're going to keep in mind. On eclipse day, with your glasses on, the first thing you'll see is a small bite on the western side of the sun. Again, the solar eclipse timer app can tell you exactly what time this will happen wherever you are standing. As the minutes pass, the color of the sky and things around you will become a little duller. The wind may even calm down as the atmosphere cools within the growing shadow. About 10 minutes before totality, the sun will look like a thin crescent and everything will go dark.

But don't take off your eclipse glasses just yet. You may notice some animals acting strangely. Horses are known to start shaking their heads and tails. Dogs can get anxious. Birds might stop flying or burst into their evening songs. Humans start making strange ooh and ah sounds. And in these final seconds before totality, some really interesting things happen. Just before the last ray of sunlight disappears, the valleys and ridges of the moon's surface cut into the crescent, leaving tiny drops of light flickering along the edge of the sun just before the moon obliterates them. In 1836, the British astronomer Francis Baily first recorded this phenomenon and today these light beads are named after him.

Just before the last of these beads disappears, you will begin to see the sun's atmosphere, the corona. With the sunlight blocked, shreds of the corona emerge as this faint ring around the moon. Then, the last drop of light passing through the moon illuminates part of the crown, creating what is called the diamond ring. There is one last thing until the crown becomes visible: take a look at some light surface like a sidewalk or a white sheet. If you're lucky, you might see little bands of light and dark scribbling across the surface. These are shadow bands. They are super weak.

They look like the shadow of water rippling on the sand. They don't always happen and the strangest thing is that no one knows for sure why they happen. The best guess is that turbulence in the air interferes with the last narrow strip of remaining sunlight, sort of like what makes stars shine. And then, just like that, the sun sets. Welcome to the whole. Imagine this, the shadow of the moon falls on you and where the sun was, there is only a black disk surrounded by a bright corona. Everything is as bright as during the full moon.

It's midday, but some bright stars and planets are now visible in the sky. During totality, you can take off your eclipse glasses and look directly at the overcast sun, and there are some interesting things you can only see during these few minutes of totality. Keep an eye out for reddish cloud shapes surrounding the moon's disk. They are called prominences, hot clouds of gas that rise from the sun along tangled magnetic field lines. In fact, you can see some of them in the first photograph anyone took of an eclipse in 1851. The best thing about these prominences is that they only last about a day.

So anything you see during totality is completely unique at that moment. If you can look away from the eclipse for a few seconds, look around you. If you can see the horizon, you'll see what looks like a 360-degree sunrise. This is the edge of the moon's shadow, visible in the distant sky, places where the sun is not totally eclipsed. A sunrise in all directions. The sky will begin to lighten in the west and darken in the east. As the moon's shadow moves east across the Earth, the sun will soon return. Now, depending on how close you are to the center of the path of totality, you will experience anywhere from a few seconds to a few minutes of totality.

No matter where you are, it's a good idea to know exactly what time totality ends, or to have a solar eclipse timer running so you can put on your eclipse glasses before the sun returns. Suddenly you'll see a flash of light peeking through some valley on the moon's surface at the western edge of the sun. Baily's first account on this side. It could be used for another diamond ring. Over the next few seconds, more Baily beads will come and go. You'll have a second chance to look for those shadow bands if you missed them the first time.

Then everything happens the other way around. The Baily beads fuse together forming a crescent. The crescent moon grows and the sky and surroundings light up again. Before you know it, the eclipse is completely over. It's a normal day again, the sky is bright. A breeze may pick up again. The animals go back to normal, except you, you may never be normal again after seeing that. A total solar eclipse is a different experience for everyone. For some of us, it's a chance to witness an incredible cosmic event and simply immerse ourselves in awe. But for others, it is an opportunity to do science.

For centuries, people have studied the sun as it disappears behind the moon, and we have learned incredible things from it. In 1860, eclipse sketches from around the world captured a sort of tendril rising from the sun. It was probably a coronal mass ejection, a burst of plasma that can cause solar storms here on Earth. And this may have been the first time one was recorded. InIn 1868, French physicist Jules Janssen used a spectroscope to observe the solar corona during a solar eclipse and discovered the element helium 30 years before it was found on Earth. And in 1919, an eclipse helped physicists perform an important test of Einstein's general theory of relativity.

According to Einstein's theory, everything that has mass has a curve in space-time, so massive objects should act a bit like a lens, bending the path of any light that passes through them. And the sun has a lot of mass, so it should bend the path of starlight passing by it. Then, during the 1919 eclipse, scientists looked at stars very close to the darkened Sun and compared them to the normal positions of stars in the sky, and the Sun's gravity deflected the light just as Einstein predicted. You know, we often think of science as this journey from darkness to light, from ignorance to knowledge.

But during a total eclipse, it is the darkness that can illuminate. But we won't always have total eclipses on Earth. The moon is slowly moving away from Earth, so within hundreds of millions of years it will be too small in the sky to completely cover the sun. After that, there will never be another total eclipse. That's why it's incredible that we live on this planet at a time when we can see eclipses. And watching a total eclipse is the best way I can think of to think about how lucky we are to be here, right now, at this exact moment.

Something to think about. If you can, I hope you take advantage this year, next year or whenever you have the opportunity wherever you are. Stay curious. Hello everyone, thank you very much for staying until the end of the video and accompanying me where I will see this year's eclipse. I would invite you all, but I don't have enough snacks. A special thanks to everyone who supports the show on Patreon. We literally cannot do this without your help. If you'd like to learn more about how to help us make videos like this and all the wonderful things we do on this channel, there's a link in the description.

We've recently shuffled our perks on Patreon, the different tiers. We're going to play with some new things, some really cool things, like occasional live streams with a server, special posts, and a special look behind the scenes. Just click on the description and learn more. See you in the next video. Discuss that sun there, cowboy. Come on. I understand? Yes that's how it is.