字幕表 動画を再生する 英語字幕をプリント Let’s play some “what if”, shall we? Our planet rotates around its axis from west to east at a speed of over a thousand miles per hour at the equator! And this pattern has lasted for billions of years since the Earth was formed. But “what if” one day, our planet suddenly started to rotate backward, from east to west? So hey, let’s put a “different spin” on it, shall we? Ha ha… It would be one thing if the Earth's continents and oceans were situated symmetrically against the equator when the change of the direction happened. In this case, the only change people would notice would be the climate, which would turn into a mirror image of the current one. In other words, there’d be no dramatic changes. But since life on our planet is rarely about symmetry, the effects of the Earth rotating backward would be way more complicated. But keep in mind that everything will depend on how our planet would change the direction of its rotation. For example, let's imagine that it happened suddenly! Like, one day, the planet was calmly rotating from west to east, and then, in the blink of an eye, it's already moving backward, from east to west. Remember, in the very beginning, I told you about the speed of the Earth's rotation? So, in the case of an abrupt switch of the direction, an instant change in speed would make about 2,000 miles per hour! Well hold onto something! That means that everything not fixed to the ground would be hurled eastward. Buildings and other man-made structures would collapse, sending tons of debris into the air and creating chaos. The sudden change in direction would move all the water on the planet, which, in turn, would create vast tsunamis. They’d move across the planet, destroying everything in their path and literally changing the whole structure of the Earth. Oh, and don't forget about hurricane-force winds, which would essentially wipe out everything still standing after the massive waves. In short, the Earth would turn into a gloomy, muddy mess. But let's not dwell on this highly unlikely scenario and, instead, picture how different our planet would be if it rotated from east to west right from the beginning. in this case, you would see the Moon and the Sun rise in the west and set in the east. But that would be the smallest of all the differences. The thing is that the different spinning direction of the planet would create unexpected weather conditions on all the continents, and the Earth itself would be a totally different place! Some regions of the world would be colder than they are now. For example, western Europe would be plagued by severe, freezing winters every year. And, vice versa, Russia would warm up and lose the title of one of the coldest countries in the world. Some areas of the world would become much greener than they are as we know them. Other regions, on the contrary, would turn into deserts. For example, North America would be nothing more than a dry dust bowl. In South America, the Amazon rainforests would get replaced by arid sand dunes. But the area from the Middle East to Central Africa, on the other hand, would be covered with lush, dense forests. And the rest of the deserts would be either covered with grass or scattered trees. Do you think such dramatic changes have already happened sometime during the history of our planet? Write about your opinion in the comment section below! Anyway, the east-to-west rotation would also influence ocean currents. Few people know that nowadays, the climate on our planet is greatly influenced by AMOC - it's an ocean current that transports heat all over the world. On the forward-spinning Earth, this current is in the Atlantic Ocean. But should the planet start to rotate backward, AMOC would move to the Pacific. It’d be a bit stronger than the original current, and it’d bring more heat to eastern Russia. In general, there would be much more greenery on our planet, and, therefore, more oxygen for everyone to breathe. On the other hand, that might not turn out to be such a great thing. Now, the ocean is swarming with phytoplankton bacteria. But on that different Earth, instead of plankton, cyanobacteria would dominate. These billion-year-old bacteria were some of the first inhabitants of our planet. But the problem with them is that they pump out huge amounts of oxygen. Now if they replaced all other kinds of bacteria, they would completely transform the Earth's atmosphere. Thus, it would contain so much oxygen that people would simply be unable to breathe and, therefore, it would be hard for them to exist on the planet! That's why the chances are high that on a backward-spinning Earth, people would be replaced with a completely different species. But even if it did happen, we wouldn't know about that, would we? In any case, it's almost impossible to imagine the conditions that could make our planet begin spinning backward! So, I guess this is just one of those hypothetical questions like, "What if the Earth's core cooled down?" But wait, indeed, what would happen then? We’d have quite a cool core of course… Now s omewhere incredibly deep beneath the surface of our planet lies the Earth's core - a ball of scorching-hot iron which is surrounded by boiling liquid metal. The temperature of the Earth's core is more than twice as high as the temperature on the surface of the Sun! And so far, it seems to work well for all of us. But could the planet function if its core turned into a frozen rock? One of the things that makes life on the Earth possible is the geomagnetic field. It's like a powerful superhero that protects us from all the harmful stuff attacking our planet from space, including highly charged particles from the sun and cosmic radiation. What's more, thanks to this geomagnetic shield, solar winds can't strip away the Earth's atmosphere. You may ask, "What does the geomagnetic field have to do with the red-hot core of the planet?" The thing is that this very field is created by the Earth's core! You don't notice it, but when the planet spins, the speed of its solid inner core, and the speed of its liquid outer core are different. As a result, the speed difference creates electric currents, which, in turn, generate the geomagnetic field. Now, let's imagine that both parts of the Earth's core cooled down for some inexplicable reason. In this case, the worst would happen - our planet would simply lose its magnetic field! Uh-oh, but if there’s no magnetic field, there's also no atmosphere! That's why some time later, the Earth would start to resemble Mars a little bit too much for my liking. First, you wouldn't be able to breathe without an oxygen mask and a pressure suit. Rocks, gas, water, and everything else wouldn’t be heated by the boiling core anymore. The Earth would grow colder and colder. There would be no earthquakes; volcanoes would stop spewing lava, and the continents wouldn't be drifting apart bit by bit as they do now. Unfortunately, people wouldn't be around to feel happy about the geological stability. The eternal cold and lack of oxygen would either finish us, or prevent us from living normal lives. And then, there would be the massive problem of protecting the planet from space radiation, remember? It's not very clear what exactly would happen to the planet if it lost the electromagnetic field, but it wouldn’t be anything good. The Earth would probably see a radioactive wave onslaught, which would overheat it to a degree (to a degree) at which it would become uninhabitable. Or it would suffer from solar wind attacks, which would sweep away the oceans, seas, lakes, and rivers. But whichever guess is correct, the Earth would turn into a lifeless, cold rock in any case. Whew! Kinda shakes you right down to the core, huh? Well, the only thing I can say at this point is, Let’s take care of this earth, the only home we have in the universe, and “let’s keep spinning, let’s keep spinning”…. Hey, if you learned something new today, then give the video a like and share it with a friend! And here are some other videos I think you'll enjoy. Just click to the left or right, and stay on the Bright Side of life!