 Hello and welcome here to a little video on the subject of the geomagnetic field. Basically, we already know the Earth's magnetic field from the fact that when we have a compass in our hand, this compass roughly points towards the North Pole at every point on the Earth with the compass needle's own North Pole. And the question of course is, why is that? Why does the compass always point towards the geographic North Pole? The whole thing is due to the Earth's magnetic field. This is a magnetic force field that surrounds the Earth. And why the Earth has this field we'll look at afterwards. At the moment we can imagine that there is a huge magnet inside the Earth. The question is, where does this magnet have its North and where does it have its South Pole? As a reminder, the compass needle points towards a North Pole, upwards towards the geographic North Pole. So can this really be the magnetic North Pole that we imagine in here? Not really, because the North Pole and the North Pole two poles that are the same repel each other. So logically there must be a magnetic South Pole there, and that is actually the case. We stick to our idea that there is a magnet inside. It would actually be at South Pole at the top, where we would actually assume the North Pole. In fact, mankind has long thought that there was a big magnet hidden in the Earth. We'll look at what's really there at the end. And so that you can see that I'm not cheating, there are actually two magnets hidden. And you can see that the North Poles are each down. The geographic North Pole, what has been defined, is where the Earth rotates around the two axes. That is a magnetic South Pole. The whole thing is slightly shifted, so not exactly in the same place. We will discuss that at the end. And the geographic South Pole, so like the Antarctica, is actually what would be called the North Pole from a magnetic point of view. As promised, we are now getting a bit away from the idea of a large magnet stuck in the Earth, but rather thinking about where this magnetic field could come from. And that's simply because the Earth is fluid inside. It has different fluid levels and layers. And these liquids also contain metallic substances that move here and that generate this magnetic field, similar to a coil. There, two electrons move, which create a magnetic field. It has also something to do with the rotation of the Earth and the currents that result from it. What can of course happen is that at some point the currents no longer flow so nicely. That a closed magnetic field results. That has happened several times in the history of the Earth. Then the magnetic field has actually collapsed. The Earth was then exposed to cosmic rays without protection. And then, of course, it can also happen that the magnetic field reverses its polarity. We have had this before too, but it only happens every 100,000 years. Then the compass needle suddenly points with the North Pole down. It's also possible and that has also happened several times. At the moment it's still the case that our magnetic North Pole is down and our magnetic South Pole is up. Thank you for watching this video. I hope you enjoyed it.