The Earth itself is a huge magnet, and the geomagnetic field formed not only helps the compass to discern the direction, but also protects the Earth's atmosphere from the solar wind, which would otherwise have become Mars.
However, unlike ordinary magnets, the earth's magnetic poles will swap positions, and the reversal of the north and south magnetic poles has occurred many times in the history of the earth, and some scientists believe that human beings are now facing a new geomagnetic reversal, which will not only affect the navigation and migration ability of birds, but also cause large-scale power outages.
From a geophysical point of view, the Earth's magnetic field mainly comes from the liquid iron-nickel flow around the Earth's core, and it is their movement that constantly cuts the magnetic inductance lines and then produces a magnetic field, astronomers believe that Mars 4 billion years ago also had a similar magnetic field, but then the Martian core cooled too fast, and the Martian magnetic field ceased to exist, causing the Martian atmosphere to be constantly stripped by the solar wind, from a blue planet with an ocean and atmosphere to the red planet we see today.
Geologists have studied the volcanic rocks in history, and found that in the past 10 million years, the earth has had dozens of geomagnetic reversals, on average, four or five times every million years, and it can be said that it is a very frequent phenomenon in the history of the earth's 4.5 billion years, but this also shows that the flow of iron and nickel inside the earth is very active, and the earth's core will not cool down in a short period of time, so that the earth will become Mars。
Many people who don't know the truth often think that the geomagnetic reversal will cause the earth's magnetic field to lose its effect for a period of time and then affect all aspects of the earth, but in fact, the geomagnetic pole and the geomagnetic field are two things, and the reversal of the former will not affect the effect of the latter, and even the impact on bird migration we mentioned earlier may not happen, because the history of birds on the earth is much longer than that of humans, and they have been very experienced in several magnetic pole reversals in history.
On the contrary, the science and technology of human civilization in recent hundreds of years have never considered the consequences of the reversal of the magnetic poles, so some people believe that if the magnetic poles are suddenly reversed in the future, it is not nature but human beings themselves who will be really affected.
If we peel the earth apart like an onion, the innermost core is actually weightless, and the liquid iron-nickel flow near it is affected by gravity much less than the gravity on the ground, so for a long time in the future, the liquid iron-nickel in the core of the earth will not stop flowing, and the geomagnetic field will exist for a long time.
The only problem is that human civilization cannot live on the earth forever, and one day in the future we will go to space without the protection of the geomagnetic field to work and live for a long time, or even go to other planets in the solar system, such as the moon or Mars.
Overall
Whether it is the magnetic field of the earth, or the magnetic field of other planets in the solar system, they are things that human civilization must abandon in the future, and even without considering the simulation of the earth's gravity, the future human civilization will have to adapt to the low gravity environment on the moon and Mars, when the bones to muscles will change, and the children who grow up on Mars and the moon may no longer be able to adapt to the gravity environment of the earth.