The origin of cosmic magnetic fields remains one of the deepest mysteries of cosmology. A research team made up of representatives from several different institutions is trying to explain this.
Naturally occurring magnetic fields are found throughout the universe. They were first spotted on Earth thousands of years ago and used for navigation before they were even understood. On the other hand, magnetism was discovered in the sun at the beginning of the twentieth century. With the advancement of technology and the advent of advanced telescopes, scientists have realized that these fields are ubiquitous.
Research on the genesis of the magnetic field in the universe was conducted by representatives of the Massachusetts Institute of Technology, Princeton University and the University of Colorado at Boulder. Thanks to their efforts, it was possible to describe the basic processes that generate the field from being fully magnetized to the point where it is strong enough for the dynamic mechanism to control and amplify the field to the size we observe.
Through the process of induction, large generators known as dynamos convert mechanical energy into electromagnetic energy. This is what we use to power electronic devices for example. The main feature of a dynamo is that it needs a magnetic field to function. Research into the propagation of seismic waves indicates that part of the Earth’s core consists of molten nickel and iron. Therefore, the researchers speculated that the convective motion of this fluid and the Earth’s rotation somehow combine to produce the Earth’s field.
Similarly, it happens in other parts of the universe. In stars, galaxies, and the voids between them, the liquid conducting electricity is not molten metal, but plasma. In such a medium, the dynamo effect can amplify the current magnetic field, as long as it starts at a certain lower level. This was the unknown, which is why the authors of the new research were shown in the pages PNASI have addressed this issue.
The authors explain how a seed field can be created and what basic processes take place in it. It is noteworthy that plasma in interstellar space is much less concentrated than inside stars. The lower density means that the particles in this plasma never collide, which greatly affects their behaviour. Ultimately, the scientists concluded that the first magnetic fields could be produced spontaneously by general, large-scale motions. Besides, just like on Earth, mechanical energy is converted into magnetic energy.
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It turns out that one of the main observations is that the field amplitude can increase from zero to the level where the plasma is “magnetized”. In other words, the presence of the field strongly influences the plasma dynamics. At this point, the traditional dynamo mechanism can enter the game and raise the fields to the observed levels.
