ILLUSTRATES Tila Barrionuevo
EDITION Felipe van Deursen
– (Tila Barrionuevo/)
It is a gigantic magnetic distortion created by the Earth’s core, which works like a magnet. The core is divided into two parts, the inner part, formed by iron, nickel and other metals in solid state, and the outer part, in which these elements are in liquid form.
Because of Earth’s rotation, liquid metals are in constant motion, which produces electrical currents. This is called the Dynamo Theory, which says that the electrical charges in the outer core originate the magnetic field, which influences the entire planet. Its main function is to maintain the atmosphere and, consequently, life on Earth.
The magnetic field protects the air layers by minimizing attacks from solar winds. Without such a defense, particles released by the Sun would strip the planet’s atmosphere.
Such a big magnet, man!
Magnetic field influences from earthworms to northern lights
– (Tila Barrionuevo/)
1.STOP THE MACHINES
When massive solar flares come into contact with Earth’s magnetic field, a magnetic storm occurs. These particles ejected by the Sun create electrical currents, which interfere with the Earth’s field. Thus, disturbances affect aviation equipment, satellites, communication and navigation systems.
2.RUN AND LOOK AT THE SKY
The aurora borealis and australis are the result of attempts by charged particles, ejected by the Sun, to penetrate the atmosphere. When these ions reach the Earth’s magnetic field, they are deflected, mainly towards the poles. There, they interact with oxygen and nitrogen atoms, which release photons (particles of light), thus creating the auroras.
3. ANIMALS
A study at the University of Texas (USA) identified a molecule in the earthworm’s brain that acts as a sensor that orients the animal in relation to the magnetic field. Another study says that magnetism works not only as a compass but also as a viewfinder for migratory birds: it reinforces brightness and colors in the birds’ field of vision, guiding them
UPSIDE DOWN
The magnetic poles are not always in the same place.
Science still doesn’t know why, but the magnetic poles are not fixed. Today, the north magnetic pole, where the field lines come from, is close to the South Pole. The south magnetic pole, where the lines go, is close to the North Pole. Therefore, compasses point north. The last time the poles were reversed was around 780,000 years ago.
CONSULTANCY Jorge Deveikis Junior, physicist and Master’s student in physics teaching at USP
SOURCES Unesp Faculty of Sciences (São Paulo), Geological Survey of Brazil, Physics.org, Cosmo Magazine, MIT, Inpe and Nasa; study A New Type of Radical-Pair-Based Model for Magnetoreceptionseveral authors