Birds, whales, butterflies and many other animals instinctively know which way north is. Even dogs are prone to shitting given the planet's magnetic poles. If animals sense magnetic fields, are we capable of this? Is it possible with this ability, say, to find your car in a parking lot?
It turns out that this is not an easy question to answer.
Magnetoreception
Scientists who wanted to explore the ability to sense magnetic fields - magnetoreception, as it is also called - was initially only laughed at. Moreover, they even scoffed at studies involving animals, for example, carrier pigeons, although now it is considered obvious that pigeons find their way home, focusing on the Earth's magnetic field. Modern scientists have discovered that virtually every migratory animal, be it a bird or fish, has a built-in compass. Magnetoreception, surprisingly to many, is possessed by animals such as lobsters, worms, frogs and snails.
But what about people? In the 1980s, British biologist Robin Baker conducted a series of experiments that seemed to show that humans have an innate sense of orientation. In one experiment, he blindfolded the participants, put them on a bus and drove them along a winding road away from home. When the blindfold was removed, the participants had to orient themselves and determine in which direction their house was. The catch was that a piece of magnet was put in the bandage for some participants, and a piece of copper for others. Those with a piece of brass in their armband could almost always point in the direction of the house; and those participants who had a magnet in the bandage could not.
But when other scientists tried to replicate Baker's experiments, they didn't get the same results. And after Baker published an article in 1983 where he argued that the human sinuses react to a magnetic field, the American geophysicist Joe Kirshvink disagreed with him.
But later Kirschvink himself began to conduct experiments to identify a person's ability to perceive a magnetic field. To address the shortcomings of previous research, he did something differently. He measured the brain waves of the subjects using EEG (electroencephalography) instead of observing their behavior, which can be interpreted in different ways; and he placed the subjects inside a Faraday cage, a metal cage that protects against electromagnetic interference and thus helps to ensure that the results were not affected by radio waves or other interference. He used a magnetic field designed to simulate the earth's magnetic field. What did he manage to find out? When the magnetic field rotated counterclockwise, there was a decrease in alpha waves - this indicated thatthat neurons in the brain were activated in response to a magnetic field. Kirshvink came to the conclusion that humans do possess magnetoreception.
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Two theories
Scientists are now putting forward two leading theories. Magnetite, a magnetic iron ore that Baker claimed to be in a person's sinuses, is still in play. It is extremely sensitive to magnetic fields and can be strong enough to indicate to animals not only where north is, but also the coordinates of their location. It is found in the beaks of birds and in the nose of fish, and has even been found in the human brain. Others, however, believe that magnetite may only be part of the immune system, with no role in navigation.
Another theory has to do with a protein with the intriguing name of cryptochrome. Wavelengths of light convert it into a molecule known as a "radical pair", with two unpaired electrons spinning in the same direction or in opposite directions. Under the influence of a magnetic field, electrons change their direction of motion, and the chemical behavior of the molecule also changes. Scientists have gathered some compelling evidence of this process in bird watching.
Summing up, we have to admit that scientists have not fully figured out whether people are susceptible to the Earth's magnetic field, or whether these are just relics of our evolutionary past. We also don't know what might trigger this process. But one thing's for sure: finding a car in a parking lot will never be easy.