A California geophysicist claims that humans, like some fish and birds, have a built-in "biocompass" that allows us to sense magnetic fields, including the Earth's field, according to the Science journal news service.
"The Faraday cage was the key to this discovery - just a few years ago, when we installed it in our laboratory and protected the participants of the experiments from interference in the form of radio waves and electromagnetic noise from computers, elevators and other devices, we began to get something worthwhile." - says Joe Kirschvink of the California Institute of Technology in Pasadena (USA).
Magnets, how do they work?
Kirshvink and his colleagues, biologists and geophysicists, have been trying for several decades to unravel the mystery of how almost all birds and many fish and even sea turtles are able to “see” the lines of force of the Earth's magnetic field, memorize their pattern and use it to search for spawning grounds, wintering zones and beaches.
The work of this mechanism is not fully understood, there are many different hypotheses about the principle of the "biocompass" - for example, scientists have discovered "magnetic" receptors in the beaks of pigeons, among the neurons of the retina of birds of robins and fruit flies. It is believed that humans are not sensitive to magnetic fields, but this opinion is often disputed.
One of the hypotheses states that the sensitivity to the magnetic field depends on proteins from the cryptochrome family (CRY), which are present in the human body, which gave reason to believe that we have a sixth, "magnetic" sense, which almost stopped working for some then for evolutionary reasons.
The Californian geophysicist decided to seriously search for an answer to this question by creating a special "magnetic" laboratory in which the direction and strength of the field can be flexibly changed by increasing or increasing the voltage on the induction coils that surround the room in which the volunteer sits. This entire system was shielded from the outside world with the aforementioned Faraday cage - essentially a wire mesh box connected to a grounding system.
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Grounded magnetism
When a participant in the experiments was sitting inside this "cage", Kirshvink and his colleagues monitored how the pattern of his brain activity changed using an electroencephalograph made of brass and other non-magnetic materials. In total, 19 people passed through this system, including Kirschvink himself, as well as scientists from Japan, checking the results of his work.
For the purity of the experiment, the work of the computer that controls the voltage on the coils of the "cell" was tuned in such a way that neither the participants in the experiment, nor the scientists themselves knew whether it changes the magnetic field inside the "cell" or simply suppresses external sources of electromagnetic fields.
An analysis of the results of this experiment, according to the Californian geophysicist, showed that a person really has a sixth magnetic sense and can sense the direction of magnetic fields, although he does it worse than animals. According to him, all participants in the experiments reacted in the same way to changes in the strength and direction of the field, which was reflected in their electroencephalogram.
For example, the rotation of the magnetic field led to a decrease in the strength of the alpha rhythms in the brain with a delay of several hundred milliseconds, which suggests that our nervous system was processing information about changes in the strength and direction of the field. Interestingly, this effect was not always manifested - the brains of the volunteers reacted to the magnetic field only when rotating counterclockwise and up and down.
As Science says, other scientists took such conclusions with caution - they have no doubt that Kirschvink really conducted all these experiments and did not alter their results, but they are not sure of his interpretation of the data obtained. On the other hand, the geophysicist himself claims that his Japanese colleagues get similar results in their experiment with a similar setting, and is ready to say that humans really have a sixth sense.
