Research results that 'even humans can feel the earth's magnetic field if they are hungry men'

Some birds, such as migratory birds, are known to have the ability to fly in the correct direction by perceiving the Earth's magnetic field (geomagnetism) . Regarding the ability to perceive such geomagnetism, the research result that 'human men detect geomagnetism by blue light' was announced in 2019.

Blue light-dependent human magnetoreception in geomagnetic food orientation
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0211826

The geomagnetism is quite weak on the surface of the earth, and it has at most one-hundredth the magnetic force of a magnet attached to a refrigerator. However, in previous studies, studies have been published in which migratory birds and sea turtles detect the geomagnetism to determine the direction and location.

Loggerhead turtles choose a beach with a 'magnetic field' similar to the one on which they were born as a spawning site --GIGAZINE

by Tony Hisgett

In 2018, it was reported that the ability to detect this geomagnetism is related to the protein ' cryptochrome ' that reacts sensitively to blue light in the eyeball in the case of migratory birds.

Birds are likely to judge the direction by looking at the earth's magnetic field with their 'eyes' --GIGAZINE

by Richard Hurd

This cryptochrome is also present in the human eye. However, in an experiment conducted by Kwon-Seok Chae and others at Kyungpook National University in South Korea in 2019, we found that 'only men' detected the geomagnetism visually.

In this experiment, subjects were asked to identify the north with their eyes closed while wearing earmuffs. The laboratory is maintained at a brightness of 3 x 10 ^-4 lux, which corresponds to a moonless night, and subjects are first taught the north direction and then use a swivel chair to change the direction. I was asked to point north after being obscured. In addition, based on the hypothesis that 'ancient human beings hunted by relying on the earth's magnetic field', the subject was placed in a starvation state, and under the two conditions of 'getting chocolate chips when the answer is correct' and 'not getting the correct answer'. The experiment was conducted.

As a result of the experiment, when 'you can get chocolate chips' and 'the subject is a man', the rate of the subject facing north was significantly higher. In addition, as a control experiment, experiments were also conducted in the 'state in which the direction of the magnetic field was changed' and 'the state in which the light was set to zero with an eye mask', but in this case, there was no bias in the direction in which the subject was facing. ..

From the above results, the research team states that even human beings 'may be able to perceive the north by relying on light if they are starving men.'

In 2021, a research team at the University of Tokyo announced that 'flavin molecules' existing in cells are reacting with magnetism. We are taking a step forward to elucidate the full picture of our ability to detect magnetism.

Direct observation of the magnetic sensitivity of biomolecules in living cells | The University of Tokyo
https://www.u-tokyo.ac.jp/focus/ja/articles/z0508_00093.html