The brain cells of birds sense Earth's magnetic field (varying between approximately 25-65 microtesla) and can journey thousands of kilometers without a map. We cannot see this perception with the naked eye, yet we observe migratory birds leaving the sky almost simultaneously in flocks, their regular returns each season. As if beneath the earth's surface there exists an invisible wire drawing all living things, and birds read it very well.
Invisible compass, thousands of kilometers away
The brain cells of birds sense Earth's magnetic field (varying between approximately 25-65 microtesla) and can journey thousands of kilometers without a map. We cannot see this perception with the…
Phenomenon
Infrared
Technical data
How is this invisible signal measured?
The values below reflect the typical range of this phenomenon.
Spectrum
Infrared
Intensity
Extreme
Density
Saturated
Frequency
50 Hz
Signal signature
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