An old letter from Albert Einstein has been discovered in which the famous physicist pondered the possibility of animals with “super senses” and their ability to perceive the physical world in ways humans cannot. The letter was written in response to an inquiry from engineer Glyn Davys about animal perception and its potential implications for scientific understanding. Although the original inquiry has been lost, it seems to have prompted Einstein to consider the possibility that migratory birds and carrier pigeons might lead to a better understanding of an as yet undiscovered physical process.
More than 70 years after writing the letter, we now know that Einstein was right about at least one thing: the ability of birds to sense Earth’s magnetic field using special photoreceptors in their eyes. Evidence has also emerged to suggest that other animals such as marine turtles, dogs, and bees can also detect magnetic fields, although not necessarily via the eyes.
While Davys seems to have been interested in how this knowledge could inform future technology, Einstein stressed the need for more biological research to truly reveal the ways in which different species perceive the world. He noted the recent discovery by Karl von Frisch that bees navigate using the polarization patterns of light and suggested that “a new kind of sensory perception, resp. of their stimuli, would be revealed through the behavior of the bees”.
Decades later, we have indeed learned a great deal about the behavior of bees and other animals, with this knowledge already informing technology such as the cameras on our mobile phones. However, much remains unknown about exactly how these creatures perceive light and magnetic fields, and it is thought that the mechanisms may differ between species.
Even Einstein’s rejection of the concept of entangled electrons, which would be necessary for a photoreceptor to sense a magnetic field, has since been challenged by recent research revealing that human cells can dynamically respond to changes in the magnetic field. Overall, the discovery of Einstein’s letter serves as a reminder of the cross-disciplinary nature of scientific inquiry and how insights from one field can be valuable for researchers in others.