The mystery of avian navigation has confounded biologists for generations. It’s well accepted that birds can “sense” the Earth’s magnetic fields and that they use this “sense” to navigate their way across the surface of the earth.
But no one has been able to locate the center of the “sense” or figure out a mechanism by which the birds made use of it.
That is until just recently. There’s a group of scientists that theorize that the birds are actually making use of quantum entanglement at the macroscopic level.
“The system Vedral and co have studied is a model that describes how birds navigate using the Earth’s magnetic field. The most recent thinking is that birds have molecules at the back of their eyes that are sensitive to both photons and the orientation of the Earth’s magnetic field. When one of these molecules absorbs a photon, an electron pair is split and one of these electrons is transferred to another part of the molecule to another. These electrons then form a ‘radical pair’ that are entangled.
In the absence of a magnetic field, this pair would recombine to form the original molecular state. But the Earth’s magnetic field can flip the spin of one of these electrons allowing them to recombine in a different way and leaving the molecule in an alternative chemical state that the bird can sense. The result is that bird ‘sees’ the Earth’s magnetic field as it flies.
This raises an interesting question: how long does this entangled state last?
Vedral and co have done the numbers and say it lasts for at least 100 microseconds. That’s an extraordinary figure. The best humans have measured is 80 microseconds for so-called electron spin relaxation in C60 buckyballs.”
Read the full article here.
Besides being way cool if true, this system would represent a macroscopic manifestation of entanglement. For those who are trying to find the effective limits of this uniquely quantum mechanical phenomenon, this is might likely call for some re-tuning of the models.
Yay for bird-brains!