Are birds using quantum entanglement to navigate?

Sounds wild, but it may well be so.

  • Birds' navigation using Earth's very faint magnetic fields suggests an incredible level of sensitivity.
  • There's reason to think that sensitivity may be based on quantum entanglement in cryptochrome in their eyes.
  • Identifying the role of quantum physics in biology could lead, well, who knows where?

Okay, this is far from confirmed, but it's pretty radical, and exciting. It's a possible and plausible answer to a question that's puzzled biologists ever since the manner in which birds navigate became apparent. The question is: How can birds possibly be able to perceive and follow something as faint as the Earth's magnetic field? The possible answer? It may be that they perceive it through the interaction of entangled quantum particles in their eyes.

Behind this hypothesis is years of confirming and seeking to explain birds' phenomenal sensitivity to Earth's magnetic field. The most plausible explanation for it has to do with the effect of the magnetic field on entangled molecules of a chemical in birds' eyes, Cry4, or cryptochrome. Other animals, and plants, share the chemical, though it's believed that birds have developed their own variant. Quantum entanglement, Einstein's "spooky action at a distance," is a topic that comes up often at Big Think because it's a theoretical vehicle upon which some of the strangest and most interesting new ideas ride. Here's what we mean:

And now this.

The theory

(Michal Ninger/Shutterstock)

When a photon, a light particle, hits a cryptochrome molecule in a bird's eye, it knocks loose an electron that may then become associated with a second molecule. The two molecules then both have an odd number of electrons, and they become a radical pair. Since the oddness of both of these radicals was created simultaneously by that loosened electron, the spins of one electron in each molecule of cryptochrome become locked together in relation to each other and the radical pair becomes entangled.

This entangled state is extremely fragile, and temporary, so it won't survive beyond just 100 microseconds (1/10,000th of a second). But during that brief interim, the radical pair will be in either one of two states. The suspicion is that the Earth's magnetic field affects the amount of time the molecules spend in either state, and changes to the duration of these states somehow tells the bird where he or she is. The exact means by which the bird perceives them is unknown, though it's been suggested that it may have to do with one or both states causing the presence of absence of some as-yet-unidentifed chemical.

Why this isn’t just craziness

(NASA)

Supercomputer model of Earth's magnetic field.

This might not seem to make sense because magnetic fields are so weak, but it's real. How weak? "The energy of interaction of a molecule with a ≈50-μT magnetic field is >6 orders of magnitude smaller than the average thermal energy kBT, which in turn is 10–100 times smaller than the strength of a chemical bond," according to a 2009 study, Chemical magnetoreception in birds: The radical pair mechanism. However, "It has been known since the 1970s that certain chemical reactions do in fact respond to applied magnetic fields." (Our emphasis.) The study also notes that radicals always seem to be involved.

The radical pair theory is really the best explanation for birds' navigation systems we have, since experiments attempting to detect effects of magnetic fields directly on biological processes — bypassing chemistry — have come up empty-handed.

The study proposes that perhaps photons are throwing electrons far enough from their normal thermal equilibrium that they remain entangled long enough to respond to the subtle cues coming from the planet's magnetic field. Quantum entangled particles created by scientists last for mere nanoseconds. One such scientist, Erik Gauger, tells Nova, "It seems nature has found a way to make these quantum states live much longer than we'd expect, and much longer than we can do in the lab. No one thought that was possible."

Proof of birds' sensitivity

(Morphart Creation/Shutterstock)

Map of Earth's magnetic field, 1895.

A number of experiments to confirm what's going on are cited in the paper, some of which the authors find more convincing than others. However, the most compelling evidence of birds' amazing sensitivity comes from experiments with caged European robins, whose navigation abilities were easily disrupted. "Linearly polarized radio frequency fields 100 times weaker than the Earth's field (≈500 nT), with frequencies of 7.0 MHz or 1.315 MHz, are sufficient to disrupt the migratory orientation of caged European robins." (Again our emphasis.) Playing with the magnetic field also easily baffled the birds, with researchers finding a "20–30% increase or decrease in the intensity of the ambient magnetic field is sufficient to disorient caged birds."

Entangled echoes

Clearly, avians possess an almost unbelievably delicate sensing mechanism of some sort. The intersection of quantum mechanics and biology — even human biology — is a fascinating notion. As mentioned above, some wonder if it may also relate to consciousness and other currently bewildering phenomena. If we can come to fully understand the mechanics or chemistry of birds' impressive capabilities, what other mysteries might we be able to unlock?

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A map of America’s most famous – and infamous

The 'People Map of the United States' zooms in on America's obsession with celebrity

Image: The Pudding
Strange Maps
  • Replace city names with those of their most famous residents
  • And you get a peculiar map of America's obsession with celebrity
  • If you seek fame, become an actor, musician or athlete rather than a politician, entrepreneur or scientist

Chicagoland is Obamaland

Image: The Pudding

Chicagoland's celebrity constellation: dominated by Barack, but with plenty of room for the Belushis, Brandos and Capones of this world.

Seen from among the satellites, this map of the United States is populated by a remarkably diverse bunch of athletes, entertainers, entrepreneurs and other persons of repute (and disrepute).

The multitalented Dwayne Johnson, boxing legend Muhammad Ali and Apple co-founder Steve Jobs dominate the West Coast. Right down the middle, we find actors Chris Pratt and Jason Momoa, singer Elvis Presley and basketball player Shaquille O'Neal. The East Coast crew include wrestler John Cena, whistle-blower Edward Snowden, mass murderer Ted Bundy… and Dwayne Johnson, again.

The Rock pops up in both Hayward, CA and Southwest Ranches, FL, but he's not the only one to appear twice on the map. Wild West legend Wyatt Earp makes an appearance in both Deadwood, SD and Dodge City, KS.

How is that? This 'People's Map of the United States' replaces the names of cities with those of "their most Wikipedia'ed resident: people born in, lived in, or connected to a place."

‘Cincinnati, Birthplace of Charles Manson'

Image: The Pudding

Keys to the city, or lock 'em up and throw away the key? A city's most famous sons and daughters of a city aren't always the most favoured ones.

That definition allows people to appear in more than one locality. Dwayne Johnson was born in Hayward, has one of his houses in Southwest Ranches, and is famous enough to be the 'most Wikipedia'ed resident' for both localities.

Wyatt Earp was born in Monmouth, IL, but his reputation is closely associated with both Deadwood and Dodge City – although he's most famous for the Gunfight at the O.K. Corral, which took place in Tombstone, AZ. And yes, if you zoom in on that town in southern Arizona, there's Mr Earp again.

The data for this map was collected via the Wikipedia API (application programming interface) from the English-language Wikipedia for the period from July 2015 to May 2019.

The thousands of 'Notable People' sections in Wikipedia entries for cities and other places in the U.S. were scrubbed for the person with the most pageviews. No distinction was made between places of birth, residence or death. As the developers note, "people can 'be from' multiple places".

Pageviews are an impartial indicator of interest – it doesn't matter whether your claim to fame is horrific or honorific. As a result, this map provides a non-judgmental overview of America's obsession with celebrity.

Royals and (other) mortals

Image: The Pudding

There's also a UK version of the People Map – filled with last names like Neeson, Sheeran, Darwin and Churchill – and a few first names of monarchs.

Celebrity, it is often argued, is our age's version of the Greek pantheon, populated by dozens of major gods and thousands of minor ones, each an example of behaviours to emulate or avoid. This constellation of stars, famous and infamous, is more than a map of names. It's a window into America's soul.

But don't let that put you off. Zooming in on the map is entertaining enough: celebrities floating around in the ether are suddenly tied down to a pedestrian level, and to real geography. And it's fun to see the famous and the infamous rub shoulders, as it were.

Barack Obama owns Chicago, but the suburbs to the west of the city are dotted with a panoply of personalities, ranging from the criminal (Al Capone, Cicero) and the musical (John Prine, Maywood) to figures literary (Jonathan Franzen, Western Springs) and painterly (Ivan Albright, Warrenville), actorial (Harrison Ford, Park Ridge) and political (Eugene V. Debs, Elmhurst).

Freaks and angels

Image: Dorothy

The People Map of the U.S. was inspired by the U.S.A. Song Map, substituting song titles for place names.

It would be interesting to compare 'the most Wikipedia'ed' sons and daughters of America's cities with the ones advertised at the city limits. When you're entering Aberdeen, WA, a sign invites you to 'come as you are', in homage to its most famous son, Kurt Cobain. It's a safe bet that Indian Hill, OH will make sure you know Neil Armstrong, first man on the moon, was one of theirs. But it's highly unlikely that Cincinnati, a bit further south, will make any noise about Charles Manson, local boy done bad.

Inevitably, the map also reveals some bitterly ironic neighbours, such as Ishi, the last of the Yahi tribe, captured near Oroville, CA. He died in 1916 as "the last wild Indian in North America". The most 'pageviewed' resident of nearby Colusa, CA is Byron de la Beckwith, Jr., the white supremacist convicted for the murder of Civil Rights activist Medgar Evers.

As a sampling of America's interests, this map teaches that those aiming for fame would do better to become actors, musicians or athletes rather than politicians, entrepreneurs or scientists. But also that celebrity is not limited to the big city lights of LA or New York. Even in deepest Dakota or flattest Kansas, the footlights of fame will find you. Whether that's good or bad? The pageviews don't judge...

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