[Pollinator] Honeybees are found to interact with Quantum fields

[Laurie Adams]

Honeybees are found to interact with Quantum fields

@ Physics     May 15 2005, 03:27 (UTC+0)

 

Honeybees like these may have means to interact with the Quantum world

By Adam Frank

COPYRIGHT (C) 1997 Discover

COPYRIGHT (C) 2004 Gale Group

 

How could bees of little brain come up with anything as complex as a dance
language? The answer could lie not in biology but in six-dimensional math
and the bizarre world of quantum mechanics.

 

Honeybees don't have much in the way of brains. Their inch-long bodies hold
at most a few million neurons. Yet with such meager mental machinery
honeybees sustain one of the most intricate and explicit languages in the
animal kingdom. In the darkness of the hive, bees manage to communicate the
precise direction and distance of a newfound food source, and they do it all
in the choreography of a dance. Scientists have known of the bee's dance
language for more than 70 years, and they have assembled a remarkably
complete dictionary of its terms, but one fundamental question has
stubbornly remained unanswered: How do they do it? How do these simple
animals encode so much detailed information in such a varied language?
Honeybees may not have much brain, by they do have a secret.

 

This secret has vexed Barbara Shipman, a mathematician at the University of
Rochester, ever since she was a child. "I grew up thinking about bees," she
says. "My dad worked for the Department of Agriculture as a bee researcher.
My brothers and I would stop at his office, and sometimes he would how show
us the bees. I remember my father telling me about the honeybee's dance when
I was about nine years old. And in high school I wrote a paper on the
medicinal benefits of honey." Her father kept his books on honeybees on a
shelf in her room. "I'm not sure why," she says. "It may have just been a
convenient space. I remember looking at a lot of these books, especially the
one by Karl von Frisch."

 

Von Frisch's Dance Language and Orientation of Bees was some four decades in
the making. By the time his papers on the bee dance were collected and
published in 1965, there was scarcely an entomologist in the world who
hadn't been both intrigued and frustrated by his findings. Intrigued because
the phenomenon Von Frisch described was so startlingly complex; frustrated
because no one had a clue as to how bees managed the trick. Von Frisch had
watched bees dancing on the vertical face of the honeycomb, analyzed the
choreographic syntax, and articulated a vocabulary. When a bee finds a
source of food, he realized, it returns to the hive and communicates the
distance and direction of the food to the other worker bees, called
recruits. On the honeycomb which Von Frisch referred to as the dance floor,
the bee performs a "waggle dance," which in outline looks something like a
coffee bean--two rounded arcs bisected by a central line. The bee starts by
making a short straight run, waggling side to side and buzzing as it goes.
Then it turns left (or right) and walks in a semicircle back to the starting
point. The bee then repeats the short run down the middle, makes a
semicircle to the opposite side, and returns once again to the starting
point.

 

It is easy to see why this beautiful and mysterious phenomenon captured
Shipman's young and mathematically inclined imagination. The bee's finely
tuned choreography is a virtuoso performance of biologic information
processing. The central "waggling" part of the dance is the most important.
To convey the direction of a food source, the bee varies the angle the
waggling run makes with an imaginary line running straight up and down. One
of Von Frisch's most amazing discoveries involves this angle. If you draw a
line connecting the beehive and the food source, and another line connecting
the hive and the spot on the horizon just beneath the sun, the angle formed
by the two lines is the same as the angle of the waggling run to the
imaginary vertical line. The bees, it appears, are able to triangulate as
well as a civil engineer.

 

Direction alone is not enough, of course--the bees must also tell their hive
mates how far to go to get to the food. "The shape or geometry of the dance
changes as the distance to the food source changes," Shipman explains. Move
a pollen source closer to the hive and the coffee-bean shape of the waggle
dance splits down the middle. "The dancer will perform two alternating
waggling runs symmetric about, but diverging from, the center line. The
closer the food source is to the hive, the greater the divergence between
the two waggling runs."

 

If that sounds almost straightforward, what happens next certainly doesn't.
Move the food source closer than some critical distance and the dance
changes dramatically: the bee stops doing the waggle dance and switches into
the "round dance." It runs in a small circle, reversing and going in the
opposite direction after one or two turns or sometimes after only half a
turn. There are a number of variations between species.

 

Von Frisch's work on the bee dance is impressive, but it is largely
descriptive. He never explained why the bees use this peculiar vocabulary
and not some other. Nor did he (or could he) explain how small-brained bees
manage to encode so much information. "The dance of the honeybee is special
among animal communication systems," says Shipman. "It conveys concise,
quantitative information in an abstract, symbolic way. You have to wonder
what makes the dance happen. Bees don't have enough intelligence to know
what they are doing. How do they know the dance in the first place? Calling
it instinct or some other word just substitutes one mystery for another."

 

Shipman entered college as a biochemistry major and even spent some time
working in a biology lab studying the hemolymph--the "blood"--of honeybee
larvae, but she quickly moved her interest in bees to the side. "During my
freshman year," she says, aI became more attracted to the beauty and rigor
of mathematics." She switched her major and eventually went on to graduate
school and to a professorship at the University of Rochester. For several
years it seemed as though she had wandered a long way from her childhood
fascination.

 

Then, taking an unlikely route, she found herself once again confronting the
mysteries of bees head-on. While working on her doctoral thesis, on an
obscure type of mathematics known only to a small coterie of researchers
well-versed in the minutiae of geometry, she stumbled across what just might
be the key to the secrets of the bee's dance.

 

Shipman's work concerned a set of geometric problems associated with an
esoteric mathematical concept known as a flag manifold. In the jargon of
mathematics, manifold means "space." But don't let that deceptively simple
definition lull you into a false sense of security. Mathematicians have as
many kinds of manifolds as a French baker has bread. Some manifolds are
flat, some are curved, some are twisted, some wrap back on themselves, some
go on forever. "The surface of a sphere is a manifold," says Shipman. "So is
the surface of a bagel--it's called a torus." The shape of a manifold
determines what kinds of objects (curves, figures, surfaces) can "live"
within its confines. Two different types of loops, for example, live in the
surface of a torus--one wraps around the outside, the other goes through the
middle, and there is no way to transform the first into the second without
breaking the loop. In contrast, there is only one type of loop that lives on
a sphere.

 

Mathematicians like to examine different manifolds the way antiques dealers
browse through curio shops--always exploring, always looking for unusual
characteristics that expand their understanding of numbers or geometry. The
difficult part about exploring a manifold, however, is that mathematicians
don't always confine them to the three dimensions of ordinary experience. A
manifold can have two dimensions like the surface of a screen, three
dimensions like the inside of an empty box, four dimensions like the
space-time of our Einsteinian universe, or even ten or a hundred dimensions.
The flag manifold (which got its name because some imaginative mathematician
thought it had a "shape" like a flag on a pole) happens to have six
dimensions, which means mathematicians can't visualize all the
two-dimensional objects that can live there. That does not mean, though,
that they cannot see the objects' shadows.

 

One of the more effective tricks for visualizing objects with more than
three dimensions is to "project" or "map" them onto a space that has fewer
dimensions (usually two or three). A topographic map, in which
three-dimensional mountains get squashed onto a two-dimensional page, is a
type of projection. Likewise, the shadow of your hand on the wall is a
two-dimensional projection of your three-dimensional hand.

 

One day Shipman was busy projecting the six-dimensional residents of the
flag manifold onto two dimensions. The particular technique she was using
involved first making a two-dimensional outline of the six dimensions of the
flag manifold. This is not as strange as it may sound. When you draw a
circle, you are in effect making a two-dimensional outline of a
three-dimensional sphere. As it turns out, if you make a two-dimensional
outline of the six-dimensional flag manifold, you wind up with a hexagon.
The bee's honeycomb, of course, is also made up of hexagons, but that is
purely coincidental. However, Shipman soon discovered a more explicit
connection. She found a group of objects in the flag manifold that, when
projected onto a two-dimensional hexagon, formed curves that reminded her of
the bee's recruitment dance. The more she explored the flag manifold, the
more curves she found that precisely matched the ones in the recruitment
dance. "I wasn't looking for a connection between bees and the flag
manifold," she says. "I was just doing my research. The curves were nothing
special in themselves, except that the dance patterns kept emerging."
Delving more deeply into the flag manifold, Shipman dredged up a variable,
which she called alpha, that allowed her to reproduce the entire bee dance
in all its parts and variations. Alpha determines the shape of the curves in
the 6-D flag manifold, which means it also controls how those curves look
when they are projected onto the 2-D hexagon. Infinitely large values of
alpha produce a single line that cuts the hexagon in half. Large' values of
alpha produce two lines very close together. Decrease alpha and the lines
splay out, joined at one end like a V. Continue to decrease alpha further
and the lines form a wider and wider V until, at a certain value, they each
hit a vertex of the hexagon. Then the curves change suddenly and
dramatically. "When alpha reaches a critical value," explains Shipman, "the
projected curves become straight line segments lying along opposing faces of
the hexagon."

 

The smooth divergence of the splayed lines and their abrupt transition to
discontinuous segments are critical--they link Shipman's curves to those
parts of the recruitment dance that bees emphasize with their waggling and
buzzing. "Biologists know that only certain parts of the dance convey
information," she says. "In the waggle dance, it's the diverging waggling
runs and not the return loops. In the circle dance it's short straight
segments on the sides of the loops." Shipman's mathematics captures both of
these characteristics, and the parameter alpha is the key. "If different
species have different sensitivities to alpha, then they will change from
the waggle dances to round dances when the food source is at different
distances."

 

If Shipman is correct, her mathematical description of the recruitment dance
would push bee studies to a new level. The discovery of mathematical
structure is often the first and critical step in turning what is merely a
cacophony of observations into a coherent physical explanation. In the
sixteenth century Johannes Kepler joined astronomy's pantheon of greats by
demonstrating that planetary orbits follow the simple geometric figure of
the ellipse. By articulating the correct geometry traced by the heavenly
bodies, Kepler ended two millennia of astronomical speculation as to the
configuration of the heavens. Decades after Kepler died, Isaac Newton
explained why planets follow elliptical orbits by filling in the
all-important physics--gravity. With her flag manifold, Shipman is like a
modern-day Kepler, offering, in her words, "everything in a single
framework. I have found a mathematics that takes all the different forms of
the dance and embraces them in a single coherent geometric structure."

 

Shipman is not, however, content to play Kepler. "You can look at this idea
and say, `That's a nice geometric description of the dance, very pretty,'
and leave it like that," she says. "But there is more to it. When you have a
physical phenomenon like the honeybee dance, and it follows a mathematical
structure, you have to ask what are the physical laws that are causing it to
happen."

 

At this point Shipman departs from safely grounded scholarship and enters
instead the airy realm of speculation. The flag manifold, she notes, in
addition to providing mathematicians with pure joy, also happens to be
useful to physicists in solving some of the mathematical problems that arise
in dealing with quarks, tiny particles that are the building blocks of
protons and neutrons. And she does not believe the manifold's presence both
in the mathematics of quarks and in the dance of honeybees is a coincidence.
Rather she suspects that the bees are somehow sensitive to what's going on
in the quantum world of quarks, that quantum mechanics is as important to
their perception of the world as sight, sound, and smell.

 

Say a bee flies around, finds a source of food, and heads straight back to
the hive to tell its colleagues. How does it perceive where that food is?
What notation can it use to remember? What teens can it use to translate
that memory into directions for its fellow bees? One way, the way we
big-brained humans would be most comfortable with, would be to use
landmarks--fly ten yards toward the big rock, turn left, duck under the
boughs of the pine tree, and see the flowers growing near the trunk. Another
way, one that seems to be more in line with what bees actually do, would be
to use physical characteristics that adequately identify the site, such as
variations in Earth's magnetic field or in the polarization of the sun's
light.

 

Researchers have in fact already established that the dance is sensitive to
such properties. Experiments have documented, for example, that local
variations in Earth's magnetic field alter the angle of the waggling runs.
In the past, scientists have attributed this to the presence of magnetite, a
magnetically active mineral, in the abdomen of bees. Shipman, however, along
with many other researchers, believes there is more to it than little
magnets in the bees' cells. But she tends not to have much professional
company when she reveals what she thinks is responsible for the bees'
response. "Ultimately magnetism is described by quantum fields," she says.
"I think the physics of the bees' bodies, their physiology, must be
constructed such that they're sensitive to quantum fields--that is, the bee
perceives these fields through quantum mechanical interactions between the
fields and the atoms in the membranes of certain cells."

 

What exactly does it mean to say that the bees interact with quantum fields?
A quantum field is a sort of framework within which particles play out their
existences. And, rather than assigning an electron to one position in space
at one particular time, you instead talk about all the different places the
electron could possibly be. You can loosely refer to this collection of all
possible locations as a "field" smeared out across space and time. If you
decide to check the electron's position by observing it, the interaction
between your measuring device and the field makes the electron appear to be
a single coherent object. In this sense, the observer is said to disturb the
quantum mechanical nature of the electron.

 

There is some research to support the view that bees are sensitive to
effects that occur only on a quantum-mechanical scale. One study exposed
bees to short bursts of a high-intensity magnetic field and concluded that
the bees' response could be better explained as a sensitivity to an effect
known as nuclear magnetic resonance, or NMR, an acronym commonly associated
with a medical imaging technique. NMR occurs when an electromagnetic wave
impinges on the nuclei of atoms and flips their orientation. NMR is
considered a quantum mechanical effect because it takes place only if each
atom absorbs a particular size packet, or quantum, of electro-magnetic
energy.

 

This research, however, doesn't address the issue of how bees turn these
quantum-mechanical perceptions into an organized dance ritual. Shipman's
mathematics does. To process quantum mechanical information and communicate
it to others, the bee would not only have to possess equipment sensitive to
the quantum-mechanical world; to come up with the appropriate recruitment
dance, it would have to perform some kind of calculation similar to what
Shipman did with her flag manifold. Assuming that the typical honey-bee is
not quite intelligent enough to make the calculations, how does the bee come
up with the flag manifold as an organizing principle for its dance? Shipman
doesn't claim to have the answer, but she is quick to point out that the
flag manifold is common both to the bee dance and to the geometry of quarks.
Perhaps, she speculates, bees possess some ability to perceive not only
light and magnetism but quarks as well.

 

The notion that bees can perceive quarks is hard enough for many physicists
to swallow, but that's not even the half of it. Physicists have theorized
that quarks are constantly popping up in the vacuum of empty space. This is
possible because the vacuum is pervaded by something called the zero-point
energy field--a quantum field in which on average no particles exist, but
which can have local fluctuations that cause quarks to blink in and out of
existence. Shipman believes that bees might sense these fleeting quarks, and
use them--somehow--to create the complex and peculiar structure of their
dance.

 

Now here's the rub. The flag manifold geometry is an abstraction. It is
useful in describing quarks not as the single coherent objects that
physicists can measure in the real world but as unobserved quantum fields.
Once a physicist tries to detect a quark--by bombarding it with another
particle in a high-energy accelerator--the flag manifold geometry is lost.
If bees are using quarks as a script for their dance, they must be able to
observe the quarks not as single coherent objects but as quantum fields. If
Shipman's hunch is correct and bees are able to "touch" the quantum world of
quarks without breaking it, not only would it shake up the field of biology,
but physicists would be forced to reinterpret quantum mechanics as well.

 

Shipman is the first to admit that she is a long way from proving her
hypothesis. "The mathematics implies that bees are doing something with
quarks," she says. "I'm not saying they definitely are. I'm just throwing it
out as a possibility." And when she publishes her research, probably
sometime next year, no doubt many scientists will be turned off by her
dragging quarks and quantum mechanics into the picture.

 

"The joining of mathematics and biology is a fascinating endeavor and is
just getting under way," says William Faris, a mathematician at the
University of Arizona. "Connecting quantum mechanics directly to biology is
much more speculative. I frankly am skeptical that the bee dance is related
to quantum mechanics. The mathematics she uses may be related to a
completely different explanation of the bee dance. This is the universality
of mathematics. To venture into quantum mechanics may be a distraction."

 

Shipman isn't the first scientist to go out on a limb trying to link biology
to quantum mechanics. Physicist Roger Penrose of Oxford University has
postulated that nerve cells have incredibly tiny tubes that serve as quantum
mechanical detectors, and other physicists have expressed similar ideas, but
they are by no means widely accepted.

 

It is risky for a young scientist to take on a radical theory. Championing
an unproved or unpopular idea is a good way to put your academic career on
permanent hold. "My thesis adviser was worried, too," says Shipman. "He was
happy to know that I am beginning collaborations with biologists."

 

However, Shipman is too excited about the ideas to care about the risk. "To
make discoveries that cross disciplines, someone has to start. I know there
is always resistance to new ideas, especially if you are approaching the
problem from a different perspective. Sometimes theory comes before
discovery and points the way toward the right questions to ask. I hope this
research stimulates other researchers' imaginations."

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Laurie Davies Adams

Executive Director

Pollinator Partnership

423 Washington St., 5th floor

San Francisco, CA 94111

 

415.362.1137 PHONE

415.362.3070 FAX

lda at pollinator.org

www.pollinator.org

 

Our future flies on the wings of pollinators.

National Pollinator Week  - June 22-28 - join the national campaign today at
www.pollinator.org!

 

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