You Are Here(ISBN=) 英文原版

    “[A] smart, deeply satisfying exploration of
how creatures from insects to humans handle the complexities of
physical space.” –The Cleveland Plain Dealer
　　”Delightfully lucid. . . . Ellard has a knack for distilling
obscure scientific theories into practical wisdom.”–Jonah Lehrer,
New York Times Book Review
　　”One of the finest science writers I’ve ever read. . . . . It’s
fun, pure fun.”—Los Angeles Times
　　”[A] fascinating . . . rundown of the processes involved in
keeping us and other animals moving in the right direction.” –The
Globe and Mail

    An eye-opening exploration of the intriguing
and often counter-intuitive science of human navigation and
experience of place.
    In the age of GPS and iPhones, human beings it
would seem have mastered the art of direction, but does the need
for these devices signal something else—that as a species we are
actually hopelessly lost. In fact we’ve filled our world with signs
and arrows. We still get lost in the mall, or a maze of cubicles.
What does this say about us? Drawing on his exhaustive research,
Professor Collin Ellard illuminates how humans are disconnected
from our world and what this means, not just for how we get from A
to B, but also for how we construct our cities, our workplaces, our
homes, and even our lives.

　　Colin Ellard is an experimental psychologist at the University
of Waterloo, the director of its Research Laboratory for Immersive
Virtual Environments, and an international expert in the psychology
of navigation. The results of his research have been published in
scientific journals for more than twenty years. Ellard lives in,
and regularly gets lost in, Kitchener, Ontario.

    Chapter 1
　　Looking For Targets
　　Simple Tactics for Finding Our Way
　　That We Share With All Other Animals
　　Following the light of the sun, we left the Old World
　　We’ve all done it. At a meeting, a conference, a wedding, or a
simple potluck gathering with friends, the food appears. Though
manners may prompt us to restrain ourselves for a few minutes, our
antennae wave, our restless feet shuffle, and we make a beeline for
the tables. If a scientist were to hover above us and measure our
movements, it would be easy to show the average guest-to-plate
distance as a steadily decreasing mathematical function. This class
of behavior, called taxis, is the simplest kind of spatial behavior
that can be imagined. All that is required is a target (that
magnificent roast of beef), a sensor or two (our well-tuned
nostrils and eyes), and some kind of motive force (sore feet
squeezed into formal shoes will do nicely).
　　Life does not always treat us so kindly, though. On our way to
the table, Longtalker Larry makes a perfect intercept course. How
to rearrange the missile trajectory so as to home in on the
canape?s while avoiding verbal entanglement with Larry? The buffet
table has two rows of food. On the closest side is Aunt Betty’s
famous potato salad, but it looks a little bland. The better bet is
Sarah’s Spicy Potatoes, but they’re just out of reach. We’ll need
to thread our way through a crowd, momentarily losing sight of the
target completely, in order to plan the return foray to starch
Valhalla on the distal side of the room. What’s the quickest way?
Perhaps the party is in a building we’ve never seen before. The
sweet aromas are everywhere, but compared to what vision gives us,
they don’t make much of a spatial cue. Which way do we go first?
How do we conduct an efficient search?
　　Compared with many of the stories of feats of navigation that I
will relate to you, finding your way to and then around a table
full of food is small potatoes (Sarah’s if you’re lucky).
Nevertheless, all such behaviors, ranging from the trivially simple
taxis to the complex wayfinding task, point to one basic truth of
biology. Unlike the potted geranium sitting in my window, you and
I, like all other animate beings, need to be able to move from one
place to another to survive. In order to remain nourished, I must
get up from my chair and go to the fridge to find food. In order to
avoid a premature demise, I need to leap out of the way of the bus
that hurtles down the road toward me. The whole raw biological
point of my individual survival is to reproduce. But this, too,
requires movement. In order to pass my genes on, I need to be able
to get up and walk around until I find a mate. (This, you may
argue, is something of an oversimplification.) To survive, we must
come to terms with space and time. Whatever the physicists and
philosophers might say about these things, movement is defined as a
change in place over some duration of time. Given this, it is not
at all surprising that nature has produced a wide array of
mechanical devices that produce movement (legs, wings, fins, and so
on). In addition, we have evolved an even more impressive arsenal
of tools that allow us to know where to move—that is, to find our
way through space to important goals such as sustenance, warmth,
safety, and sex.
　　The simplest tricks of navigation are perhaps so obvious that we
don’t even think of them as being tricks. You are walking down the
aisle in a grocery store when, just ahead of you, you see the box
of spaghetti you’ve been seeking. With little or no conscious
effort, the box is soon in your hand and then in your shopping
cart. What’s to explain? This seemingly trivial piece of
behavior—moving to a clearly visible target—is something that we do
hundreds of times a day. Such behaviors are required of all animals
that move, yet they are accomplished in a wide variety of
ways.
　　The most primitive kinds of animals, one-celled creatures such as
bacteria, though their needs may be simple, must still possess a
basic toolkit that allows them to find their way to conditions that
sustain life: light, heat, and sustenance. Sometimes these
unicellular denizens of our soil, water, and even our own bodies
can employ a search strategy much like a child playing a game of
blind man’s bluff. Their rates of movement rise and fall with the
activity of sensors tuned to the concentrations of heat, light, or
chemicals that surround them, and these changes in movement bring
them inexorably into contact with their goal. Other than the
movement of a plant bending toward the light, it is difficult to
imagine a simpler mechanism by which a living thing can deal with
the problems of space.
　　In other cases, such tiny creatures as these may possess
specialized equipment to help them guide their movements. In 1996,
a group of scientists, headed by Dr. David McKay of NASA’s Johnson
Space Center, claimed they had discovered fossil evidence for the
existence of life on Mars in a lump of meteoric rock that had been
collected from the Antarctic. Analysis of the chemical composition
of the rock left little doubt that it was of Martian origin, and
the peculiar formations inside the rock looked suspiciously
biological. Researchers thought they could see tiny cell bodies,
reminiscent of our own earthly bacteria.
　　As some of McKay’s early evidence has been disputed by others,
the initial excitement has died down, but he remains convinced that
the particles of magnetite that were found in the sample once
constituted a part of a Martian life form. Magnetite is found in
various places on our planet, but one of the most interesting homes
for this magnetic mineral is inside single-celled organisms that
employ a unique style of navigation. So-called magnetotaxic animals
use particles of magnetite as tiny compasses that orient their
bodies with planetary geography. Though these magnetite bodies take
advantage of the earth’s magnetic field in exactly the same way
that makes the Boy Scout compass face north, in this case it is not
to help them to read maps correctly but to do something much
simpler: the magnetite pulls these tiny aquatic animals downward
into the lakebeds lining their watery homes, where they find food,
safety, and comfortable temperatures. The origin of the magnetite
found in McKay’s samples is a matter that still swirls in
controversy, but if he is correct, not only will his discovery
constitute the first evidence of extraterrestrial life but his
claim will be based on an elementary form of navigation.