DISCOVER Vol. 26 No. 11 | November 2005 | Technology
SOMETIMES,
WHEN THINGS GET SUFFICIENTLY WEIRD, SUBTLETY NO
longer works, so i'll be blunt:
The gleaming device I am staring at in the corner of
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LONG CLOCK

Prototype number two of
the Clock of the Long Now is, at nine feet tall, a diminutive
model of the final version, which is expected to be at least
60 feet tall and will have multiple displays. This prototype
records the changes in the relative positions of Earth and
the five other planets that humans can eyeball without a
telescope. "If you came up to the clock thousands of years
from now, you could still read the time, even if you did
not have the same time system we use now," says designer
Danny Hillis.
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a machine shop in San Rafael, California, is the most audacious
machine ever built. It is a clock, but it is designed to do something
no clock has ever been conceived to do—run with perfect
accuracy for 10,000 years.
Everything about this clock is deeply unusual.
For example, while nearly every mechanical clock made in the last
millennium consists of a series of propelled gears, this one uses
a stack of mechanical binary computers capable of singling out
one moment in 3.65 million days. Like other
clocks, this one can track seconds, hours, days, and years. Unlike
any other clock, this one is being constructed to keep track of
leap centuries, the orbits of the six innermost planets in our
solar system, even the ultraslow wobbles of Earth's axis.
Made of stone and steel, it is more sculpture
than machine. And, like all fine timepieces, it is outrageously
expensive. No one will reveal even an approximate price tag, but
a multibillionaire financed its construction, and it seems likely
that shallower pockets would not have sufficed.
Still, any description of the clock must begin
and end with that ridiculous projected working life, that insane,
heroic, incomprehensible span of time during which it is expected
to serenely tick.
Ten thousand years.
The span of time from the invention of agriculture
to the present. Twice as long as the Great Pyramid of Giza has
stood. Four hundred human generations.
How?
Or more to the point, why?
Most humans
are preoccupied with the here and now. Albert Einstein, echoing
the sentiments of other deep thinkers of the modern era, argued
that one of the biggest challenges facing humanity is to "widen
our circle of compassion" across both space and time. Everything
from ethnic discrimination to wars, such reasoning goes, would
become impossible if our compassionate circles were wide enough.
That is exactly why W. Daniel Hillis, the man whose
insights underlie the world's most powerful supercomputers, has
spent two decades designing and building
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LONG
VIEW

Clock designer Danny Hillis,
standing next to an early plywood and aluminum prototype,
knows that looters and vandals pose a significant threat
to his engineering marvel, no matter how well it works.
"The most dangerous period will be the couple of hundred
years after I'm dead, before the clock is really old and
assumes historical importance," he says. "So there will
have to be a caretaker. That's part of the plan."
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prototypes of what he has dubbed the Clock of the Long Now. The
clock in the corner of the machine shop, you should understand,
is a prototype, the second prototype. Nonetheless, even the prototype
can tick away for 10,000 years. Hillis and his team just finished
it a few weeks ago. There will be more prototypes over the next
few decades before the final, much larger version is embedded in
a mountain in Nevada.
The clock idea originally sprang from Hillis's
observation that in the 1980s, all long-range planning seemed
to smack into a wall called the year 2000—the nice, round
number seemed to be the omega point for everyone from software
programmers to international policymakers: "Nobody could even
think about the year 2030. It bugged me." Because technology began
10,000 years ago—there are pot fragments at least that old—Hillis
decided to build a clock that would tick that long into the future,
conceptually fixing humanity in the center of 20 millennia. Musician
Brian Eno, Hillis's friend and a clock project collaborator, dubbed
that vast span "the long now." The clock of his dreams, said Hillis
in 1993, "ticks once a year, bongs once a century, and the cuckoo
comes out every millennium."
The final version, which will be at least 60 feet
tall, frankly strikes more than a few people as pointless. "Many
people are completely uninterested. They think it's nonsense,
a waste of time," Hillis says. And he concedes that "in the world
of ideas, it's an odd one."
Still, project insiders have found that the idea,
like the clock itself, ticks away patiently, incrementally engaging
skeptical minds. "People will make some flippant comment, then
come back months later with an idea about how to make it work,"
says Alexander Rose, a codesigner and executive director of the
Long Now Foundation, which finances the clock.
Hillis, at first motivated by a vague desire to
promote long-term thinking, has been transformed by his idea:
"Now I think about people who will live 10,000 years from now
as real people." His eyes take on a distant focus as he says this,
as if he sees them massed on the horizon. "I had never thought
that way before."
But Hillis, who has been known to drive a fire
engine to work, also cautions against regarding the Clock of the
Long Now too gravely: "This project has a lovely kind of lightness
to it."
Genius is
a shabby, abused, and degraded noun, but Hillis reminds one of
what it should mean. He is cochairman and chief technology officer
of Applied Minds in Glendale, California, a 21st-century analogue
of Thomas Edison's Menlo Park laboratories. There, an elite engineer
corps patents a river of inventions ranging from voice encryptors
to cancer detectors. Universally called Danny, Hillis is affable
and witty but tends to veer abruptly into subjects like lattice
theory, which "describes a piece of graph paper in n dimensions,"
and from there the conversation becomes a labyrinth impossible
to negotiate.
"Danny's intelligence is the rarest of kinds,"
says Rose. "The sheer practicality of his knowledge makes him
a true genius."
As an MIT undergrad in 1975, Hillis and his friends
built a binary computer out of 10,000 Tinkertoy pieces. It could
beat all comers at tic-tac-toe. About a decade
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LONG COUNT

A top-down view of a serial-bit
adder reveals a cam slider, the long silvery piece with
channels carved in its end, which triggers binary calculations
as it rotates in a carriage over bit pins on a fixed disk.
A 360-degree rotation constitutes one tick of the mechanism.
The clock ticks just twice a day, at noon and at midnight.
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later he invented an electronic mainframe computer called the Connection
Machine that worked somewhat like a human brain; instead of one
processor, it had 65,536, all firing at once like buzzing neurons,
a model that supercomputers have used ever since. The irony is inescapable:
The architect of the world's fastest machine now designs the world's
slowest.
The trip to Hillis's office is a cross between
a Disney ride and the multidoor opening sequence of the 1960s
television show Get Smart. I enter a low-slung industrial building,
meet Hillis in the lobby, follow him into a red, British-style
phone booth, pick up the receiver, wait for him to say the password,
and follow him through the false back when it opens into a cavernous
workroom. I then pass under a 13-foot-tall, five-ton, four-legged
robot he designed, marvel at his new invention that instantly
makes three-dimensional maps of any place in the world, then settle
into his gadget-strewn office complete with a New Yorker cartoon
of a gypsy behind a crystal ball who says: "Why ask me about the
future? Ask Danny Hillis."
So that's what I do: "How do you build a clock
that will keep perfect time for 10,000 years?"
Hillis, who loves gadgets and was once Walt Disney
Imagineering's vice president for research and development, smiles
and begins to explain the
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HOW STARS TELL US THE
TIME
One universal way to visualize
the passage of time is to make a dynamic model of the heavens.
The changing relationship of Earth and the five inner planets
can be calculated based on how long it takes each planet
to revolve around the sun, which ranges from 87.97 Earth
days for Mercury to 10759.50 Earth days for Saturn. Here,
the diagram shows the conjunction of the planets on November
15, 2005.
HOW THE CLOCK CAN BE
READ
The Clock of the Long Now
prototype features an orrery, a simplified planetary display.
The shperical cage of the orrery, called the firmament,
is tilted at 23.27 degrees, the angle of he Earth's axis
in relation to the flat plane of the planets as they radiate
out form the sun. The cage includes a celestial equator
with degree markings for measuring the alignment of the
planets at any given time.
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challenges involved. The clock must remain accurate for 100 centuries
while sitting on an atmospherically, geologically, and worst of
all, culturally violent planet. To forestall looting (the bane of
many built-for-the-ages projects, such as the Egyptian pyramids),
it cannot contain parts made of jewels and expensive metals. In
case of societal collapse, it must be maintainable with Bronze Age
technology. It must be understandable while intact, so that no one
will want to take it apart. It must be easily improved over time,
and it must be scalable so that the design can be shown via smaller
prototypes.
"The ultimate design criterion is that people
have to care about it," says Hillis. "If they don't, it won't
last."
All straightforward, but ludicrously daunting.
Time can mean many things, but Hillis's machine needs to track
a particularly messy version: Earth-surface clock/calendar time,
which is based on a byzantine agglomeration of astronomical rotations,
orbits, and perturbations of hugely varying lengths, overlaid
with arbitrary cultural whims about how to divide it up. What
kind of machine can, for 10 millennia, accurately reconcile hours,
days, weeks, months, leap years, leap centuries, the precession
(wobbling around an axis) of planetary orbits, and, grandest cycle
of all, the 25,784-year precession of the equinox?
Answer: a digital one. A calculation that extends
to 28 bits is accurate to one in 3.65 million—or in clock
terms, one day in 10,000 years. Bits and bytes are typically rendered
electronically, but Hillis says he "rejected electronics from
the start. It would not be technologically transparent and probably
not durable. I could quickly see that the clock had to be mechanical."
So Hillis invented—and patented—a
serial-bit adder, or a mechanical binary computer. Instead of
using "voltage on" or "voltage off" to define zeros and ones like
a typical electronic computer, the disk-shaped adder uses levers
that can rest in either the "0" or "1" position. An individual
adder can be programmed with 28 pins—what a programmer would
call 28 bits—to represent in binary code any number displayed
by the clock, such as the lunar cycle of 29.5305882 days. A cam
slider with special grooves carved into it spins over the adder's
pins, reading the pins and levers and ticking the levers back
and forth with each revolution until it reaches the desired number
and "overflows." At that point, the slider pops out of the clock's
side—rather like a cuckoo popping out on the hour—and
engages a small wheel, which in turn moves some part of the clock's
display. The clock's guts are a stack of serial-bit adders, each
controlling a different part of the display.
As if that were not complicated enough, the final
clock will require a helical column called the "equation of time"
cam. Its purpose will be to make the
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HOW THE
CLOCK COMPUTES

The clock is driven by
binary mechanical computers called serial-bit adders with
one adder per planet. An adder consists of a disk with an
outer set of bit-pin levers, each of which can take on a
value of "1" or "0," as well as an inner ring of fixed bit
pins programmed with a mathematical constant that represents
the duration of the planet's orbit. (A) The levers and pins
are read by a series of channels in a cam slider that rotates
in a carriage. (B) The slider also adds sums by tripping
levers as it goes. (C) During each rotation, the slider
jitters back and forth as it accumulates sums. (D) When
the accumulated sums reach an overflow value, the slider
pops out of the carriage and catches a Geneva wheel. (E)
The movement of the Geneva wheel updates the planetary display.
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conversion from absolute time to local solar time. Using a stylus
that traces the cam's rather feminine shape, the clock will be able
to compensate for elliptical eccentricities in Earth's orbit around
the sun and the tilt of Earth's axis. These two celestial phenomena
"beating against each other," as Hillis puts it, produce variations
in the the sun's apparent rate of travel through the sky that would
add up to about 15 minutes per year over the clock's lifetime. (That
a short section of the cam vaguely resembles a nude female's hips
and thighs isn't accidental: Hillis twiddled and tweaked to make
the cam look like that. "Other configurations could have worked,
but it would not have looked nearly as wonderful," he says.)
Still, no mechanical clock, however cleverly crafted,
can keep perfect time for 10,000 years. So Hillis added solar
synchronization: A sunbeam striking a precisely angled lens at
noon triggers a reset by heating, expanding, and buckling a captive
band of metal.
And what about power? By harnessing natural processes
like temperature or pressure changes, "there are lots of ways
to make it totally self-winding," says Hillis. "But I want people
to engage the clock, not forget it." So the perfect power system
could handle neglect but would respond to love. The final clock,
untended, will wind itself enough to keep its pendulum swinging
and track time, but human visitors—perhaps by merely stepping
on a platform—could also wind the display. "So when you
visit the clock, it shows the last time someone was there," says
Hillis. "When you wind it, it catches up to now and stops, set
for the next person. It rewards attention."
The last question, what to display, gives Hillis
the most pause. All cultures recognize days, months, and years
because they spring from simple "once around" astronomical cycles,
but hours, weeks, centuries, and other divisions are arbitrary,
varying wildly across times and places.
Hillis is still mulling how to handle that, but he knows
for sure that the final clock will somehow mirror the positions
of the planets relative to the stars and to one another. "That
will be one of many displays it has," he says.
Hillis is in the process of rolling out these and
more ideas in a series of increasingly complex prototypes. The first
one, now on permanent display at the Science Museum in London, was
financed by an anonymous donor who lent it to the museum. "The deal
we offer is, if you fund the next stage of the development of the
clock, we will give you a prototype," says Hillis. "We have spent
millions of dollars so far—I don't know the exact number."
The nine-foot-tall London clock uses a slowly
rotating torsional pendulum, ticks once every 30 seconds, and
tracks hours, sidereal and solar years, centuries, phases of the
moon, and the zodiac—and happens to be hauntingly beautiful.
Incredibly, its three-year-long construction was completed in
a mad rush scarcely one hour before midnight on December 31, 1999.
That meant there was no time to test it before the switch to the
year 2000, the most complex date change in the Gregorian system
since the year 1600 because it involved a once-in-400-years leap
year exemption.
Yet at midnight, "it bonged twice. It was perfect.
That was a great moment," says Hillis softly. "Some people say
their millennium experience was anticlimactic. Mine wasn't."
In his biodiesel-powered Toyota Land Cruiser,
Alexander Rose drives me from the Long Now Foundation's office
in the historic Presidio district in San Francisco across the
Golden Gate Bridge to Rand Machine Works, a metal shop in San
Rafael that's about the size of a three-car garage. In a dark
back corner the second prototype is rising, adder ring by adder
ring. It is funded by billionaire Nathan Myhrvold, former chief
technology officer of Microsoft and a longtime Hillis pal. The
clock's builder is Chris Rand, a nonpareil build-anything machinist
who has helped craft everything from the Star Wars land cruisers
to America's Cup yachts. This project, he says, is working on
him.
"I think about everything more long term now,"
he says.
Someday this clock may become a holy object, but
for now it's a half-finished project in a gritty shop that infidels
can touch and tinker with. I scoot the adder arm around with my
index finger. A complex series of channels cut into its end makes
it jitter back and forth as it slides over pins. The whole thing
is so brilliant it makes me laugh. Gears constitute the heart
of the calculation engines of most other mechanical clocks, but
as friction grinds them down, they get smaller, which means they
move faster, which means they lose accuracy. But an adder's pin—even
a worn one—is either there or not there, at either "1" or
"0" until the thing shears clean through, which in a big clock
with massive pins should take more than 10,000 years. Genius.
Still, materials remain a tricky question. The
prototypes so far have been made largely of stainless steel, but
the metals that will compose the final clock remain in doubt.
"Just about nobody is doing research on materials that will last
for thousands of years," says Rose.
Hillis, Rose, and Rand will make at least one
more prototype after this one, but before Hillis dies, they will
build the big one. The Long Now Foundation made a
serious commitment to the final clock when, in 1999—or,
as foundation literature renders this and all other years, "01999"—it
bought 180 acres of desert mountain land adjoining Great Basin
National Park in eastern Nevada. Dry, remote, and geologically
stable, the site has one other serendipitous attribute—it
is studded with bristlecone pines, the world's oldest living things.
At the Long Now Foundation's office, Rose hands me a core section
of a bristlecone on the property. "This is just the outer trunk,
just 1,000 years, from 944 to 2003," he says. Some bristlecones
in the area are nearly 5,000 years old. The clock site may be
the only spot on Earth where commencing a 10,000-year process
seems like a halfway sensible thing to do.
Hillis's plan for the final clock, which he reserves
the right to change, has it built inside a series of rooms carved
into white limestone cliffs, 10,000 feet up the Snake
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LONG STACK

The Long Now prototype's
calculation engine consists of six serial-bit adders, stacked
like pancakes. The long shaft, topped with small gears,
is part of a Geneva wheel mechanism. The clock features
six of these devices. Each one links an individual serial-bit
adder to a large gear that moves a planet in the display.
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Range's west side. A full day's walk from anything resembling a
road will be required to reach what looks like a natural opening
in the rock. Continuing inside, the cavern will become more and
more obviously human made. Closest to vast natural time cycles,
the clock's slowest parts, such as the zodiacal precession wheel
that turns once every 260 centuries, will come into view first.
Such parts will appear stock-still, and it will require a heroic
mental exertion to imagine their movement. Each succeeding room
will reveal a faster moving and more intricate part of the mechanism
and/or display, until, at the end, the visitor comprehends, or is
nudged a bit closer to comprehending, the whole vast, complex, slow/fast,
cosmic/human, inexorable, mysterious, terrible, joyous sweep of
time and feels kinship with all who live, or will live, in its embrace.
Or so Hillis hopes.
Some people will no doubt make a pilgrimage to
the cavern, but for the next century at least, that will probably
require some commitment, as the site is "as far as you can get
from civilization within the continental United States," Hillis
says. "That will help people forget about it and avoid the contempt
of familiarity."
Most people, however, will never visit the clock,
just as most people never visit the Eiffel Tower. They will only
know that it exists. That knowledge alone will acquaint them with
the Long Now, and that is part of the plan. "When Danny first
proposed the clock and I told people about it, they would say,
'What?' " says Stewart Brand, cochairman of the Long Now Foundation's
board of directors. "Now as I go around, people come up and say,
'Hey, Stewart, how's the clock coming?' People are already engaged
by it, and it is working on them. It exists before it exists."
Even after it exists, the idea of the clock will no doubt change
more minds than the clock itself.
How much power resides in that deceptively simple
idea? Ask yourself in a month.