Lauren Ipsum: A Story About Computer Science and Other Improbable Things

I feel I should warn you: You won’t find any computers in this book. If the idea of a
computer science book without computers upsets you, please close your eyes until you’ve
finished reading the rest of this page.

The truth is that computer science isn’t really about the computer. The computer is just
a tool to help you see ideas more clearly. You can see the moon and stars without a telescope, smell
the flowers without a fluoroscope, have fun without a funoscope, and be silly sans
oscilloscope.

You can also play with computer science without you-know-what. Ideas are the real stuff of
computer science. This book is about those ideas and how to find them. In fact, most of the
characters, places, and thingamajigs in Userland are actually based on those ideas. Check out the
Field Guide at the back of the book to learn more about them!

Lauren Ipsum had been lost in the woods all morning. The poor girl didn’t know where she
was or where she was going.

It had all started with an argument. Her mother wanted her to go to summer school, and
naturally Laurie didn’t want to go. “Children in other countries go to school year
round,” her mom said. “We aren’t in other countries,” Laurie replied.
“Extra classes are how to get ahead,” Mom said. “Summer is for having fun,”
Laurie insisted. The argument went on and on and got loud near the end. To calm down, Laurie took a
walk in the woods.

When people are faced with something they don’t want to do, they often do something they
aren’t allowed to do instead. Before long, Laurie had gone farther into the woods than she had
ever gone before.

Being lost was kind of fun. Out here, Laurie could be anything she wanted to be, and there was
no one to tell her different.

She was a secret ninja, moving like a ghost through the ancient forest. Light and shadow
danced under the leaves, and she danced with them. No one could hear her stealthy ninja footsteps.
No one would see her coming until it was too—

“
Chiguire!
” said a voice up ahead. A shape came toward her
out of the darkness. Was it an angry spirit? A dire beast?

“
Argot!
” the creature said. It was like a mouse-dog, or a
dog-mouse. That is to say, it was the size of a dog, but it looked more like a mouse. It walked
right up to Laurie and began nuzzling her hand in a very un-beast-like way.

“Aw, you’re so friendly!” Laurie said, in a rather un-ninja-like
fashion.

“
Repl!
” it said, as it put a webbed foot on her knee.

“You’re a funny-looking thing, aren’t you? What’s your name, huh? What
should I call you?”

“
Argot!
”

“Okay, I’ll call you Argot. Are you hungry? What do . . . things like you
eat?” She offered it some peanuts.

“
Snarfl!
” it snarfled, eating out of her hand.

“Hey, little guy,” she said, tickling its chin, “you don’t know the
way back to Hamilton, do you?”

“
Hamilton!
” it said excitedly.

“You do know a way?”

“
Lalr!
” it lalred, tongue hanging out.

“So where is it?”

“
Isit!
” it said.

“I mean, how do I get there?”

“
Gether!
” it answered.

“You’re just repeating what I’m saying, aren’t you?”

“
Arentyou!
” it said.

“That’s what I thought. Animals can’t talk.”

So now I’m lost
, Laurie thought to herself.
How do I get
unlost?
She remembered something about moss growing on the north side of trees. There
wasn’t any moss, so that was out.
The sun rises in the east and sets in the
west.
It was late morning, and the sun was almost overhead. No help there either.

She wandered around, flipping her lucky red poker chip. If the chip landed on heads, she
walked to the left for a while. If it landed on tails, she walked to the right for a while.

“
Burble
. . .” Argot waddled behind her, making nonsense
noises.

“No, don’t follow me, Argot. Shoo!”

“
Bitblit?
”

“I like you, but I’m not allowed to have a dog. Or a mouse, or a dog-mouse, or
whatever you are. Go along now—go home!”

No matter what she said, the ugly little thing wouldn’t give up. It seemed willing to
follow Laurie all the way to . . . wherever she was going.

Maybe if I wait for the stars to come out
, she thought to herself.
No, that’s silly. I don’t know which stars are which!

“
Frobit!
” Another creature like Argot, but bigger, came out
of the underbrush. It tried to lick her face.

“Ugh, your breath stinks!”

“
Wibble!
” A third creature came up from behind and butted its
head against her.

“Whoops! Hello to you, too.”

“
Tanstaafl!
”

“
Zork!
”

More creatures were coming from all directions. The noise was getting louder.

“Uh,” Laurie uhhed.

“
Parsec!
”

“
Wurfl!
”

“
Lilo!
”

Argot’s friends were no longer just nuzzling. They were crowding all around her, pushing
and shouting. She was being mobbed.

Laurie panicked and ran. The gang of creatures howled and chased after her.

“
Nyquist!
”

“
Quux!
”

“
Fifo!
”

She could barely stay on her feet, running through the tangled underbrush, but she was too
afraid to slow down.

Her escape was blocked by a tall green hedge that stretched in both directions. Once upon a
time it might have been part of a garden, but now it was wild and disorderly. Laurie squeezed her
way through a gap in the hedge and kept running until she thought she was safe. The creatures were
far behind.

The forest looked different on the other side of the hedge. For one, the trees had red and
black stripes. Black tree trunks split into two red branches. Those split into four black branches,
which split into eight red branches, and on and on, until the branches ended in millions of tiny
black leaves. In fact . . .

“
Foo!
”

“
Bar!
”

“
Baz!
”

The creatures were still chasing her! Laurie tried to run away again, but she couldn’t
go very fast. Her throat was raw, and her legs were beginning to tremble.

“
Wysiwyg!
”

“Help! Stop it!” she cried, hoping someone would hear her. “Make them
stop!”

A small man carrying a large pack stepped in between Laurie and the mob. Dishes and pots and
pans and cowbells rattled around. The creatures halted a few paces away, making awful, angry
noises.

“Are you okay, miss?” he said.

“These—these
mouse-dogs
won’t leave me
alone!”

“
Epsilon!
”

“
Olap!
”

“It’s just a bunch of Jargon,” he said. “Hold still and stay
calm.” He cupped his hands to his mouth.

“STANI!” he shouted at them.

All of the Jargon froze, their ears aquiver.

“CEPAT! AFVIGE!
SCHNELL! SCHNELL!
”

And just like that, they were gone, running away into the gloom of the forest.

Laurie collapsed against a tree. “Th-thank you,” she said.

“Sure thing, miss. Just rest here a while,” the man said. He dropped his pack with
a loud jangle, then sat on top of it.

“What’s a Jargon?” she asked once she’d caught her breath.

“Jargon live in the swamps. They feed on attention. If they can’t get that,
they’ll settle for fear and confusion.”

“But the first one was so friendly! I just talked to it a little and it started
following me.”

“That’s how it starts,” he said. “A little Jargon doesn’t look
like much. Some people even keep them as pets. But they form packs, and they are very
dangerous.”

“That’s terrible!”

He shrugged. “What can you do? Stand your ground and act confident. If you show any
fear, a pack of wild Jargon will run you right over.”

“What did you say to make them leave?”

“I have no idea. It sounded good, though, didn’t it?” he said. “So
what’s your name, miss?”

“My name is Laurie. I think I’m lost.”

“That’s wonderful!” the man said. “I’m lost too.”

“Oh no! You mean you don’t know where you are?”

“No, I know exactly where I am.”

“So you don’t know where you’re going?”

“I know exactly where I’m going. I’m on the way home.”

Laurie was almost too confused to feel confused. “But if you know where you
are
,” she said, “and you know where you’re
going
, how can you be lost?”

“Because I don’t know how I’ll get there,” the man grinned.
“I’m a Wandering Salesman.”

“A Wandering Salesman? What’s that?”

“We wander from town to town, selling and buying. There are two rules: you have to visit
every town before going home, and you can’t visit any town twice. Every road is the road home
except the road behind me.”

“So you always go to the next place you’ve never been to?” she asked.

“That’s right! You’re guaranteed to get home eventually,” he said.
“It’s only logical. Along the way I’ve seen the sunrise over the Towers of Hanoi
and climbed the Upper Bounds. I’ve sat down at the Lookup Table and floated on the Overflow
River. It’s a good life. Being lost can be fun!”

“It’s not fun for me anymore,” said Laurie. “I don’t really know
where I am, or where I’m going,
or
how to get there.”

“Hmm. Mostly lost is fun, but completely lost is serious. You’re going home too,
right?”

“Yes, I want to go home!” she said.

“And where do you live?”

“I live in Hamilton with my mom. Do you know where it is?”

“Not a clue. Never heard of it!” he said cheerfully. “But that’s one
out of three, anyway. You have a definite goal.”

“Um, I guess so.”

“And I know where
I
am, and since we’re in the same place,
that means I know where
you
are. You are in the Red-Black Forest, near Mile
Zero.”

The what near who?
she thought to herself, but the man was still
talking.

“. . . now you know where you are and where you are going!” the Salesman said.
“You are only
mostly
lost.”

“But I still don’t know how to get there!”

“Hmm,” he hmmed, thinking it over. “I know someone you should talk to: a
wise lady named Eponymous Bach.”

“Where is she?”

“She lives in Bach Haus at the end of Bach Way, in the town of—”

“Bach?”

“How did you guess? Bach is an excellent Composer. At the very least, she can name your
problem.”

That sounded like a much better plan than waiting for moss to grow!

“Okay, I’ll do it. Will you go with me?”

“I would love to, Laurie. But I’ve just come from visiting Bach,” said the
Salesman.

“Oh. That means you can’t go back, right?”

“Right. I can take you up to the road, but from there you are on your own.”

The Wandering Salesman showed her the way to the edge of the forest. Just past the last tree
was a road sign. “Ah, here we are,” he said. “Route One, Mile Zero.”

“I’ve never seen a Mile
Zero
,” said Laurie.

“Everything has to start somewhere. It may not look like much, but this is a very
special place. You might even say it’s the starting point of the whole System.”

“What comes after Mile Zero?”

“Mile One, of course. And right after that is the town of Bach. Are you
ready?”

“Yes, I think so. Thank you!”

“You’re welcome, Laurie. Good luck! Maybe our paths will cross again.” The
Wandering Salesman headed off, cowbells and pans rattling, to a place he’d never been
before.

And so did Laurie.