FSF, October-November 2006
Page 23
According to the physicists, that's not what's going on at all. They say that the electrons are moving. When you turn on the headlights, you throw a switch and complete an electric circuit. That circuit is a path along which negatively charged electrons can move.
Electrons move from the negative terminal through the headlights to the positive terminal. Though the lights come on as soon as you throw the switch, an electron will take several hours to make the journey from the negative terminal to the positive terminal. (But that's a story, which we'll save for another day.)
So here's the problem. Electricians talk about electricity as Franklin did. They treat electric current as if it goes from the positive terminal of the battery, through the circuit, to the negative terminal. That's how they talk about it. They give this mythical flow of positive charges a name: the conventional current.
Even after all these years at the Exploratorium, there are days when Pat is not so sure she believes in atoms, electrons, protons, and other particles too small to see. (This is a situation that will be corrected or exacerbated over the next year. Pat is currently working on a project dealing with nanotechnology, which is all too small to see. More on that next column.) But even on days when Pat accepts atoms without blinking, even on days when she can accept the flow of electrons through the wire, she has a problem with the flow of positives that engineers talk about.
There is no flow of positives. That positive flow is the legacy of Ben Franklin and his electric fluid. The original model for understanding electricity—which was very useful when Franklin came up with it—lives on to make trouble.
Of course, that's the way science works. Any model we have for the universe—whether it's a model for light or a model for electricity or whatever—breaks down at some point. The model is not the thing. The model is a human invention—a fantasy—intended to explain the thing. It's a way of understanding the invisible, the intangible.
The trick in science is picking the simplest model that gives the right answer. And Franklin did that as well as he could at the time. He realized that the model involving the two kinds of electricity postulated by others could be simplified, and he did so. And in doing so, he left us with a mythical current that flows in the direction that electrons do not.
About Those Lightning Rods
We can't leave a discussion of Ben Franklin and electricity without mentioning the story that every schoolchild knows: Ben Franklin flew a kite in a thunderstorm. Why? To generate sparks so that he could compare the behavior of those sparks to the charges generated in his down-to-earth experiments. As a result of this experimentation, he proposed that lightning was nature's own electrostatics experiment.[1]
[Footnote 1: Franklin was lucky. When Georg Richmann repeated this experiment in St. Petersburg lightning struck the kite, came down the string and killed the experimenter. If you learn one thing from this story it is this: don't fly a kite in a thunderstorm!]
Having made the connection between electrostatics experiments in the laboratory and those in nature, Franklin found a practical application for his new ideas and invented the lightning rod. A lightning rod is a metal rod sticking up from the rooftop of a building and connected by a good conductor (a heavy copper wire) into the earth.
A full explanation of how a lightning rod works is a little tricky. Paul can demonstrate how it works with a Van de Graaff generator, the static electricity device near to the hearts of science demonstrators everywhere. Suppose you had set up a metal object near a Van de Graaff generator and had sparks jumping happily from the generator to the metal object. Suppose you used an insulated handle to hold a pointed metal rod connected to the earth (referred to by electricians as the “ground") and bring the point near the Van De Graaff generator. The sparks would stop.
Why? Because when a pointed object is electrically charged, electric forces are concentrated near the point. These forces rip apart air molecules, ionizing them. The space around the point is filled with charged particles, which discharge the generator faster than charge can build up.
The same thing happens with a lightning rod. The pointed rod discharges the local electrostatic charges and helps prevent a lightning strike.
Franklin's discovery that lightning is an electrical discharge had an enormous social impact. With Franklin's invention, people could protect themselves from lightning, a wild force of nature. At the time, this accomplishment was regarded by many as being just as important as his role in the American Revolution. As Anne-Robert Jacques Turgot wrote of him in 1776: “Eripuit caelo fulmen, sceptrumque tyrannis” ("He snatched lightning from the sky and the scepter from tyrants").
Since Franklin's time, scientists have continued studying lightning. Yet they still do not have a model that explains it fully. They know that in most cumulonimbus clouds a region of negative charge forms near the bottom of the cloud while a region of positive charge forms near the top. But they don't know the mechanism by which the charge is separated inside the cloud, or why falling raindrops leave some of their charge at the bottom of the cloud as they continue to fall to the ground.
To measure the charge distribution in the clouds, adventurous scientists fly gliders into these thunderstorms with an electronic version of your tape electroscope. Did you ever wonder what you can do with a bachelor's degree in physics? At the National Center for Atmospheric Research, Paul once saw a job listing looking for someone with a bachelor's degree in physics, a glider pilot's license , and parachuting experience. The job was flying gliders into thunderstorms. Why did the applicant need parachute experience? Because the thunderstorms sometimes ripped the wings off the gliders!
You now know better than to fly a kite in a thunderstorm, but there are plenty of dangerously intriguing scientific puzzles yet to be solved for those who would like to follow in Ben Franklin's footsteps.
The Exploratorium is San Francisco's museum of science, art, and human perception—where science and science fiction meet. Pat Murphy and Paul Doherty both work there. To learn more about Pat Murphy's science fiction writing, visit her web site at www.brazenhussies.net/murphy. For more on Paul Doherty's work and his latest adventures, visit www.exo.net/~pauld.
Coming Attractions
For the December issue, our cover story is a new one by M. Rickert, whose “Journey into the Kingdom” was considered breathtaking by a good portion of our readership. In “The Christmas Witch,” she takes us to New England, where a long local tradition of witchcraft has some very modern—and very horrific—results.
Fans of Jonathan Strange & Mr. Norrell will be glad to hear that we have a story by Susanna Clarke scheduled to run next month. In fact, it's a tale of the Raven King, but even if you haven't read Ms. Clarke's novel, you're apt to find “John Uskglass and the Cumbrian Charcoal Burner” a delightful read.
We also expect to see that intrepid explorer of the nosphere, Guth Bandar, return next month in a new adventure from the mind of Matthew Hughes. In “Bye the Rules,” Bandar's rivalry with Didrick Gabbris attains new heights (or lows, depending on one's perspective).
Looking ahead, we've got lots of great stories in the works, including new ones by A. A. Attanasio, Fred Chappell, Ron Goulart, Marta Randall, and Bruce Sterling. Subscribe now and you'll reap the rewards throughout the year.
Pol Pot's Beautiful Daughter (Fantasy) by Geoff Ryman
Much of Geoff Ryman's work has shown a strong interest in Asia, including The Unconquered Country and more recent stories such as “The Last Ten Years in the Life of Hero Kai” (from our Dec. 2005 issue), the award-winning novel Air, and his most recent book, The King's Last Song. In case you can't guess from the title, his new story is about Cambodia. It's completely untrue and highly compelling.
In Cambodia people are used to ghosts. Ghosts buy newspapers. They own property.
A few years ago, spirits owned a house in Phnom Penh, at the Tra Bek end of Monivong Boulevard. Khmer Rouge had murdered the whole family and there was no one left alive to inherit it. People cycl
ed past the building, leaving it boarded up. Sounds of weeping came from inside.
Then a professional inheritor arrived from America. She'd done her research and could claim to be the last surviving relative of no fewer than three families. She immediately sold the house to a Chinese businessman, who turned the ground floor into a photocopying shop.
The copiers began to print pictures of the original owners.
At first, single black and white photos turned up in the copied dossiers of aid workers or government officials. The father of the murdered family had been a lawyer. He stared fiercely out of the photos as if demanding something. In other photocopies, his beautiful daughters forlornly hugged each other. The background was hazy like fog.
One night the owner heard a noise and trundled downstairs to find all five photocopiers printing one picture after another of faces: young college men, old women, parents with a string of babies, or government soldiers in uniform. He pushed the big green off-buttons. Nothing happened.
He pulled out all the plugs, but the machines kept grinding out face after face. Women in beehive hairdos or clever children with glasses looked wistfully out of the photocopies. They seemed to be dreaming of home in the 1960s, when Phnom Penh was the most beautiful city in Southeast Asia.
News spread. People began to visit the shop to identify lost relatives. Women would cry, “That's my mother! I didn't have a photograph!” They would weep and press the flimsy A4 sheets to their breasts. The paper went limp from tears and humidity as if it too were crying.
Soon, a throng began to gather outside the shop every morning to view the latest batch of faces. In desperation, the owner announced that each morning's harvest would be delivered direct to The Truth, a magazine of remembrance.
Then one morning he tried to open the house-door to the shop and found it blocked. He went ‘round to the front of the building and rolled open the metal shutters.
The shop was packed from floor to ceiling with photocopies. The ground floor had no windows—the room had been filled from the inside. The owner pulled out a sheet of paper and saw himself on the ground, his head beaten in by a hoe. The same image was on every single page.
He buried the photocopiers and sold the house at once. The new owner liked its haunted reputation; it kept people away. The FOR SALE sign was left hanging from the second floor.
In a sense, the house had been bought by another ghost.
This is a completely untrue story about someone who must exist.
* * * *
Pol Pot's only child, a daughter, was born in 1986. Her name was Sith, and in 2004, she was eighteen years old.
Sith liked air conditioning and luxury automobiles.
Her hair was dressed in cornrows and she had a spiky piercing above one eye. Her jeans were elaborately slashed and embroidered. Her pink T-shirts bore slogans in English: CARE KOOKY. PINK MOLL.
Sith lived like a woman on Thai television, doing as she pleased in lip-gloss and Sunsilked hair. Nine simple rules helped her avoid all unpleasantness.
1. Never think about the past or politics.
2. Ignore ghosts. They cannot hurt you.
3. Do not go to school. Hire tutors. Don't do homework. It is disturbing.
4. Always be driven everywhere in either the Mercedes or the BMW.
5. Avoid all well-dressed Cambodian boys. They are the sons of the estimated 250,000 new generals created by the regime. Their sons can behave with impunity.
6. Avoid all men with potbellies. They eat too well and therefore must be corrupt.
7. Avoid anyone who drives a Toyota Viva or Honda Dream motorcycle.
8. Don't answer letters or phone calls.
9. Never make any friends.
There was also a tenth rule, but that went without saying.
Rotten fruit rinds and black mud never stained Sith's designer sports shoes. Disabled beggars never asked her for alms. Her life began yesterday, which was effectively the same as today.
Every day, her driver took her to the new Soriya Market. It was almost the only place that Sith went. The color of silver, Soriya rose up in many floors to a round glass dome.
Sith preferred the 142nd Street entrance. Its green awning made everyone look as if they were made of jade. The doorway went directly into the ice-cold jewelry rotunda with its floor of polished black and white stone. The individual stalls were hung with glittering necklaces and earrings.
Sith liked tiny shiny things that had no memory. She hated politics. She refused to listen to the news. Pol Pot's beautiful daughter wished the current leadership would behave decently, like her dad always did. To her.
She remembered the sound of her father's gentle voice. She remembered sitting on his lap in a forest enclosure, being bitten by mosquitoes. Memories of malaria had sunk into her very bones. She now associated forests with nausea, fevers, and pain. A flicker of tree-shade on her skin made her want to throw up and the odor of soil or fallen leaves made her gag. She had never been to Angkor Wat. She read nothing.
Sith shopped. Her driver was paid by the government and always carried an AK-47, but his wife, the housekeeper, had no idea who Sith was. The house was full of swept marble, polished teak furniture, iPods, Xboxes, and plasma screens.
Please remember that every word of this story is a lie. Pol Pot was no doubt a dedicated communist who made no money from ruling Cambodia. Nevertheless, a hefty allowance arrived for Sith every month from an account in Switzerland.
Nothing touched Sith, until she fell in love with the salesman at Hello Phones.
Cambodian readers may know that in 2004 there was no mobile phone shop in Soriya Market. However, there was a branch of Hello Phone Cards that had a round blue sales counter with orange trim. This shop looked like that.
Every day Sith bought or exchanged a mobile phone there. She would sit and flick her hair at the salesman.
His name was Dara, which means Star. Dara knew about deals on call prices, sim cards, and the new phones that showed videos. He could get her any call tone she liked.
Talking to Dara broke none of Sith's rules. He wasn't fat, nor was he well dressed, and far from being a teenager, he was a comfortably mature twenty-four years old.
One day, Dara chuckled and said, “As a friend I advise you, you don't need another mobile phone."
Sith wrinkled her nose. “I don't like this one anymore. It's blue. I want something more feminine. But not frilly. And it should have better sound quality."
"Okay, but you could save your money and buy some more nice clothes."
Pol Pot's beautiful daughter lowered her chin, which she knew made her neck look long and graceful. “Do you like my clothes?"
"Why ask me?"
She shrugged. “I don't know. It's good to check out your look."
Dara nodded. “You look cool. What does your sister say?"
Sith let him know she had no family. “Ah,” he said and quickly changed the subject. That was terrific. Secrecy and sympathy in one easy movement.
Sith came back the next day and said that she'd decided that the rose-colored phone was too feminine. Dara laughed aloud and his eyes sparkled. Sith had come late in the morning just so that he could ask this question. “Are you hungry? Do you want to meet for lunch?"
Would he think she was cheap if she said yes? Would he say she was snobby if she said no?
"Just so long as we eat in Soriya Market,” she said.
She was torn between BBWorld Burgers and Lucky7. BBWorld was big, round, and just two floors down from the dome. Lucky7 Burgers was part of the Lucky Supermarket, such a good store that a tiny jar of Maxwell House cost US$2.40.
They decided on BBWorld. It was full of light and they could see the town spread out through the wide clean windows. Sith sat in silence.
Pol Pot's daughter had nothing to say unless she was buying something.
Or rather she had only one thing to say, but she must never say it.
Dara did all the talking. He talked about how the
guys on the third floor could get him a deal on original copies of Grand Theft Auto. He hinted that he could get Sith discounts from Bsfashion, the spotlit modern shop one floor down.
Suddenly he stopped. “You don't need to be afraid of me, you know.” He said it in a kindly, grownup voice. “I can see, you're a properly brought up girl. I like that. It's nice."
Sith still couldn't find anything to say. She could only nod. She wanted to run away.
"Would you like to go to K-Four?"
K-Four, the big electronics shop, stocked all the reliable brand names: Hitachi, Sony, Panasonic, Philips, or Denon. It was so expensive that almost nobody shopped there, which is why Sith liked it. A crowd of people stood outside and stared through the window at a huge home entertainment center showing a DVD of Ice Age. On the screen, a little animal was being chased by a glacier. It was so beautiful!
Sith finally found something to say. “If I had one of those, I would never need to leave the house."
Dara looked at her sideways and decided to laugh.
The next day Sith told him that all the phones she had were too big. Did he have one that she could wear around her neck like jewelry?
This time they went to Lucky7 Burgers, and sat across from the Revlon counter. They watched boys having their hair layered by Revlon's natural beauty specialists.
Dara told her more about himself. His father had died in the wars. His family now lived in the country. Sith's Coca-Cola suddenly tasted of anti-malarial drugs.
"But ... you don't want to live in the country,” she said.
"No. I have to live in Phnom Penh to make money. But my folks are good country people. Modest.” He smiled, embarrassed.
They'll have hens and a cousin who shimmies up coconut trees. There will be trees all around but no shops anywhere. The earth will smell.
Sith couldn't finish her drink. She sighed and smiled and said abruptly, “I'm sorry. It's been cool. But I have to go.” She slunk sideways out of her seat as slowly as molasses.