A Shortcut Through Time: The Path to the Quantum Computer - Softcover

Johnson, George

Softcover

ISBN 10: 0375726187 ISBN 13: 9780375726187

Verlag: Knopf Doubleday Publishing Group, 2004

Inhaltsangabe

In this remarkably illustrative and thoroughly accessible look at one of the most intriguing frontiers in science and computers, award-winning New York Times writer George Johnson reveals the fascinating world of quantum computing—the holy grail of super computers where the computing power of single atoms is harnassed to create machines capable of almost unimaginable calculations in the blink of an eye.

As computer chips continue to shrink in size, scientists anticipate the end of the road: A computer in which each switch is comprised of a single atom. Such a device would operate under a different set of physical laws: The laws of quantum mechanics. Johnson gently leads the curious outsider through the surprisingly simple ideas needed to understand this dream, discussing the current state of the revolution, and ultimately assessing the awesome power these machines could have to change our world.

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Über die Autorin bzw. den Autor

George Johnson writes about science for The New York Times. His most recent books, Strange Beauty: Murray Gell-Mann and the Revolution in Twentieth-Century Physics and Fire in the Mind: Science, Faith, and the Search for Order, were finalists for the Aventis and Rhone-Poulenc science book prizes. He has also won the AAAS Science Journalism Award. He is codirector of the Santa Fe Science-Writing Workshop and a former Alicia Patterson fellow. Mr. Johnson lives in Santa Fe. He can be reached on the World Wide Web at talaya.net.

Auszug. © Genehmigter Nachdruck. Alle Rechte vorbehalten.

Chapter 1

"Simple Electric Brain Machines and How to Make Them"

I don't know where I first saw the advertisement for the Geniac Electric Brain construction kit, but I knew I had to have one for Christmas. It was the early 1960s, and like a lot of science-crazed kids I was obsessed with the wonderfully outrageous idea of "thinking machines." I devoured the picture stories in Life magazine and the Saturday Evening Post about the electronic behemoths manufactured by companies like International Business Machines, Univac, and Remington Rand. The spinning tape drives and banks of blinking lights were as exciting to me as the idea of space travel. Two of my favorite books were Tom Swift and His Giant Robot and Danny Dunn and the Homework Machine-testaments to the eerie fantasy of automating human thought. One day, flipping through one of my favorite magazines-probably Boys' Life or Popular Science-I stumbled upon an unbelievably tantalizing ad.

"Can you think faster than this Machine?"

Below the provocative headline was a picture of the Geniac with its sloping panel bedecked with six large dials and a row of ten bulbs. Who knew what kind of mysterious circuitry was hidden inside?

"GENIAC, the first electrical brain construction kit, is equipped to play tic-tac-toe, cipher and decipher codes, convert from binary to decimal, reason in syllogisms, as well as add, subtract, multiply and divide. . . . You create from over 400 specially designed and manufactured components a machine that solves problems faster than you can express them." Such was the promise of the Oliver Garfield Co., 126 Lexington Avenue, New York 16, N.Y. (This was before zip codes replaced the old numbered postal zones.) To a boy growing up in Albuquerque, the location of this modern Frankenstein laboratory seemed promisingly exotic and far away.

"Send for your GENIAC kit now. Only $19.95. . . . We guarantee that if you do not want to keep GENIAC after two weeks you can return it for full refund plus shipping costs."

There was nothing to lose. I began my lobbying effort, making it clear to my parents that receiving a Geniac was all that mattered to me. Then I waited, my brain charged with the kind of high-voltage anticipation that can only accumulate in someone still in the first decade of life.

Christmas morning I sat on the floor anxiously opening presents, keeping my eye out for one large enough to hold the pieces of an electronic computer. Finally a likely box emerged from behind the tree. I tore off the wrapping.

Decades later I still remember the disappointment I felt as I explored the contents of the cardboard package. The title of the instruction manual was intriguing enough: "Simple Electric Brain Machines and How to Make Them." But how was anyone to carry out such an ambitious project with the meager, humdrum parts that had been supplied?

Digging through the pile, I was crestfallen to find that the bulk of the kit consisted of some decidedly low-tech pieces of particle board called Masonite: a big square one and six smaller round disks, each drilled with concentric patterns of little holes. This was complemented by an assortment of hardware you might find in a kitchen junk drawer or a toolbox in the garage: ten flashlight bulbs and sockets, a battery and battery clamp, a spool of insulated wire, several dozen nuts, bolts, and washers, a bunch of small brass-plated staples (referred to in the typewritten instructions as "jumpers"), and the tools for assembling this detritus into what would supposedly function as a digital computer-a hexagonal wrench for gripping bolts (a "spintite") and a screwdriver.

Finally there was a simple on-off switch, described rather melodramatically in the manual: "This is the switch that enables you to put suspense and drama into your machine; for you set everything the way it should be, then talk about it and explain it, and finally when you have your listener all keyed up and ready, you (or he) throw the switch . . ."

I'd been had. There were no vacuum tubes, no transistors, or capacitors, or resistors-the colorful components I'd found from eviscerating dead radios and TV sets. All I'd gotten for Christmas was a handy-dandy kit for stringing together mindlessly simple circuits of switches and bulbs. The nuts and bolts were to be placed in various holes on the square wooden panel and connected one to the other by wires running underneath. The little metal jumpers were to be inserted into holes in the Masonite disks, the ends bent over to keep them in place. When the disks were attached to the panel, with more bolts and washers, they could be turned to and fro so that the jumpers touched the heads of the bolts, forming connections that caused the lightbulbs to flash on and off. It was all just switches-simple enough for a child to understand.

Reluctantly I opened the manual, published, disconcertingly, in 1955, and saw that it contained the familiar explanations of the wonders of electricity. ("You can think of a battery as a pump, which is able to push electrons, or little marbles of electricity, away from the plus end of the battery and towards the minus end of the battery . . . A flow of electrons is an electric current.")

The instructions went on to show how to assemble circuits and switches into various question-answering machines.

1.Whom do you prefer: (a) Marilyn Monroe? or

(b) Liberace?

2.How would you put a thread in a small hole: (a) wet it? or (b) tap it?

3.Would you rather spend a day: (a) shopping on Fifth Avenue? or (b) hunting in the woods?

Depending on how you answered these and three other questions (rotating the six circular switches so that they pointed to A or B), the current in the wiring would flow to one of two bulbs, M or F. The result was called a "Masculine-Feminine Testing Machine."

Never mind the musty Eisenhower-era philosophy. Scientifically, the whole thing seemed obvious and dumb. Just changing the paper labels would turn the machine into a tester for, say, whether you were a Jock or a Brain (the 1960s version of "nerd"): "Would you rather spend a rainy afternoon: (a) building a crystal radio? or (b) working out in the gym?" The meaning was all in the eye of the beholder.

As I paged through the manual, other projects appeared slightly more interesting. The switches could be wired to make machines that added numbers. Turn dial A to indicate the first number, turn dial B to indicate the second, and if the copper paths behind the panel had been correctly platted, the lightbulb that came on would be the very one labeled with the proper answer. (And if you made a mistake and didn't feel like redoing the wires, you could just move around the tags.)

Rig the machine another way and you could subtract or multiply. Wire up the "Reasoning Machine" described on page 25 of the guide and turning switch A to indicate "All fighter pilots are bomber pilots" and switch B to "No bomber pilots are jet pilots" would light the bulb for "No fighter pilots are jet pilots." QED. A syllogism (and a reminder that something can be logical but not true).

It was all terribly anticlimactic. Only years later would I realize that an utterly profound idea was slowly insinuating itself into my head: a computer is indeed just a box with a bunch of switches. The Geniac was "semiautomatic," as the manual put it: You had to turn the dials by hand to light the lights. And to "reprogram" the machine, you had to unscrew nuts with the "spintite" and shift the wires around. But suppose that some of the bulbs were replaced with little motors. When activated by the proper combination of settings, the...

Details zur Ausgabe

• Verlag: Knopf Doubleday Publishing Group
• Erscheinungsdatum: 2004
• Sprache: Englisch
• ISBN 10: 0375726187
• ISBN 13: 9780375726187
• Einband: Taschenbuch
• Anzahl der Seiten: 224
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: preigu; mail@preigu.de; ; Lengericher Landstr. 19; Osnabrück; 49078; Deutschland