Bruce Sterling - Essays. FSF Columns

Or so it's hoped -- and planned. The real Internet of the future may bear very little resemblance to today's plans. Planning has never seemed to have much to do with the seething, fungal development of the Internet. After all, today's Internet bears little resemblance to those original grim plans for RAND's post- holocaust command grid. It's a fine and happy irony.

How does one get access to the Internet? Well -- if you don't have a computer and a modem, get one. Your computer can act as a terminal, and you can use an ordinary telephone line to connect to an Internet-linked machine. These slower and simpler adjuncts to the Internet can provide you with the netnews discussion groups and your own e-mail address. These are services worth having -- though if you only have mail and news, you're not actually "on the Internet" proper.

If you're on a campus, your university may have direct "dedicated access" to high-speed Internet TCP/IP lines. Apply for an Internet account on a dedicated campus machine, and you may be able to get those hot-dog long-distance computing and file-transfer functions. Some cities, such as Cleveland, supply "freenet" community access. Businesses increasingly have Internet access, and are willing to sell it to subscribers. The standard fee is about $40 a month -- about the same as TV cable service.

As the Nineties proceed, finding a link to the Internet will become much cheaper and easier. Its ease of use will also improve, which is fine news, for the savage UNIX interface of TCP/IP leaves plenty of room for advancements in user-friendliness. Learning the Internet now, or at least learning about it, is wise. By the turn of the century, "network literacy," like "computer literacy" before it, will be forcing itself into the very texture of your life.

For Further Reading:

The Whole Internet Catalog & User's Guide by Ed Krol. (1992) O'Reilly and Associates, Inc. A clear, non-jargonized introduction to the intimidating business of network literacy. Many computer- documentation manuals attempt to be funny. Mr. Krol's book is *actually* funny.

The Matrix: Computer Networks and Conferencing Systems Worldwide. by John Quarterman. Digital Press: Bedford, MA. (1990) Massive and highly technical compendium detailing the mind-boggling scope and complexity of our newly networked planet.

The Internet Companion by Tracy LaQuey with Jeanne C. Ryer (1992) Addison Wesley. Evangelical etiquette guide to the Internet featuring anecdotal tales of life-changing Internet experiences. Foreword by Senator Al Gore.

Zen and the Art of the Internet: A Beginner's Guide by Brendan P. Kehoe (1992) Prentice Hall. Brief but useful Internet guide with plenty of good advice on useful machines to paw over for data. Mr Kehoe's guide bears the singularly wonderful distinction of being available in electronic form free of charge. I'm doing the same with all my F&SF Science articles, including, of course, this one. My own Internet address is bruces@well.sf.ca.us.

Here on my desk I have something that can only be described as

miraculous. It's a big cardboard envelope with nine thick sheets of

black plastic inside, and on these sheets are pictures of my own brain.

These images are "MRI scans" -- magnetic resonance imagery from

a medical scanner.

These are magnetic windows into the lightless realm inside my

skull. The meat, bone, and various gristles within my head glow gently

in crisp black-and-white detail. There's little of the foggy ghostliness

one sees with, say, dental x-rays. Held up against a bright light, or

placed on a diagnostic light table, the dark plastic sheets reveal veins,

arteries, various odd fluid-stuffed ventricles, and the spongey wrinkles

of my cerebellum. In various shots, I can see the pulp within my own

teeth, the roots of my tongue, the boney caverns of my sinuses, and the

nicely spherical jellies that are my two eyeballs. I can see that the

human brain really does come in two lobes and in three sections, and

that it has gray matter and white matter. The brain is a big whopping

gland, basically, and it fills my skull just like the meat of a walnut.

It's an odd experience to look long and hard at one's own brain.

Though it's quite a privilege to witness this, it's also a form of

narcissism without much historical parallel. Frankly, I don't think I

ever really believed in my own brain until I saw these images. At least,

I never truly comprehended my brain as a tangible physical organ, like

a knuckle or a kneecap. And yet here is the evidence, laid out

irrefutably before me, pixel by monochrome pixel, in a large variety of

angles and in exquisite detail. And I'm told that my brain is quite

healthy and perfectly normal -- anatomically at least. (For a science

fiction writer this news is something of a letdown.)

The discovery of X-rays in 1895, by Wilhelm Roentgen, led to the

first technology that made human flesh transparent. Nowadays, X-rays

can pierce the body through many different angles to produce a

graphic three-dimensional image. This 3-D technique, "Computerized

Axial Tomography" or the CAT-scan, won a Nobel Prize in 1979 for its

originators, Godfrey Hounsfield and Allan Cormack.

Sonography uses ultrasound to study human tissue through its

reflection of high-frequency vibration: sonography is a sonic window.

Magnetic resonance imaging, however, is a more sophisticated

window yet. It is rivalled only by the lesser-known and still rather

experimental PET-scan, or Positron Emission Tomography. PET-

scanning requires an injection of radioactive isotopes into the body so

that their decay can be tracked within human tissues. Magnetic

resonance, though it is sometimes known as Nuclear Magnetic

Resonance, does not involve radioactivity.

The phenomenon of "nuclear magnetic resonance" was

discovered in 1946 by Edward Purcell of Harvard, and Felix Block of

Stanford. Purcell and Block were working separately, but published

their findings within a month of one another. In 1952, Purcell and

Block won a joint Nobel Prize for their discovery.

If an atom has an odd number of protons and neutrons, it will

have what is known as a "magnetic moment:" it will spin, and its axis

will tilt in a certain direction. When that tilted nucleus is put into a

magnetic field, the axis of the tilt will change, and the nucleus will also

wobble at a certain speed. If radio waves are then beamed at the

wobbling nucleus at just the proper wavelength, they will cause the

wobbling to intensify -- this is the "magnetic resonance" phenomenon.

The resonant frequency is known as the Larmor frequency, and the

Larmor frequencies vary for different atoms.

Hydrogen, for instance, has a Larmor frequency of 42.58

megahertz. Hydrogen, which is a major constituent of water and of

carbohydrates such as fat, is very common in the human body. If radio

waves at this Larmor frequency are beamed into magnetized hydrogen

atoms, the hydrogen nuclei will absorb the resonant energy until they

reach a state of excitation. When the beam goes off, the hydrogen

nuclei will relax again, each nucleus emitting a tiny burst of radio

energy as it returns to its original state. The nuclei will also relax at

slightly different rates, depending on the chemical circumstances

around the hydrogen atom. Hydrogen behaves differently in different

kinds of human tissue. Those relaxation bursts can be detected, and

timed, and mapped.

The enormously powerful magnetic field within an MRI machine

can permeate the human body; but the resonant Larmor frequency is