Global warming means bad winters

kw: book reviews, science fiction, global warming, climatology, near-future, alternate history, trilogies

I read Kim Stanley Robinson's Forty Signs of Rain a few years ago, before beginning these reviews. The second book in the trilogy, Fifty Degrees Below, came out about a year ago, and Sixty Days and Counting is due out in a half year (Spring 2007).

Fifty Degrees Below continues Frank's assignment at NSF, working with Director Diane Chang. Frequently, the book goes on as a pure continuation of its forerunner, so much so that one can get a little lost if reading it without having read the other. A trilogy author has to balance the needs of readers who first encounter a sequel against those familiar with earlier work. I know too much explaining the "obvious" can get annoying to one's more faithful readers, but annoying new readers is also risky.

There are two stories here. The private story of Frank's love life is woven into a realistic portrayal of a major expected effect of polar warming: shutdown of the Gulf Stream. This portrait is well-researched and well-presented. It ought to be required reading by all policy makers, particularly those (sadly, mostly 'conservatives' who are bent on anything but conservation) who deny human-caused (or at least human-emphasized) warming.

Frank comes across as a neo-cave man. As the novel opens, he must move out of a borrowed apartment, and recent severe flooding in the DC area has driven housing costs very high. He winds up living in a "distributed" home: his office, the back of his van, a tree shelter, and a health club. A flood-damaged park near the National Zoo is his backyard. He hangs with homeless guys and begins running with a small band of compulsive Ultimate Frisbee players. They are portrayed like a neolithic hunting party in their camaraderie...rather apropos, I'd say.

The book ends with a massive effort to re-start the Gulf Stream with a half million tons of salt, and with Frank's love interest in hiding from her "blacker than black" spook of an ex-husband.

A subtext is electronic surveillance via "chips", poppy-seed-size microwave transponders, the offspring of the RFID chips retailers want to put in clothing (eventually all goods). A little physics knowledge is the spoiler here: The most efficient wavelength a single-wire antenna can transmit is four times its length. A millimeter-size chip, unless it's attached to a longer wire, works best at a 4-mm wavelength, or a frequency of 75 Ghz. Even at this resonant frequency, the received (and thus echoed) signal strength is proportional to the square of the antenna length, so you just can't get much of a signal into or out of such a little chip, even at its best frequency.

Passive RFID (no battery) works by bathing the chip in pulses of strong microwaves at its resonant frequency; the chip is briefly powered by each pulse to respond with a serial number modulating that frequency. So, some of the energy runs the little processor that encodes the number, and most of the rest can get re-emitted.

I'm a radio ham, and have fooled around with microwaves. RFID works pretty well at frequencies in the 1-3 Ghz range. Such devices require a 1- to 3-inch (25 to 75 mm) antenna. You only lose about half the energy if you coil the antenna up, as long as it is still the size of a dime, more or less. However, remember that the energy capture, and thus that available for re-radiation, drops as the square of the length of the antenna.

Inch-size chips work at ranges of a few inches, less than a foot even with a 3-inch straight antenna, unless you whack them with a large microwave pulse, large enough for someone to feel. Then their "echo" can be detected a few meters away. You need an expensive sniffer that can send a big pulse, then turn on a very sensitive receiver in a nanosecond or less to receive the return signal. Go from 75mm to 3mm in wavelength, and the signal drops by a factor of 625. You can receive it from a few meters away only if you have a meter-size dish pointed exactly at the little chip!

The rice-grain-size passive chips people now put in their dogs work at a range of about six inches. You have to sweep the reader over the dog's back at least that close. You're not going to drive down the street and pick up an echo from your dog's chip. Although I expect technology to improve a lot, I suspect chips cannot get any smaller than a sesame seed, and still be detected by a doorway-mounted device as you step through.

The use of tiny chips does lend a frisson of drama to the narrative. I just wish the author had thought, you don't need to destroy chips or even shed them to avoid detection. If you know a chip is in your sweater, just wrap your sweater in foil and drop it into a carry bag. The dark gray bags made of conductive plastic, that many electronic components come in, are ideal "chip shields." If someone should implant a chip in your arm, you can hide by wearing any long-sleeved shirt with a lot of metallic threads woven in. These aren't popular now, but I expect them to resurge...

There is a lovely scene in the book, a regatta at the North Pole. The sun is depicted as standing still in the sky on midsummer's day. Actually, it'll circle the sky at an elevation of 23 degrees. I wonder how many readers will catch that one.

However, pardon my quibbles; the book is a great read, and on a subject with which I have much sympathy. I'm awaiting Sixty Days and Counting.