SOLAR AND COSMIC RADIATION

When the space shuttle astronauts lost regular radio contact with the earth in early October, some confusing reports blamed this on "bursts of cosmic radiation." As it later turned out, it was an uninteresting human error (on earth), but it was a good first guess, for coincidentally there was a solar flare about that time.

A flare is a sudden eruption of both ultraviolet and corpuscular radiation. The ultraviolet part can silence short-wave communication on the illuminated half of the globe [AtE July 83], but does not affect the microwaves used for space links. But the electrons and other charged particles hurled out by the sun, though most of them are deflected by the earth's magnetic field to other regions in space, can penetrate into computer memories and slightly change the data and programs stored there. To counter this effect, the space shuttle's five computers use "obsolete" magnetic core memories, which are slower, but also less sensitive, and the programs are backed up on magnetic tape.

The phenomenon, incidentally, has little to do with the "electromagnetic pulse" (EMP) in a nuclear detonation [AtE Jul 82], though here, too, outdated but robust equipment will stand up to it better. (Some Soviet military equipment still uses vacuum tubes rather than semiconductors, but it is unclear whether this is intentional hardening against EMP or just lagging technology.)

Although space jargon calls the phenomenon a "cosmic upset," it is not really caused by cosmic rays, to which the media mostly attributed the mishap before it was forgotten along with the entire shuttle flight. (By the end of that week, Newsweek did not consider the flight worthy of space; it had to give way to Carter, Mondale and the poor girl from the lowly Italian neighborhood.)

Cosmic rays produce neutrons which react with nitrogen nuclei in the atmosphere, giving rise to radioactive carbon 14, and this is used in "carbon dating." While the fossils, bacteria and other organisms in an archeological find were alive, they breathed and absorbed C^14 fresh off the atmospheric production line, but ever since their death it has been decaying (halflife 5568 years). The C^14 now present in any object must have been there since that death; it cannot have come about by any chemical changes. Therefore if the relative activity of this isotope in the sample can be reliably measured (often it cannot), the time of death and hence the age of the object can be established.

In another space item, our August issue explained why the Soviet-planted story of the Korean airliner cooperating with the space shuttle in a spy mission was a physical impossibility. Nevertheless, the story keeps being repeated not only by the professional liars of dezinformatsiya and their parrots in The Nation, but by government-enforced-sterilization promoter David Brower [AtE Sep 84], whose article "KAL 007: What knew; when we knew it" has appeared in two "environmentalist" journals: Not Man Apart (Friends of the Earth, Sept 84) and the Sierra Club Yodeler (Sept. 84).

Brower has something to yodel about. After being fired from the Friends of the Earth for his habit of dipping into funds that are not his [AtE Sep 84], he sued the directors who fired him for such a petty technicality; and after he promised to withdraw the suit, they took him back and agreed that "no party would be required to admit any wrongdoing" (Not Man Apart, Aug. 84).