WITH the impudence of crab grass, hoaxes are popping up on the May landscape. Two networks, NBC and ABC, bought film purported to show the blaze over Chernobyl as photographed by a Yugoslav tourist less than 10 miles away. The infernal sight turned out to be smoke pouring from the chimneys of a cement factory in Trieste, Italy.
Then a man who deserves to remain anonymous appeared on a couple of talk shows that surely want to remain anonymous, passing himself off as the founder of a service called the Fat Squad. If you happened to be on a diet -- and were faltering -- the Fat Squad, Inc. would send a trained and vigilant employee to your home to put you and your refrigerator under 24-hour surveillance. Mattresses would be shaken down at night for the hidden candy bar.
A midnight snack of potato chips stashed in your linen closet behind the lavender sachet? Forget it. These are pros, these are experts.
To prove it, a somewhat overweight woman appeared with the anti-flab entrepreneur, testifying to the ruthless benefits of the service.
Somebody finally caught on. The woman turned out to be an actress, the man a veteran hoaxster, last seen peddling the healthful virtues of powdered roaches.
He maintained -- one last hoax? -- that he was exposing the gullibility of the news media as a public service. That's what they all say.
A third case of merry Maytime hoax is the publication of ``The Pentagon Catalog,'' compiled by Christopher Cerf and Henry Beard for Workman Publishing Company. The motto of ``The Pentagon Catalog'' reads, ``We will not be oversold,'' adding: ``If you find that any of the products listed in this catalog are offered for sale by a retail outlet or mail-order company at a higher price, bring us that price and we will top it.''
There follow detailed drawings and descriptions of a $2,043 nut, a $7,622 coffeemaker, a $74,165 ladder, and a famous toilet seat.
This is not a hoax, you say? These are the outrageous prices paid by the real-life Pentagon to real-life contractors?
Well, what do you know!
Chris and Hank actually footnote and document their price tags. Still, let the description stand: hoax. After all, somebody is being flimflammed, fellow taxpayers.
``The Pentagon Catalog'' came out just after 98 percent of the members of the National Academy of Sciences declared they doubted that ``star wars'' -- the biggest single military expenditure ever projected -- would provide an effective shield against a nuclear attack.
This is not saying that the Strategic Defense Initiative is a hoax. But what with the cement factory in Trieste, the Fat Squad, and ``star wars,'' we are living so close to the edge of science-fiction fantasy that a little tilt, one way or the other, makes about as much sense as everything else.
We have to remind ourselves how vulnerable we are to hoaxes in this frenzied world where ``facts'' and ``factoids'' are freely dispensed without much discrimination, and any hypothesis can be blithely described as ``fail-safe'' -- even when it involves experiments on the nuclear frontier.
Indeed, the sober habits of patient verification that protect us from errors seem to be coming under fire. When more than 6,500 scientists presented a petition to Congress pledging to turn down money for ``star wars'' research, this was not seen as an act of conviction and some self-sacrifice on the part of those who would stand to profit, Pentagon-Catalog style, by keeping their mouths shut.
Instead, the under-secretary of defense for research and engineering has threatened to cut off funds to universities whose scientists express honest and informed doubts about the workability of a weapons system.
``I have a tough time with disloyalty,'' the under-secretary, Donald Hicks, has been quoted as saying. ``If they want to go out and use their roles as professors to make statements, that's fine. It's a free country. . . . I'm also free not to give the money.''
But can scientists demonstrate loyalty more profoundly than by advising laymen of the truth as they see it? Should they tell everybody that the O-rings are just fine because they sense that's the A-OK message their administrators want to hear?
A lot of Americans have spent the past month chiding the Soviets for not being open and forthcoming about the available data on Chernobyl. It would be inconsistent to chide our scientists for being too open and forthcoming about what they know, or believe they know. And it would be indecent to intimidate them for speaking up to the best of their knowledge by rewarding them with a metaphorical Siberia.
The evidence is in, from Galileo on: If the findings of scientists are subject to political pressures, science itself turns into a hoax.
A Wednesday and Friday column