Some parts of the US economy may have slowed down, but not the flow of ideas and inventions.
In corporate research centers, basement workshops, and university laboratories, inventors keep on inventing. And in studios, theaters, and backyards, authors and artists keep on turning out their work.
A visitor to the Georgia Institute of Technology here gets just a sampling of some of the those ideas by glancing through what one official calls a ''Sears catalog'' of ideas for sale: patented inventions and copyrighted material. The catalog includes a computer program to spot potential weaknesses in bridges before they are built, a device to keep wheelchairs from rolling backward on an incline, and part of a computer system that could lead to improved air traffic safety control by faster processing of data.
In 1981 the number of patent applications was 114,710, higher than any time in the past decade. Oscar Mastin, a spokesman for the US Patent and Trademark Office, says the application rate does not appear to have slowed this year, either. The number of copyrights issued by the Library of Congress has climbed from nearly 332,000 in 1978 to more than 468,000 in the 12 months ending this September.
Selling new ideas is getting harder, however, according to those who keep scanning the creative horizons for new ideas and investors to run with them.
While coming up with an idea may not cost a great deal of money, putting it into production usually does. There is an ''incredible inertia'' in industry today when it comes to spending money on new ideas, says Tom Regino of the Rain Hill Group in New York, which tries to match inventors with investors. Foreign investments in US inventions is picking up, however, he said.
Cuts in federal funds for research of various kinds is thought to be slowing the creation of new inventions.
''For every $1 million (cut in federal funds for research) there is probably one good idea (never developed),'' says Steve Bacon, a spokesman for Research Corporation, which tries to match university inventors with investors.
Only a small percentage of new works ever brings a profit to the authors or inventors, but that apparently does not discourage some people from trying.
Universities, which account for only about 2 percent of the patents issued in the United States, are looking to royalties on creations by their staffs as a way to help fund further research. One idea making about $500,000 a year in royalities for Georgia Tech is the program for testing bridge and building weaknesses before construction.
In a second-floor laboratory, computer scientist David B. Green III, who helped design the program now licensed for use by several major companies, lightly taps some simulated data into the keyboard of a computer. He wants to know how much weight an arch can hold.
He gets his answer in a long list of numbers, but to make their meaning clearer, he taps again and the list is replaced by an orange arch - collapsing. Had it been a real test, lives might have been saved by avoiding faulty construction.
Inventions by individuals account for about one out of four patents issued. Georgia Tech's switchboard was inundated with calls from private inventors when a magazine article mentioned the university's work in preparing patent applications (which they do only for staff and faculty inventors).
Inventors ''can't understand'' why it has become harder to sell their ideas, says Vladimir Dvorkovitz of Ormond Beach, Fla., an organizer of technology fairs where ideas and investors are brought together.
But while US firms may be showing increased reluctance now to invest in new ideas, ''some of the more interesting inventions are being grabbed'' by Europeans or the Japanese, says Mr. Dvorkovitz. Foreign inventors are active, too. The percentage of US patents issued to foreign inventors has increased to 37 percent since 1965.