August 14, 1983

HOBOKEN NOT yet 21 and still in braces and sneakers, Edward Johnson has created a novel and, he says, much more reliable, way of interpreting electrocardiograms. Others his age - and younger - have found enzyme differences in the livers of victims of acquired immune deficiency syndrome (AIDS), built artificial lungs or kidneys or have worked on one of more than a dozen technical projects involving computers and chemistry, synthetic medicinal chemistry or biomedical studies. Eighteen young scientists took part this summer in a program at the Stevens Institute of Technology here. And they did so not for credit, but for the love of research. Most are still in their teens, and all were selected through a rigorous screening process.

EVERETT J. WARNER, a quiet man who lived 73 of his 94 years above his paint store on Main Street, was never known to attend church, but when he died last spring, he astonished the Village of Greenport by leaving most of a $2 million-plus estate to six churches and one synagogue in the village. ''He had never darkened our doors,'' said the Rev. Rocco Gallitelli, pastor of St. Agnes Catholic Church, where the late Mrs. Warner was a communicant. ''I saw him briefly when he was in the hospital, but it was more of a social visit,'' said the Rev. Joel Bibey of the First Baptist Church of Greenport. ''It was his way to say thank you to the village in which he lived all his life - he loved Greenport,'' said Oscar Goldin, his friend and president of Tifereth Israel Synagogue. There is only one string attached to the bequest. The money must be used locally. The will stipulates that it may not be transmitted to higher church authorities anywhere else.

In almost every museum in the Western world there is at this moment a new generation of curators. Not yet broken on the wheel, they can't wait to excel. They are out to form collections without parallel, to organize exhibitions that will draw visitors from all over, and to publish scholarly catalogues that will rival those of the National Gallery in London. Organized, motivated, competitive, driven and most often specialized, they came qualified, they came recommended, and they're all set to go. Yet being a curator is like conducting an orchestra. You can pass all the exams. You can be a doctor a dozen times over. But in the one case, as in the other, the only way to learn it is to do it. The great conductor of the past did not come to prominence by winning an international competition. He began as a coach in some ratty little town in the Austro-Hungarian provinces, and he did everything, all day and all night, till one day the top man got sick and someone told the coach to come running.

THE ROSENBERG FILE A Search for the Truth. By Ronald Radosh and Joyce Milton. 608 pp. New York: Holt, Rinehart & Winston. $22.50. WERE Julius and Ethel Rosenberg guilty of transmitting American atomic secrets to the Soviet Union in the 1940's, or were they scapegoats of the cold war whose execution was a grave miscarriage of justice? That both are true is the intriguing argument of Ronald Radosh and Joyce Milton in their definitive account of the controversial case, ''The Rosenberg File: A Search for the Truth.''

No pine tar was involved, but the Mets still got embroiled in an odd brush with the rules last night in Shea Stadium while they were defeating the Chicago Cubs, 5-1, for the 10th victory in their last 13 games. The victory was chiefly the work of Tom Seaver and Jesse Orosco, whose pitching helped the Mets survive their strange encounter with the umpires over ''coach's interference.'' The coach was Bobby Valentine, who was accused of trying to prompt a balk by the Cubs' pitcher. Instead of a balk Valentine prompted a ruling by the umpires that wiped out the runner at third base and removed the coach from the game for unsportsmanlike conduct.