What was going on when I was born?

The Producer Price Index for finished goods rose six-tenths of 1 percent in June as food prices increased for the first time in seven months, the Bureau of Labor Statistics reported. Although the June rise exceeded May's unusually small gain of four-tenths of 1 percent, it was still small enough to support the Reagan Administration's contention that inflation has fallen below the ''double-digit'' rate of 10 percent a year. (Page Dl.) The Administration said that it would strongly resist protectionist pressures and mount vigorous challenges to subsidized competition and other trade-distorting measures by foreign governments. The longawaited policy statement on trade, which was approved by the Cabinet, underscores the Administration's commitment to market forces as its guiding principle in foreign trade. (D2.)

A valve at an aqueduct was opened here today, apparently by vandals, starting a chain reaction that burst two huge pipelines and cut off Newark from its main water supply. ''It's an imminent catastrophe,'' said James F. Conley, the chief engineer of Newark's Division of Water Supply. Mr. Conley said that unless the city could activate two existing pipeline interconnections with three other water supply systems and could build two new ones, parts of Newark ''will be out of water'' in five days. Other Communities Affected The pipelines that ruptured, he said, normally carry about 75 million of the 120 million gallons a day used by 600,000 people in Newark and parts of Elizabeth, Bloomfield, Belleville and Wayne. Those four other communities, all of which purchase some of their water from Newark, began planning for alternative supplies. Mayor Kenneth A. Gibson of Newark declared a water emergency in the early afternoon, prohibiting all nonessential uses of water, including lawn watering, car washing and opening of hydrants for any purposes other than firefighting.

SUPREME COURT BY STEVEN R. WEISMAN WASHINGTON, July 7 - President Reagan announced today that he would nominate Sandra Day O'Connor, a 51-year-old judge on the Arizona Court of Appeals, to the United States Supreme Court. If confirmed, she would become the first woman to serve on the Court. ''She is truly a 'person for all seasons,' '' Mr. Reagan said this morning, ''possessing those unique qualities of temperament, fairness, intellectual Remarks on Court post, page A12. capacity and devotion to the public good which have characterized the 101 'brethren' who have preceded her.'' White House and Justice Department officials expressed confidence that Judge O'Connor's views were compatible with those espoused over the years by Mr. Reagan, who has been highly critical of some past Supreme Court decisions on the rights of defendants, busing, abortion and other matters.

Gov. William A. O'Neill signed a bill today allowing doctors to prescribe marijuana cigarettes for patients suffering from glaucoma or the side-effects of cancer treatments. The General Assembly defeated a similar bill in 1980, when even Ella T. Grasso, then Governor, who suffered from prolonged nausea after radiation treatment for cancer, declined to support the idea. This spring, however, the House of Representatives unexpectedly passed the bill after Representative Robert C. Sorensen, Democrat of Meriden, told a hushed chamber he was undergoing chemotherapy and on some days faced pain so severe he could not stand erect.

The Reagan Administration plans to announce shortly that while it is committed to halting the spread of nuclear weapons abroad the United States will be a ''clearly reliable and credible'' supplier of nuclear technology for peaceful purposes. This policy is contained in an eight-point set of guidelines that has been prepared by the State Department and submitted to the White House. The White House is expected to issue the list before a meeting in Ottawa July 20-21 of the leaders of seven industrial nations. The spread of nuclear weapons will be one of the items on the agenda.

A seven-day strike against private garbage haulers in 108 northern and central New Jersey communities ended today when 1,400 drivers and loaders accepted a three-year contract that gives them a 50 percent pay increase. Garbage trucks in the 12 affected counties will begin rolling early tomorrow. and Picket signs that had blocked municipal sanitation employees will come down from entrances to landfills. The new contract was accepted after a long and confusing day in which the union members first rejected an agreement hammered out by negotiators in an 18-hour session at the Sheraton Heights Hotel in Hasbrouck Heights. When that proposal was rejected, the negotiators immediately went into new talks. The union then approved a proposal that gives the drivers the $155-a-week raise over three years that was contained in the proposal they rejected, but adds three days of sick leave a year and guarantees that double time for work on the sixth day will go to workers with seniority. The drivers currently earn $310 a week for an average sixday, 48-hour week, and the loaders get about $50 less.

Because of an editing error, an article Monday on corporate philanthropy incorrectly described the membership of the Conference Board. It includes corporations, government agencies and educational institutions.

Judge Sandra Day O'Connor's place in history is already secure, based on today's announcement that she will be President Reagan's nominee as the first woman on the United States Supreme Court. But if her past is prologue, after her Senate confirmation Judge O'Connor might well go on to leave even larger ''footprints on the sands of time,'' as Mr. Reagan, quoting Longfellow, described the mark of United States Justices. Thus far in her 51 years, Judge O'Connor has compiled an impressive list of academic, civic, political and legal achievements. ''She's finished at the top in a lot of things,'' said Mary Ellen Simonson of Phoenix, who was a legislative aide when Mrs. O'Connor was majority leader of the Arizona State Senate, the first woman in the nation to hold such a leadership position.

After several earlier unsuccessful attempts, the first solar-powered airplane succeeded today in crossing the English Channel. It took an atypically sunny English summer afternoon and a fiveand-a-half-hour flight, but late this afternoon, the Solar Challenger dropped slowly onto the concrete landing strip of Manston Royal Air Force Base, on the southeastern coast of England. Designed by Paul MacCready, who also designed the first humanpowered plane to cross the Channel, the 210-pound Solar Challenger is powered by 16,000 photovoltaic cells on the wings that convert solar energy to electricity, which drives the motor. No Battery Power Other airplanes have flown on solar power, but only the Solar Challenger has been able to do so without the help of storage batteries. The project was paid for largely by DuPont and employed many high-strength, low-weight materials made by that company.

Anti-abortion groups today denounced President Reagan's decision to nominate Judge Sandra Day O'Connor to the Supreme Court, but initial reaction in the Senate, which will vote on confirmation, was favorable. ''I commend the President for the courage of his decision,'' said Howard H. Baker Jr., the Senate Republican majority leader. ''I am delighted with his choice, and I pledge my full support for her confirmation by the full Senate.'' The National Right to Life Committee, an amalgam of anti-abortion lobbying groups in the 50 states, said that it would mobilize its members to ''prevail upon senators to oppose this nomination.'' The committee said that Judge O'Connor was ''pro-abortion'' as a member of the Arizona State Legislature.

Bishop Jozef Glemp of Warmia was named today by Pope John Paul II as Archbishop of Gniezno and Warsaw and the Primate of Poland, succeeding Stefan Cardinal Wyszynski, who died on May 28. The new head of the Church in this overwhelmingly Roman Catholic nation said he would continue the policies begun by his predecessor of dialogue and cooperation with both the Government and the Solidarity labor union. ''I am convinced I must follow the road laid out by Cardinal Wyszynski,'' he said in an interview. ''The work of the Primate is not political. It is pastoral. But if we in the church are to do our duty, we must not remain above social issues. If the Solidarity and other social movements want to follow the truth and the light, we will give them our protection. It is in line with the proper role of the church.''

''She is truly a 'person for all seasons,' possessing those unique qualities of temperament, fairness, intellectual capacity and devotion to the public good which have characterized the 101 'brethren' who have preceded her.'' - President Reagan on Sandra Day O'Connor, his nominee for the Supreme Court. (A1:6.)