What was going on when I was born?

OUT there, far, far away where Earth is a mere pinpoint of light and the Sun is a pale disk of diminishing consequence, a hardy little spacecraft cruises on and on into the unexplored. No machine of human design has ever gone so far. Pioneer 10 has traveled to the reaches of Pluto, a distance it achieved yesterday, and is advancing toward the edge of the solar system. From out there, now 2.7 billion miles away, Pioneer's eight-watt radio transmitter sends faint messages back to Earth every day, whispers of discovery. The transit time of these reports, traveling at the speed of light, is 4 hours and 16 minutes. And by the time the signals arrive at tracking antennas, they have all but vanished, their strength reduced to 20-billionths of a watt. But scientists with the patience to extract the signals out of the background noise and to decipher their messages are learning for the first time what it is like in the outermost solar system. It is cold and dark and empty, as they knew it must be. A tenuous wind of solar particles, the million-mile-an-hour solar wind, still blows outward. Cosmic rays race inward. A virtual vacuum it may be, but nothingness, it seems, is a relative condition.

A proliferation of laws and regulations controlling the administration of Federal programs continues to cause widespread confusion despite efforts by the Reagan Administration to ease the problem, according to a new nonpartisan study. The Advisory Commission on Intergovernmental Relations, a research agency created by Congress, reached this conclusion in an extensive report on the effects of Federal regulation on state and local governments. An advance copy of the report's findings and recommendations, to be published in several weeks, was made available to The New York Times. The agency found that President Reagan's efforts to reduce burdensome regulations have helped businesses more than state and local governments.

PUBLIC high school students are spending less time on traditional academic subjects and more on ''personal service'' courses such as driver education or home economics than their counterparts did in the 1960's, according to a new study. The study, based on analysis of 8,800 high school transcripts, also found that the proportion of students in academic, or collegepreparatory, programs had declined by a quarter, while the number in the less demanding ''general'' tracks had more than tripled. Cliffor Adelman, the author of the study, described these trends as a ''systematic devaluation'' of the content of American high school curriculums. He said the movement away from college-preparatory courses was ''particularly striking'' because it was occurring even among students who intended to go to college.

President Reagan has agreed to appoint a special envoy to El Salvador to help deal with political and human rights issues there, a White House official said tonight. The appointment, at ''ambassador level,'' was described by Administration sources as a gesture of conciliation toward Congress, and especially toward Representative Clarence D. Long, Democrat of Maryland and chairman of a powerful House appropriations subcommittee. Mr. Long's panel has been holding up action on the President's request for $60 million in military aid for the Salvadoran Government, which is battling a left-wing insurgency. The White House official, who declined to be identified, said he could not disclose the name of the special envoy. Details of the appointment are being included in a letter to be sent to Representative Long, according to Administration officials.

Merrill Lynch & Company - parent of Merrill Lynch, Pierce Fenner & Smith Inc., the nation's largest brokerage firm - announced yesterday that net income more than quadrupled to $126.9 million in the first quarter, a record for that period, as a result of the prolonged stock market rally and record trading volumes. In reporting these results at its annual meeting in New York, Merrill Lynch also announced a two-for-one stock split - its first stock split since becoming a publicly-owned company in 1971 - and an 11 percent increase in its quarterly dividend. The sharp rise in earnings at Merrill Lynch, which has been one of the leaders on Wall Street in diversifying in recent years into other financial services, is in line with similar first-quarter gains at other big brokerage and investment banking concerns. For example, net income at the E.F. Hutton Group rose more than twelvefold, while Paine Webber Inc. gained more than sixfold.

The Socialist Party of Mario Soares won general elections today but fell short of a majority that would enable it to govern alone. The results mean that the 58-year-old Socialist leader, who served twice as Prime Minister between 1976 and 1978, will be forced to seek an alliance with parties to his right. With almost three-quarters of the districts counted, the Socialists had won 35 percent of the vote, compared with 28 percent for the Social Democrats. The Communists were running at 18 percent and the Christian Democrats at 12 percent.

In a reversal of strategy, Thomson-Brandt, the nationalized French electronics company that tried to become the nucleus of a European videotape recorder industry last year, said today that it would manufacture Japanese instruments instead. Under a licensing agreement signed with Japan's Victor Company, Thomson said it will start building up to one million Japanesedesigned machines at a new factory in France by the end of this year. Others will be built by its German subsidary, Telefunken, at a plant in Berlin. Thomson's choice of a Japanese partner was in contrast to its attempt last year to develop a strong European manufacturing operation through a takeover of Grundig, a big German electronics concern.

Hugh Trevor-Roper, the British historian, who said in The Times of London on Saturday that he was satisfied with the authenticity of 60 volumes presented as the diaries of Hitler, said today that he was no longer sure the writings were genuine. Professor Trevor-Roper, who is also a director of The Sunday Times of London, said The Sunday Times would not begin publication of the diaries ''until satisfaction on this point can be had.'' The newspaper originally planned to begin publication May 8. 'Cannot Be Pronounced Genuine' Speaking to reporters after a news conference at the headquarters of Stern magazine here, Professor Trevor-Roper, who was sent to Germany in 1946 by Churchill to confirm Hitler's death, said of the documents: ''I am not saying they are not genuine. I am saying they cannot be pronounced genuine.''

A picture caption last Tuesday, describing a Capitol demonstration by Republican Representatives who favored a tax reduction, incorrectly described effects of repealing the third installment of President Reagan's cut. The Treasury Department has said a typical median-income family would lose $3,500 in tax savings from 1983 to 1988 if Congress repealed both the third year of the tax cut and the linking of taxes to inflation, scheduled to take effect in January 1985.

Stock prices fell yesterday as many investors cashed in some of their profits. The main casualties were some of the recently strong technology, transportation and brokerage issues. At the final bell, the Dow Jones industrial average was down 9.09 points, to 1,187.21. In the overall market, declining issues on the New York Stock Exchange outnumbered those that advanced in price by 1,059 to 613.

At a time when the major film studios have been retrenching, the Cannon Group, a company controlled by two Israeli cousins, has grown into one of the biggest and most successful independent movie producers. This year, Cannon, based in an office on Sunset Boulevard, overlooking the storied junction of Hollywood and Vine, has achieved commercial - if not critical - acclaim with ''10 to Midnight,'' starring Charles Bronson, and ''The Last American Virgin.'' Most of its films do not even make it to American theaters. Cannon's forte is low-budget, American-style films for overseas markets. And those films have financed the company's pheneomenal growth.

THE Soviet Union, ending a yearlong silence, has revealed how 20 scientists and technicians at a research station deep in the Antarctic survived 227 days in the frigid polar winter after a fire had destroyed their life-sustaining diesel power plant. The near-tragedy, in which the powerhouse engineer was killed in a vain attempt to save the diesel units, was disclosed in interviews published in the Soviet press while the survivors were recovering from their ordeal on their way home aboard an Antarctic expedition ship, the passenger liner Bashkiriya. They reached the Black Sea port of Odessa on March 13. The incident occurred at the Vostok station, halfway between the coast and the United States outpost at the South Pole. Vostok is one of seven Soviet stations in Antarctica, and the place with the lowest recorded temperature on the earth, 127 degrees below zero Fahrenheit, in August 1960.