What was going on when I was born?

''I am directing N.A.S.A. to begin a search in all of our elementary and secondary schools and to choose as the first citizen passenger in the history of our space program one of America's finest: a teacher.'' - President Reagan. (A1:6.)

THE world of science is belatedly recognizing the genius of one of its most important, eccentric and enigmatic inventors, Nikola Tesla. A century after he arrived penniless on the docks of New York City, Tesla is receiving credit for brilliant achievements that outdid those of his contemporaries, Edison and Marconi. And more than 40 years after the recluse died in a Manhattan hotel room, in the company of the pigeons who were his favorite companions in the final years of his life, he is at last being elevated to the pantheon of the world's great inventors. It was Nikola Tesla, not Marconi, who invented the first radio; it was Tesla, not Edison, who devised the system of electric power disribution now used throughout the world. Working in small laboratories in midtown Manhattan and Greenwich Village, Tesla invented the polyphase electric motor, the bladeless steam turbine and the radio-guided torpedo. Some scientists say it was Tesla who first conceived ideas for a ''Star Wars'' type of military shield in space.

The strike by hospital workers has been so marked by errors, bitterness and disintegrating agreements that those involved say they have never witnessed a labor dispute quite its equal. There were a number of reasons that set this strike apart; among them, the interest of the city's municipal union leaders, who are in the process of negotiating contracts for their 250,000 members. The leaders have been mindful of the influence a hospital settlement, particularly a modest one, would have on their talks, and their position was felt at the negotiations. Further complicating the process has been the position of the union representing hospital and nursing-home workers, District 1199 of the Retail, Wholesale and Department Store Workers Union, A.F.L.-C.I.O. The union, which broke its affiliation with the national union in the spring under the leadership of its president, Doris Turner, is torn by internal strife. This put Mrs. Turner in the position of negotiating under severe pressure, knowing that her future would turn on the outcome.

Atlantic Richfield said it would take a $785 million write-down against third-quarter after-tax earnings in its troubled metals and minerals businesses, which it intends to sell. With the sales proceeds, it plans to buy 25 million of its shares, probably during the next six months. (Page D1.) Atari said it would introduce a range of personal computers soon, but provided few details. It was the first major product announcement for the troubled consumer electronics concern since it was taken over in July by Jack Tramiel. (D1.)

A dispatch from Washington Thursday about investigations into reported problems with brakes in General Motors X-model cars contained two inaccuracies. It should have said that a Federal case against General Motors focused on allegations that the brakes had a tendency to lock, not that Federal officials had found a high incidence of brakes locking. Also, the case is a civil suit, not a criminal action.

President Reagan announced today that an elementary or secondary schoolteacher would be chosen as the first ''citizen passenger'' to fly into space aboard the space shuttle. His announcement temporarily dashed the hopes of thousands of other citizens, including artists, writers, journalists, entertainers, celebrities and students, who have flooded the National Aeronautics and Space Administration in recent years with requests that they be flown into space. But they and others from occupations that lost out this time may yet get their chance. The space agency said it expected to take the teacher aloft in late 1985 or early 1986 and thereafter would fly from two to four private citizens a year on shuttle missions.

Iraq has won a military advantage in its war with Iran as a result of ''massive arms sales'' to Baghdad by France and the Soviet Union and an effective American-led boycott on military sales to Teheran, a staff report of the Senate Foreign Relations Committee said. (Page A1, Col. 1.) The sixth poor Soviet grain harvest in a row appears likely. After a summer of hot, dry weather in some areas and unusually heavy rain in others, a cold snap now threatens to cut short the Siberian growing season. The United States estimates that Moscow will have to import 43 million tons of grain, only 3 million less than the record in 1982. (D1:1-2.)

The Atlantic Richfield Company said today that it would take a one-time $785 million write-down against third-quarter after-tax earnings to reflect the anticipated sale of the company's minerals and metals units and a portion of its chemical operations. The amount, which would be the difference between the value of the units and their sale price, represents 7 percent of Arco's net worth. The minerals division consists of the Anaconda Minerals Company, which owns copper, molybdenum and coal properties. The metals units includes aluminum operations that have been offered for sale to Alcan Aluminium Ltd. of Canada in a deal valued at more than $1 billion. That sale has been challenged, however, on antitrust grounds by the United States Justice Department.

The passions unleashed by the Rev. Jesse Jackson's Presidential candidacy are complicating affairs for Walter F. Mondale, particularly in the South, where supporters of the two men continue to fight each other. In many cases, Jackson partisans are angry at those blacks who worked for the Presidential nomination of the former Vice President rather than the civil rights leader. Some black Mondale supporters holding elective office are finding themselves politically threatened by Jackson followers; State Senator Julian Bond of Georgia beat back such a challenge in a primary earlier this month. In other cases, Jackson supporters are locked in opposition to party leadership more than ever on issues of local concern. The infighting is an additional burden for the Mondale campaign as the Democratic candidate works to mend fences with Mr. Jackson in a region where the black vote could be the difference between winning and losing in November. Mr. Jackson and other black political leaders meet Tuesday with Mr. Mondale over the extent to which they will campaign for the ticket.

With crime rates declining, the Justice Department reported today that the nation's prison population had reached a record of 454,136, or almost double the total of 10 years ago. This meant, the department said, that one out of every 520 Americans was in a Federal or state prison as of June 30. Steven R. Schlesinger, director of the Justice Department's Bureau of Justice Statistics, said that although the number of prisoners was at a record level, the rate of increase appeared to be slowing. ''At the same time,'' he said, ''these prisoners are at least temporarily unable to victimize the public, and this may partially explain the recent decrease in crime rates.''

TORONTO FILMS that portray extreme violence against women sexually stimulate nearly a third of all men - even though the films may contain relatively little that is explicitly sexual, according to a newly reported study. Several researchers have found, moreover, that repeated viewings of films such as ''Friday the 13th'' and ''The Texas Chainsaw Massacre'' instill attitudes in the minds of the viewers that are similar to those found in rapists. For instance, viewers, including women, become more callous in the face of the films' portrayals of violence toward women and more likely to believe that a woman who was raped wanted to be. Other data show that such scenes have proliferated in commercial films in the last two years. A survey found that one in eight movies commercially released in 1983 depicted violent acts against women, a sharp increase from 1982 when the rate was one movie in 20.

The names of six banks cited for balance sheet ''window-dressing'' have become public. Page D19. Mexico and its foreign-bank creditors achieved a major breakthrough in their debt negotiations over the weekend under which the country would be allowed to repay its debts over 14 years and at a considerably lower interest rate than it has been paying, according to banking sources.