What was going on when I was born?

A Federal judicial panel today consolidated 18 lawsuits against the Union Carbide Corporation for pretrial proceedings in New York City. The pending suits, all filed in this country, grow out of the gas leak disaster at Bhopal, India. Lawyers in the case said they expect more than 20 other pending Bhopal cases - and possibly all similar cases yet to be filed - to go to the same Manhattan court, the Federal District Court for the Southern District of New York. In today's ruling, the Judicial Panel on Multidistrict Litigation called New York the most convenient place to consolidate such cases, partly because of the proximity of Union Carbide's headquarters at Danbury, Conn.

Stella Fernandez, a short, bubbly widow in her 50's, seemed an unlikely president of the 75-member Van Nest Civilian Patrol as she puttered about her kitchen, deftly tossed chicken stuffing, spooned it into a plump roaster and then sat down to wait patiently for it to cook. What is equally deceptive is the community - a 24-square-block enclave of tightly packed, two-story frame houses developed in the late 19th century before there were paved streets. ''It's all kind of cozy, like a little village where nothing ever happens,'' she said of the area at the bottom of a funnel formed by the Penn Central railroad tracks veering northeast and the Bronx River Parkway heading northwest. But things do happen in Van Nest and in all the other close-knit, Balkans-like neighborhoods that make up the 49th Precinct, the city's newest. Despite its appearance, this is the city, with all its attendant concerns. There are seven resident-manned, volunteer civilian block patrols within the area.

''INSTEAD of wedding 'until death do us part,' couples will enter matrimony knowing from the start that the relationship is short-lived. And when the opportunity presents itself, they will marry again . . . and again . . . and again.'' This prophecy, made by Alvin Toffler 15 years ago in his classic work, ''Future Shock,'' is coming true, according to therapists and divorce lawyers who see a growing number of people who have been married three and even four times. ''A generation or two ago you entered a marriage and you stayed with it for better or worse,'' said Dr. Clifford Sager, director of family psychiatry at the Jewish Board of Family and Children's Services in New York City. ''Today we are seeing much more short-term bonding, with an increasing number of men and women going through serial marriages.'' The professionals and those who have been through serial marriages cite many reasons. Among them: the comparative ease of divorce, and the greatly lessened social stigma that it now carries; a romanticization of marriage that cannot live up to the long-term reality; a ''flip the dial'' attitude that fosters moving on as soon as problems or ennui set in; the economic independence of women; a level of affluence that makes multiple families possible for some; an attitude among the so-called me generation that places fulfillment of personal needs ahead of compromise or sharing, and medical advances that have prolonged vigorous life.

Maj. Gen. Joseph A. McChristian, who was chief of intelligence for Gen. William C. Westmoreland in Vietnam for two years, testified yesterday that General Westmoreland acted improperly in 1967 by delaying a cable to Washington reporting higher enemy strength because it would be ''a political bombshell.'' ''It was improper not to send a strength report forward based on political considerations,'' General McChristian told the jury in the trial of General Westmoreland's $120 million libel suit against CBS. General McChristian, who left Vietnam for another assignment two weeks after the cable incident, recalled General Westmoreland saying he wanted to study the cable, and he testified that he did not know what the commander had done with the data in it. The basis for General Westmoreland's suit is a 1982 CBS documentary, ''The Uncounted Enemy: A Vietnam Deception,'' that charged a ''conspiracy'' by General Westmoreland's command in Vietnam in 1967 to show progress in the war by understating North Vietnamese and Vietcong strength. General Westmoreland testified last November that he wanted a full briefing on General McChristian's new figures and eventually informed his superiors of the data. But General McChristian contradicted General Westmoreland's testimony about the cable incident on a number of points. And he took issue with General Westmoreland's testimony that the Vietcong's self-defense forces were not a military threat and could not be counted accurately.

Under strong pressure from its lenders, Eastern Airlines yesterday began struggling to reach important labor agreements by 12:01 A.M. tomorrow, a timetable set by the company's labor consultant, William J. Usery. Mr. Usery set the deadline as part of a broad package of proposals aimed at reaching agreement with Eastern's three major unions. Eastern endorsed the proposals, but separately said it would continue to impose wage concessions ranging from 18 to 22 percent, a position that is anathema to the unions. Initial reaction to the Usery plan itself by one major union official was negative.

All of their recollections of Auschwitz seemed to begin the same way. They arrived at the station, the train door slid open, and they tumbled out onto the walkway, where they heard the voice of a Nazi guard shouting above the tumult: ''Twins, twins, are there any twins here?'' None of the Jewish twins knew at the time that by responding to this beckoning call they would become guinea pigs in the grotesque human experiments of the Nazi SS doctor Josef Mengele, who was known as the ''Angel of Death'' for the way he dispatched people to the gas chambers with a flick of his wrist but often with the softest smile on his lips. Roughly 100 of those twins, dwarfs and others who survived Dr. Mengele's Auschwitz experiments gathered in Jerusalem over the last three days for an international hearing. It was part of the worldwide ceremonies marking the 40th anniversary of the liberation of the death camp and was intended to draw attention to the crimes of the Nazi doctor, who remains at large to this day.

''You get the impression,'' said Joan Pine, wife of the Professor of the Year, ''that he's not smart enough to put up an umbrella if it's raining.'' For the record, Mrs. Pine is happily married and appears to be the model of conjugal allegiance. She volunteers that her husband, Charles, is a genius, and she likes to tell the story of how, when he was preparing for his doctoral finals, he came to a new topic cold the night before the test and had it mastered by morning. A quick study who gets his head wet, which is another way of saying that genius is often otherwise engaged. Now, for example, at lunch, the Professor of the Year is so deep in Pythagoras that he has just stuck his arm into his apple pie and ice cream.

THURSDAY, FEBRUARY 7, 1985 International Australia will have to renege on a pledge to aid American planes in monitoring a planned MX missile test. In an announcement that apparently startled American officials, Prime Minister Robert Hawke said he would have to cancel the agreement to provide Australian base facilities for United States surveillance planes because of opposition in his party. (Page A1, Column 4.) About 100 Jewish survivors who were brutalized in the Auschwitz medical laboratories of Dr. Josef Mengele have gathered in Jerusalem for an international hearing. The meeting, attended by twins, dwarfs and others, is part of worldwide ceremonies marking the 40th anniversary of the liberation of the death camp. The hearing is designed to draw attention to the crimes of the Nazi doctor, who remains at large. (A1:3-5.)

For many corporate treasurers the financial world is much safer these days because of a new technique to manage risk called the interest rate swap. But accountants and banking regulators are growing increasingly concerned that not enough is known about the risk it poses to the financial institutions that arrange and stand behind the burgeoning amount of these swaps. ''As more transactions are done with a greater spectrum of companies this becomes a more important issue,'' said Thomas Macy, chairman of the banking committee of the American Institute of Certified Public Accountants and a partner of Price Waterhouse. Also looking closely at the risk implications of the swaps business are the Federal Reserve Board, the Securities and Exchange Commission, the Comptroller of the Currency and the Financial Accounting Standards Board. E. Gerald Corrigan, the new president of the Federal Reserve Bank of New York, said in a speech last June that swaps are one of the new risk- hedging devices whose risks are not fully understood and that therefore they give him ''a tinge of uneasiness.''

With its 40 checkout lanes and 75 aisles, the new Bigg's ''hypermarket'' here could well be called the Mount Everest of American supermarkets. The bustling store, which is one and a half times the length of a football field, sells everything from cucumbers to computers, poultry to pocketbooks, eclairs to exercise bicycles. With 60,000 items on sale, four times that of most supermarkets, Bigg's is as much a jump from the typical supermarket as the supermarket was from the mom and pop grocery. Combination Store ''We're neither a supermarket nor a department store,'' said Jacques LeFoll, executive vice president of Hyper Shoppes Inc., the 90 percent French-owned, American-based company that runs Bigg's. ''We're both.''

THEY are a hardy lot, these flea marketeers, for even on such frigid weekends as we've had this winter they make it their business to unfold their kilims, bokharas and dhurries for display, lay out collections of 1940's chrome toasters and coffee urns, Victorian crystal jewelry, antique terra cotta and vintage clothing and pile up their Ecuadorean ponchos. To be sure, most flea markets move indoors in winter. However, three of the city's most beguiling, set up by P.T.A.'s and held half outdoors, half indoors in schoolyards and cafeterias at 77th Street and Columbus Avenue, at 67th Street off York Avenue and on Greenwich Avenue between the Avenue of the Americas and Seventh Avenue, attract hundreds of dealers. For those who set up outdoors - including survivors of the summer Greenmarkets with their jars of wildflower honey and apple cider - snow, gusts of wind and bitter cold are nothing more than temporary, though uncomfortable, costs of doing business. ''It's hard to sell in this weather,'' said Huseyin Aktug, scarf wrapped around his neck and lower jaw, dancing slightly to keep his feet warm in the schoolyard of Public School 183 on 67th Street between York and First Avenues. Behind him, hung over the schoolyard fence and laid out around him, was his collection of Oriental rugs. ''But I like to keep contact with my customers,'' he said. ''They will come back when it is warm.''

An attack on the military pension system by David A. Stockman, the budget director, drew angry responses today from veterans' groups, Pentagon officials and some Congressional champions of the military. But some key members of Congress picked up Mr. Stockman's call for reform and said this might be the year for a major overhaul of military compensation. ''I would have said it differently, but Stockman is right,'' said Representative Les Aspin, the Wisconsin Democrat who heads the House Armed Services Committee. ''Military retirement is too expensive. The Pentagon has failed to grapple with this issue.''