What was going on when I was born?

At 7 A.M., when the miners gather here at the edge of the Bitterroot Mountains, the air is sweet with the smell of Douglas fir. By 7:15, the men have descended 5,000 feet in a narrow elevator shaft and walked 800 feet along the muddy quartzite corridors to a work space where the 85-degree air is thick with humidity. For six to eight hours, they will drill, dynamite and clear away ore. Silver miners, like businessmen, prefer to return to the same work space every day, but lately at the Hecla Mining Company's Lucky Friday Mine here, many have been shifted around to drill at the richest part of the vein. Two major mines and a smelter have already been closed in the Silver Valley, a sliver of wooded land 20 miles long and 5 miles wide. Given the low quality of the ore at the mines, along with rising production costs and declining metals prices, they were no longer economical to operate. Another mine has been closed temporarily.

AS public attention focuses on such land-based missiles as the MX and the Pershing 2, the United States Navy is accelerating development of a submarine-launched ballistic missile expected to dramatically increase naval destructive power. The missile, known as Trident 2, is intended to give the Navy's missile submarines a potency comparable to virtually any land-based weapons system. It also may complicate efforts to bring the arms race under control. ''Trident 2 will be the most destabilizing first-strike weapon ever built,'' Representative Thomas J. Downey, a member of the House Budget Committee study group on defense, asserted early this year. The Suffolk Democrat's opinion is shared by some, but by no means all, arms controllers.

David Begelman was removed today as chairman and chief executive officer of United Artists, the second major movie studio he has been forced to leave. Mr. Begelman resigned under pressure from Columbia Pictures in 1978 some months after he had been accused of embezzling $61,008 from Columbia by forging checks and of taking an additional $23,000 in improperly documented expenses. He pleaded no contest to those charges. Although no reason was given for his latest departure, most of the 11 films that were made by United Artists under Mr. Begelman's leadership have failed to make money at the box office.

Giddings & Lewis Inc., one of the nation's largest machine tools manufacturers, rejected today as ''inadequate'' a $260 million takeover offer by the American subsidiary of AMCA International Ltd. of Montreal and urged its shareholders to vote against the bid. However, the AMCA International Corporation of Hanover, N.H., said it would continue with its $25-a-share offer for all of Giddings's 10.4 million shares outstanding. Some analysts said that AMCA could raise its bid. ''It's the weakest rejection I've ever seen,'' said Peter von Ond, a securities analyst at Nesbitt, Thomson, Bongard Inc., a brokerage firm in Montreal. ''Giddings can't find a 'white knight' to come to its rescue; they don't have any legal challenges and investors are ready to take the money and run.''

The provision in the Senate Finance Committee's tax bill authorizing the withholding of income taxes on stock dividends and interest payments, once given little chance of success, is gaining adherents, and passage by the House now seems likely, House Demoratic sources said over the weekend. ''The opposition we expected isn't there yet,'' a Democratic aide said. Similarly, the ranking Republican on the Ways and Means Committee, Barber B. Conable Jr. of upstate New York, was reported by industry and Congressional sources to have tempered his earlier opposition. ''It's something he thinks is worth looking at,'' said a source close to Mr. Conable.

''We ourselves are satisfied on the basis of the evidence available to us that the Argentine Government accepts that active hostilities are at an end, thereby enabling us to act on the release of prisoners of war in accordance with Article 118 of the third Geneva Convention.'' - Statement of the British Foreign Office on the Falkland conflict. (A10:4.)

CHICAGO A PROGRAM offering loans to parents of college students, which the Reagan Administration had counted on to help compensate for the cuts in student aid, has been seriously hampered by bankers' reluctance to participate. Some of the nation's largest lending institutions, including the Chase Manhattan Bank in New York, Continental Illinois Bank in Chicago and the Bank of America in San Francisco, have declined to participate in the program, even though they all offer traditional student loans. ''Bankers are not sure of how this program should be administered, and that lack of clarity has inhibited them,'' said Edward Fox, president of the Student Loan Marketing Association, a quasi-public agency, known as Sallie Mae, that finances state loan associations. According to Sallie Mae officials, most of the nation's 14,000 banks have balked at participating. When Congress changed the Guaranteed Student Loan Program to exclude families with annual incomes above $30,000, the expectation was that an alternative, known as Parent Loans for Undergraduate Students, would fill the gap. This program, established in the Carter Administration, makes loans of up to $3,000 to parents, with the interest rate, now 14 percent, based on the average yearly rate for certain Treasury bills. Repayment of interest must begin 60 days after the loan is taken out.

International Washington lifted the sanctions it imposed against Argentina at the outbreak of the Falkland war. But Administration officials said the ban on military sales remained in effect, pending a review of both the situation in the Falklands and any progress Argentina has made in human rights. (Page A1, Column 6.) Release of the last 593 Argentines held by Britain was scheduled after London received assurances from Buenos Aires that it planned no further military action over the Falklands. Declaring the war officially at an end, the Foreign Office said that the prisoners would be sent home as soon as possible. (A10:3-5.)

Negotiations between hospital workers, ranging from X-ray technicians to laundry handlers, and 55 voluntary hospitals and nursing homes in New York City and on Long Island are at a stalemate, and the workers' union has issued a strike notice for Thursday morning. If there is a strike, doctors, nurses and administrators will stay on the job, keeping the institutions open for curtailed services. In the last five days there have been virtually no negotiations between the union, District 1199 of the National Union of Hospital and Health Care Workers - which is negotiating the contract for 46,000 of its 70,000 members -and the League of Voluntary Hospitals and Homes of New York. A league spokesman, James S. Vlasto, called the situation ''gloomy.''

IN sharp contrast to early fears, the birth control pill does not appear to cause any cancer, according to recent research, and, in fact, evidently protects many women from getting cancers, particularly those of the ovaries and of the lining of the uterus. American and British researchers have found that the protection seems to last as a long as a decade after a woman stops taking the pill. The findings, pointing to an extraordinary instance in which a drug appears to prevent cancer, are only part of the evidence suggesting that the pill, although not entirely free of hazard, has wide-ranging health benefits. A review of the recent medical literature shows that other unexpected effects of the pill range from reduced incidence of irondeficiency anemia to pelvic inflammation to, perhaps, rheumatoid arthritis.

Members of Parliament reacted with shock and indignation today to a report that an intruder sneaked into Queen Elizabeth's bedroom in Buckingham Palace early Friday morning. Disclosing details of the incident at a noisy session of the House of Commons, Home Secretary William Whitelaw said the Queen had dealt with the situation in a ''calm way.'' He also said that security measures at the palace would be intensified. Mr. Whitelaw spoke after Members of Parliament publicly criticized the security of the palace. Politicians and the public, who have long assumed the heavily guarded palace to be secure, were shocked by the report of the intrusion, which was published in The Daily Express this morning.

Shortly after retaining bankruptcy counsel last December, Western Airlines installed as its chairman and chief executive officer Neil G. Bergt, who promised to make the carrier profitable by the third quarter of this year. Several months later, after cutting its yearly labor costs by about $70 million, increasing its daily flights to 68 from 29 and restructuring its route system, the airline says there is a good chance it will report a second-quarter profit. And with a recent ruling by a Civil Aeronautics Board law judge in favor of Western's proposed merger with Wien Air Alaska, another piece of Mr. Bergt's survival plan appears to be falling into place. Cautious on Forecasts Nonetheless, Western is not making any claims just yet. Industry analysts as well as Western's lenders and employees note that labor concessions were won for only a year, that Western's total liabilities stood at $465 million by the end of the first quarter and that the Wien merger is still subject to C.A.B. and shareholder approval.