Television news junkies were entertained the other day with pictures of sound technicians attempting to recreate the noise of President Kennedy's assassination. The chaps had been sent to Dallas by the House Assassination Committee, which is attempting to find out what really, really, really happened there 15 years ago, as well as what transpired in Memphis when Dr. Martin Luther King was murdered 10 years ago.

The money being cast on the ground with these endeavors is less important than the mind set of the people, inside Congress and out, who want this done. What they are attempting is to know the unknowable. It's like trying to communicate with God on His level.

First off, it's impossible to recreate anything. Nothing happens the same way twice, not even if you stage it, for the very good reason that to duplicate an event you have to know what happened and if they knew what happened that day in Dallas, they would hardly need to do this to find out.

Beyond that, you can't ever know what happened any time, any place anywhere. Our best knowledge is approximate, secondary and variable. No event illustrates the point better than the murder of John Kennedy.

Here is this man, gunned down at high noon or shortly after, in front of hundreds if not several thousand persons, many of whom pride themselves on being trained observers - the police and news people who were present. As if that were not enough, a movie was made of the actual shooting, not to mention innumerable snapshots.

If there has ever been an event the exact particulars of which are known and understood, shouldn't it have been this one? If we still don't know precisely what happened, the answer lies with what constitutes knowledge. Or, as they say, what's to know?

Nevertheless, the hunt goes on for Lee Harvey Oswald's accomplices. They've even used computers to scan and rescan every photograph taken on that day to resolve those hidden others and make them come out of the shadows. Yet they elude detection.

Through the years of doubting, the Warren Commission findings stand. The holes remain, the contradictions, the unanswered questions, and yet the conclusions of that sloppy and unsatisfactory commission hold, because if Oswald didn't do it, nobody did. Oswald and the Warren Commission or it didn't happen.

Nevertheless, the search, always unavailing, for some trace of the conspiracy is ever pushed forward. Since the murder of the president, the term conspiracy nut has lost its original meaning of someone drawn to join conspiracies. Now it means someone who's convinced there is one.

Are conspiracy nuts nutty? Not really. You can understand them when you study James Earl Ray telling his story to the committee and the nation. Can this minor-league crook work his murderous way on us all?

It is those thoughts which propel people to look for a conspiracy.

The search for conspiracy is the search for purpose. We need to believe it was not armed, meandering morons who did these things, but a malevolent intelligence. That way, awful as the assassinations are, there is a point to them. In place of aimless evil, we seek for deliberate evil, for then there is the possibility of deliberate good.

That's why the phrase so often repeated by officialdom - "He acted alone" - makes us crackers. These degraded, despicables are spiritually unacceptable.

The converse of a Ray or a Sirhan is the true conspirator, the terrorist. The IRA bomber, the arsonists who burned 300 people alive in Iran the other day, the kidnap/killers of Aldo Moro - all these acts were committed by sane, thoughtful persons who believe they had been given the right. Those technicians in Dallas stumble on, not realizing that what they seek to discover is ever so much worse than random, maniac murders, because after the madman has stopped, the purposeful violence goes on.