Recalling where you were and what you were doing when news broke of an epic event is a hackneyed but reassuring way of measuring the impact. Readers of a certain age will remember precisely where they were on hearing that President Kennedy had been shot i

Recalling where you were and what you were doing when news broke of an epic event is a hackneyed but reassuring way of measuring its impact on society.

Readers of a certain age will remember precisely where they were on hearing that President Kennedy had been shot in Dallas. Six years later some of the same people sat up until 3am to watch flickering images of man first touching the moon.

Just 10 years ago, you would have had to have been on the moon to escape the Sunday morning bulletins which broke the barely believable news that Diana, Princess of Wales, was dead.

Much more cataclysmic events have occured in the past 50 years but especially when an iconic figure dies in tragic and unpredictable circumstances, associated images seem to be seared on our collective memories like video grabs, allowing us to pause, rewind and replay them almost at will.

For those who were alive at the time, the death of President Kennedy in November 1963 is almost as vivid as that of Diana 34 years later. The doomed cavalcade, the blood-stained coat worn by widow Jackie, three-year-old John Kennedy Jnr saluting his father's coffin... compelling images that have been replayed often enough to replenish the dullest memory.

The sequences associated with Diana's death will endure as well, but there is little comparison in how the news of these events was broadcast and received.

Long before Sky and CNN, news of the Kennedy assassination came in fragments, often by word of mouth. In those halcyon days for the printed page, people eager for information gathered outside their local newspaper offices, where staff had been called in to post the latest news agency bulletins on the windows for all to see.

There was none of the instant reshuffling of television schedules we would automatically expect from broadcasters nowadays, but though I was only 10 at the time, I remember vividly that the front page of Ireland's Saturday Night, a newspaper normally devoted to the day's sport. On this evening it was filled instead with stark black and white images of what had taken place 5,000 miles away.

News of Diana's accident and death went around the world in a flash. An estimated 2.5 billion people watched the funeral; just as many had stared for hours at pictures of a tunnel in Paris, and a broken black Mercedes.

In years to come, the change in how so momentous an event as this would be dissipated on a worldwide scale might be just as pronounced.

The explosion in internet broadcasting - uncontrollable, relentless and unconfined - will have a profound impact on how true-life epics are presented and perceived, when next we witness an event that makes time stand still.

Geoff Martin, Editor, Ham&High Series