Is technology bringing history to life or distorting it?

When John F. Kennedy's convertible was crossing Dealey Plaza, he was five minutes from the Trade Mart in Dallas, where 2,000 people were waiting to hear him give a speech. The president never spoke those words.

Until now. Sort of.

Fifty-five years later, in one of the many groundbreaking and controversial ways history is becoming less about dates and more about data, technology has extended Camelot by another 18 minutes. JFK finally delivered that last speech in his own “voice.”

Taking more than 116,000 snippets of speech from samples of the 35th president's other recordings, a Scottish “voice cloning” firm has produced a Kennedy-esque rendition of his final scripted words:

“America's leadership must be guided by the lights of learning and reason,” a virtual version of that unmistakable Boston Brahmin accent intones, “or else those who confuse rhetoric with reality and the plausible with the possible will gain the popular ascendancy with their seemingly swift and simple solutions to every world problem.”

The effect is powerful, if not perfect. At its best, Kennedy is clearly doing the talking; hearing him complete his mission for that day has moved many listeners to tears. At its worst, a robotic inflection on some phrases makes it sound like JFK inhabits an automated voice mail system. (“Press two for racial justice in our time.”)

Whatever its shortcomings, the Kennedy speech is just the latest way that history is being digitally re-created, updated and manipulated as never before. From meticulously colorized photographs to immersive virtual-reality battlefields, scholars, artists and entrepreneurs are dragging the old days into the computer age. And scholastic standards are straining to keep up.

The U.S. Military Academy is working on a phone-based app along the lines of Pokémon Go that will let visitors see how George Washington's troops strung a massive iron chain across the Hudson River. A team in North Carolina has synthesized an important but unrecorded 1960 speech by Martin Luther King Jr., acoustically accurate down to the echoes in the Durham church.

Another has created a visual and acoustic model of John Donne's 1622 “Gunpowder Plot Sermon” in the courtyard of London's St. Paul's Cathedral, complete with archaic English and murmuring yeomen. A future, theater-based version may include the smells of horse dung and rotting fruit.

The digital-age ability to make history more visceral has many in the field giddy.

“It feels a little like we've been given the ability to time travel,” said Seth Denbo, director of digital initiatives at the American Historical Association.

But not everyone is embracing the magic. For many history purists, creating images and sounds that depend on guesswork, subjective choices and even acting rubs against cherished academic norms. How do you footnote the barking of a medieval dog?

“I did have one senior professor say, 'This is a bridge too far for me,' and resign from my advisory committee,” said North Carolina State University historian John Wall, who led the digital re-creation of Donne's sermon with a grant from the National Endowment for the Humanities.

Kennedy scholar Jeff Shesol said he appreciated the interest the synthesized JFK speech was bringing to a little-known bit of presidential rhetoric. But he found the audio rendition to be “creepy and unsettling.”

He compares the undelivered Dallas speech to a solemn address written for President Nixon if the Apollo 11 moon landing had ended in catastrophe.

“The power of these speeches is that they were never given,” said Shesol. “There is a cognitive dissonance for me hearing Kennedy's voice utter words that he never uttered.”

Denbo, who has a doctorate in history from the University of Warwick in England, compares the potential of digital history to the enormous popularity of video games, such as the historically accurate blockbuster Assassin's Creed. “The appeal isn't just the excitement of playing the game, it's also getting an idea of what these historical spaces and experiences were like for people in the past,” he said.

Enthusiasts say technology allows students - and customers - to tap into the feelings behind the facts. A colorized photo of a frightened little girl in Auschwitz makes her less like an archived shadow and more like children we see every day. It is easier to comprehend how Henry V spurred his outnumbered troops into battle by hearing his exhortations rather than just reading them.

Victoria Gallagher has long studied King's “Fill Up the Jails” speech, delivered at Durham's White Rock Baptist Church in 1960. It came soon after the first of the lunch counter sit-ins and is considered King's pivotal endorsement of nonviolent confrontation.

But no recording of the night has ever been found. So she made one.

“We're not trying to create an exact replica,” said Gallagher, a University of North Carolina communications professor and head of the school's Virtual MLK project. “What we are trying to do is give people a real sense of what it was like to be in that church.”

The recreation combines performance, scholarship and tech. The team put 250 people in a church of the correct dimensions after acoustic engineers wired it from pulpit to balcony. Actor Marvin Blanks delivered the speech. Played back in a special room at the campus library with Dolby 5.1 Surround Sound and 270 degrees of 3-D images, well ...

“I tell you what, people have started to cry being in that space,” Gallagher said.

The project is now working on an animated virtual-reality version, in which goggle-wearing viewers will be able to move about an animated sanctuary. A student has already performed King wearing a motion-capture suit. They are purchasing digital “assets” from gaming companies, where it has proved tricky to find off-the-shelf humans to fill the pews.

“It's interesting how few black people they have available who are not thuggish,” Gallagher said.

The Kennedy project was the idea of Alan Kelly, a JFK-admiring ad man in Dublin. With funding from his firm, Rothco, and the Times of London, he hired CereProc, a Scottish technology firm that creates digital voices for people who lose their own through disease (including one for film critic Roger Ebert).

Mining more than 800 Kennedy speeches, technicians clipped individual bits of speech called phonemes, and then every phoneme next to every other phoneme. They ran the file through proprietary software and typed in the Dallas speech.

“We can get the voice to say anything,” said CereProc's Graham Leary. Not that they would. “We don't want him saying things he never would have said.”

What could go wrong?

Kelly said the public response has been positive. But when he offered to give the recording to the John F. Kennedy Library in Boston?

“They sent back a fairly curt, 'Not at this time,' “ Kelly said.

In an email to The Washington Post, a library official said, “This work would not fall into the guidelines of materials that we accept.”

Institutions are watching as the booming field of “digital humanities” struggles to remain attached to academic moorings. An international body of scholars has developed a set of guidelines known at the London Charter. And practitioners are working on ways to let the viewer know how much of what they're experiencing is based on primary sources and where the facts come from and how much is interpretation.

Lisa M. Snyder has experimented with many ways to annotate the hyper-detailed digital models of Chicago's 1893 World Columbian Exposition she's been developing for 20 years. In some, she has rendered sections that are based on conjecture in a lighter shade than those that can be documented, just as dinosaur skeletons have plaster fill-ins for the missing bones.

Now her team, with NEH funding, is creating ways for footnotes to automatically reveal themselves as users navigate the cyber-setting. “When you're walking near the transportation building, information about the color scheme will pop up,” Snyder said.

Color has been a big challenge for an event that was documented in black-and-white. For clues about the hues, she mines all manner of newspaper accounts, watercolors of the scene, faded guidebooks.

“I do a tremendous amount of research,” said Snyder, an architectural historian at UCLA. “But in the end, this is my interpretation of what it looked like.”

Color is also the digital palette for Brazilian artist Marina Amaral, who has gained a following with her carefully researched tinting of historical images. Her photos include haunting updates of Abraham Lincoln, Rasputin and a turn-of-the-century banana dock in New York. Her recent colorization of the Auschwitz headshot of 14-year-old Czeslawa Kwoka went viral.

“The research is the most important part of the process,” Amaral said by email. “I am aware that these photographs are historical documents, and I want to be as accurate as possible.”

Amaral and other historical-photo tinters have stepped into a manipulation debate that rages from newspaper photo departments to museum archives. But some historians give her credit for her deep research and fine hand.

“I think these are amazing,” said Samuel Wheeler, the state historian of Illinois, based at the Lincoln Presidential Library in Springfield.

It was Civil War photography that sparked his career choice in the first place, Wheeler said. Seeing carefully done color versions only adds to his understanding, and excitement.

“I think color photography heightens people's empathy,” he said. “Black-and-white is a cue to a bygone era. These don't replace the originals, they add to them.”

Historians are counting on technology to make the subject more interesting for young people whose ideas of olden times may stretch only to the BlackBerry era.

At West Point, the number of history majors has doubled in the last five years as the department has launched a multitude of digital projects. It has created an interactive textbook with animated maps, “The West Point History of Warfare,” and is working on virtual renditions of Gettysburg, Antietam and Julius Caesar's Gallic campaign. Students recently flew drones over Normandy to capture images for an augmented reality program that can produce, with a regular smartphone, a 3-D hologram of the invasion on a tabletop.

“We're bringing D-Day to every cadet at West Point,” said Col. Ty Seidule, head of the academy's history department. “From my perspective, history is too important to be boring.”