URBANA – Around the world, big screens show Tom Hanks trying to save the Vatican from antimatter that, if exposed, will destruct with enough force to vaporize a chunk of Rome.

Well, that's the fiction of "Angels & Demons" anyway.

Around the country, physicists like the University of Illinois' Kevin Pitts and Mark Neubauer – scientists who work with facilities that produce the real antimatter – will be hosting dozens of public talks about the real physics behind the movie magic.

"The movie touches on the kind of science that we do – which doesn't happen very often," Pitts said.

"We think that it's an opportunity to clarify," said Neubauer, who was at CERN, the Geneva lab that's an "Angels & Demons" plot point, when Tom Hanks visited for the movie.

Both will be clarifying on Friday, when they'll welcome anyone – kids included – to a free 7 p.m. lecture "Deciphering the Science Behind the Movie" in Loomis Lab on northeast corner of Goodwin Avenue and Green Street in Urbana on the UI campus.

"Antimatter is real, we really do produce it," Pitts said.

That happens at places like CERN or Fermilab in northern Illinois, where scientists do collide matter together at speeds a "tiny, tiny fraction lower than the speed of light," Neubauer said. "We focus energy to create different kinds of matter."

That collision creates "like a spray of lots of different kind of particles," he said.

Following a thread of Dan Brown's book and the movie, the scientists compare how in ancient times people tried to understand elements like earth and fire.

In a way, Pitts said, colliding particles is like learning about cars by crashing them to see what parts fly out. "I like to refer to it as destructive imaging," he said.

But rather than destroying the planet, the goal is to learn about it at a teeny tiny scale. "The general idea is we're trying to understand nature at the smallest level we can, ... nature at its most fundamental layer," Pitts said. "We're trying to find out more about what makes the universe tick."

Some of these particles may be used for benefits like new cancer therapy using antiprotons and in positron emission tomography (PET scans), where antimatter is used to image the human body, Pitts said.

Some particles will be matter, which Pitts said is "everything that is around us." Matter's mirror image is antimatter, particles of the opposing charge. And while most of Earth is made of of matter, very tiny amounts of antimatter exist, including in "the radioactive decay of the atoms in your body," Neubauer said.

Like in the movie, "when matter and antimatter come into contact ... then you have what's called an annihilation," Pitts said.

Well, that sounds kind of scary. In "Angels & Demons," the bad guys get hold of one-quarter gram of antimatter and threaten to blow up Vatican City.

But in 50 or so years of making antimatter in real life, "all the antimatter they've ever produced is 10-billionths of a gram," Neubauer said – sufficient energy to heat up a cup of coffee, Pitts said.

"To produce a quarter-gram would take you like 200 million years," Neubauer said.

And then there's the storage of antimatter – kept in a vacuum in the movie. But while scientists have figured out how to trap a single particle of antimatter, "as you start to add more and more, they repel each other," Neubauer said.

They also say antimatter won't make a good source of alternative energy, since it takes so much energy to collide particles to make antimatter.

But as many of the scientific facets of the book and movie have been fudged, Pitts and Neubauer say it has value, partly by raising people's interest in the real research of particle physics.

At the talk, they say they won't give spoilers to people who haven't read or seen author Dan Brown's work.

"We're gonna try to keep it non-technical," Pitts said. "We're hoping that maybe this might reach a different group of folks so we can give them a sense of what this is like."

If you go

What: Free public lecture about the science behind "Angels & Demons"

Who: University of Illinois physicists Kevin Pitts and Mark Neubauer

Where: 141 Loomis Lab, northeast corner of Goodwin Avenue and Green Street in Urbana

When: 7 p.m. Friday

For information, visit http://physics.illinois.edu/outreach/honors.