The Earth's geomagnetic field is dying -- and that spells Doomsday for this planet.

The good news is that it could take another billion years to happen. The bad news is that it could occur within the next century.

Prominent California geophysicist J. Marvin Herndon lays it all out in a theory to be officially announced at 5 p.m. today in Washington by the National Academy of Sciences. The scenario he envisions is the product of decades of research into the Earth's core and its relation to the geomagnetic field. But much to his astonishment, a new Paramount movie, The Core, has conjured up a vision of Armageddon which Herndon finds uncannily close to his own.

In the film, opening March 28, unexplained catastrophes begin afflicting the globe. Humans wearing pacemakers drop dead without warning. Birds go mad when they lose their powers of navigation and begin throwing themselves against buildings. The Golden Gate Bridge in San Francisco and the landmarks of ancient Rome start ripping themselves apart and collapsing. Electrical storms proliferate and wreak havoc everywhere, causing hundreds of lightning strikes per square kilometre. And there's the threat of worse to come -- of airplanes falling from the sky and of a microwave radiation effect which will literally cook the planet.

When Herndon finally saw the movie three nights ago he repeatedly found parallels between his own research and the screenplay by producer Cooper Layne and Ottawa writer John Rogers.

"The movie depicted very well some of the things that might happen," he says. But he says the film doesn't exaggerate and that it could have envisaged further catastrophic events. "Electrical currents induced in power line grids would blow out transformer stations all over the world. You would have currents induced in oil and gas pipelines. Radio communication would no longer exist. Satellite electronics would be short-circuited.

"Ultimately we will have to face the same kind of problems facing people in the movie and, ultimately, we won't have a way to fix it."

Herndon has spent his life pondering the puzzle of the Earth's magnetic field. He's following in the footsteps of Albert Einstein, who once acknowledged that this is "one of the most important problems in physics."

Herndon's focus has been on the Earth's core and its relationship to the geomagnetic shield. The latter is the invisible shield protecting planet Earth from dangerous charged particles. Herndon notes that people already worry about the effect of solar storms on the planet -- and says that their most obvious manifestations are sudden and sometimes damaging power surges. "But it would be magnified hugely if we had no shield."

The National Academy of Sciences is publishing Herndon's findings following a program of rigorous tests at the prestigious Oak Ridge National Library and a series of peer reviews by academy colleagues.

Herndon has concluded that the core of the Earth is actually a nuclear reactor which in turn is the "nuclear furnace" that fuels the Earth's geomagnetic field. Once this furnace burns out, as little as 100 years from now, the geomagnetic field will fail and will not be able to restart.

In the upcoming film, physicists discover that the Earth's inner core has stopped rotating, and that the planet's geomagnetic field is collapsing. A crack team of scientists decides that the only way of reactivating the core is to travel 6,400 kilometres into the centre of the Earth in an untested subterranean craft and detonate a nuclear device there in the hope of triggering the core back into action.

Herndon says he didn't even know that The Core had been made until last summer, a few days after Discovery Magazine had published an article outlining his conclusion that the centre of the Earth was really a nuclear reactor. He had decided to relax one afternoon and see a movie and minutes after entering the theatre he saw a preview for The Core and immediately called director Jon Amiel and producer David Foster to introduce himself.

"Ultimately people on Earth will have to face the same kind of crisis that people in the movie are facing," Herndon says.

Foster says it's an amazing coincidence that Herndon should be publishing his research only weeks before the movie's release and he admits that he hopes the film's commercial prospects will benefit as a result.

Herndon emphasizes that the events have happened independently of each other. In fact, he says his paper would have been published several months ago had he not agreed to further peer judgment.

"I had three additional reviews by National Academy members and none of them could find anything wrong with the science of the paper."

Herndon, who heads the San Diego-based Transdyne Corporation and operates his own Web site (nuclearplanet.com), believes methods are already available to determine how much time is left before the death of the magnetic field. He says one way would be to study the helium content of lava residue from volcanic eruptions.

He also refuses to be dismissive of the solution to the crisis offered in the film -- sending a vessel to the centre of the Earth.

"I would say that it would be a huge technological challenge but so is putting man on the moon."