E-Bombs Could Spell Digital Doomsday

Oct. 19 -- After attacks with airliners and assaults with anthrax-laced mail, security experts are pondering when — and how — future attacks may come.

Nuclear bombs, biological warfare and other "weapons of mass destruction" are scary possibilities, but some experts offer a lesser-known potential threat: E-bombs.

The good news about these so-called electronic bombs is they aren't directly harmful to humans or structures like buildings or bridges.

But the bad news for technological nations like the United States is that as the name implies, e-bombs go after electronic devices — computers, radios, telephones, and almost anything that uses transistors, circuits, and wiring.

Invisible and Instant Device-Killers

Powerful e-bombs can "kill" electrical equipment by rapidly creating and transmitting a huge burst of electrical energy into the atmosphere. That sudden explosion of energy results in an electromagnetic pulse, or EMP.

The circuits and wiring in electrical devices act like antennas and pick up the invisible EMP wave as it moves through the air. And depending on the distance from the explosion and the strength of the EMP burst, the affected electronics will either become temporarily disabled or completely overloaded and destroyed by the excess energy.

The destructive nature of an EMP was discovered during early American nuclear weapons testing. When an atomic bomb was exploded high above Earth in 1958, the sudden release of gamma radiation in the air resulted in a massive EMP wave. Street lamps as far away in Hawaii were blown out while navigation systems were disrupted for 18 hours by residual fluctuating interference.

Non-Nuclear Options

Since then, scientists have researched EMP and other "directed energy weapons" and developed designs that don't require a massive nuclear explosion to create devastating EMP bursts. One such "conventional" EMP weapon, for example, is the so-called flux compression generator, or FCG.

It's a bomb that uses a tube of conventional explosives surrounded by a coil of copper wire. A battery charges the coil and creates an electromagnet. But when the bomb explodes, the electrically charged coil shorts out and compresses the magnetic waves into the destructive EMP.