Force Fields

"Shields up!"

A famous phrase in the Star trek series that is the first order that captain Kirk says to the crew, raising force fields to protect the starship Enterprise against enemy fire.

Force fields are vital that the tide of the battle can be measured by how the force fields is holding up. Whenever power is drained from the force fields, the Enterprise suffers more and more damage to the hull.

What is force field? In science fiction, it's simple: a thin and invisible yet impenetrable barrier able to deflect lasers and rockets. It could have profound effects on every aspect of our lives. The military could use force fields to become invulnerable, creating an impenetrable shield against enemy missiles and bullets. Bridges, superhighways and roads could be built by a simply pressing a button. Entire cities could appear instantly in the desert, with skyscrapers made entirely out of force field. Force fields appearing over cities could enable the inhabitants to modify the effects of the weather-high winds, blizzards, tornadoes-at will. Cities could be built under the oceans within the safe canopy of a force field. Glass and steel could be entirely replaced.

However, a force field is perhaps one the most difficult devices to create in the laboratory. In fact, some physicists believe it might actually be impossible.

The concept of force fields originates from the work of the great nineteenth-century british scientist Michael Faraday.

The young faraday was fascinated by the breakthroughs in uncovering the mysterious properties of two new forces: electricity and magnetism. Faraday was hired as Professor Davy's secretary, he slowly began to win the confidence of the scientists at the royal institution and was allowed to to conduct important experiments of his own.

In 1829, Faraday was free to make a series of stunning breakthroughs that led to the creation of the generators that would energize entire cities and change the course of the world civilization.

The key to Faraday's greatest discoveries was his "force fields". If one places iron filings over a magnet, one finds that the iron filings create a spiderweb-like pattern that fills up the space. These are Faraday's lines of force.

The theories behind force fields?

A plasma window. If a gas is heated to a high enough temperature, thus creating a plasma, it can be molded and shaped by magnetic and electrical fields. It can be shaped in the form of a sheet or window. In addition, the "plasma window" can be used to separate a vacuum from ordinary air. In another words, one might be able to prevent air within the spaceship from leaking out into space, thereby creating a convenient, transparent interface between outer space and the spaceship.

But the plasma window needs a combination of several other technologies stacked in layers to vaporize incoming projectiles.

The outer layer could be a super charged plasma window, heated to temperatures high enough to vaporize metals in an instant.
A second layer could a curtain of thousands of crisscrossing high-energy laser beams that would heat up objects that passed through it, effectively vaporizing them.
The third layer would be a lattice made of "carbon nanotubes", tiny tubes made of individual carbon atoms that are one atom thick and stronger than steel by a hundred times by comparison.

However, these several layers would not fulfill the science fiction force field because it would be transparent and therefore incapable of stopping a laser beam.

To stop a laser beam, the shield would also need to possess and advanced form of "photochromatics". This is the process used in sunglasses that darken by themselves upon exposure to UV radiation. Photochromatics are based on molecules that can exist in at least two states. In one state, the molecule is transparent. But when it is exposed to UV radiation, it instantly changes to the second state, which is opaque.

One day, we might be able to use nanotechnology to produce a substance as tough as carbon nanotubes that can change it properties when exposed to laser light.

It might be able to simulated many of the properties of force fields by using a multilayered shield, consisting of plasma windows, laser curtain, carbon nanotubes and photochromatics. But developing such a shield could be many decades or even a century away.

Give these consideration, force shields would be classified as Class I impossibility-something that is impossible by today's technology, but possible within a century or so.