Force Fields

The energy fields featured as a plot device on shows such as Star Trek would certainly be of considerable value to the military- the premise appears to involve some form of invisible barrier which performs the function of conventional armour, though more effectively; projectiles and energy weapons either bounce off of or are absorbed by the shield. The same principle considered in the previous 'Light Sabre' post may be used to form an energetic barrier of sorts- simply projecting a series of points where laser light is focused could form a 'wall' of intense heat sufficient to destroy incoming projectiles that attempted to pass through it.

The science fiction force field defences were also effective against energy weapons, and is unclear how this could be achieved, but in any case, attempting to simultaneously project some form of 'blocking' energy around an entire spacecraft simultaneously will inevitably require considerably more power than would generating an energy beam at a single point with power equal to or greater than the 'shield energy' at the same point. Assuming both weapon and shield are both provided by the same power plant, such a spacecraft will not be able to withstand an attack by its own guns (it would be 'unbalanced' in old naval parlance).

Point defence is much more efficient- energy can be focused and targeted rapidly by computer control, in order to intercept incoming projectiles at specific points. The previously referenced developments in 3-d laser projection illustrate the flexibility achievable by such a system.