Passive Camouflage vs Stealth vs Cloaking vs Active Camouflage

If you can see it, you can kill it.

This is the basic premise in real modern warfare. It is also the premise behind the technologies used by military equipment in The Local War universe. So, what are the differences behind the various ways to hide, and how do they work?

Passive Camouflage: This is the camouflage most of us are probably familiar with. If you’ve ever seen a soldier in a camouflage uniform, that’s passive camouflage. The idea is to break up the pattern that says “I am a person” and (hopefully) blend into the background. It works, to a point. When I was in the Army, I was on a hillside one day in waist-high grass wearing my old-school Battle Dress Uniform (“camis”). I spotted an “enemy” patrol approaching my position, quickly knelt down before they saw me, and held absolutely still. That patrol, six people, walked right past me not ten feet away (3 meters) and never saw me. I felt totally exposed, even looked them in the face, and yet they just walked right past. It was my first lesson in just how good passive camouflage can be—provided you don’t move. That is the Achilles’ heel of passive camouflage. Our eyes are evolved to detect movement. Once something moves, it is easy for us to spot.

In The Local War universe, objects in space are non-reflective black. This allows them to blend into their background, making them difficult to see. The downsides are that they block the light of background stars, and if they move this can make them visible by the trail of stars they eclipse. If their background isn’t black, it’s less helpful. It also doesn’t hide heat or other emissions from the object.

Stealth: We hear a lot about this tech these days, from stealth fighters and bombers to stealth technology on warships. In science fiction, stories often contain the word “stealth” as if it magically makes things disappear, even though you could look out a window and see the thing plain as day. Stealth is a catchall phrase that describes minimizing the detectability of an object. A stealth fighter uses structural angles, special paints, and other tech to reduce the radar reflection it produces, so instead of looking like a fighter on enemy radar, it might look like a bird. Stealth fighters also use techniques to minimize the heat signature of their engines for infrared sensors, and may even employ sound dampening tech to make them harder to hear. They also include internal weapons bays so that non-stealthy missiles and bombs don’t give the game away until they’re ready to be used.

The Local War universe uses stealth, though it may be less obvious. Military craft have reservoirs inside to store heat that is generated internally from people, systems, and weapons fire, only releasing that heat when it would become harmful to occupants or technology. All weapons are stored and launched internally so they don’t reveal the launching platform when they fire. As munitions are also camouflaged, a warship could fire many salvos of missiles and railgun slugs without ever being detected. Additionally, engine exhaust is shielded from view unless the observer is behind the engine and can see it in use. One final piece: shields. Any object traveling at 20%-30% the speed of light needs protection from space debris. Can’t get around this one. Deflector shields in science fiction are usually portrayed as a large energy shield around the entire ship. Problem is, such a shield would be easy to detect. The Local War universe gets around this problem by instead using millions of small overlapping shields that extend only a short distance from the hull. Combined with angled hulls, this protects the ships while minimizing the risk of detection, except at close range.

Cloaking: Made popular by Star Trek, cloaking is the bending of light around an object so the object effectively becomes invisible. As portrayed in science fiction, cloaking is energy intensive and not completely effective due to distortion effects around the object. In Star Trek, for instance, a Romulan Warbird must decloak before it can fire, and the distortion can sometimes be seen visually. Real cloaking tech (and, yes, people are researching it) uses the same principal of bending light but hasn’t made it out of the lab, yet (that we know). On the Science Channel, there was a program several years ago where one research team had developed a material that could, by its properties alone, bend light around a fabric, more like the Cloak of Invisibility in Harry Potter than a Romulan Warbird.

Cloaking is not used in The Local War universe, because there is something better.

Active Camouflage: If there is one future technology that military researchers are after, it’s this one. Think of the movie Predator. The Predator could hide in a tree and its suit would actively “look” at its background and then portray that background to observers, effectively making the Predator invisible. This was the inspiration for the active camouflage systems in The Local War universe, but it also inspired real world research that continues today. This is actually not new. Like so many things, Nature got there first. If you’ve ever seen a chameleon or an octopus change its skin color actively to match the background it’s moving through, that is a form of active camouflage.

Active camouflage is the bread and butter of military tech in The Local War universe. Military equipment “looks at” its background across the entire electromagnetic spectrum and then radiates energy equivalent to that background on the opposite side, effectively making the ship invisible across most of the electromagnetic spectrum. The tech has evolved to the point where viewing angle makes no real difference except at close range.

Hope that helps explain the concepts behind hiding in The Local War universe. Other factors can give away the presence of an object, like engine exhaust products and even gravitational lensing, but overall, it is very difficult to see objects employing active camouflage and stealth.