quote:
Originally posted by Cybes:
er, why? unless you assume relativistic effects like making a black-hole around yourself... in which case the whole notion of interstellar flight breaks down anyway.
a bullet is extremely difficult to detect when in flight compared to at rest - it's going too fast to see. but a speedboat at rest on the open ocean is a lot more difficult to spot than one going at full tilt - the moving one generates a highly visible wake and spray plume.
Passive sensors detect some sort of energy emmission. A bullet is ballistic. It is not expending any energy, at least not in a vacuum. So, in a vacuum there would be nothing to detect that would change based on speed. Firing the bullet would make a big emmission, though, and the higher the muzzle velocity (i.e. the bigger powder charge you burn) the bigger the emmission will be.
A reaction drive spacecraft, like anything we could aspire to build today, works like your bullet except that instead of being fired out a barrel it carries its fuel on board. So, when it is burning the engine it is emmitting big-time. A reaction spacecraft has to burn the engines to change course, too. No burn = fly in a straight line at constant speed forever (unless you get caught in a gravity well).
SE4 ships change course instantaneously, and lose speed when they lose engines. Ergo, they don't use reaction drives. Since they lose speed when they lose engines, they must need to run all the engines full out to get full speed. Logically, to travel less than full peed means either all the engines throttled back or some of them turned off. Either way, more speed = more energy being expended. That is what the passive sensors pick up. Ergo, the more movement points you expend during a turn the bigger your signature would be. The way to model that in the program would be that passive sensors would, at each range, have a minimum signature they could detect. The program would check your signature against that for all enemy units in the system, using your closest point of approach, and adjusting your signature strength for stealth, cloaks, speed, etc... If you pass through a sector where your current signature strength is detectable, the other guy gets an appropriate message at the beginning of his next turn. Going active with your own sensors would decrease the minimum signature for you to detect things in sectors near your ship, but greatly increase your own signature.
[This message has been edited by Barnacle Bill (edited 23 January 2001).]