It’s more like having soldiers with pistols fighting a swordfight distance, that’s what sci-fi battles look like.
I’ll repeat that missing using energy weapons (without any shields intervening) should be impossible.
Robert Heinlein. Starship Troopers. Mobile Infantry, capsule drops from orbit, powered armor… The opening chapter is the best futuristic infantry combat scene ever written.
I always get the shakes before a drop.
Eff me…I said “Future War” in two different threads. I meant The Forever War.
We’ve had past threads on this, and there has not been sufficient defense of this popular factoid.
There is no technology that we no of right now to hide a ship. However there is no physical reason why a vessel must radiate heat equally in all directions.
So it’s absolutely fair game in sci fi to conceive of cloaked ships or whatever.
Other than that I agree with all your points.
The best handling of the questions of space combat I’ve seen is in CJ Cherryh’s novel Hellburner.
This is about the development of ships for space combat. It’s set in a military environment, with different services, different manufacturers with their own agendas, test pilots from different backgrounds (Earth, asteroid mining, interstellar merchanter ships, etc.), intense pressure for results, politics, media to deal with, etc.
The main debate is about whether human pilots are capable of dealing with combat at such high speeds, even pilots with exceptional reaction times and hyperfocus, or whether the AI should solely be in charge. The AI systems are not conscious, but like improved versions of current AI.
The main characters are the test pilots and crews, and their point of view is that humans are unpredictable in combat and AIs are not. The enemy can get the ‘signature’ of a particular brand of AI and predict its moves. Human pilots can take risks and make unpredictable moves that an AI wouldn’t, and this gives the critical edge in combat. But humans can also make mistakes that an AI wouldn’t.
There are also issues with the command structure and integration among the four key members of the flight team:
Nav - broad view of the whole unfolding situation and near-future plans.
Helm - pilot hyperfocused on the immediate necessary moves and situation.
Longscan - combination of all available sensor info + AI prediction of positions and possible moves of all ships and objects, enemy, friendly and neutral, at distances of up to several light seconds + human insight and intuition over the AI. You can only see what the situation was slightly in the past, and try to predict current moves.
Armscomp - targets, priorities, weapons systems, firing authorizations, interdicted objects and vectors - human sitting over AI system.
The four individuals sitting those posts have to be tightly integrated, on the same wavelength, and totally able to trust and understand each other.
Also going on in the novel is military bureaucracy, a disastrous test mission in which a prototype was destroyed and the crew killed, an attempted murder, strong characters, personal issues - and a lot of deadpan humor.
Hellburner is the sequel to Heavy Time, but you don’t necessarily have to have read the earlier book, there is enough background to understand the characters and situation.
People still are able to breach a choke point in real life and overwhelm the defenders though. If you watch the scene the Stormtroopers start off with a sort of breaching charge that causes a loud flash-bang effect and causes the defenders to recoil. Then the Stormtroopers rush in two by two and immediately start firing before the Rebels have time to react. The Rebels open fire but this short delay has already allowed a steady stream of Stormtroopers to pour in and despite the Rebel fire the Stormtrooper counter fire is enough to cause the Rebels to break and retreat. It’s not bad tactics on the Empire’s part actually if they had to take the ship in one piece.
Yeah, that’d be bad. But it’d also be bad to not use Terminators, and your enemy uses Terminators, and you all die.
It’ll take just one side being willing to risk the dangers of terminators in order for them to become SOP.
A ship that is painted black (like, VantaBlack- or Singularity Black-levels of absorption) and pumps all waste heat into, say, some kind of laser (like in Brin’s Sundiver), would effectively be invisible everywhere except where that laser was aimed, right?
Please do the basic courtesy of not dismissing a technically valid argument as a “factoid”, particularly when you have done nothing to demonstrate that it is somehow flawed or based on inaccurate assumptions. The temperature of the interstellar medium is just slightly above the 2.7 kelvin temperature of the cosmic microwave background; even an object at room temperature will stand out against that distinctly, and any object inside the orbit of Jupiter will absorb enough solar irradiance to have a much higher temperature than the interplanetary medium around it. Any spacecraft with a significant power system, and especially one that has a warm or hot gas propulsion system, i.e. any kind of rocket (be it chemical, ion, nuclear thermal, et cetera) is going to generate a lot of waste heat at very high temperature internally (thousands to millions of kelvin, depending on the nature of the system) as well as leaving a long trail of superheated gas or ionized plasma behind it. Getting rid of all of this extra waste heat is a problem in and of itself; doing it in such a way as to render a spacecraft essentially invisible against the interplanetary or interstellar background is an exercise in futility.
There is a fundamental understanding about the nature of heat here. Heat is thermal energy, or to put it another way, kinetic energy at the level of individual particles which is randomized and within a closed adiabatic volume has no net momentum. You can organize heat energy to do useful work, which is what heat engines like heat pumps do, but only at the expense of creating more waste heat. In terrestrial situations, we have access to “cold temperature reservoirs” in the form of rivers, lakes, streams, or the atmosphere to which unwanted heat energy can be transferred by conducted or convection; in space, however, the only sustainable means of rejecting (getting rid of) heat is by radiation to the background, and while that works efficiently with really high temperature differentials at lower differentials it requires a massive outward facing radiating surfaces. This isn’t just some kind of engineering problem that can be improved with higher internal efficiencies; it is a fundamental limit of thermodynamics and radiative heat transfer. So extracting “waste heat” and converting it into coherent laser energy will actually generate more heat than it will reduce, and there is no feasible way around this problem, notwithstanding that high energy lasers tend to be very inefficient themselves and produce prohibitive amounts of waste heat. [POST=8002013]Here is further discussion on why lasers cannot be used to reject heat out of a closed system.[/POST]
Laser cooling is used to cool individual atoms by reducing their momentum through photon interactions, but that is because the laser and its power source is external to the atoms. You can’t just somehow pump heat into a lasing cavity and squirt it out into space; heat is really a state property of a system and you can’t change that state (to a lower entropy) without increasing global entropy, e.g. radiating thermal energy outward. I suppose you could (try to) insulate a spacecraft so that no heat can escape, and then have some active cooling system that would collect heat and dump it to directional radiators that could be faced away from a potential opponent, but you’d end up with a ship that has massive aft-facing radiator surface area (with the forward facing “back side” also having to be insulated or cooled to prevent it from radiating) for even a very small amount of heat produced, which would look nothing like any spaceship in science fiction.
Stranger
“Factoid” is the proposition “It’s impossible to hide a ship in space” which has not been sufficiently supported IMO. I wouldn’t call an argument a factoid because that wouldn’t make any sense.
There is no point going over the arguments presented in the other thread. For the purpose of this thread suffice it to say that I think all the arguments for that factoid are talking about engineering issues or even commit the fallacy of incredulity. They are not fundamental physical reasons why it would be impossible, which is what would be necessary to rule it out even from speculative sci fi.
In poisoning the well by persisting in the use of a pejorative descriptor and then refusing to actually address any point of the technical discussion above you illustrate that you have no actual basis for your statement.
Stranger
How about the other end of the EW spectrum? Stealth that is less invisibility and more signature management seems like it could combine well with jamming and decoys. I’m not sure how those would transpose in a space setting but you might be able to make an educated guess.
At a guess, the reaction engines that are being used to propel any particular ship are going to be recorded, much like we do now with the sound signatures of ships. So a taco section on a spaceship is going to see a multi spectrum event on its sensors and optical sensors will give a guess on mass and heat sig, and hopefully giving you a confidence level of what your facing.
Stealth is not really a requirement in space, as you have it by default. Your sensor bubble is as only as large as the power you push through for active searching. The more interlinked sensors you have, the bigger your bubble. I believe our current bubble is somewhere close to lunar orbit. Anthing further out, say the pluto orbit we might not notice until something optical sees it.
Forgive my hijack and my ignorance, but wasn’t the Picard Maneuver just the way Jean-Luc kept pulling his uniform tunic down? 
Noted, and it’s an argument I’ve seenbefore. But the argument relies on treating the ship+laser as a closed system. If you aim that laser at something that allows you to “export” the entropy away from the ship, doesn’t that get rid of that problem?
It’s *also *a tactic.
How about a ship coasting with its engines off? Accelerate outside sensor range, move in silently, launch your weapons and then turn you reactor back on to get out of there. Seems pretty stealthy to me.
Would you not have a heat signature from left support, internal lighting systems, artificial gravity, assuming it exists?
Sure, but compared to the engines it would be minuscule, maybe small enough so that the ship can allow it to build up inside for a few days.
No, it has nothing to do with treating the laser and its emissions as being internal to the ship. In fact, regardless of the system used to reject energy from the system in the ship, no method of trying to reject heat out of the system into space using any internal heat pump cycle is going to be more efficient than the efficiency of just radiating the heat directly to space because the heat pump itself generates additional heat in doing the work of moving energy within the system from one state to another. This is notwithstanding the inherent poor efficiency of high energy lasers, so even if you posit some kind of future very high throughput diode-like laser, the essential fundamental thermodynamic limitation remains. The energy emitted by a laser is actually very low entropy, which means net entropy of the system—and therefore wate heat produced—increases.
In terrestrial applications, heat pumps work by getting their energy from an external source—generally electricity from a remote power plant, or mechanical energy from an internal combustion engine driven compressor located outside the system—and using this to drive the compression-expansion cycle which pulls energy from a lower temperature chamber to one at higher temperature. This is possible because the Earth is replete with cold temperature reservoirs that are vastly greater than the amount of energy needed for refrigeration which are literally right outside, but in space, the only reservoir is the background of space, so operating a heat pump just generates more waste heat within the system of the ship to be radiated away. Now, you might use a heat pump cycle within the ship to cool specific areas more efficiently than passive heat transfer would allow, but the net result is going to be higher system entropy and more heat to reject.
Stranger