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  • Engine/Propulsion

    Since I found no topic on this, I took the liberty of creating one.
    These Propulsion systems would be created by a type 0 civilization. So it would be in the early game. It would mostly be for Stellar Exploration, and/or Aircrafts.

    "We are a Type 0 civilization, which extracts its energy from dead plants (oil and coal). Growing at the average rate of about 3% per year."

    - Chemical rockets
    - EM propulsion (rail guns)
    - Ionic engines
    - Fission power

    "Type I – this civilization harnesses the energy output of an entire planet.

    A Type I civilization would be able to manipulate truly planetary energies. They might, for example, control or modify their weather. They would have the power to manipulate planetary phenomena, such as hurricanes, which can release the energy of hundreds of hydrogen bombs. Perhaps volcanoes or even earthquakes may be altered by such a civilization."

    Later more complex and faster propulsion engines would be created and manufactured. These are for a type 1 civilization.
    The Theoretical ones are as follows:

    - Photonic drive
    - Ram-jet fusion engines

    "A Type II civilization may resemble the Federation of Planets seen on the TV program Star Trek (which is capable of igniting stars and has colonized a tiny fraction of the near-by stars in the galaxy). A Type II civilization might be able to manipulate the power of solar flares."

    Type 2 Civilization would develop these systems. I dont think this game would be able to harbor a type 3 civilization.

    - Antimatter drive
    - Von Neumann nano probes

    "Propulsion systems may be ranked by two quantities: their specific impulse, and final velocity of travel. Specific impulse equals thrust multiplied by the time over which the thrust acts. At present, almost all our rockets are based on chemical reactions. We see that chemical rockets have the smallest specific impulse, since they only operate for a few minutes. Their thrust may be measured in millions of pounds, but they operate for such a small duration that their specific impulse is quite small.

    NASA is experimenting today with ion engines, which have a much larger specific impulse, since they can operate for months, but have an extremely low thrust. For example, an ion engine which ejects cesium ions may have the thrust of a few ounces, but in deep space they may reach great velocities over a period of time since they can operate continuously. They make up in time what they lose in thrust. Eventually, long-haul missions between planets may be conducted by ion engines.

    For a Type I civilization, one can envision newer types of technologies emerging. Ram-jet fusion engines have an even larger specific impulse, operating for years by consuming the free hydrogen found in deep space. However, it may take decades before fusion power is harnessed commercially on earth, and the proton-proton fusion process of a ram-jet fusion engine may take even more time to develop, perhaps a century or more. Laser or photonic engines, because they might be propelled by laser beams inflating a gigantic sail, may have even larger specific impulses. One can envision huge laser batteries placed on the moon which generate large laser beams which then push a laser sail in outer space. This technology, which depends on operating large bases on the moon, is probably many centuries away.

    For a Type II civilization, a new form of propulsion is possible: anti-matter drive. Matter-anti-matter collisions provide a 100% efficient way in which to extract energy from mater. However, anti-matter is an exotic form of matter which is extremely expensive to produce. The atom smasher at CERN, outside Geneva, is barely able to make tiny samples of anti-hydrogen gas (anti-electrons circling around anti-protons). It may take many centuries to millennia to bring down the cost so that it can be used for space flight.

    Given the astronomical number of possible planets in the galaxy, a Type II civilization may try a more realistic approach than conventional rockets and use nano technology to build tiny, self-replicating robot probes which can proliferate through the galaxy in much the same way that a microscopic virus can self-replicate and colonize a human body within a week. Such a civilization might send tiny robot von Neumann probes to distant moons, where they will create large factories to reproduce millions of copies of themselves. Such a von Neumann probe need only be the size of bread-box, using sophisticated nano technology to make atomic-sized circuitry and computers. Then these copies take off to land on other distant moons and start the process all over again. Such probes may then wait on distant moons, waiting for a primitive Type 0 civilization to mature into a Type I civilization, which would then be interesting to them. (There is the small but distinct possibility that one such probe landed on our own moon billions of years ago by a passing space-faring civilization. This, in fact, is the basis of the movie 2001, perhaps the most realistic portrayal of contact with extra-terrrestrial intelligence.)

    The problem, as one can see, is that none of these engines can exceed the speed of light. Hence, Type 0,I, and II civilizations probably can send probes or colonies only to within a few hundred light years of their home planet. Even with von Neumann probes, the best that a Type II civilization can achieve is to create a large sphere of billions of self-replicating probes expanding just below the speed of light. To break the light barrier, one must utilize General Relativity and the quantum theory. This requires energies which are available for very advanced Type II civilization or, more likely, a Type III civilization.

    Special Relativity states that no usable information can travel locally faster than light. One may go faster than light, therefore, if one uses the possibility of globally warping space and time, i.e. General Relativity. In other words, in such a rocket, a passenger who is watching the motion of passing stars would say he is going slower than light. But once the rocket arrives at its destination and clocks are compared, it appears as if the rocket went faster than light because it warped space and time globally, either by taking a shortcut, or by stretching and contracting space."

    Last edited by Jeremy Buloch; December 8, 2002, 02:16.
    Naval Imperia Designer

  • #2
    1. Anti-electrons are also called positrons.

    Special Relativity states that no usable information can travel locally faster than light. One may go faster than light, therefore, if one uses the possibility of globally warping space and time, i.e. General Relativity. In other words, in such a rocket, a passenger who is watching the motion of passing stars would say he is going slower than light. But once the rocket arrives at its destination and clocks are compared, it appears as if the rocket went faster than light because it warped space and time globally, either by taking a shortcut, or by stretching and contracting space."
    Do you mean, that if someone makes a trip that would take conventional engines 100 years, it would still take 100 years for the person inside it (person = long dead), only for the rest of the universe it was really fast?

    That could be usefull for probes, but not people.
    Michiel Helvensteijn
    SPDT Member: Helpmate


    • #3
      OK, but there are still questions:
      1) How your manage to employ rail guns in prop? Yes, there is analagous effect, called Magnetic Hydrodynamics Drive, inside-out version of Magnetic Hydrodynamics Generator and this effect, in fact, was used for prototype jet drives, but this thing is much more comprehansive, including external powerful magnets and fuel "doping" with conductive media. I'm wondering that schema your mean... this may be invention, BTW.
      2) Your defenitely forgot about laser/maser/etc. external drives. The main problem with reactive prop is that you must accelerate fuel along with payload, and thus spend more fuel. This is evil exponential formula, and it's even more evil for sub-light travel. Some time ago, I've calculated that any vessel must convert 1/2 of its starting mass into light (excellent AM drive) in order to accelerate (just accelerate, remember!) to 0.6 of speed of light. External power source is much better in this aspect as power source and any "fuel" is at home. But light quants coming from accelerator will become more "weak" as velocity goes up due to Doppler's shift, so you can cheat anyone, you can cheat even mommy, but you can't cheat universe. This drive has hard times with interstellar medium and returning home, too.
      3) Fission drives may be solution for traveling, say to Mars, possible even to Jupiter (I mean human expeditions). For more distant trips, it is't especialy good, as it has humble "specific momentum". It's due to "low" stream temperature, as it's hard to use uranium hotter than 10.000K safely.
      4) Your forgot fusion dirves. They may be nice, as plasma may be accelerated even for ~100 km/s and faster. BTW, it's hard to accelerate to speeds much more than propulsion stream's.
      5) Warping space at any non-microscopic disstansies must involve masses about Schwarzschild's mass for same diameter, likewise you're creating black hole with that diameter. This is like "space fabric stiffness", IMHO. If your employ some quantum effect for using this mass "in credit" your must be prepared that travel may be probabalistic (for example, 10% of ship arrived safely, 80% arrived somewhere 100.000 l.y. above Galaxy disk, 10% converted to pure energy at start site, percents are from net mass, not distinct places).
      And, one more. Special Relativity is't for high gravity fields, it's for high speeds only. It can't even predict Mercury anomal "inequality" correctly, let alone warp drives. You must employ General Relativity, it's 1000% more mathematicaly beautifully and harder to explain.
      If you don't see my avatar, your monitor is incapable to display 128 bit colors.
      Stella Polaris Development Team, ex-Graphics Manager


      • #4
        The only real way I see railgun (well, mass driver) type propulsion useful is when one wishes to move an astroid or small moon, just slap a nice fat mass driver on it (or built it using robots) and fling bits of the astroid into deep space to move and/or spin the astroid.

        Seems to me that ion drives and fission/fusion drives (either ion or plasma based) are the best realistic bets, altough it could be possible for propulsion technology to be helped along a bit by the friendly aliens...

        And prehaps the ability to build stargates (more the "Lost in Space" type than the "Stargate SG1" type...), mainly for gameplay reasons, making it possible to quickly forces between friendly worlds, to make defense easier.


        • #5
          Wow! Move asteroid... collision course... deflect enemy comet defence using same rail gun... BOOM! I've forgot this kind of weapon, really! Nice idea!
          BTW, Einstain's theory inhibits solutions involving disappearing/appearing objects. But universe may be in fact more fun we're currently thinking.
          If you don't see my avatar, your monitor is incapable to display 128 bit colors.
          Stella Polaris Development Team, ex-Graphics Manager


          • #6
            BTW, Einstain's theory inhibits solutions involving disappearing/appearing objects.
            Not exactly. In fact recently, a laboratory has announced the teleportation of a photon
            Ok, ok, a photon is mass-less etc. etc., but Einstein say it's possible to curve space-time... so it will be quasi-relistic have stargates or similar.
            Aslo the gods are impotent against men's stupidity --Frederich Shiller
            In my vocabulary the word "Impossible" doesn't exist --Napoleon
            Stella Polaris Development Team -> Senior Code Writer (pro tempore) & Designer


            • #7
              Vultur is right. Recently an Australian research team managed to teleport a laser beam with two transporters that were 5 metres away from each other, so teleporting isn't too much Star Trek science after all.
              "Kids, don't listen to uncle Solver unless you want your parents to spank you." - Solver


              • #8
                There's a difference between teleportation, and faster-than-light travel. In quantum teleportation (as we know it), you transfer the quantum state of an object (in this case, a photon) from one place to another, and destroy the original in the process by observing it, and sending the results of the observation to the "receiver" via regular means. So this doesn't really have much significance in space ship propulsion, as far as I know.

                Now, that being said, I think that if you're going to have interstellar empires, FTL travel is a must. It's just too darn slow to move your fleets ships sub-light speed. Who's going to ever move their flagship from a solar system to another, if they waste 50-100 years of game time in the process? Not to mention that during that time, the system the flagship is headed may revolt and you have to either turn back or face the welcoming committee. Not very interesting, from gameplay point of view.

                Well, that's just my opinion. I confess I don't know much about games of interstellar strategy.


                • #9
                  The flagship should be built with alien technology, and thus have the ability to move considerably faster. (prehaps the alien colony ship doesn't fly back into space, and instead the colonists salvage it to build your flagship?)


                  • #10
                    "When discussing the possibility of interstellar travel, there is something called “the giggle factor.” Some scientists tend to scoff at the idea of interstellar travel because of the enormous distances that separate the stars. According to Special Relativity (1905), no usable information can travel faster than light locally, and hence it would take centuries to millennia for an extra-terrestrial civilization to travel between the stars. Even the familiar stars we see at night are about 50 to 100 light years from us, and our galaxy is 100,000 light years across. The nearest galaxy is 2 million light years from us. The critics say that the universe is simply too big for interstellar travel to be practical.

                    Similarly, investigations into UFO’s that may originate from another planet are sometimes the “third rail” of someone’s scientific career. There is no funding for anyone seriously looking at unidentified objects in space, and one’s reputation may suffer if one pursues an interest in these unorthodox matters. In addition, perhaps 99% of all sightings of UFO’s can be dismissed as being caused by familiar phenomena, such as the planet Venus, swamp gas (which can glow in the dark under certain conditions), meteors, satellites, weather balloons, even radar echoes that bounce off mountains. (What is disturbing, to a physicist however, is the remaining 1% of these sightings, which are multiple sightings made by multiple methods of observations. Some of the most intriguing sightings have been made by seasoned pilots and passengers aboard air line flights which have also been tracked by radar and have been videotaped. Sightings like this are harder to dismiss.)

                    But to an astronomer, the existence of intelligent life in the universe is a compelling idea by itself, in which extra-terrestrial beings may exist on other stars who are centuries to millennia more advanced than ours. Within the Milky Way galaxy alone, there are over 100 billion stars, and there are an uncountable number of galaxies in the universe. About half of the stars we see in the heavens are double stars, probably making them unsuitable for intelligent life, but the remaining half probably have solar systems somewhat similar to ours. Although none of the over 100 extra-solar planets so far discovered in deep space resemble ours, it is inevitable, many scientists believe, that one day we will discover small, earth-like planets which have liquid water (the “universal solvent” which made possible the first DNA perhaps 3.5 billion years ago in the oceans). The discovery of earth-like planets may take place within 20 years, when NASA intends to launch the space interferometry satellite into orbit which may be sensitive enough to detect small planets orbiting other stars.

                    So far, we see no hard evidence of signals from extra-terrestrial civilizations from any earth-like planet. The SETI project (the search for extra-terrestrial intelligence) has yet to produce any reproducible evidence of intelligent life in the universe from such earth-like planets, but the matter still deserves serious scientific analysis. The key is to reanalyze the objection to faster-than-light travel.

                    A critical look at this issue must necessary embrace two new observations. First, Special Relativity itself was superceded by Einstein’s own more powerful General Relativity (1915), in which faster than light travel is possible under certain rare conditions. The principal difficulty is amassing enough energy of a certain type to break the light barrier. Second, one must therefore analyze extra-terrestrial civilizations on the basis of their total energy output and the laws of thermodynamics. In this respect, one must analyze civilizations which are perhaps thousands to millions of years ahead of ours."

                    Yes, the flagship should be built with alien technology. So lets discuss alien propulsion, shall we?
                    I'm curious would this alien civilization have this type of power:
                    "Type III – this civilization harnesses the energy output of a galaxy, or about 10 billion time the energy output of a Type II civilization." They have Colonized the galaxy itself.

                    Naval Imperia Designer


                    • #11
                      Seems like common sense that Type III is beyond the scope of the game, since by definition there can exist only one such civilization in the galaxy (and no room for smaller ones, either).

                      As for FTL propulsion, I think it's best to just handwave it away with wormholes or warp drives, and avoid excessive explanations. It's all magic anyway, but you need it to make the game interesting, so it's kind of a necessary evil. Whatever technical characteristics the drives may have should be determined solely by gameplay concerns: for example, star trekkish warp drives are good if you want to make a point about travel time, wormholes might be instantaneous but cost more energy, and so on...


                      • #12
                        BTW, I always found lots of joy in watching how selfish people are
                        Why universe may be "fair" to such a short-living persons? Time needed to travel to nearest star may seems impossible huge to us, but imagine the same travel from point of view of someone billiion-years living. Type III, you said? We can't imagine such a society, but it's sure that mind (individual or collective, does't matter) must live for _eons_, longer than planets, longer than stars... Just imagine weekend journey from point of view of one day living butterfly.
                        But, due to gameplay reasons, we need some kind of really fast space travel. Modern physics seems to tolerate such a thinks only in its dark corners, such are:
                        1) Really high gravity fields, there both Relativity and Quantum Electrodyncamics must join, but we still do't know how)
                        2) Some dirty tricks with space-time continuum, with magnitude not less than black hole (that means mass/energy around mass of big planet... really big thorn in a side for insurance companies), in fact may be (1)
                        3) Some clever tricks with very basic properties of matter, would it be primal strands, quarks or something else.
                        4) Your suggestins?
                        If you don't see my avatar, your monitor is incapable to display 128 bit colors.
                        Stella Polaris Development Team, ex-Graphics Manager


                        • #13
                          Here's a pretty extensive list of various alternatives:


                          I suggest the decision as to what kind of faster-than-light drives are used is based entirely on gameplay concerns, in other words just decide what characteristics the drive needs to have in order to make an interesting game, and then handwave appropriate technology. For example, you could have

                          1) Slow drive, but with small energy consumption (alcubierre warp drive?).

                          2) Instant travel, moderate, limited distance (artificial wormhole, need to build/send the receiving hole in advance).

                          3) Fast drive, heavy energy consumption, can travel anywhere (folding space time thingamajig).

                          ... and so on.


                          • #14
                            Really extensive list of "possiblites", thanks.
                            BTW, we still can't find any space anomalies that demonstrate something beyond speed of light. I know that 3 theorists may explain things by 4 different ways, but we still completely out of FTL phenomena. Possible except is so-called "inflation theory" of universe expansion.
                            If you don't see my avatar, your monitor is incapable to display 128 bit colors.
                            Stella Polaris Development Team, ex-Graphics Manager


                            • #15
                              It looks like we fogot about simple STL travel, that encompasses all the battle activity, IMHO, as every way to send things FTL seems to be too "special" to shoot around in progress.
                              If you don't see my avatar, your monitor is incapable to display 128 bit colors.
                              Stella Polaris Development Team, ex-Graphics Manager