Engine/Propulsion

[Jeremy Buloch]

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."


-J.B.-

[Michiel]

1. Anti-electrons are also called positrons.

2.

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.

[targon]

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.

[Blake]

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.

[targon]

Wow! Move asteroid... collision course... deflect enemy comet defence using same rail gun... BOOM! I've forgot this kind of weapon, really! Nice idea!
Stargates:
BTW, Einstain's theory inhibits solutions involving disappearing/appearing objects. But universe may be in fact more fun we're currently thinking.

[Vultur]

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.

[Rasbelin]

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.

[Leland]

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.

[Blake]

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?)

[Jeremy Buloch]

"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.

-J.B.-

[Leland]

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...

[targon]

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?

[Leland]

Here's a pretty extensive list of various alternatives:

http://www.projectrho.com/stardrv.txt

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.

[targon]

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.

[targon]

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.

[DeathByTheSword]

ok this may sound very sci-fi but what about travelling in an other deminsion one that close to ours an 'shadow' deminsion. this shadow deminsion would be the stuff that would fill 4D space in a 3D perpestive....we live in a 3d world but space is 4D...best way to make that understandeble is to see our world (a 3D one) as a 2d surface. this surface is folded over eachother this way you get 3D object...now taking in to account that one sheet of it was 3D you created a 4d picture...if there was a way to punch a hole in the 3D space right after that another 3d world would be.....only in our point of view it would be 100.000 lightyears away. now if we would make a distant between one sheet of 3d and another and call that the shadow demision then we would have a very fast way of travel.......just an idea i had after reading a book

[Gateway103]

DBTS, I recall such wrapping of space-time continnum idea from before, and regardless the feasibility of artificially achieving this, I believe worm holes operating on similar ideas too.

Targon is right that we'll most likely to have space battle only at STL, and perhaps only in systems (i.e. not in the middle of nowhere in space). Those of you who have played Ascendency and/or have followed MOO3 would recall the idea of Starlane or Wormhole-networks, similar things exist for Space Empires.

Wormholes are supposedly instantaneously, but Starlane, in MOO3, aren't instantaneously but depend on the ship and the condition of the Starlane (condition may be improved/downgraded). Lastly, MOO3 also offer the so called off-road travel, which is substantially slowerly than Starlane, but can bypass Starlane networks and go anywhere. This can be explained with perhaps some limited space wrapping field generated by ships that works on the principle of wormholes, just much limited in range. This off-road travel offers interesting strategies to bypass choke points and enemy frontier defenses. Of course, to balance it out, they are much slower and the enemies may detect you long before you reach the destination, so good luck with the welcoming parties

Anyway, so systems may perhaps be naturally linked by these Starlane or Wormhole, at the outer-fringe. I know we haven't found one yet in real life, or have theories to suggest such things but for game purposes, it may be tolerable, just set the thing in general to be at the fringe of the star system (away from gravity wells). So for ships to transit, from system A to C, it may need to transit FTL to system B, then STL through system B to reach the next starlane entrance, and then FTL to system C's fringe. This provides interesting strategic aspects, such as blocking the exit/entrance, place mines, weapon platforms around entrance, and sneaking your cloaked scouts into the system to do some spying, sneak through enemy controlled system(s) to get to the other side (perhaps contacting a potential allies?), etc.

So to recap:
Wormhole style - Systems are linked by wormhole networks, which offers instantaneous transition from entrance to exit. The ships using such wormholes, however, may need some space device to protect themselves and/or making sure the ride is safe, so to speak.

Starlane style - similar to wormholes, except the transition isn't instantaneous, but must take some time depending on the condition of the Starlane as well as the ships in transit. Starlane may be improved/downgraded via various means.

Off-Road travel - Some short range space wrapping device, perhaps alien in origin, that allows local wrapping of space-time continnum, allowing the ships in question to travel at STL velocity, but across FTL distance (e.g. the ship really travelled say 1000 km in wrapped space-time, but in normal space-time, the distance may be say 1 million km). This would be perhaps energy instensive and a slow FTL drive, but nevertheless could work, if each turn if sufficiently long (half an year to an year perhaps)

In-system travel - In system travel would be STL, say some fraction of C depending on your ship design and propulsion technology. It is at this speed that combat would occur, and only in system (I don't like interception in FTL, consider you'll at most get a flyby shot. Not to mention firing during wormhole or starlane transit is, if not possible, probably dangerous.)

Just some morning babbling.
Sorry the whole post isn't very coherent or structured... I'm just thinking out loud.

-Gateway103

[DeathByTheSword]

ok have anyone of you ever played Pax Imperia..it uses the same system as gateway just described...only the off-road travel is new is cool for more freedom of play....but pax imperia is a most to check out if you are talking about space travel like we are doing now....about the black holes...yes they work the same way..sort of....first of all we we need a better and stabler way to move FTL then blackholes they are to powerfull.....maybe very old blackholes would become more stable (this isnt true but still) what kind of explanation are we going to use to travel from system to system

[Jeremy Buloch]

Yes, I've played Pax Imperia, in fact it's one of my favorite games. I'm sure that gateway has played it too. I faintly remember him telling me, I think. Well I have nothing to add at this moment. I just wanted to answer your question DBTS.
-J.B.-

[DeathByTheSword]

it is a great game only battles are a bit dull it is all about who have the most firepower and not with tactics....but anyways this is a threadjack

[Jeremy Buloch]

Well I've pulled alot of stunts with my one crusier against 10 destroyers. My crusier won. So I would call that a tactic.
Ok now back to topic or was this the topic.
-J.B.-

[DeathByTheSword]

ok just one more thing i have one with one cruiser against max number of destoyer so that isnt really a tactic cruisers are just that much better!......

[targon]

Pax Emperia (AKA Pah emperia) was good game (while space combat was boring and AIs too soft). Ascendancy, MOOs, Conquest: FB, Remember Tomorrow all use some kind of wormhole transport (and Stars! too, while it's focused of warp transport. Hey! Even Star Controls used the same to some degree!). So at least we are in good company
But it is't realistic. Things looks like we have to forgot about "realism" regarding to space travel at least while people live less than 10K years or more and can't afford themselves off-system travel at the only realistic sub-light.

[Blake]

Rather than making the ships go faster, we could also move the planets closer together, say make the game take place in a patch of space where the average distance between stars is 0.5-2 lightyears, that way even with speeds of like 20% c spaceships would be able to reach other worlds in a reasonable amount of time....

Hey prehaps we can say that advanced aliens "warp" the human colony ships to this patch of space, chosen because it's reasonably isolated and full of rich worlds for the human race to start a new empire (in the vastness of the universe there are bound to be a few [billion] regions that satisfy those requirements)

So I just threw realism out the window, but it'd primarly be unrealism in the backstory, not the game itself.

[targon]

This is't real, too.
Reason is that habitalbe worlds must have long and good history, nothing like supernova explosions nearby or shock waves crossing galactic gas thru the system. So forgot about galaxy core or buldge. This places are simply to "hot", filled with gas, radiation and ancient horrors like heavy back holes.
Another thing: in order to be "rich" solar system must be filled with heavy elements, not simple primal hydrogen/helium. That means long and forbidden history, including vast supernova explosins creating heavy elements; some hundred millions years later, supernova clouds form new stars. Our Sun is about 4th generation of stars... So forgot about first-stage population (huge sphere of ancient stars encompassing the Galaxy disk) or tight associations (spherical groups, for example), they are too old, stable and consists from light elements.
So we move to Galaxy disk. And it is't hospitable place yet. You see, galaxy "arms" are "self function" of Galaxy itself and rotate with "self frequency" as rigid body. Stars, on other hand, move with their own "phase" speed. Most of them cross Galaxy arms frequently, and they made a mistake, as arms are life-threating places, filled with hot gas and young blue stars searing fragile life sprouts with hard radiation.
The only safe haven on Galaxy disk is so-called corotation zone, there phase and self speeds equals. And (Surprise!) our Sun lies exactly here, between arms. The only wrong thing with corotation zones is that they are't especialy good populated with stars...
So star-rich regions are simply dangerous or sterile, while hospitable areas are poorly populated

[Blake]

Yeah, I'm actually aware of that. Hence my reference to "the vastness of the universe" such areas will be freakish. They will be really freakish. But with billions of billions of stars out there, is it too much to ask that a few dozen find themselves close together and with nice worlds

[Jeremy Buloch]

Magnitron drive (An Idea of mine, or at least I think. ) -

A 'Magnitron Drive" Hmmm... Sounds like a magnetic drive does it not? It would repel the object at a very fast velocity similar to a magnet when the south pole and south pole come together. Or vise~versa. It would have to work some way but I'm not sure how. Its only an Idea I got when I was reading up on magnetic repulsion. I think this could work. If there are any technological difficulties with this then please say so. I'm open to feedback on any paticular subject.
Also I've been busy and all with my studies but I will try to come here more often.
-J.B.-

[Leland]

One obvious question... what does the "magnitron drive" repel the object from?

[Kuciwalker]

A star.

[Jeremy Buloch]

It would, I think repel itself away from a star. But I was thinking of using it in an atmosphere. Where it could repel against a form of matter. Such as water or ground for instance.
-J.B-