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Duality
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Post by Duality »

lee wrote:
Duality wrote: As for the insystem fuel, how about replacing it with the so-called solar battery energy?
No chance! :) In Terminus, there were some very small fighters that couldn´t carry reactors and had to be run on batteries. It was a major PITA to have only battery power that constantly ran out. The first thing you would do was getting a ship that can be equipped with a reactor. Reactor fuel also went out, but at a much slower rate than battery power --- and you could turn off you reactor to save fuel rather than overcharging the battery. But fuel didn´t went out so quickly that you needed to save it.

As for the problem of running out of energy, you could call for repair tucks. They would cost 100000 credits and come flying to you from a nearby station or planet, dock to your ship and repair all systems to 50% and recharge the battery to 50%.

Self-recharging batteries would nice, but only as an option you could choose from. And you would need to buy some solar panels that would impact mannouverability ...
What if there was technoology with the ability to produce miniture or micro reactors?

There is also a great need to think of the gameplay dynamics to add in vegastrike as well besides adding 100% realism.

Yeah some realism aspects can be gameplay friendly and some can not.
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Post by Silverain »

Re: fuel and power sources. I had a conversation with the Minister of Information some time ago about this question. While nothing is set in concrete (we are beta!), the current joy is something like:

Ships have a power reactor (of certain output strengths) which uses a fuel to produce energy. Current primary fuel source is a fusion reaction (deuturim-deuturim reaction I think). Anti Matter was considered but deemed a bad idea for common power provision because of the danger of carrying many kilograms of AM in a ship that could see combat (probably used for specialised purposes e.g. deep space/non wormhole exploration).

Anyway, the fusion reaction provides energy which is used by the ship systems, and stored in capacitors. Fusion waste product provides thrust material.

Stored energy provides power for weapons, SPEC & jump drive (shields require constant energy drain from generated energy, not using stored energy).

Concerning fuel storage. How about: because of intersystem jump, intrasystem SPEC, ships are not expected to be in space and moving under normal propulsion for a very significant amount of time. As such, rather than huge tons of storage, only a lesser amount is required. I.e. propulsion is still reaction, and is used for movement near points of interest. But, this does not need large amounts of fuel. SPEC multiplies normal movement to a high degreee, but uses energy for field manipulation, not expelling fuel for additional thrust, and jumping is similar in theory to SPEC, just a higher order usage of energy. So only need carry fuel for reactor and thrust for a smaller proportion of a journey.

Hmm, <thought crime>, maybe a reason for the limitation to max velocity is excessive fuel consumption to attain high speeds when storage is limited...

JackS, please correct or expand as you see fit.
THOUGHT CRIME! [points finger] THOUGHT CRIME!
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Post by jackS »

In no particular order -

The current fuel of choice (was previously D) is Li-6 deuteride (only ~75% as efficient as D-D reactions, but with much lower neutron production, and I don't even want to think about the neutron output from D-T) I don't recall the energy/mass of He3-He3 reactions off the top of my head nor can I locate a reputable figure from a brief search. He3-He3 would be nice (it's aneutronic and produces 2 protons that would be quite convenient for direct electical power generation), but there are abundance considerations. D - He3 produces even fewer neutrons than D - Li-6, and is a good candidate for direct electrical power generation -- D +He3 -> He4 (3.6 MeV) + p (14.7 MeV) -- but we again have abundance issues with He3. p+11B is effectively aneutronic and the fuel sufficiently abundant, but the energy/unit mass is very poor.

I'm not adverse to changing the fuel type, given a good reasons/data for doing so. Antimatter, however, remains something I'm not comfortable with considering for non-military applications due to safety concerns - having to model every ship as a multi-gigaton (and that's just for the fuel in a 50 ton fighter) bomb would require significant changes in how and at what distance vessels, planets, and installations allowed each other to interact, and it would be a royal pain to simulate. I have attempted to avoid powerplant options less likely than antimatter or fusion (at least for the known extant species) and will continue to do so.

The particulars of the fusion system in use in the reactors have been somewhat intentionally understated. IECF is a nice concept, but research from the late 1990s points to it being impossible for IECF to reach break-even with the more popular aneutronic (He3-He3 and p+B11) fuels due to losses from braking radiation (although losses for D-T in an IECF were negligible and losses for D-He3 and D-D were acceptable). Put simply, we don't know how to build the sort of fusion reactor that VS needs, and I'd rather handwave than idly speculate. I'm willing to constrain the abilities of the reactor based upon the energy densities of fusion reactions for whatever fuel we finally settle on (the effective energy density is a config variable) and to investigate various consequences of our fuel choice, but I believe spending time on detailing the particular mechanisms by which the fusion reactors work to be an almost certainly less than fruitful task.

Oddly enough, we don't currently consume fuel for generating energy, only for propulsion. I consider this a conceptual modeling bug. Consumption of fuel by the reactors has been a slated addition for some time, and will probably be done this summer (made slightly less trivial by wanting to ensure that our changes don't make more arcadish mods difficult to implement/maintain).

As for propulsion, we assume two different mechanisms, one fairly realistic, and the other *magical-technobabble*. The first is thrust via acceleration of fusion reactor byproducts via a relativistic electron beam (shouldn't be too hard to create, given the high voltage current from the reactor). The "afterburners" (a horrible misnomer) would just be adjusting the control of fusion fuel (nothing is perfect) and byproduct to both the reactor and the thrusters outside of the optimal efficiency range.

The second mechanism (see the Rlaan ships with no thrusters) is to rely on the same space-time warping that gives one shields, cloaks, disruptors, SPEC and activates Jump points (how the Ancients built the jump network itself is beyond the scope of this discussion) to provide a gravity drive.

We currently model both as having the same fuel efficiency (this may change), and assume that Human and Aera development of grav-drive (aka Sofono drive) tech can only yield lower accelerations (for installation-practical models) than are desired, thus explaining the prominent reaction drives.

Either way, even being as generous as we are with efficiencies, our current "fighter" type craft can only perform a few hours of sustained acceleration before needing to refuel (and thats not accounting for fuel drain from the reactor, but, given the hideous amounts of energy it takes to move a vessel at even the 5-30 gravities that VS ships can pull, it won't affect the order of magnitude of fuel life) with 10-20% of ship's mass in fuel. As for SPEC and jump energy usage - FTL is really *magic* anyway, and so we can set the energy requirements however we see fit for game-play purposes. SPEC energy usage is artificially deflated at present relative to what it will be later, mostly due to not having enough time to balance it before the last release and wanting to avoid complaints that were being received from CVS users about running out of energy midway to the destination and having to sit in the middle of nowhere waiting for their FTL capacitor bank to recharge. Limiting the number of consecutive jumps that can be made is easily achieved on data-side by changing the ratios amongst jump cost, capacitor bank size and reactor recharge rate. Once the "free reactor energy" bug is fixed, this could be a significant source of drain on the fuel supply, requiring more frequent landings.
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Post by chuck_starchaser »

Thanks, JackS; great post; saved it to a file for future reference. It is very reassuring that you guys have given these matters so much thought.

I just wanted to point out one thing:
Helium 3 abundance is low *on Earth* but plentiful on the moon. Sun flares carry H3, but they cannot penetrate our atmosphere, but on the moon H3 accumulates. I believe a secret race is on between the US and China now, to mine the moon for Helium 3. We're talking about thousands of years' worth of Earth's total energy consumption. There are many references in Google, but this page puts it succinctly:
http://www.blog.speculist.com/archives/000193.html

Well, a lot of IECF fusion research's been hush-hush; I like the way this guy puts it:
http://fusor.net/old-boards/intranets.c ... -5136.html

There's been news of *real* desktop fusion results; I'm sure you're aware of them but just in case... Sonofusion is a bit controversial still, but the deuterium beam fusion at the last link below isn't, AFAIK.

Sonofusion:
http://www.newscientist.com/article.ns?id=dn4741
http://www.newscientist.com/article.ns?id=dn1998

Deuterium beam fusion:
http://npg.nature.com/news/2005/050425/ ... 425-3.html

In any case, if abundance of H3 is the main stumbling block in its consideration, I'd say the file could be reopened... ;-)
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Post by CubOfJudahsLion »

That calls for gas mining :) (curiously enough, one of my stalled projects is a landing shot on a gas mine for gas giants, which, if you google it, seems to be a credible enough source of material for reaction masses for many sci-fi authors.)

I'm impressed, btw. This is very hard sci-fi. This probably would make a good point of interest in the wiki, even if it's a 'working' version.
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Post by lee »

Hmmmm, where does all this lead to, and what's the benefit of it? It's somehow too complicated for me.

If the weak thrusters the ships in VS have are a result of such considerations, I don't think that they are advantageous to the game.
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Post by chuck_starchaser »

If what you mean is the low angular acceleration, I think that's just a bug. Low governor settings, which I haven't done the math, but I'm positive, with engines that can push a ship at 10G's, there's no way angular acceleration needs to be as low as it is.

In any case, I think that where this leads is the moon. Hopefully the powers that be will decide for He3-He3 fusion, or D-He3, and we'll be able to recharge fuel by landing on moons. I think mining gas giants would be a bad idea, from a science perspective, due to the technical difficulties involved in such an operation. But even if the fuel is kept as Lithium Deuteride, we'd probably find more of the stuff in moons, easier to extract, more concentrated, and without having to fight a gargantuous gravity well to get to it.

If we go back to the original topic of this thread, it was about varying energy consumption by the length of jumps taken, and I think that's a good idea. There was also suggestions with regard to in-system energy consumption, and about SPEC energy consumption.

One thing that's been in my mind for a while but never mentioned is to actually use gravity and centrifugal force. In other words, the engines may be powerful enough that you can take a straight line from one planet to another, but efficiency should be terrible; whereas a well planned trajectory could save you as much as 90% of the fuel. And one could plan trajectories while on a base. But this would only work if we used some kind of time-compression or Dreaming Device, or whatever it was called. If we use a speed multiplying scheme, for SPEC, we might as well go straight. I'm not sure I like my idea, though. With time compression, most trips would take from a few months to several years of game time... How would that square up with having a 'story'?
Well, it would actually go great with having a story if there were huge, walkable (and motorable) cities in each planet and a 'chapter' of the story happened on one planet, and then the story required some traveling, and then another 'chapter' occurred in another populous planet, and so on...
Personally I would like a game like that much more than a game where there are gazillions of planets but each planet is not much bigger than shopping mall, but that's just me...
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Post by lee »

chuck_starchaser wrote:Low governor settings, which I haven't done the math, but I'm positive, with engines that can push a ship at 10G's, there's no way angular acceleration needs to be as low as it is.
Yes, that's what I was thinking. But forward acceleration/decelaration is also too weak. For some reason, flying a ship in VS doesn't feel like flying a ship, it doesn't feel right.

And there are no engines in VS, probably because it is assumed that they aren't needed for the way how propulsion works. Is that going to change?

BTW, where do the enourmous amounts of electric power go that would probably be generated by a reactor that has sufficient output of by-products to pull a ship-mass of a few thousand tons forward at 10g? How much fuel would it take to create so much by-products?

Afair, plasma powered rocket engines have the advantage that the particles they put out move very fast so that it doesn't take so many of them to get the same thrust as it takes with slower moving particles. But if there's too much realism in the game, there would speed limits have to be assumed for the particles, and that would mean limited thrust for a given amount of particles. Also, the amount of particles used couldn't be increased indefinitely due to practical limits like the size of the jets, the amount of fuel needed and too much energy being produced.

Do some math on it, I don't think that propulsion would work out.
we'll be able to recharge fuel by landing on moons.
Then we would have to carry some mining equipment around to do the mining. It won't be as exciting as it is to scoop fuel at gas giants.
I think mining gas giants would be a bad idea, from a science perspective, due to the technical difficulties involved in such an operation.
The explanation was that fuel scoops generate large magnetic fields to suck in the fuel. And if you got too deep into the atmosphere or if you went too fast, your ship would burn. It was a very nice implementation, and realism wasn't something to bother with.

If you want to stay with realism, you'll end up where are now, in RL --- no need for a game to simulate that ...
If we go back to the original topic of this thread, it was about varying energy consumption by the length of jumps taken, and I think that's a good idea. There was also suggestions with regard to in-system energy consumption, and about SPEC energy consumption.
Well, if propulsion is a by-product of energy production, we should rather think of methods to get rid of the energy and/or of the heat involved.

And how much fuel would we need to have propulsion? I think that we can do some mathematics on it to get realistic numbers.
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Post by chuck_starchaser »

lee wrote:
chuck_starchaser wrote:Low governor settings, which I haven't done the math, but I'm positive, with engines that can push a ship at 10G's, there's no way angular acceleration needs to be as low as it is.
Yes, that's what I was thinking. But forward acceleration/decelaration is also too weak. For some reason, flying a ship in VS doesn't feel like flying a ship, it doesn't feel right.
Well, there's something amiss in VS physics, but I can't quite put my finger on it yet. The acceleration is there, 10G's give or take; --nothing to sneeze at; and speeds are measured in kilometers per second, yet for some reason it doesn't "feel" you're going anywhere nearly as fast. So, I agree with you that something's wrong; and if I haven't filed a complaint or bug report yet, it's because I'm not clear exactly what the problem is. The problem is much more evident in Privateer Remake / WCU, because there's garbage in space, there, which looks like floating pieces of cardboard boxes, that pass by as you fly; and while your speedometer reads 500 kilometers per second, the cardboard boxes hit your windshield at what looks like 200 kilometers per hour, if not even just 100. It's a disaster, IMHO... because, suppose you're passing by asteroids: If your speed is really 500 km/s, those asteroids are a few thousand kilometers across and are a few tens of thousands of kilometers away; but if you go by the intuitive speed of 100 km/hr that the cardboard boxes would seem to indicate, then the asteroids are a mere few hundred meters in size and maybe a kilometer away. So one is completely lost in terms of having any sense whatsoever of the scale of things. (And what I really hate about this is that some people don't even seem to care.) And the textures used for asteroids don't help at all: If they are thousands of kilometers across, they should show a cratered surface; if they are just hundreds of meters across they should be much more irregular in texture, but homogeneous in surface color, except perhaps for icy spots; but they look like something yet else entirely: Like decorative rolling stones with colorful layering...
In VS there are no cardboard boxes hitting your windshield at 100 km/hr, and yet I still feel lost trying to believe I'm moving at 500 km/s. Well, if I were to judge by how fast a planet gets bigger when I fly towards it, it would seem like I'm going at a lot more than 500 km/s; but when flying past other ships it again feels like 100 km/hr. But I don't know where exactly I get the feeling from, since I'm never exactly sure how big or small ships are. My guess is that there are two types of personalities among the devs: More scientific and rigorous ones, and "let's just get this darn thing to work" types; and that somehow speeds and physics are well considered for travel between planets, but brutally ignored in combat theatres: just hacked and tweaked 'by ear' to get it to some 'playable' dynamics. But like I said, I can't exactly put my finger on what's wrong, yet.
And there are no engines in VS, probably because it is assumed that they aren't needed for the way how propulsion works. Is that going to change?
Not sure what you mean by "there are no engines". What's lacking is maneuvering thrusters, in the models. Well, much more than that, because most of the ships are able to pull 10 G's in any direction, and yet I haven't seen even ONE ship model that shows thrusters pointing in any direction other than back.
Frankly, with so many ship models already in the game, I think sooner or later the engine will have to reflect the fact that acceleration may be 10G's pushing forward but 0.2 G's any other way if you're lucky.
BTW, where do the enourmous amounts of electric power go that would probably be generated by a reactor that has sufficient output of by-products to pull a ship-mass of a few thousand tons forward at 10g? How much fuel would it take to create so much by-products?
There's no conflict there, at least theoretically. Matter and energy are interchangeable. If you don't get too many byproduct atoms to throw out the back, you can throw the fewer ones you got faster. Ultimately if you throw them back at pretty close to the speed of light, their mass increases as they approach the speed of light; so you could multiply the mass of the propulsion material just by using more energy accelerating them.
Afair, plasma powered rocket engines have the advantage that the particles they put out move very fast so that it doesn't take so many of them to get the same thrust as it takes with slower moving particles. But if there's too much realism in the game, there would speed limits have to be assumed for the particles, and that would mean limited thrust for a given amount of particles. Also, the amount of particles used couldn't be increased indefinitely due to practical limits like the size of the jets, the amount of fuel needed and too much energy being produced.
Do some math on it, I don't think that propulsion would work out.
ditto
we'll be able to recharge fuel by landing on moons.
Then we would have to carry some mining equipment around to do the mining. It won't be as exciting as it is to scoop fuel at gas giants.
I think mining gas giants would be a bad idea, from a science perspective, due to the technical difficulties involved in such an operation.
The explanation was that fuel scoops generate large magnetic fields to suck in the fuel. And if you got too deep into the atmosphere or if you went too fast, your ship would burn. It was a very nice implementation, and realism wasn't something to bother with. If you want to stay with realism, you'll end up where are now, in RL --- no need for a game to simulate that ...
I disagree. RL is not that bad; just that we *choose* safety over excitement.
And whenever you step on un-realism, you create a frustration that tends to sooner or later impact something else. Deviating from realism is like lying. When you lie to someone, later on you may have to lie about something else to keep your story consistent with the first lie, and the two lies later become 4 and so on. Eventually you are grooming 2 realities: the true one, and the one of your lies. Best not to lie in the first place.
In a game of simulation, one should strive to be consistent with reality in most aspects. The question of playability should come second, because playability is like play-dough; --a much more flexible goal than self-consistency. Lost playability can be restored in no time by some creative solution. Lost self-consistency can be very hard to restore.
If we go back to the original topic of this thread, it was about varying energy consumption by the length of jumps taken, and I think that's a good idea. There was also suggestions with regard to in-system energy consumption, and about SPEC energy consumption.
Well, if propulsion is a by-product of energy production, we should rather think of methods to get rid of the energy and/or of the heat involved.
No; theoretically you don't need much mass at all, since you can convert energy into mass by relativity. Technical questions as per how would one accelerate particles to 0.0000001% of the speed of light in an engine only a few feet across are another matter; but I'd be willing to sweep such technical questions under the rug, as long as the basic questions can be answered.
And even if you get too much energy left over after that, well, once the capacitors are charged you reduce fuel consumption, or even turn the reactor off completely.
And how much fuel would we need to have propulsion? I think that we can do some mathematics on it to get realistic numbers.
4 metric tons of helium 3 would supply the world's total energy needs for one year, IIRC; so, no issue, IMO.
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Post by jackS »

chuck_starchaser wrote: Well, there's something amiss in VS physics, but I can't quite put my finger on it yet. The acceleration is there, 10G's give or take; --nothing to sneeze at; and speeds are measured in kilometers per second, yet for some reason it doesn't "feel" you're going anywhere nearly as fast.
That's because speeds are measured in kilometers/hour. Priv claims to use klicks/s but, just as with the original WC games, I think that only works out when a
"klick" is 10cm. People in general seemed very uncomfortable adjusting to high velocity inertial flight, so we set the governors really really low.
chuck_starchaser wrote: But I don't know where exactly I get the feeling from, since I'm never exactly sure how big or small ships are.
To determine the size of a ship, mesher -dims <bfxmfile> and multiply by the unit scale field in the units.csv. Smaller craft tend to be in the 20-40m long range, capital vessels can be 1-7 km long.
chuck_starchaser wrote:
And how much fuel would we need to have propulsion? I think that we can do some mathematics on it to get realistic numbers.
4 metric tons of helium 3 would supply the world's total energy needs for one year, IIRC; so, no issue, IMO.
If you ever look at your ship info in-game, you'll see that the amount of fuel you're carrying is listed in metric tons.
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Post by chuck_starchaser »

Okay, ship sizes I had it right, then, intuitively; just that I couldn't reconcile that intuition with my incorrect idea that I was flyint at 500 km/s. But if I'm only flying at km/hr, then planets should be like fixtures.
I think it's pointless for me to debate about the physics of VS; once I get more familiar with the engine, perhaps I'll try and rationalize the whole thing myself. I can see how flying at km/sec would be incompatible with dogfighting, but then again, I'd probably limit acceleration to 1 or 2 G's and make it so that one must enter geosynchronous orbit with a planet in order to dock with a space elevator station, or into low orbit for atmospheric entry; and, in either case, enemies could detect you from a long range and alter their orbit to intercept you at low relative speed. I think there are ways to make the game playable and at the same time consistent with real physics, if one is willing to put in the effort.
And, as I was mentioning earlier, the fact that most, if not all, ships sport back facing thrusters ought to be reflected in the physics, so that to accelerate in a given direction one must first point the ship in that direction. All this business of the ship's computer using lateral thrusters to compensate inertia doesn't fly if ships don't apparently have side thrusters. And when I get to it, I'll probably tackle auto-pilot as well, which should have different modes, like dog-fighting mode, docking mode, aerobraking, orbit insertion, landing, fly straight, and intercept, as well as fast vs. fuel-efficient navigation modes.
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Post by lee »

chuck_starchaser wrote: for some reason it doesn't "feel" you're going anywhere nearly as fast.
Even if you go relatively fast, like 20000 or 40000, it doesn't feel like it. Maybe we should designate a seperate discussion to the problem and see if we can make things more clearly when others kick in.
Not sure what you mean by "there are no engines".
Have you ever seen an engine in VS? :) Like buying one, repairing one, replacing one with an upgraded one or as a cargo to trade?

You can buy Engine Upgrades, but if propulsion is only a by-product of energy production, and given that there are no engines, they might better be called Propulsion Upgrades.
What's lacking is maneuvering thrusters, in the models.
Yes, and I'd love it to be in control of the thrusters when flying. And they should be strong enough ...

BTW, where do the enourmous amounts of electric power go that would probably be generated by a reactor that has sufficient output of by-products to pull a ship-mass of a few thousand tons forward at 10g? How much fuel would it take to create so much by-products?
There's no conflict there, at least theoretically.
It is somehow evident to me that a theory, pretending --- in the extreme case --- that you could accelerate a single particle like an ion or neutron as much as to accelerate a mass of several thousand tons at 10g (eventually continually for some time to get the mass up to some speed) would not work out practically.
Matter and energy are interchangeable.
If you eat a loave of bread, it is gone irreplacebly, no matter how many other loaves you can bake with the energy you gained from the one you ate.

But if I somehow sucked the energy you gained from the loave out of your body and transformed it into a loave of bred: What does that theory say about getting that same loave back that you ate?

I won't think it to be the same loave unless the theory could actually prove that it is the same loave.
the speed of light; so you could multiply the mass of the propulsion material just by using more energy accelerating them.
Ok, what does it take to accelerate a particle close enough to the speed of light as to accelerate a mass of 2000 tons continously at 10g for 60 seconds?


I don't doubt all too much that it could work in theory, but my point is that it would evidently have to work practically. To me, it's perfectly acceptable to assume that there is fuel, reactors, engines, thrusters and energy to drive spaceships in a game at fun speeds without the exact type of fuel, the working principles of the reactors, engines and thrusters and the kind of energy being disclosed in detail. But if the game insists on realistic detail and discloses it and claims to enforce these settings to get to a realistic simulation, it should be a setup that could evidently work practically. Otherwise, I would always think that it cannot actually work that way, and that would bother me.

Convince me that it would work practically. Do some mathematics on it --- I'd do it myselfe, but my mathematical skills are insufficient for such things. I think it's possible to come up with some basic numbers that indicate things like the numbers of particles needed for propulsion and then to make some educated guesses on the amount of fuel needed, the size of the reactors and some technical requirements the thrusters would have to fullfill. Once we've got these things, we can decide if it still appears sufficiently realistic that the proposed method of propulsion could actually work. If we think it does, it would be possible way to go, but if it doesn't, we should think of something else.
Do some math on it, I don't think that propulsion would work out.
ditto
You don't think it would work?
If you want to stay with realism, you'll end up where are now, in RL --- no need for a game to simulate that ...
I disagree. RL is not that bad; just that we *choose* safety over excitement.
Wahh, that's a rather optimistical statement! :) RL is not a question of choosing safety over excitement or the other way round but of struggling to fight your way through a steadyly decreasing number of options to choose from. Most of it is about functioning as to the expectations of others, for if you don't, you'll suddenly find your options significantly reduced. An ultimate option is putting an end to it, but many people don't have even that left.
And whenever you step on un-realism, you create a frustration that tends to sooner or later impact something else. Deviating from realism is like lying.
All of us live in their own reality, and everybody else deviates from ours. Since nobody can really tell what's real, we all get constantly frustrated. But that doesn't mean that we're constantly lying.

Such considerations have a tendency to end up in word games :)
When you lie to someone, later on you may have to lie about something else to keep your story consistent with the first lie, and the two lies later become 4 and so on.
That's not true. It would be impossible to lie then, or you're about constructing a tautology.
Best not to lie in the first place.
Yes, it can make things easier. But others become tremendously difficult, though that remains usually unnoticed because honest people tend to think that things are just as they are and that it would not be honest to pretend that they are not or that they could be different. And there are many things that could be easier for honest people it they were willing to lie about them. I'm struggling with these things, sometimes, but I try to avoid it and to remain honest.

Am I lying to myselfe when I try to avoid it? Is trying not to lie a lie in itselfe?
Lost playability can be restored in no time by some creative solution. Lost self-consistency can be very hard to restore.
That's very good reasoning :)
Well, if propulsion is a by-product of energy production, we should rather think of methods to get rid of the energy and/or of the heat involved.
No; theoretically you don't need much mass at all, since you can convert energy into mass by relativity.
You still need some amount of energy in an appropriate fashion to achieve propulsion. You need a considerable amount of such energy to (continously) accelerate some mass of 2000 tons at 10g.

No matter how much mass you convert into energy or the other way round, the above amount of energy doesn't change, and the suitable fashion of it doesn't change much --- unless we assume, for example, propulsion is achieved by force fields that cling to the structure of the universe to 'tow' the ship forward.

My knowledge of such things is insufficient, thus I cannot yet imagine how it could practically work without getting into technical problems with either too much energy or too much heat or both of it (letting aside other possible problems).
Technical questions as per how would one accelerate particles to 0.0000001% of the speed of light in an engine only a few feet across are another matter; but I'd be willing to sweep such technical questions under the rug, as long as the basic questions can be answered.
But that is a basic question. It's like loosing self-consistency to set up great background theories with so much seriousness and then not to check out if they can, with sufficient evidence, yield workable solutions with at least the same seriousness. It may be considered as a kind of lying to construct a truth that renders impossibilites --- like in simple logic, where an assuption is made and something is deduced from it, it may turn out that the deduction is false and thus, the assumption must also be false unless the logic is false. Besides, it's important to learn that the way of reality is indeed not to care about that, thus logic is somewhat irrelevant there. Reality is not self-consistent in the first place.

As for playability, it's important that propulsion works in a suitable manner, no matter what theoretical background is behind that. If we cannot come up with a sufficiently consistent theoretical background now, we can as well maintain self-consistency and playability by not giving such a background at all, or better, some background vague enough to be acceptable by and sufficiently explaning things to players and still not restricting us in providing a better background later.

Players do not play a theoretical background, but a game.
And even if you get too much energy left over after that, well, once the capacitors are charged you reduce fuel consumption, or even turn the reactor off completely.
What if I still need propulsion?
And how much fuel would we need to have propulsion? I think that we can do some mathematics on it to get realistic numbers.
4 metric tons of helium 3 would supply the world's total energy needs for one year, IIRC; so, no issue, IMO.
How many by-product particles are needed to propulse the ships in VS? How much fuel does it take to produce these particles?

BTW, if only 4 tons of helium 3 can give so much energy, how hard are they to come by? Is there still abundancy problems then?
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Post by chuck_starchaser »

Not that hard. And you wouldn't need 4 metric tons in a ship; there'd be enough energy in a teaspoon of H3, probably, to accelerate you at 10G's for weeks.
Check the first link in my linkful post, a page or two back.

As far as having enough material for propulsion, let me try and explain it again:
Theory of Relativity (which for all practical purposes isn't a theory any longer, as this is verified every day in particle accelerators) says that matter cannot travel faster than the speed of light. If you have a charged particle spinning arround in a cyclotron and it's already going at pretty close to the speed of light, if you try to accelerate it, it will get a little closer to c, and its mass will increase. If you double its energy again, it will get another little bit closer to c, and its mass will nearly double. Protons coming out of some of the larger accelerators can have a mass as large as a pound.

The formula, IIRC, was something like...

mm = mr / sqrt( 1 - (v/c)^2 )

where mm is the mass in motion, mr is the mass at rest, and v is the velocity.

Thus, it does not matter how much material you got to throw out back; --as long as it is not zero, whatever amount of energy you put into accelerating particles out the back, you'll have spent it on propelling the ship forward. In fact, the less the mass of particles you got, the more efficiently you run.

Now, accelerating particle to pretty close to the speed of light is something that is done in large cyclotron, synchrotron or betatron facilities, or at linear accelerators, and it usually takes many kilometers, if not thousands of kilometers for a particle to be imparted so much energy. I'm not sure how this could be done in a small engine, but it probably would not rely on a moving electric field. We'd need many orders of magnitude more coupling than is presently possible. This IS a technical problem, and maybe we'll need mambo jumbo to solve it for now.

P.S.: Yeah, I never realized that engines were not upgradable...
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Post by jackS »

chuck_starchaser wrote:Not that hard. And you wouldn't need 4 metric tons in a ship; there'd be enough energy in a teaspoon of H3, probably, to accelerate you at 10G's for weeks.
I'm going to have to disagree.

consider a 50 metric ton vessel (here we will ignore changes in mass due to fuel consumption - which wouldn't matter if your conjecture is correct)

accelerate at 10*9.18m/s^2 for 1 day = 60*60*24 seconds starting from a rest state.


V0 =0;
Initial kinetic energy of the vessel =0
V=at (here we will ignore relativistic effects, they won't be significant yet, we're only getting to around 0.02C)
Vday=10*9.18(m/(sec*sec))*(60*60*24)sec = 7,931,520 m/s
End kinetic energy of the vessel = 1/2*50000kg*(7931520m/s)^2
End kinetic energy = 1.57e18 J = 3.76e17 calories = 3.76e5 kt
Delta ke = 3.76e5 kt

I don't have a convenient energy/mass number for He3-He3, so I'll use D-D instead (you tend to get less energy as you use heavier components so this is probably an overoptimistic number) D-D fusion ~= 82kt/kg

3.76e5kt/(82kt/kg) = 4,588 kg = 4.588 metric tons = one really dense teaspoon.

(and here we have ignored efficiency of extraction issues)
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Post by jackS »

lee wrote:
Even if you go relatively fast, like 20000 or 40000, it doesn't feel like it. Maybe we should designate a seperate discussion to the problem and see if we can make things more clearly when others kick in.
Absent personal experience travelling at 20-40 km/h in RL, I can't say much about what that experience is supposed to feel like :)

However, what I think you'll find if you examine it is that our mental perception of speed is highly relative. The view outside of a 737 at cruising altitude tends to slowly drift by, giving no concrete indication of how fast you're going unless you reconcile the actual sizes of the structures you're passing, and even then, (at least for me) the gut level of "fast" doesn't really kick in until you're much closer to the ground (and getting a lot more motion blur).

Also interesting is how we become accustomed to moving at a certain speed. After a long freeway drive at 75mph the 45mph avenue seems to crawl, and you'd almost think you could run faster than you now appear to be moving... until you look straight to the side and see buildings zipping past.

In space there's just about diddly to serve as a stream of points of reference. I'm willing to bet that if you were going 20-40km/h in VS over a set of structures of discernable size, you'd get a much more potent sensation of motion.
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Post by chuck_starchaser »

Yeah, I shouldda done the math before teaspooning... Just one thing, though; you're using the figure of 50 metric tonnes for the ship as 50 metric tonnes *mass*; which would be about 500 metric tonnes *weight* on Earth; a pretty dense ship ;-) .. well, medium size, I guess.

Coming back to the perceptual problem:

I'm not sure it relates to speed. When I'm going at high SPEC speeds, planets or stars passing by do not necessarily appear smaller to me. I think the problem is interpolated by the brain from acceleration. 10G's is too darn high, IMHO. We have no experience in our daily lives of such strong accelerations. How about making typical acceleration for most ships about 1G forward and 0.1 G in any other direction?

Would probably make the engines easier to explain, for a fringe benefit... ;-)
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Post by Guest »

Why the nitpicking?

VS would be better served by having real planetary flight (/me looks at those privateer mod pics... and that opensource fractual earth sim) then adjusting little things and calling it progress.
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Post by chuck_starchaser »

Planetary flight is very difficult. It will take time. And there's no reason why a smaller problem cannot be fixed before implementing some big feature.
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Post by Duality »

Well needless to say if you want a seamless planetary flight, you may need to re-create vegastrike's flight engine and the universe data in a different format from scratch all over again. It would take years to add the seamless planetary flight with the current engine.

The best thing it can happen is, non-seamless planetary flight if you want it the quickway.
Last edited by Duality on Mon May 16, 2005 2:18 am, edited 1 time in total.
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Post by lee »

chuck_starchaser wrote: As far as having enough material for propulsion, let me try and explain it again:

Protons coming out of some of the larger accelerators can have a mass as large as a pound.
Yes, I go along with that, but there's one thing I still don't understand: If I'm not mistaken, to accelerate continously, you need more than one particle or more than a few particles. The way to accelerate won't be to pop a particle with a mass of one pound every now and then out of the thrusters with all your might but flowing out many particles instead, probably with lower mass, as a steady stream. When you pop them, acceleration would be jerky --- you will get to an average acceleration with that, but it would get very hard on the ship and on the passengers, as a kind of vibration.

Now, if we can agree on needing a steady stream, the following questions come up:


* How many particles do we need?
* Can we get enough of them?
* How much energy do we have to produce in order to get that many particles?
* What do we do with the --- eventually ecxessive amounts of --- energy?


If I get it right, there must be some 'balanche' between the amount of particles, the energy that's used to accelerate them and the mass of the ship. That would mean that we cannot put energy into accelerating particles indefinitely because the acceleration would get out of bearable tolerances --- and it probably means that there's some minimum acceleration because the amount of energy produced is related to the amount of particles that become available. If we try to stay below minimum acceleration, we would go jerky at best; if we go beyond some maximum, we would overdo it and blow up the thrusters or get unmanagable amounts of energy or squeeze the hull somewhat flat due to too much acceleration.

My point is that these things should be thoroughly worked out mathematically. Some reasonable assumptions will probably have to be made to do it, but I think it can be done.

Then, we can see wether the model is sufficiently evident to practically work or not. If it is, it would be really great, and we could put it to work in the game.

All things like ships, cargo and upgrades already have a mass assigned. We can use that in the model of propulsion and get to realistic numbers for acceleration, fuel consumption and such. We can create a couple of engines and thrusters to be bought as upgrades ...
In fact, the less the mass of particles you got, the more efficiently you run.
How comes? Is that because you can use more energy to accelerate them?
thousands of kilometers for a particle to be imparted so much energy. I'm not sure how this could be done in a small engine, but it probably would not rely on a moving electric field. We'd need many orders of magnitude more coupling than is presently possible. This IS a technical problem, and maybe we'll need mambo jumbo to solve it for now.
Provided that the model works out, imho it would be no problem to assume that engines/thrusters have been developed that can sufficiently accelerate particles. Since we need streaming engines rather than popping ones, particle speed can be kept low enough.
P.S.: Yeah, I never realized that engines were not upgradable...
Well, you can even buy a blank hull and fly it around. That shouldn't work, imho :)


BTW, please somebody do something to the forum so that it doesn't log me out every 30 seconds or so ...
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Post by chuck_starchaser »

I didn't mean that we should throw a 1-pound particle once a second. I only mentioned 1-pound mass particle as a way of example. What I meant was that if you had a situation, for a given exhaust velocity, that more energy was being created than needed, but not enough byproduct material, that you could use energy to accelerate that material closer to the speed of light, and get a multiplicative effect for the mass. But you'd definitely keep a steady stream. The rate at which you'd fuse atoms would certainly be into the billions or trillions per second, or more; which are minute quantities anyhow.
Quote:In fact, the less the mass of particles you got, the more efficiently you run.
How comes? Is that because you can use more energy to accelerate them?
Well, less material: The impulse is linear with the energy input, but if particles move faster, less particles are needed. And because of the relativistic increase in mass of the particles as they approach the speed of light, the efficiency formula is not capped by the speed of light. So, even with finite material to eject, the more energy, the more impulse, all the way to infinity. (Well, almost, unless we get down to one particle per second, of course.)
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Post by lee »

jackS wrote: In space there's just about diddly to serve as a stream of points of reference. I'm willing to bet that if you were going 20-40km/h in VS over a set of structures of discernable size, you'd get a much more potent sensation of motion.
Something is odd ... The problem is probably not related to speed or to the perception of it, but I can't tell yet where it comes from.

Things that probably contribute much to it are the weak thrusters, the lack of an auto pilot and the possible 'rapidness' of attacks performed by small fighters like the Hyena and the Aevant.

These things literally add up: Because of the weak thrusters, changes in the direction of flight can take ages, thus it takes ages to get from one location to another without an auto pilot, and then, you get suddenly shot down by hordes of small fighters like the Hyena (popping out of nothing) which can fly, at a distance of about 200--300 meters, around a Goddard that has fully been upgraded to maximum thrust even faster than the Goddard can turn.

To some degree, I've managed to survive by accelerating to speeds of about 6--12k. That allows me to fly through the horde of attackers so fast that they don't have enough time to shoot me down and to outrun them by accelerating further and engaging SPEC until they are out of reach. Once out of reach, I can turn and take them out one by one, but that, again, takes ages.

It is a somewhat ridiculous method of dogfight for a game. And how's that supposed to work in multiplayer games?

Anyway, if you play it that way to some extend, and with some practice, you start to get a bit of the right feeling of flight.

But I'm lacking good ideas how things could be improved ...

One idea that has come to mind is a modification of the SPEC drive: They didn't have that in Frontier, but they had an auto pilot. If you were to fly from one planet to another, for example, the auto pilot accelerated the ship until half of the distance was overcome, then it decelerated. Thus, you could fly at maximum speeds across long distances and yet arrive at reasonable speeds at your target.

If the SPEC drive would be modified --- or if we had an auto pilot doing it instead --- traveling time could be further reduced in VS. Just have the auto pilot accelerate and decelerate the ship free of gouvernor settings appropriately, and let it use SPEC.

Then, thrusters ... We'll have to see the outcome of the propulsion model.

Hm, how comes that all the ships have the same room for upgrades? If larger ships had more room for them, they could be upgraded further and thus have better shields, better thrusters and engines and such. They would even need more room for upgrades because they would need upgrades with more performance which would inevitably be larger.

Another thing is Milspec ships. Not being able to sell the equipment they come with is odd. I cannot upgrade the reactor or the shields or capacitors and such on my Goddard for that. I'm not sure if doing it would allow for a better Goddard, but maybe ...
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Post by lee »

chuck_starchaser wrote:What I meant was that if you had a situation, for a given exhaust velocity, that more energy was being created than needed, but not enough byproduct material, that you could use energy to accelerate that material closer to the speed of light, and get a multiplicative effect for the mass.
Ok, you can do that in theory, but not practically. Maybe it doesn't matter anyway because the particles will be numerous enough, I can't tell.
But you'd definitely keep a steady stream. The rate at which you'd fuse atoms would certainly be into the billions or trillions per second, or more; which are minute quantities anyhow.
Hmm, that's somehow very tempting, having an engine creating large amounts of energy from very little fuel with great efficiency and then using that energy to accelerate the very exhaust to get usable propulsion.
Well, less material: The impulse is linear with the energy input, but if particles move faster, less particles are needed. And because of the relativistic increase in mass of the particles as they approach the speed of light, the efficiency formula is not capped by the speed of light. So, even with finite material to eject, the more energy, the more impulse, all the way to infinity. (Well, almost, unless we get down to one particle per second, of course.)
Sorry, I still don't get why it's more efficient to use particles that have less mass. Somehow I think the mass of the particles shouldn't matter, as you need more energy to accelerate particles of more mass and likewise get more propulsion from them.

Hm, maybe the point is that by having less mass in total, you need less energy to accelerate?
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Post by chuck_starchaser »

lee wrote:These things literally add up: Because of the weak thrusters, changes in the direction of flight can take ages, thus it takes ages to get from one location to another without an auto pilot, and then, you get suddenly shot down by hordes of small fighters like the Hyena (popping out of nothing) which can fly, at a distance of about 200--300 meters, around a Goddard that has fully been upgraded to maximum thrust even faster than the Goddard can turn.
I'm with you there. I complained about precisely that at the WCU forum, and was told that centrifugal force was not modelled. So I said "how come it's not modelled?! We should model it!" And was told this would negatively impact gameplay. :-(
I hate it when "gameplay" is used to defend every bug one reports...
Well, that was WCU. I thought centrifugal force would be modelled in VS, but if what you say is true, it would indicate it is the same as in WCU. I've never played VS for long...
But the problem might come from somewhere else:
At least when playing WCU, I think I noticed that pressing the "~" key, the Sheldon glide, I seemed to be able to turn faster. Maybe it's that the computer is firing the side thrusters to try and compensate inertia, and while they are firing you don't have as much turning thrust. I donno. But I hate that: Doesn't make any rational sense to see ships in the distance flying around me faster than I can turn...[/quote]
If the SPEC drive would be modified --- or if we had an auto pilot doing it instead --- traveling time could be further reduced in VS. Just have the auto pilot accelerate and decelerate the ship free of gouvernor settings appropriately, and let it use SPEC.
Good idea. I need to get to know the engine... I could do that. And I might throw in gravity and centrifugal force, too.
Then, thrusters ... We'll have to see the outcome of the propulsion model.
Hm, how comes that all the ships have the same room for upgrades? If larger ships had more room for them, they could be upgraded further and thus have better shields, better thrusters and engines and such. They would even need more room for upgrades because they would need upgrades with more performance which would inevitably be larger.
I'd like to see (or code myself) a comprehensive ship design interface; have many models and brands of everything, add-ons you can buy. In one screen you'd have a representation of the ship with slots to place sensors, mounts for guns and engines, a launch bay you can fill with things like mines, probes and long distance, inertial torpedoes. Then screens that look like rooms inside a ship, so in the reactor room you'd have fuel tank and emergency fuel tank, tanks for lubricant and hydraulic fluid, pumps and hoses and gauges and whatnot. In the electronics room there'd be a big rack full of rack-mount electronic modules: Main computer, various sensor interfaces, comms, and plenty of space for add-ons. One tiny example: An addon module could feature trigger override when it senses that your shots would hit a friendly. I've got a gazillion little ideas like that.

R.E.: Mil-Spec, I just checked "I-hate-mil-spec.net" is not taken; maybe we should grab it... ;-)
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Post by chuck_starchaser »

R.e.: efficiency; maybe I overstated, I'm not sure. Definitely more efficient in terms of mass required... Right! I remember now: Many years ago I read a book in rocketry and I don't remember the formulas, but it made a point to show how efficiency increases with exhaust velocity. But, precisely as you said, that efficiency was based on the fact that exhaust material has to be carried aboard the ship. So, yeah, if we could, in fact, eject particles not only at near the speed of light, but close enough to it to increase their mass by a large ratio, we could achieve very high efficiencies, as a few metric tonnes of H3 and/or deuterium would be all we need to carry aboard, as opposed to hundreds of tonnes of some material to eject.

Gee! I wonder if anybody ever thought of constructing interplanetary probes using ion engines several kilometers long (using light materials), that can accelerate xeon ions to within, say, a part per million of the speed of light. This could just be the ticket.
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