-Velocity-

The major flaw in your assertion here is the assumption that the anti-nuclear extremists respect any form of logic and reason.

Yes, as I noted very early in the thread, if we assume that most of the volume of a fuel tank is used to store fuel, then the density of fuel is around the density of water, 1000 kg/m^3. If we assume that only like 15% of a fuel tank is actually used to store fuel, which is, to me, a nonsensical, stupid assumption, then we arrive at a density of fuel of being 5000 kg/m^3. In the end, what I did for my xenon tanks was make my converted Jumbo64 hold 28 m^3 of liquid xenon, for a total of 856000 units of xenon fuel (assuming a density of 3057 kg/m^3). As the Jumbo 64 has a volume of 36.8 m^3, my xenon Jumbo 64 utilizes 76% of its volume to store xenon. It also turns out that the stock xenon tank included with the game is rather inefficient, holding only like 50% of its volume in xenon fuel (though, I haven't actually measured it precisely). However, I think that is roughly in line with other very small fuel tanks that hold rocket fuel. I also doubled the dry mass of my liquid xenon Jumbo 64 on the premise that it needed more structural reinforcement due to the high mass of liquid xenon. Now, can someone make a model of a nuclear reactor with actual heat sink fins? All the nuclear reactors I have seen in various mods (like the DSM mod) have terribly unrealistic models. You've got to have a heat gradient to harvest energy from your nuclear reactor, and the only way to get that heat gradient in space is a bunch of black heat radiator panels. In a good model, the radiator panels probably ought to glow a faint red from the heat near the reactor, too. Is there a huge barrier to entry in 3D modelling, like having to buy ten thousand dollar 3D modelling software?

OK, I guess we ARE in agreement then. I guess my point is that humans are very narrow minded. Most of us do not even realize this. There are just so many ways that the universe can combine various physical laws to make astounding and unique phenomenon you simply have to expect the unexpected. It's similar to how narrow-minded fools at the end of the 19th century would have said that space travel was forever impossible. They had a knowledge of Newtonian physics, thermodynamics, electromagnetics, etc. and they knew how much energy is produced when you combine liquid oxygen and a fuel like liquid hydrogen or kerosene. Given the blueprints for the Saturn V, they would have understood almost everything about how it worked with enough study and without having to stray outside their knowledge of the physical laws. Really, they had all or almost all the physical laws they needed for space travel. They were just too arrogant and confident in their own world view to realize that if something is not disallowed by the physical laws, you CANNOT EVER rule it out. Assuming the survival of civilization, our own future will contain a lot of things NO ONE has ever foreseen. But, if we were to bring a piece of future technology back to the present and analyze it, most likely, we be able to understand how it does all the things that it does within our current set of the laws of physics (seeing as we appear to have exhausted the limit of practical physics discoveries- but even that MIGHT be a wrong assumption, especially in the more distant future).

Fuel density is 5000 kg/m^3? I know the wiki SAYS that, but that's ridiculous and makes no sense considering the entirety of the facts. It would imply that only a small amount of a fuel tank is actually used to store fuel, and the rest is just empty, wasted space. As I said in my initial post, a Jumbo 64 is 1.25m in radius, and 7.5m long. This gives it a volume of 36.8 m^3. At the same time, we know that the Jumbo 64 has a fuel mass of 32000 kg. At a density of 5000 kg/m^3, you only need 32000 kg/ 5000 kg/m^3 = 6.4 m^3 to hold 32000 kg of fuel. So, if fuel is really 5000 kg/m^3, then the Jumbo 64 only uses 6.4/36.8*100 = 17.3% of its volume to hold fuel. The rest of it is just empty, wasted space. I don't believe that likely; the simplest explanation is just that liters are NOT, in fact, liters. Either meters are not really meters, liters are not really liters, or full fuel tanks are almost entirely empty space. Liters not actually being liters only invalidates the numbers you see when you're fueling fuel tanks, as that's the only place that liters are ever counted. And hell, where does it actually SAY those are liters? I only see it in the wiki. No fuel tank descriptions say liters. However, meters are clearly intended to be meters. And if fuel density is really 5000 kg/m^3, then you NOT ONLY have to account for why fuel tanks are almost entirely empty space, but ALSO the "odd" coincidence that when you use a REALISTIC density for fuel, the mass of the fuel in the fuel tanks exactly matches what you would expect if the fuel tanks are, in fact, mostly filled with fuel like they SHOULD be. Again, the simplest explanation I see is that liters are not liters. I think I'm just gonna call them "kerbal gallons" (kals) due to the fact that the value of 1 kal being close to the actual value of the gallon, and also due to the similarity that gallons are an inconvenient and confusing unit, too.

Thanks... that makes me feel a lot better. I did do a forum a search (multiple forum searches) and couldn't find the discussion. Also, the KSP wiki backed up the 1 unit = 1 L assumption, so I found it of no use. Maybe instead of liters, the unit of fuel should be called "Kerbal gallons" or "kerballons"? Anyway, it actually looks like I could realistically fill a Jumbo 64 up with almost 1 MILLION units of xenon , xenon is a very heavy gas and liquid xenon is over three times denser than water.

OK. Sorry if this has been asked before, but I seem to have found an inconsistency in the units of measure for rocket fuel, if it is assumed to be liters. I found this while I was playing around with creating my first mods (very large xenon tanks), and was trying to figure out how much xenon I should put in them. First of all, by comparing dry mass and empty mass of the stock xenon tank and its fuel capacity, I saw that one unit of xenon fuel is actually 0.1 kg. A little odd, but whatever. OK, fine. So now I wanted to figure out how much xenon fuel I should put in a modified Jumbo 64 tank. The Jumbo 64 supposedly, by my understanding, holds 6400 liters of rocket fuel. The number of liquid fuel units and oxidizer units certainly add up to 6400. However, rocket fuel is like, maybe on average (if using kerosine and liquid O2), *roughly* around the density of water, about 1000 kg/m^3, which is the same as 1 kg/L. I noticed that the difference between the dry weight and the full weight of the Jumbo 64 is in fact 32 metric tons, or 32000 kg. Thus, the Jumbo 64 actually should hold about 32000 liters of fuel (using the 1 liter = 1 kg approximation), NOT 6400 liters. The final nail in the coffin against liters being the unit of rocket fuel was when I measured the dimensions of the Jumbo 64- they are 2.5 meters by 7.5 meters. That is a volume of pi*1.25^2*7.5 = 36.8 m^3. 36.8 m^3 is 36800 liters. This agrees VERY CLOSELY with my predicted volume of 32000 liters based on the density of rocket fuel and the mass difference between a full and empty tank, especially if you allow for a bit of dead space inside the tank. So using two completely different approaches, one based on density and weight and one based on volume, we arrive at the conclusion that the unit of measure for rocket fuel is NOT, in fact, liters. It is something else. It would appear that the volume of rocket fuel in game is actually around 5 liters per unit (32000 L / 6400 units = 5 L/unit). So what in the heck is going on? Anybody know? Am I just doing something incredibly stupid? Or are the units of rocket fuel actually GALLONS?!?! If so, it would agree closely with the numbers then (1 gallon = 4.5 liters).

How did you get things to stick to the Novapunch fuel tanks? Everything I put on them has a tendency to detach for no valid reason, and also, they appear to be indestructible, which REALLY puts a damper on the fun of launch failures. (In fact, every Novapunch part appears to be indestructable ) We might not want to admit it, but the spectacular failures are half the fun of testing new rocket designs Have these issues been fixed, or was it something peculiar to my install of the mod? I've been stuck with the 3.75 meter KW rocketry tanks, but at least the Novapunch engines are usable to me.

Humans are not infinitely intelligent and we cannot foresee all the different ways in which the laws of physics can come together to produce wholly unexpected and novel phenomenon. Earth *does not* have a monopoly on all planetary processes, and studying Earth alone will only take you so far. In general, if you go into the unknown expecting it to behave exactly like you think it should, you could miss something very important that simply doesn't fit your preconceived notions. It's always safest to expect the unexpected. It wouldn't be "the unknown" if it always behaved according to "the rules". In this case, you're ruling out even the remote possibility that there could be some small spring on the surface of Mars that slowly trickles water out onto the surface over the course of a few years (where that water rapidly boils away or freezes or sublimates or does all three). Still, right at the mouth of the spring, there could be flowing water on the ground that persists for years, as it is continuously replenished by a pressurized and heated underground aquifer. You grant that it's possible that water might burst out in short episodes, so under what basis can you rule out that it might, very rarely, slowly trickle out instead of burst out? I'll tell you- you're ruling it out solely on the basis that it doesn't conform to the way you expect water to behave on Mars. The universe doesn't know or care what your preconceived notions are, and if something is not explicitly disallowed by the laws of physics, it cannot be ruled out entirely. Especially when an extremely similar phenomenon is already considered likely to exist.

Maybe not. I WOULD have thought the oceans, but I have heard that water helps lubricate plate tectonics, and that there is a considerable amount in the mantle. However, I didn't think it was liquid, I didn't think it was comparable to the amount in the oceans, and I thought most of it was bound up in the rocks chemically, but I honestly never thought about it much. I suppose the mantle has high enough pressure it can keep water liquid up to pretty high temperatures. What is it? Am I getting warm?

Ok. I don't see where there is any disagreement, other than what the definition of "flowing water" is. I am not talking about permanent rivers or lakes or even streams; to me, occasional rare "burps and spurts", as you put them, can count as flowing water, because the water could still last long enough on the surface to flow, MAYBE a few kilometers at best (probably more like a few hundred meters), and carve a few short features. The lifetime would be short and dependent on salinity, pressure, and temperature. As I understand it, this is, in fact, what scientists ARE talking about when they are discussing recent evidence of "flowing water" on Mars. Not flowing, STABLE water. HOWEVER, MAYBE, if the water was "lucky", it might spurt out of the bottom of the Hellas Basin on a warm day, somehow maintain itself in the right temperature range all day long, and only freeze when the sun went down at night. MAYBE, once in an even rarer while, when the Sun comes up the next day, some will remain and it might remelt and sit there for a second day, somehow maintaining that narrow temperature range... but it's gonna be a very, very rare event probably. I just hate totally unequivocal statements like "I refuse to accept the possibility of <insert here>." Nature can surprise you. The ignorant man thinks he knows everything; the wise man knows nothing is truly certain. It is certainly within the realm of possibility- very unlikely but possible that there is a spring somewhere on the surface of Mars where a small trickle of water has been flowing out onto the surface and collecting in some small pool as it evaporates/boils/freezes/sublimates away, and has been doing this continuously for years. We probably would have spotted something like it already with MRO, but still... it's possible, especially if water can spurt out in "burps" from time to time. Do you refuse to accept even the remote possibility of such a feature, either in the recent past, the present time, or near future?

This is my 1500 ton + interplanetary carrier-tanker. The point of it is to carry landers to various distant planetary locations and also bring along enough spare fuel to supply extended and repeated landing and exploration operations. Basically, it becomes a big orbiting fuel depot (it carries the fuel of like 38 Jumbo-64 tanks). This version currently is assembled out of separately launched stern and bow sections. I'm using a heavy lift design that weighs around 3000 tons (sans payload) and can put over 500 tons into LKO (so, to get get an 800 ton segment into orbit on a heavy lift rocket only capable of 500 tons, obviously, the segments must donate some of their initial fuel to the fourth stage. I just top the ship off after it is assembled.) (If you're wondering what the sideways-facing engines are for near the top- how else do you think I keep this bastard under control and pointed in the right direction?! Those engines are on action groups, I toggle them off and on to steer the rocket.) Anyway, I'm going to try going bigger, much bigger, just to see if it can be done. Also, you folks who build giant stuff out of stock parts... I'm impressed!!! That takes some real skills Mods that add huge tanks make things SO much easier (and managable on the CPU)... I just wish the Novapunch 5 meter tanks wouldn't be so buggy for me.

Wrong. Why didn't you look it up first? http://en.wikipedia.org/wiki/Hellas_Planitia The highest pressure at the lowest elevation in this region of Mars is supposedly 1.16 kPa. The lowest pressure at which water can be a stable liquid is 0.612 kPa, this is the triple point. It is possible for liquid water to remain stable in this area of Mars, but in a narrow temperature range. To quote the wikipedia article, Technically, it shouldn't even be necessary to mix salt into the water to keep it liquid, distilled water should be stable if the temperature is right, but salt would certainly help, as it would lower the melting point, and extend the range in which water would be stable. BUT, all that said, while it is technically true to say that there are still places where water is stable on the surface of Mars, it is important to remember that it is only in a narrow range of temperatures (like maybe 10-20 degrees C, don't remember the exact range), unlike Earth, where water is stable over comparatively a huge range of temperatures (100 degrees C). Furthermore, those temperatures lie near the upper end of the hottest temperatures Mars experiences. BUT, again, you mix in the right antifreeze compound, and you could certainly extend that range quite a bit- how much exactly, I don't know though. Personally, I wouldn't say there is "no doubt" that Mars has liquid water pockets underground, it seems like a strong possibility, but we need to collect more evidence at this point.

Actually, there are still a handful of (low) places on the surface Mars where the pressure (and temperature, too, on "warm" days) can support stable liquid water (barely!). It's really not that much of a stretch to imagine that somewhere underground, it could melt, and be stable for longer periods. It only needs to break out onto the surface very rarely to carve the evidence for recent water flow we seem to have spotted. Just because Mars, on the surface, initially looks cold and dead and dry doesn't mean it is; if there is anything planetary science has taught us, it is to expect the unexpected. A geologically active moon only 500 km across with giant geysers and probable liquid water lakes under its surface is a FAR more unlikely proposition than a Mars that has maintained a few pockets of liquid water deep underground, and yet, Enceladus exists.

Simply that Earth has been subject to no interference by any of these hypothetical intelligent races, at least, no obvious interference, and the likely explanation is no interference at all. We are "all natural", "pristine". If intelligent life is common and they like to settle habitable extrasolar planets, as all the tradditional science fiction stories go, then Earth would have been colonized billions of years ago. I frequently read Wikipedia; I am fairly certain I already read that one. Edit: I don't know if I did or not, but most everything in there I at least read somewhere else. You're not going to find much disagreement here. I'm just surprised to find someone else who actually cares about science, I thought I was the only one. Really, honestly, no one that I know personally actually finds science and knowledge exciting. It's pretty ironic that most folks will respond to news about science with the remark, "I don't care, how does that affect me?", while voraciously watching every single video they can find of whatever trashy celebrity is currently in the news. Oh and of course, then when science comes out with something that doesn't conform to their cherished notions of how the universe should work, then they will be the first to tell the scientist to how wrong they are. Stupidity, plus being too stupid and arrogant to even realize that an expert in a field might know more about it than you do, that takes the cake. Oh well, I guess someone has to clean out the toilets, right? But anyway, I should have probably stopped already, this is too far off topic.

That's just more of a problem of realistic physics, I think. In low gravity, there is much less force holding you to the ground, so of course there is much less traction. My first Munar lander was in fact a rover (why bother ever sending a stationary lander when it is not much extra trouble to just put wheels on it and make it a rover instead? That was my logic, at least.) Anyway, oh boy, was it dangerous to drive- I had the center of gravity way too high for the weak Munar gravity. I redesigned my rover, placing the center of gravity much closer to the ground, and it was a HUGE improvement- it was MUCH easier to drive around and MUCH harder to flip. Under the weakest gravities though, like Minimus, if you want something for exploring the surface, it really just becomes easier and safer to fly around on little sub-orbital hops from spot to spot, rather than actually trying to drive anywhere.

To me, the idea that the intelligent life is rare seems an unlikely explanation for the pristine, untouched nature of our world. Considering the size of the galaxy and the sheer number of habitable worlds, unless intelligence is VERY rare, I think it is more likely that Earth's pristine nature is saying something about the typical behavior and/or technology of intelligent civilizations. But I grant that intelligent life being just very rare could alone account for this, I just feel it unlikely on nothing more than a hunch. Hopefully, we'll know more in a few decades after a few spectral surveys of nearby Earth-like planets, enough to base our guesses on hard evidence instead of hunches.

We are on the verge of launching telescopes that will be able to characterize the atmospheres of Earth-like planets within a few dozen light years. So, Earth's spectral signature has been SCREAMING "Oxygen!" "Water!" "Biology is here!" "Habitable world!" across hundreds (thousands, really) of light years for any reasonably advanced intelligent civilizations to see for the 2.4 BILLION years it has had an oxygen atmosphere, and yet, here we are, no one has invaded or tried colonization. We only see evidence of one origin of life (as all life shares the same DNA bases, protein chiralities, etc), and any serious alien colonization would have left evidence behind (such as a separate tree of life, artifacts, orbiting structures, etc.). The only logical reason I can think of for an alien invasion is that they might see us as threats. But why would we be threats to them? Already, the pristine and untouched nature of our ideal habitable world argues against the idea that civilizations expand and colonize habitable worlds. So why would we be viewed as a threat when we would would not seek to expand and try to colonize their worlds, invading their territory? I find it more likely that advanced alien civilizations, if they exist, do not undergo the expensive process of interstellar travel very often, because you can find billions of years of energy and abundant building materials around your own home star. There's no real need to go ANYWHERE, other than just basic exploration- much of which can be carried out from afar with telescopes anyway.

This may sound crazy, but I'm not sure that we're really capable of understanding whatever the real answer is to why the universe exists at all. I mean, like the ultimate reason that anything exists at all, may be beyond our comprehension, just as visualizing 4, 5, 6, etc. dimensional space is beyond the ability of our 3-dimensional minds, but we can describe it mathematically. It may be that the question is meaningless, and there IS no reason. Does there HAVE to be a reason that physical laws governing a multiverse exist? What law of physics exists that says that there has to be a reason that the laws of physics exist? The problem is that, logically, I don't see where you don't eventually come down to something irreducible that simply "just is", and that has no deeper "why?" that can be answered (there is a name for such things, anyone remember it?). You see, even religion does not answer the question, because while religion can explain why the universe and the laws of physics exist, it can't explain where God came from, or why God should be required to exist. (Thus, as an explanation for the reason for the ultimate existence of everything, I personally find religion unsatisfactory. Religion requires a more complex explanation for the origin of the universe than solely the laws of physics alone, as it requires not only the laws of physics to exist but an extremely complex universal intelligence as well. Thus, we can eliminate God as a likely explanation for the origin of the universe/physical reality via Occam's Razor. Feel free to disagree if you want, I won't be offended.)

I would think that the laws of physics and math would be pretty universal, as they are the "operating system" of the universe, and we all live in the same universe. Once they decoded our own particular way of representing mathematical equations, intelligent civilizations that are as advanced or more advanced than us should recognize Newtonian physics, quantum mechanics, Relativity, etc. While these sets of laws are not the full description of the universe, they are simplifications (even Newtonian physics is very accurate under most conditions) to whatever the full description of the universe really is, and they should recognize them for what they are. We haven't been able to unify Relativity and quantum mechanics largely because these laws are such good approximations for how the universe really works that we have, as yet, been unable to make an experiment that defies their predictions.

Things I hate: 1) 32 bits. WE NEED MOAR MEMORY, CAPTAIN! I run out of memory with my big ships all the !@$$ing time, and it really pisses me off that in the year 2013, game devs would still be making 32 bit executables. I've got 16 GB of memory, and my computer is four and a half years old. 2) Kraken 3) Kraken 4) Kraken 5) Single core, though I realize that multicore programming is still a big challenge. Things I love: 1) Pretty much everything else. Don't let my above gripes get in the way of my overall opinion of KSP- KSP is an awesome game overall, and it's not even done yet!

I don't think that the KSP aerodynamic models, probably even with FAR, are good enough for something somewhat scientifically accurate like what you are suggesting, but I could be wrong. Maybe something with orbital maneuvers would be better instead? Maybe figuring out optimal orbital transfer maneuvers for various planets, mixing in different gravitational assists? Also, like, how often are the planets properly aligned to do such maneuvers?

No, they should not. Theoretically, I know from mechanics that it doesn't matter where a moment (a twisting force- a torque) is applied to a structure, the end result is the same. So it shouldn't matter. Control surfaces do not apply moments, they apply a force, so it can matter very much where you put them, and if I remember correctly, there was also a bug where the control surfaces were canting in the wrong directions in some cases, can't remember what those were, but I thought that was fixed? Edit: all that said, you wouldn't want to place your reaction wheels somewhere that was structurally weak, but that's just common sense.

I have made pretty large mods for other games, so that is definitely a possibility one day. I'm not sure though that the kinds of things I would like to mod though are actually mod-able yet, and I don't have the time for such a project at this moment. Also, I can do lots of computer code, but suck at artwork :/

Yea, OK, maybe I did get a little carried away with myself, I do love sarcastic humor, so sorry about that. At least I had a fun time making that post It was just the first few sentences of your post that I took offense to- I think that there are a lot better (and slightly more respectful) ways to say what you were trying to say there other than (effectively) "this isn't Orbiter, so either go join NASA or shut up." That's at least how it felt to me, no matter what your original intentions were with those statements. My point is the "argument" that "this isn't <insert game name here>" is not even a valid argument for anything at all, as it can be used to justify the removal or exclusion every single feature and aspect of the game, or, as you use it, just those features that you don't want. I think the real question, the answer to which would go a long way towards solving this small debate to one side or the other, is what level of realism is KSP eventually intended to be? (There's no reason you can't have "cartoon" universes that follow very realistic physical laws and have very realistic physical bodies.) I don't know if Squad has ever really addressed that what level of realism KSP is intended to be (everything I've seen though seems to indicate that they are shooting for as realistic as practicality and fun will allow). Heck, maybe they don't even know themselves.

Yea, it's stupid, but I figure that the only way I am going to fully solve my fuel flow problems is to simply feed all engines in an asparagus stage from a single tank. Basically, each asparagus stage has a central, "main" tank, and all engines in that asparagus stage are either attached to the central tank, or fed by a fuel line coming off the central tank. Any additional fuel tanks in that asparagus stage have one-way fuel connections going from them to the central tank. It sucks, but as far as I can see it, it's the only way to make the fuel tanks drain in the right order. It will mean that I will to waste a lot of mass on engine mounts.