Basil

Re: Average Seperation The first line from that paragraph: "Others argue that the conditions for life, or at least complex life, are rare." I'm suggesting not that they're rare per se, but that they have only recently (from an astronomic POV) come into being. Thus, there's a growing number of sentients out there, but not yet so many we ought to have been visited. BTW, after re-reading that page, I notice there's a highly important assumption to the Fermi Paradox: sentient species continue indefinately, or at least for a very, very long time. Yet the Drake Equation leaves the question of "how long" up to the user to decide. If FTL is impossible, and a sentient species dies off (for whatever reason) in a few thousand years, there is no paradox; we haven't been visited because nobody's run into us before they died off, and odds are we won't ever be. Yeah, the Fermi Paradox is a very interesting thing. Makes me think about all sorts of things!

Re: Something Star Hero needs, but hasn't. LOL. At least you didn't reinvent the wheel. Actually, I think Solar Hero ought to cover (at least in general terms) all the known and theorized STL drives: rockets (chemical, electric/ion, nuclear [constant & pulsed], antimatter), light sails, ramjets (Bussard, catalytic, RAIR), beamed energy, electormagnetic "rails", pellet stream, etc. Hey, Steve L.! I recommend The Starflight Handbook: A Pioneer's Guide to Interstellar Travel by Eugene Mallove and Grefory Matloff. Has solid info, clearly presented. Although it's aimed at interstellar flight, the info is highly usefull for interplanetary flight. Good stuff for Solar Hero. Oh, and it also goes into speculation about FTL!

Re: Average Seperation An interesting varient on Hoyle's theory. One thing: the life within each "bubble" would be based on similar chemistry, but that in another bubble might be based on very, very different chemistry. However, it should be reasonably easy to deliberately "seed" new planets (at least, those that *could* support life). While some sapients might "cross the desert," I would think most would put their efforts into "vitaforming" (altering to support/have life) planets that got missed.

Re: Something Star Hero needs, but hasn't. After reading this thread (as it is so far), I have to agree that a build system does not belong in Star Hero. Star Hero covers an entire genre, and a build system limits it too much. In fact, I think the percentages for systems given on page 192ff and elsewhere should not have been given, or given as a range, with suggestions as to when/where to use the high end, middle, and low end of the ranges. However, for Alien Wars, Terran Empire, and the upcoming prequel Solar Hero, I think a build system is imperitive. This is, after all, a specific setting, and there should be a coherent design to things. IMO, that design should be told to the players in that setting. And when that setting is supposed to be "hard(-ish) SF," it's even more necessary. This is especially important so that when (not if) the players want their characters to build their own starship (or radically refit one), the GM isn't forced to say "No, you can only have what's on this list". It might seem you can just tell the poor GM "figure out the points, and make them pay those &/or pay X credits/solars/BUCS/whatever." But that's not good enough, it seems to me. You just know someone's going to go "How much cargo space is there?" or "Can we fit a Mark XXII wizzbang in where the old Mark III was? If not, can we tear down a wall and canniblize some space from the cargo bay/staterooms/galley/etc.?" However, Alien Wars and specifically states that rockets (chemical, nuclear) are the only STL drives used. So how they must work is important to understand. True. However, two points: 1) To suggest that there be some sort of "how do you build a starship" system exist and be told to the players, in a specific setting, is much different from saying that setting, or the entire genre book hew to physics as we know it. 2) If a RPG book says that rockets are the STL existant, then that book ought to be written with some understanding of, and respect for, the physics of rockets.

Re: Something Star Hero needs, but hasn't. A couple of short notes regarding my long, math-filled post: 1) I refered to "the end velocity" for simplicity. In fact, what the formula uses in "delta-V", which is the total change in velocity. A rocket that accelerates to 10,000 m/s, spins around, slows to a stop, speeds back up going the way it came from, up to 10,000 m/s, the spins around a decelerates to a stop exactly where it started from has an "end velocity" of 0 m/s, but a delta-V of 40,0000 m/s. And it's 40,000 m/s you'd use in the formula. 2) from Alien Wars p.125, repeated in Terran Empire p.158: "Trvel within Hyperspace depends on two things: first, a ship's normal propulsion (since the ship has to propel itself through Hyperspace);..." Thus, the whole matter of propellent mass fraction applies to FTL as well as STL. Frankly, I don't think the writer thought things through at all.

Re: Alien Wars: Before hyperdrive, there was... That'd work. Of course it raises the question: when does Earth get a one-world government? Also, what of the UN's "no exploitation of outer space" treaty (I forget its proper name)? In fact, how does that debating group called "The United Nations" turn into "the United Earth" -- of course, those questions don't have to be answered now. That's what "Solar Hero" is for.

Re: Alien Wars: Before hyperdrive, there was... It'd also be a ***** to store! It would be dangerous in the extreme, be subject to "shrinkage", etc. Also, the "antimatter photonic" rocket idea (advanced by Eugen Sänger in the 1950's) is unworkable. The current thinking is to use antiprotons only, and either "channel" the pions produced when they interact with protons, via a "magnetic nozzle", or to use the interaction to heat a propellent (such as hydrogen, water, methane, etc.) and have that "fly out the back". Either one means a noteworthy amount of propellent. BTW, according to The Starflight Handbook, for anitmatter rockets (for use in the Solar System, mind you!) to be feasible, the cost of making antiprotons has to come down to ~$10 million per milligram, and the current (1989) cost is $100 billion per milligram.

Re: Alien Wars: Before hyperdrive, there was... Well, that's a & to me.

Re: Alien Wars: Before hyperdrive, there was... Now there's some info that ought to have been in Alien Wars (& maybe Terran Empire). That gives some highly useful background info. The problem with even fusion power plants is the propellent fraction has to be enormously high, or the travel times are enormously long. Or, you don't settle outside the Solar System at all. Of course, even inside the Solar System, travel times are high between planets. And the easiest way to go faster that Hohmann orbits is not fusion-powered (near) constant acceleration, but light sails. I'm sorry, but I'm just not buying the whole timeline for Alien Wars. I know it's jsut a game, and hand-waving is expected and perfectly fine. But in a supposedly gritty, "realistic" sub-genre like Military SF, a good deal of 'respect' for physics-as-we-know-it is a desideratum. And on lthe whole matter of propulsion, Alien Wars falls down on the job.

Re: Alien Wars: Before hyperdrive, there was...

Re: Alien Wars: Before hyperdrive, there was...

Re: Average Seperation Great reading there! Thanks a lot! The Percolation Hypothesis is a fascinating idea. Just one problem from the Science Fiction POV: it requires that there be no FTL (or, at least, that FTL be not a whole lot faster than c, and that the FTL drive can't go faster than some specific number). There is, BTW, another 'solution' to the Fermi Paradox. If it took the galaxy about 5 billion years to build up a fraction of trans-helium elements sufficient for life-bearing planets to form, and if it takes at least, say, 4 billion years for technological sapients to evolve, then Homo sapiens sapiens is among the first, and we haven't been visited because our 'predecessors' haven't gotten this far. One thing about this speculation: in the Drake Equation it is no longer Lc/Lg, but Lc/Le, where Le is the time during which technological sapients could have evolved. If that is 1 billion years, the Drake Equation's result is mutiplied by 10!. A counter-intuitive result to put it mildly.

Re: Average Seperation Well, the Star Hero approach deals with a "habitable zone" for the galaxy, similar to the "green zone" around a star -- the area in which a habitable planet can exist. For example, in the core of the galaxy, the radiation level is too high, and the frequent close passes of stars are unlikely to leave stable planetary systems intact. If you rule out those parts of the galaxy unlikely to host planets where "life as we know it" could exist, then you get quite a bit less than the actual volume of the physical galaxy. If you look at my first post, you will see I determined the volume of the Galactic Habitable Zone from the figures given in Star Hero. Thus, its size is a different matter from the size for the galaxy as a whole. BTW, Dust Raven: I just realized I didn't use the numbers (15,000 ly and 35,000 ly) you gave in your original post. Using those, the volume of the GHZ is about 3.14 * 10^12 cubic ly. Also, there's only about 86 billion stars in that volume, so there's only about 2100 civilizations. These two changes lead to an average separation of --- 1140 ly. The two factors balance out, after all.

Re: Average Seperation Which is what I said, I just also explained why. Again, just what I said. BTW, I prefer "3.62 * 10^12" because it's clear to anyone who's done enough arithmetic to recognize "^" as the "to the power of" symbol. I'd use superscripts if I knew how to do them on these boards. OTOH, "3.62c12" is only known to those who've used some specific computer programs. Using "The Cambridge Atlas of Astronomy", we get the following dimensions for the galaxy (all are approximate): Central Bulge: Diameter: 6 kiloparsecs Thickness: 1 kiloparsec Disk: Diameter: 30 kiloparsecs Thickness: 300 parsecs Halo: Diameter: 30 kiloparsecs Converting to lightyears (and giving radii as appropriate): Central Bulge: Radius (actually semi-major axis): 10,000 ly Thickness (actually minor axis): 3000 ly Disk: Radius: 50,000 ly Thickness: 1000 ly Halo: Radius: 50,000 ly (NB: the radius of the Halo may actually be 60,000 ly or more, but I'd rather use the more conservative value) The Central Bulge is an oblate sphereoid, so the formula is (pi)*(4/3)*(semi-major axis squared)*(semi-minor axis), which is about 6.28 * 10^11 ly. The whole disk is a cylindar with a hole through it: (pi)*(50,000^2 - 10,000^2)*(1000) = about 7.54 * 10^12. So the overall total is about 8.17 * 10^12 for the disk and bulge. (This is about 45% higher than the figure you gave). The halo + disk + bulge (or grand total) volume is (pi)*(4/3)*(50,000^3), or about 5.24 * 10^14. Which is about 64 times as big as the disk+bulge. However, the density of stars is around 1/100,000 or less.

Re: Alien Wars: Before hyperdrive, there was...

5th Edition, page 166, says "At the GM's option, a character can shape his Explosion like a Cone (loses 1 DC per 2") or a Line (loses 1 DC per 3") for the same +1/2 value,..." Assuming a GM allows this, does this change the fall-off-distance increase for additional +1/4? That is, does one say "well, with a spherical Explosion, for a further +1/4, the DCs fall of more slowly by the same amount as the basic Explosion, therefore for a 'channeled' Explosion, the DCs should also fall off more slowly by the basic amount."? Or does one say "+1/4 is 1" more slowly, no matter if the Explosion is spherical or 'channelled'."? That is, does changing to a Cone or Line give a one-time boost to the fall-off distance, or does it change the unit-of-measure for the basic & the improved fall-off distance? To give a specific example, If I have: EB, 8d6, Explosion (Cone, +1/2) I would subtract the first die at 2" out, the second die and 4" out, the third at 6" out, etc. With: EB, 8d6, Explosion (Cone, one level of increase, +3/4) Would I subtract the first die at 4", the second at 8", etc., or the first at 3", the second at 6", etc?

Re: Something Star Hero needs, but hasn't. [snipping a lot, to get to the point I want to respond to] Actually, it's a LOT worse than this. For any craft accelerated by "throwing stuff out the back" (BTW that "stuff" is known as propellent), there is a formula that relates the velocity the craft reaches, the velocity of the propellent, the total 'take off' mass, and the 'end' mass (that is, the mass of everything that isn't "thrown out the back"). Conventionally, the ratio (take-off mass/end mass) is called R. Using e (the base of the natural logarithms), we take e^(end velocity/velocity of the propellant) = R. Now, if the craft accelerates at 5 m/s for 30 days, it's final velocity is 12,960,000 m/s. Burning Be-H2 in O2 gives the fastest chemical propellent velocity (7050 m/s). Stick in the numbers, and you get R = 2 * 10^798. Which means, to get one picogram to do what the Centauri-class does, requires a f**king GAZILLION universes of propellent. It is estimated that fusion rockets with have propellent velocities of 25,000 to 2,000,000 m/s. The slowest of those gives R=1.4 * 10^225, which is still impossible. The fastest gives R=652; IOW the 100,000 ton craft needs over 65 million tons of propellent---the mass of a small asteroid. OTOH, if we assume the 100,000 tons is *starting mass*, then the end mass is about 153 tons; not useful at all. And note: all of this is utterly fixed by the laws of physics. If you want a craft that isn't nearly-all propellent, you need a "rubber-(pseudo)-science" STL. Which would, it seems to me, work against the whole feel of Alien Wars. Two technical notes: 12,960,000 is about 4.3% of the speed of light; although slight relativistic effects would occur at that speed, we can ignore it for this discussion (especially since relativistic rocket formulae are a pain). Second, all the above facts & formulae come from The Starflight Handbook: A Pioneer's Guide to Interstellar Travel, by Eugene Mallove & Gregory Matloff. The authors are professors, and experts in rocketry. So yeah, this really is how rockets work.

...what? IOW, what FTL existed before "hyperdrive", in the 'official' Terran Empire/Alien Wars timeline? Alien Wars, page 125, boxed text, gives the introduction of the Class Alpha Hypredrive as happening in 2203. Yet on page 7 it says The Colony Act was passed by the Senate on 2104. Obviously, something preceded Hyperdrive. OK, I'll bet 2104 is a typo for 2204. Still, with Alpha Centauri 4.4 ly away, and Class Alpha going 1.2 ly per year, it would take 3.7 years for a spaceship to get to Alpha Centauri. Obviously, there is no way hyperdrive was the first FTL. So, what is the ***OFFICIAL*** answer to "what FTL came before Class Alpha Hyperdrive?" Or is this a lack of continuity to the TE/AW timeline?

Re: Average Seperation With 2450 civilizations, each "has" about 1.49 * 10^9 cubic ly, for a distance of ~1140 ly. Hope that helps!

Re: Superhero Images Out of interest, are you going to allow hot-linking (aka image hosting) on your server? Freewebs, unfortunately, doesn't allow that. :/ If not, people can always upload their full sized images to your site (or Freewebs), and make their own thumbnail-sized copies and upload those to the boards, if they want to give an idea of the pic to readers here.

Re: Superhero Images Unfortunately, I haven't, having come to these boards in only the last few months, and only found out about this and the other art threads in the last week. As I said in that thread, I suggest using freewebs.com to hold your pictures, and link from there. Their website and uploading function is self explanatory. And they're free! And Blue, I know it's a ****load of work, but I for one would deeply love to get a chance to find any&all of your artwork I haven't yet found.

Re: Opinions requested on an application of Side Effects {much snippage occurs} ::Sigh:: There's a major brain-fart. "Laedor" is correct--not because it's the subjunctive, which it isn't, but because it's the passive. Sorry if I caused any confusion.

Re: Cartoon Hero

Re: Cartoon Hero You can find some ideas re. cartoon heroes in Adventurers Club #27, in the article "Funny Animal Champions." HTH

Re: Opinions requested on an application of Side Effects Well, that does make things simpler.