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Post by thorneel on Nov 18, 2016 0:29:53 GMT
Not sure what to call the thing. "Witch Engine" sounds cool. Or the "RAGE" (Repulsive Adhesion Generation Engine). I like Witch Engine, though it evokes something that is not quite controlled and will go horribly, horribly wrong if mishandled - and even if handled properly if you're unlucky. The kind of horror in a bottle that makes anyone wanting to use it a delusional lunatic (but that is so powerful that people will use it anyway). Roadside Picnic (the book that inspired Stalker and that I really should read at some point) apparently has a stuff called Witch's Jelly, which is described as exactly that nasty, hence the image it evokes me. I also suggest you to check the Ghost Drives articles here. The basic concept is simple: the physics-breaking reactionless engine is literally using ghosts put inside fusion reactors - so they both have plenty energy to eat and are trapped inside. But sometimes, they escape...
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Post by Crazy Tom on Nov 18, 2016 4:03:28 GMT
<abbr data-timestamp="1479417168000" title="Nov 17, 2016 16:12:48 GMT -5" class="o-timestamp time">Nov 17, 2016 16:12:48 GMT -5</abbr> srbrant said: BRILLIANT! I've already come up with some applied phlebetonium for that idea. One is an element discovered from the manipulation of strange matter that allows for force manipulation. Limitations set for it include that it will disintegrate outside of a special chamber (almost like a sort of spherical supercollider), meaning that it is completely impractical for kinetic weapons, requiring a reactor for power. If too much energy is fed into it, it becomes volatile and either crumbles apart or melts. Not sure what to call the thing. "Witch Engine" sounds cool. Or the "RAGE" (Repulsive Adhesion Generation Engine). Don't. Say. How. It. Works. I cannot stress this enough - I speak from personal experience. Treat it like a black box, and make sure conservation of momentum and energy are observed, but don't go into any other sort of detail about it. What it does should be clear - how it does it should be avoided. For example: Weapons: You could use specialized mass drivers that make use of this force-field to accelerate payloads. But the kinetic energy achieved by said payloads has to be equal to less than the energy imputed into the mass driver, and the ship must deal with the resulting recoil. Propulsion: You cannot escape the rocket equation. If you don't have a Alcubierre style displacement drive, then a ship will likely fly by flinging itself around planets and asteroids where it will use these fields to slingshot itself and propel itself against their mass. Thus cruises would be made up of short high acceleration 'burns' around massive bodies, and long periods in freefall between destinations. A warship that needs to maneuver in deep space would have to rely on on-board propellant tanks - perhaps a fusion torch drive separated from the ship via force-field (to reduce required radiation shielding while still allowing you to use a very powerful drive. In fact, said drive might very well double as the ship's spinal weapon depending on high tight you dialed the exhaust. Honestly, I recommend you read The Risen Empire by Scott Westefield. He has some space battles and ships that perfectly illustrate what I'm saying, blending real physics with just a touch of space magic and getting a result that is wonderfully entertaining and quite physically hard.
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Post by dpidz0r on Nov 18, 2016 4:35:33 GMT
If you don't have a Alcubierre style displacement drive, then a ship will likely fly by flinging itself around planets and asteroids where it will use these fields to slingshot itself and propel itself against their mass. What part of the planet would it push against? Some kind of vague field pushing on the entire thing, or a focused point? If the force can be focused enough at a distance, I could imagine a deranged spaceship captain using the mass of his ship to literally squish people like ants.
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Post by Crazy Tom on Nov 18, 2016 5:34:08 GMT
If you don't have a Alcubierre style displacement drive, then a ship will likely fly by flinging itself around planets and asteroids where it will use these fields to slingshot itself and propel itself against their mass. What part of the planet would it push against? Some kind of vague field pushing on the entire thing, or a focused point? If the force can be focused enough at a distance, I could imagine a deranged spaceship captain using the mass of his ship to literally squish people like ants. Radiation in nature falls off with proportional to the square of the distance. You could say that the efficiency of the field falls off with distance similarly. If that were the case, then it would be airless moons and asteroid that would be most valuable since you could skim very close to their surface to get the most efficient boost. Otherwise ships could push off planetary atmospheres. Or you can use a combination of torch drives and celestial body 'push-offs' if your calculations say ships need to accelerate too fast to get meaningful time to push off.
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Post by apophys on Nov 18, 2016 17:13:52 GMT
A lot depends on how hard you want the SF to be. My personal opinion is to dispense with any magic at all, and only use what is known to be possible (minus engineering concerns), because there's a lot of inherently interesting material there already. If you do decide on some magic, then you should at least fill out the rest of the world-building with such things.
"Discovering a godly new element" is quite a bit overdone and breaks immersion now, imho, even if you frame it as synthesized antimatter. And that won't give you force manipulation.
Force at a distance (other than the obvious way with magnets) can actually be done with laser standing waves. It's proposed for making low-mass space telescopes, by holding a super-thin mirror in place without structure. But if you want enough force to move big things quickly, you'll probably have enough intensity to melt/boil them anyway, unless they have some special coating.
Dumping heat: I'd suggest having radiators being a white-hot/blue-hot membrane or molten droplets, or storing and expelling heat in propellant. You can assume incredible advances in materials science, but you can't break thermodynamics.
Reactors: Fusion should be developed by 5525AD, so that's clearly option #1. A denser possibility is antimatter fuel, produced in stations with fusion power. Matter for annihilation reactions can easily be interstellar hydrogen scooped up in front of the ship.
Thrusters: Super-high exhaust velocity with reaction mass can be achieved in various ways: MPD, fusion, matter-antimatter annihilation, nuclear salt water rocket, railgun, coilgun, extreme laser. I'd pick one or more of these. You can radiate heat in one direction, thus having radiators double as (extremely low) thrust.
Alcubierre needs exotic material of negative mass, IIRC. That may or may not exist, but most likely doesn't. You can try pushing against stellar magnetic fields for hypothetical propulsion. There are some alternate weird things floating around that you can snag for SF, like the "EM drive" (a supposedly reactionless thruster with unknown mechanism; the legitimacy of the actual thing is rather questionable, but it makes acceptable concept fodder).
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erin
Junior Member
Smash Mouth Plays From The Depths Of Hell As You Traverse A Deep, Rat-Infested Cave
Posts: 57
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Post by erin on Nov 18, 2016 18:43:15 GMT
If you're really interested in getting FTL "right", be prepared to do a lot of deep digging since most sources will say "not possible" without any real attempt to explain further to a sufficient degree of clarity. As far as I'm aware, your most uncontroversial bet [citation needed] for FTL is wormholes. Orion's Arm has some resources detailing how it works in their FAQ and encyclopedia galactica article. This other FAQ is also a useful resource. The gist of it (as I thus far understand) is as follows: All travel is time travel; accelerating in space exchanges speed in time for speed in space, hence why you get time dilation slowdown effects from traveling at fractions of c. What's important is to avoid causality violations, and for that you want gate-type FTL, not drive-type. A wormhole gate network needs to be built in the form of a star network, or else it needs to be built "slowly" (sub-relativistic speeds). Time dilation means that you cannot bring two gates back together more than a certain distance, after you've separated them -- the amount of "wiggle room" available depends on how fast you moved the mouths apart. (99% lightspeed = very little room; sub-relativistic speed = lots of room.) All connections radiate outward from a central hub, although individual lines running out from the hub may branch off. If you build your network at relativistic speeds, take care to avoid Roman rings. I've heard some physics-types assert that drive-type FTL is possible but they mentioned something about "global causality violation is okay so long as local causality holds" and an offhand reference to the many-worlds hypothesis, which after many, many months of research I guess what they were trying to say is that "FTL works just fine as long as you assume that breaking causality forks off a parallel universe and you don't mind not being able to go back to your old one". Which is a fine basis for a science fiction setting in its own right but maybe not the kind of thing you're going for. ("Global" versus "local" in this context roughly means "at macroscale" versus "at particle scale"; i.e. the matter making up the ship itself is not traveling faster than light but the space around the ship moves the ship faster than light. If the ship's particles themselves were traveling faster than light, then no fundamental interactions between the particles could take place and you wouldn't have a ship anymore.) If you don't want to mess with this stuff though, a magic drive will suffice for most peoples' tastes.
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Post by srbrant on Nov 18, 2016 23:21:56 GMT
Forgot to mention: The engines for the ships in Kemono are like those used in Children of a Dead Earth; FTL engines can only be activated where gravity is weakest such as Lagrange points. And yes, they use fusion power. Engines have been tuned in a way so that they cannot exceed .20c in speed. Because if a neighboring empire finds that you've been soaring around at 30% the speed of light, then consider yourself to be miles-deep in shit as The Killing Star has taught us. Although in this setting it's more like a stern reprimand or war rather than outright interplanetary genocide.
As for the issue with radiators and reaction mass tanks, they tend to be smaller because of advances in heat management and fuel efficiency.
It's not so much discovering a miraculous new element as it is inventing new elements. Exotic forms of metallurgy have allowed for the creation of things like adamantium, agricite, weirdium and the alien-made ossium.
The mode for FTL is entering hyperspace, killing the STL engines and simply sailing through ethereal currents until they find a "current loop" where ether swirls around a gravity well. Then they fire it up again and exit back into normal space. The currents can vary in their speed and direction, so there is a lot of room for non-fatal error. The average superluminal travel period is 24-48 hours per lightyear.
As a joke, I was thinking of drawing a cross-section of a warp core, with the insides being so insanely minute and complex that it's impossible to determine what is what and where and how. Or of a character explaining to another of how it works, with their dialogue cut off by a long written description of a nearby loud noise - ending when the character finishes their speech.
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Post by shiolle on Nov 18, 2016 23:32:34 GMT
The gist of it (as I thus far understand) is as follows: All travel is time travel; accelerating in space exchanges speed in time for speed in space, hence why you get time dilation slowdown effects from traveling at fractions of c. What's important is to avoid causality violations, and for that you want gate-type FTL, not drive-type. Sorry, but I cannot agree with you here. There are two distinct problems with FTL: light speed barrier and causality violation. Any FTL violates causality regardless of its type. You always need two FTL transitions in different frames of reference to violate causality. I believe drive type FTL fell out of favor because there was a lot of problems found for Alcubierre drive (I don't know why Crazy Tom says it can't be used for FTL) and Krasnikov tubes are not well developed. On the other hand wormholes got a lot of attention recently. This is all explained in detail on the Atomic Rockets web site, but there is one link there I would recommend: Relativity and FTL Travel. It explains why all FTL travel equals to time travel and lists certain provisions that can be introduced to prevent FTL from causing causality regardless of the type of FTL drive. The part about special relativity can be understood without any math at all, but unfortunately that's not possible with general relativity.
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Post by srbrant on Nov 21, 2016 4:05:48 GMT
What about starship shapes? I mean, there has to be more than rods, bullets and cones, right?
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Post by nerd1000 on Nov 21, 2016 6:34:47 GMT
- Postulate one magic tech and abuse it. Figure out some sort of spooky action at a distance system that allows you to transfer force/momentum to physically objects. Don't explain how it works, because it's not possible as far as we know. Then you can use said force fields to create artificial gravity (aka paragravity) by just pushing everyone to the deck of the ship; you can use it to deploy hundred kilometer sheets of droplet radiators that will allow you to radiate to your heart's content even in combat (because the droplets will be moved around with force fields and won't be lost to space as you accelerate); it will allow you to create compact fusion reaction chambers for propulsion, power, and other fun applications; you can also use them as force fields (through in their case it's more of pushing projectiles and beams away and deploying mobile armor against lasers). This sort of momentum exchange also the structural stress on the hull to be evenly distributed through these force fields, which gives you more artistic license in terms of making ships look distinctive (no longer are you limited to making fuel tank skyscrapers). BRILLIANT! I've already come up with some applied phlebetonium for that idea. One is an element discovered from the manipulation of strange matter that allows for force manipulation. Limitations set for it include that it will disintegrate outside of a special chamber (almost like a sort of spherical supercollider), meaning that it is completely impractical for kinetic weapons, requiring a reactor for power. If too much energy is fed into it, it becomes volatile and either crumbles apart or melts. Not sure what to call the thing. "Witch Engine" sounds cool. Or the "RAGE" (Repulsive Adhesion Generation Engine). Maybe consider the culture of the civ that uses or invented the tech to come up with a name. If they're rationalist, highly scientific types who don't have much time for spirituality I'd go for some kind of dull acronym, wheras a civilization that is more spiritual (perhaps they even came upon the tech by accident and don't understand how it works) might use a more magical sounding name. Of course you could also do some lampshade hanging: how about calling it something along the lines of Momentum Alteration by Gravitational Imposter Creation, or MAGIC?
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Post by coaxjack on Nov 21, 2016 16:40:38 GMT
High Impulse Graviton/Higgs Linear Induction Null Excitation
HIGHLINE
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Post by Crazy Tom on Nov 21, 2016 20:14:01 GMT
I believe drive type FTL fell out of favor because there was a lot of problems found for Alcubierre drive (I don't know why Crazy Tom says it can't be used for FTL) and Krasnikov tubes are not well developed. On the other hand wormholes got a lot of attention recently. It's largely because IIRC the problems you mention are so much worse for FTL Alcubierre. Hawking radiation frying the interior of the bubble, not being able to control the bubble because signals can't reach the front, that sort of thing. Plus, causality violation. Speaking of wormholes, there are a lot of misconception out there about how they would work. I read that a wormhole doesn't actually function as a 'gate'. Say if you had a 1kg payload and two linked 10 kg wormholes, and you wanted to pass the object through them. You would end up with a 11 kg entry wormhole and a 9 kg exit wormhole, and the 1 kg payload on the other side. So if you have two linked wormholes, you have to balance mass transfer through them. edit: Also, the Higgs field has nothing to do with Gravity. Mass and Gravity are different things.
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Post by coaxjack on Nov 22, 2016 3:16:44 GMT
I know, I was just mashing scifi stuff together to get a cool sounding acronym.
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Post by srbrant on Nov 22, 2016 6:42:14 GMT
I can figure out the whole naming thing on my own, but what I really need to know is starship shapes. Something more than rods, cones, bullets and cylinders...
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Post by beta on Nov 22, 2016 8:21:35 GMT
As explained in a blog before the game was released ( childrenofadeadearth.wordpress.com/2016/04/12/why-does-it-look-like-that-part-2/ ), convex shapes are used because the rocket equation is a pain in the ass. You need to use as little mass as possible to armour your spacecraft (and keep the parts together in a structurally sound way) so you can maintain maximum performance. The more dry mass you add to your spacecraft, the worse it performs - acceleration, total range, cross section, turning speed, etc. If you really dislike cylinders, you could go with spheres and accept the efficiency problems with space and radiation. Would be something visually different, though might not be what you are looking for.
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