Post by namewithheld on Aug 28, 2018 3:49:13 GMT
Wow, I was away for a bit! Now I'm back, and can respond! Also, thank you all so much!
EDIT: My attempt to do multi-quoting failed utterly. *sighs* Sorry...
coaxjack Avatar
Aug 26, 2018 23:06:06 GMT -7 coaxjack said:
You end up with Mutually Assured Cleric Destruction, where you can send your arsenal of cleric-powered relativistic suicide missiles at the enemy, which they will detect and fire their own relativistic cleric missiles (RCMs). Or have a cleric summon trillions of tons of water into a sub-Schwarzschild point mass to make a black hole while on a spy mission aboard an enemy space station.
What I'm saying is that the ability to summon matter from nothing, the people with the ability, and the tools to do so will be extremely tightly regulated.
This is a very good point - though clerics have an ultimate check that goes beyond government: Deities. I highly doubt a lawful good god would be particularly happy with their clerics being used as RKVs. And while it is possible to summon trillions of tons of water using wands, you'd need a heck of a lot. I mean, you'd need 250,000 wands just to make one million tons of water. And you'd need 250,000 people to touch them and activate them (or 1 person willing to spend 250,000 rounds of combat - roughly 11 hours straight of wand-activation) to create it...
There are practical considerations to magic, after all!
shiolle Avatar
Aug 26, 2018 23:17:20 GMT -7 shiolle said:
I... wasn't expecting this. Regardless, I did some calculations just for fun.
Let's take a spaceship with 1000 tons dry mass that can accelerate at 1g when full with "fuel" and 10 km/s of delta-v. Ve is 3.67 km/s, since you mentioned using NTRs. That is an average exhaust velocity of stock water NTRs in the game. The thrust is about 10 MN and thrust power is 18.67 GW. Mass flow of water through the engine is 2.773 tons per second. That is a bit over 16 wands per second emptied, so the ship should still contain some form of tanks where the amount of water for the next maneuver is contained. Those temporary tanks are assumed to be part of the dry mass for simplicity; it should not affect calculations that much. That means that 10 km/s of delta-v requires only 38 tons of wands.
You can copy the spreadsheet I made for this from here and play with the numbers if you want. Orange fields are for input, grey for non-magical calculated values and violet are for wand-related stuff.
P.S. I can't believe I actually made a spreadsheet for hard magic spaceships!
Holy shit THANK YOU SO MUCH! If I ever get around to selling this as a splat book on DriveThruRPG, I am totally crediting you for this! And I can do that, 5e is OGL. *strokes chin* Hmm...there are already several "sci-fi" mods for 5e, but they do always end up just being fantasy in space, not actually science fiction...that sounds like an opening in the market...
gedzilla Avatar
Aug 26, 2018 23:29:59 GMT -7 gedzilla said:
Just out of curiosity, what did your rocket scienctist parents think about CoaDE ?
My dad thought it was really neat. Mom just shouted something about Hohmann Transfers from the other room while working on her cross-stitch.
treptoplax Avatar
Aug 27, 2018 5:26:41 GMT -7 treptoplax said:
For further fun, consider that this allows both (manned!) Planet-cracking relativistic missiles, and free energy / perpetual motion machines.
The key in both cases is that the newly created mass is presumably at rest with respect to its creator, which could give it considerable kinetic energy with respect to a reference frame in which the creator is moving. Launch a ship, create water on board, and catch it in a giant coilgun generating more energy than it took to launch it!
That's an element I'll have to figure out. See, my setting conception is that it takes place 600ish years after a traditional tolkien-esque fantasy world is forced into space by demonically induced climate change via a portal being ripped open on the north pole by irresponsible magic use (I'm extremely subtle with my metaphors.) So, while 600 years is a long time, they're not exactly working with modern technology, and have some gaps in their tech (i know I want fairly primitive computers to reduce the chances of the combat just becoming a bunch of robots shooting at each other.)
treptoplax Avatar
Aug 27, 2018 7:32:18 GMT -7 treptoplax said:
Also, probably no need for radiators. I haven't done the math, but I expect you could just generate and boil water, then vent the steam.
Damn it, that's a good point...I'll need to re-assign the critical hit table (one of the critical hits is "destroyed radiator."
ghgh Avatar
Aug 27, 2018 9:51:10 GMT -7 ghgh said:
treptoplax Avatar
Aug 27, 2018 7:32:18 GMT -7 treptoplax said:
Also, probably no need for radiators. I haven't done the math, but I expect you could just generate and boil water, then vent the steam.
This thread makes my head hurt. Wouldn't it depend on the temperature of the water? The steam would also be an issue especially coming off the reactor. We're not talking about steam from a tea kettle. We're talking about 2500K (assuming apophys style reactor) steam/plasma rapidly disassociating into hydrogen and oxygen which would damage the exhaust vent (pure oxygen does not play well with metal) and propel the ship in directions not intended.
Hey, we haven't even gotten to considering what the impact of Feather-Fall has on breaking! Feather-Fall is a spell that causes all objects in a 60 foot sphere to "fall at 60 feet per combat round [editor's note: this is about 10 feet per second], landing safely on the ground." Which opens up a lot of questions when 'falling' and 'ground' are entirely relative concepts. Also, what happens if 60 feet on a half mile long spaceship starts going about 3 mps while the rest is still going 5,000 kps! Nothing good, I can assume!
AtomHeartDragon Avatar
Aug 27, 2018 11:34:54 GMT -7 AtomHeartDragon said:
ghgh Avatar
Aug 27, 2018 9:51:10 GMT -7 ghgh said:
This thread makes my head hurt. Wouldn't it depend on the temperature of the water? The steam would also be an issue especially coming off the reactor. We're not talking about steam from a tea kettle. We're talking about 2500K (assuming apophys style reactor) steam/plasma rapidly disassociating into hydrogen and oxygen which would damage the exhaust vent (pure oxygen does not play well with metal) and propel the ship in directions not intended.
With unlimited water there is no need for closed cooling system. All the reactors become continuously burning, water based NTRs. When you don't want to produce net thrust, you simply thrust in opposite directions.
So, my decision to not separate reactor and thruster in the ship design rules WAS the right decision! I was worried for a second. (technically, there are reactor/thrusters - like the NTRs, and then there are just plain reactors that are RTGs or solar or magical power, and then there are just engines, like chemical rockets and stuff, but those are for edge cases, like the scrap-built goblin space raiders that are just X-ray lasers on rockets with a goblin shoved in there somewhere.)
Kerr Avatar
Aug 27, 2018 13:52:11 GMT -7 Kerr said:
Unlimited water? Use it to terraform mars while also turning a wheel for power, power interstellar missions with that amount of energy or something on that order of magnitude. You've now entered the magic of mega(infra)structures.
There's still the issue of the lack of magnetosphere on Mars, isn't there?
thorneel Avatar
Aug 27, 2018 15:13:09 GMT -7 thorneel said:
If reaction mass basically stops to be a problem, can you make a wand of create mercury instead? If you're going for thrust only, mercury is the best room-temperature liquid propellant around, being the heaviest (we'll be better ignoring radon) - the downside being of course that it has a pitiful Isp, and its rarity, the very two things we don't care about anymore.
(Fun fact: that's why the very first MPD I made with the game was using mercury as propellant for that reason. (And the third one used radon, because why not.)
And then, if your wands produce water or mercury based on volume instead of mass...
I am almost positive that there is intensive research on trying to make wands that produce other things. But since all the create water spells are clerical or divine in nature, it's basically a load of clerics praying to Shalmur the Everlight, "Dear goddess of light, we want to make 5 tons of liquid mercury!" and she's sitting there in the Outer Plains going, "...the...fuck are these people smoking?"
But this does make for a fantastic adventure hook! Someone has discovered or built a wand of create mercury and has this immense tactical advantage, which tips the balance of power in the system, and so on.
Congratulations, you just solved the heat death of the universe. The cost is we transition to a dystopian society where we breed vast legions of Wandcrafters & Clerics, selecting for traits that make one conducive to becoming a cleric or wandcrafter
Quadrillion-Quadrillion-Quadrillion-Quadrillion humans inhabit a vast Birch World orbiting a supermassive black hole, as Seed-class AIs continuously optimize mankind for Faith and Wandcraft, continuously magicking entire solar systems worth of mass in water and feeding the conjured substances into optimized Kugelblitz singularities to generate exponentially increasing power, using the power output to fuel vast transmutation machines for the sake of increasing the infrastructure and supportable population size (and thus conjuration rate).
Maybe in a few more millennia.
Also, none of this solves the real issue: The Apocalypse Stone!
EDIT: My attempt to do multi-quoting failed utterly. *sighs* Sorry...
coaxjack Avatar
Aug 26, 2018 23:06:06 GMT -7 coaxjack said:
You end up with Mutually Assured Cleric Destruction, where you can send your arsenal of cleric-powered relativistic suicide missiles at the enemy, which they will detect and fire their own relativistic cleric missiles (RCMs). Or have a cleric summon trillions of tons of water into a sub-Schwarzschild point mass to make a black hole while on a spy mission aboard an enemy space station.
What I'm saying is that the ability to summon matter from nothing, the people with the ability, and the tools to do so will be extremely tightly regulated.
This is a very good point - though clerics have an ultimate check that goes beyond government: Deities. I highly doubt a lawful good god would be particularly happy with their clerics being used as RKVs. And while it is possible to summon trillions of tons of water using wands, you'd need a heck of a lot. I mean, you'd need 250,000 wands just to make one million tons of water. And you'd need 250,000 people to touch them and activate them (or 1 person willing to spend 250,000 rounds of combat - roughly 11 hours straight of wand-activation) to create it...
There are practical considerations to magic, after all!
shiolle Avatar
Aug 26, 2018 23:17:20 GMT -7 shiolle said:
I... wasn't expecting this. Regardless, I did some calculations just for fun.
Let's take a spaceship with 1000 tons dry mass that can accelerate at 1g when full with "fuel" and 10 km/s of delta-v. Ve is 3.67 km/s, since you mentioned using NTRs. That is an average exhaust velocity of stock water NTRs in the game. The thrust is about 10 MN and thrust power is 18.67 GW. Mass flow of water through the engine is 2.773 tons per second. That is a bit over 16 wands per second emptied, so the ship should still contain some form of tanks where the amount of water for the next maneuver is contained. Those temporary tanks are assumed to be part of the dry mass for simplicity; it should not affect calculations that much. That means that 10 km/s of delta-v requires only 38 tons of wands.
You can copy the spreadsheet I made for this from here and play with the numbers if you want. Orange fields are for input, grey for non-magical calculated values and violet are for wand-related stuff.
P.S. I can't believe I actually made a spreadsheet for hard magic spaceships!
Holy shit THANK YOU SO MUCH! If I ever get around to selling this as a splat book on DriveThruRPG, I am totally crediting you for this! And I can do that, 5e is OGL. *strokes chin* Hmm...there are already several "sci-fi" mods for 5e, but they do always end up just being fantasy in space, not actually science fiction...that sounds like an opening in the market...
gedzilla Avatar
Aug 26, 2018 23:29:59 GMT -7 gedzilla said:
Just out of curiosity, what did your rocket scienctist parents think about CoaDE ?
My dad thought it was really neat. Mom just shouted something about Hohmann Transfers from the other room while working on her cross-stitch.
treptoplax Avatar
Aug 27, 2018 5:26:41 GMT -7 treptoplax said:
For further fun, consider that this allows both (manned!) Planet-cracking relativistic missiles, and free energy / perpetual motion machines.
The key in both cases is that the newly created mass is presumably at rest with respect to its creator, which could give it considerable kinetic energy with respect to a reference frame in which the creator is moving. Launch a ship, create water on board, and catch it in a giant coilgun generating more energy than it took to launch it!
That's an element I'll have to figure out. See, my setting conception is that it takes place 600ish years after a traditional tolkien-esque fantasy world is forced into space by demonically induced climate change via a portal being ripped open on the north pole by irresponsible magic use (I'm extremely subtle with my metaphors.) So, while 600 years is a long time, they're not exactly working with modern technology, and have some gaps in their tech (i know I want fairly primitive computers to reduce the chances of the combat just becoming a bunch of robots shooting at each other.)
treptoplax Avatar
Aug 27, 2018 7:32:18 GMT -7 treptoplax said:
Also, probably no need for radiators. I haven't done the math, but I expect you could just generate and boil water, then vent the steam.
Damn it, that's a good point...I'll need to re-assign the critical hit table (one of the critical hits is "destroyed radiator."
ghgh Avatar
Aug 27, 2018 9:51:10 GMT -7 ghgh said:
treptoplax Avatar
Aug 27, 2018 7:32:18 GMT -7 treptoplax said:
Also, probably no need for radiators. I haven't done the math, but I expect you could just generate and boil water, then vent the steam.
This thread makes my head hurt. Wouldn't it depend on the temperature of the water? The steam would also be an issue especially coming off the reactor. We're not talking about steam from a tea kettle. We're talking about 2500K (assuming apophys style reactor) steam/plasma rapidly disassociating into hydrogen and oxygen which would damage the exhaust vent (pure oxygen does not play well with metal) and propel the ship in directions not intended.
Hey, we haven't even gotten to considering what the impact of Feather-Fall has on breaking! Feather-Fall is a spell that causes all objects in a 60 foot sphere to "fall at 60 feet per combat round [editor's note: this is about 10 feet per second], landing safely on the ground." Which opens up a lot of questions when 'falling' and 'ground' are entirely relative concepts. Also, what happens if 60 feet on a half mile long spaceship starts going about 3 mps while the rest is still going 5,000 kps! Nothing good, I can assume!
AtomHeartDragon Avatar
Aug 27, 2018 11:34:54 GMT -7 AtomHeartDragon said:
ghgh Avatar
Aug 27, 2018 9:51:10 GMT -7 ghgh said:
This thread makes my head hurt. Wouldn't it depend on the temperature of the water? The steam would also be an issue especially coming off the reactor. We're not talking about steam from a tea kettle. We're talking about 2500K (assuming apophys style reactor) steam/plasma rapidly disassociating into hydrogen and oxygen which would damage the exhaust vent (pure oxygen does not play well with metal) and propel the ship in directions not intended.
With unlimited water there is no need for closed cooling system. All the reactors become continuously burning, water based NTRs. When you don't want to produce net thrust, you simply thrust in opposite directions.
So, my decision to not separate reactor and thruster in the ship design rules WAS the right decision! I was worried for a second. (technically, there are reactor/thrusters - like the NTRs, and then there are just plain reactors that are RTGs or solar or magical power, and then there are just engines, like chemical rockets and stuff, but those are for edge cases, like the scrap-built goblin space raiders that are just X-ray lasers on rockets with a goblin shoved in there somewhere.)
Kerr Avatar
Aug 27, 2018 13:52:11 GMT -7 Kerr said:
Unlimited water? Use it to terraform mars while also turning a wheel for power, power interstellar missions with that amount of energy or something on that order of magnitude. You've now entered the magic of mega(infra)structures.
There's still the issue of the lack of magnetosphere on Mars, isn't there?
thorneel Avatar
Aug 27, 2018 15:13:09 GMT -7 thorneel said:
If reaction mass basically stops to be a problem, can you make a wand of create mercury instead? If you're going for thrust only, mercury is the best room-temperature liquid propellant around, being the heaviest (we'll be better ignoring radon) - the downside being of course that it has a pitiful Isp, and its rarity, the very two things we don't care about anymore.
(Fun fact: that's why the very first MPD I made with the game was using mercury as propellant for that reason. (And the third one used radon, because why not.)
And then, if your wands produce water or mercury based on volume instead of mass...
I am almost positive that there is intensive research on trying to make wands that produce other things. But since all the create water spells are clerical or divine in nature, it's basically a load of clerics praying to Shalmur the Everlight, "Dear goddess of light, we want to make 5 tons of liquid mercury!" and she's sitting there in the Outer Plains going, "...the...fuck are these people smoking?"
But this does make for a fantastic adventure hook! Someone has discovered or built a wand of create mercury and has this immense tactical advantage, which tips the balance of power in the system, and so on.
Quadrillion-Quadrillion-Quadrillion-Quadrillion humans inhabit a vast Birch World orbiting a supermassive black hole, as Seed-class AIs continuously optimize mankind for Faith and Wandcraft, continuously magicking entire solar systems worth of mass in water and feeding the conjured substances into optimized Kugelblitz singularities to generate exponentially increasing power, using the power output to fuel vast transmutation machines for the sake of increasing the infrastructure and supportable population size (and thus conjuration rate).
Maybe in a few more millennia.
Also, none of this solves the real issue: The Apocalypse Stone!
