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Old 03-14-2021, 10:33 PM   #1
awesomenessofme1
 
Join Date: Mar 2016
Default [Space] Carrying capacity not connected to size of species?

I was looking through the rules for carrying capacity of planets in Space, and it doesn't look like the actual size of the dominant species matters at all. Am I missing something? Is this just an oversight? It certainly doesn't seem RAI that 1' aliens and 10' aliens should have the same carrying capacity, all else equal.

Somewhat related question: Are there rules anywhere in Spaceships for changing habitats, etc, based on the size of the inhabitants?
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Old 03-14-2021, 10:46 PM   #2
David Johansen
 
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Default Re: [Space] Carrying capacity not connected to size of species?

You could ball park it at carrying capacity is in average humans and humans average 150 lbs. So a 1500 lbs race would need 10x the carrying capacity.
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Old 03-15-2021, 07:04 AM   #3
Varyon
 
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Default Re: [Space] Carrying capacity not connected to size of species?

Carrying capacity of a planet seems like it would largely scale with food consumption, which isn't (all else being equal) linear with mass - rather, it scales roughly as the 2/3 power of mass.

To my knowledge, there aren't guidelines as to the different life support/space requirements of larger and smaller crew of space ships and space stations. I believe food, water, and oxygen consumption all scale similarly, so life support requirements should scale roughly as the 2/3 power of mass. Space is a bit more questionable. I think furniture could get away with scaling with the 2/3 power of mass - it needs to be wider and taller, but not necessarily thicker, as it spreads the weight out more - although I could see it scaling linearly. Walls and the like need to be taller and wider as well, but again I don't think they'd need to be any thicker, as they're holding in the same air pressure, so 2/3 the power of mass should work. I'd say for simplicity, even if furniture should need to scale linearly, using the 2/3 power of mass should work. This is the square of scale, so roughly you'd end up with something like the following.
Code:
SM	Mult	SSR
-6	x100	x100
-5	x49	x50
-4	x25	x20
-3	x9	x10
-2	x4	x5
-1	x2.25	x2
+0	x1	x1
+1	x0.49	x1/2
+2	x0.25	x1/5
+3	x0.09	x1/10
+4	x0.04	x1/20
+5	x0.0225	x1/50
+6	x0.01	x1/100
The "Mult" column is the actual multiplier based on the nominal height increase; the "SSR" column rounds this to scale with the Size and Speed/Range Table. You can expand this if needed - every +6 to SM is x0.01, every -6 to SM is x100. Apply the multiplier to the number of cabin-equivalents you get per Habitat (or seats per Passenger Seating, etc).
EDIT: The same table should be usable with Carrying Capacity - an SM+6 race scales calculated Carrying Capacity down to 1%, while a race of SM-6 scales it up by 100x. If a planet has, say, a Carrying Capacity of 10 billion, it could support only 100 million of the first, or up to 1 trillion of the second.
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Last edited by Varyon; 03-15-2021 at 08:10 AM.
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Old 03-15-2021, 08:12 AM   #4
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Default Re: [Space] Carrying capacity not connected to size of species?

Bio-Tech has food scaling for large and small creatures. It uses the square of scale (i.e. height), which is the 2/3rds power of mass.

Spaceships 7 says you should shift up and down the Habitat table by the SM in steps, which means habitats scale in proportion to mass. That's probably fair, as what you gain (for larger beings) by having 2/3rds scaling in walls, etc. you lose because you need more than 1/1 scaling of things like chair legs and bed supports (not much more with high TL materials, but some).
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Old 03-15-2021, 08:35 AM   #5
awesomenessofme1
 
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Default Re: [Space] Carrying capacity not connected to size of species?

OK, thank you both. Looks like the answer is that carrying capacity scales by the 2/3 power of mass and spaceship capacity scales by mass.
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Old 03-15-2021, 09:52 AM   #6
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Default Re: [Space] Carrying capacity not connected to size of species?

Quote:
Originally Posted by Rupert View Post
Bio-Tech has food scaling for large and small creatures. It uses the square of scale (i.e. height), which is the 2/3rds power of mass.

Spaceships 7 says you should shift up and down the Habitat table by the SM in steps, which means habitats scale in proportion to mass. That's probably fair, as what you gain (for larger beings) by having 2/3rds scaling in walls, etc. you lose because you need more than 1/1 scaling of things like chair legs and bed supports (not much more with high TL materials, but some).
I can see more than linear for supports, now that you mention it - cross sectional area for the supports would need to be linear to have the same pressure (as pressure is force - weight - per unit area), and then would need to be taller besides. So, I can see furniture and the like having 4/3rds scaling. If we assume roughly half the mass of an unoccupied Habitat is in that sort of stuff and the rest is in life support and walls and the like (which has 2/3rds scaling), you'd end up with linear scaling overall. I always assumed the furniture of a Habitat was only a tiny component of its mass, however, but I could be mistaken. Indeed, steerage cargo implies I may well be - that shows ~1/3 of the cabin's mass being taken up by life support and the like (a full Habitat used for steerage cargo gives available tonnage equal to roughly 2/3rds of the system's mass), which would give another ~1/3 for furniture and ~1/3 for the inhabitants, their belongings, and sundry other bits that aren't furniture and scale linearly.
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Old 03-15-2021, 04:16 PM   #7
Willy
 
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Default Re: [Space] Carrying capacity not connected to size of species?

i think itīs also important to consider the activite level of the plants occupants. A coldblooded snake needs much less food, than a warmblooded animal of the same size.
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Old 03-15-2021, 05:08 PM   #8
Rupert
 
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Default Re: [Space] Carrying capacity not connected to size of species?

Quote:
Originally Posted by Varyon View Post
I always assumed the furniture of a Habitat was only a tiny component of its mass, however, but I could be mistaken. Indeed, steerage cargo implies I may well be - that shows ~1/3 of the cabin's mass being taken up by life support and the like (a full Habitat used for steerage cargo gives available tonnage equal to roughly 2/3rds of the system's mass), which would give another ~1/3 for furniture and ~1/3 for the inhabitants, their belongings, and sundry other bits that aren't furniture and scale linearly.
The rules for 'no life support' and 'magical life support' suggest that the life support is half of a cabin's mass.

The other half is presumably the living space plus occupant, and as a 'cabin' slot is either 7.5 or 8.3333 tons (depending on ship mass) and provides accommodations for 1-4 people at ~0.1 tons each, it's apparent that the occupants are a small portion of the total mass. Indeed, the system doesn't care whether the cabins are for passengers, who's mass will have to be counted in their habitat mass, or crew who might well have a control station or workspace and thus have their mass accounted for there.
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Old 03-15-2021, 06:24 PM   #9
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Default Re: [Space] Carrying capacity not connected to size of species?

Quote:
Originally Posted by Willy View Post
i think itīs also important to consider the activite level of the plants occupants. A coldblooded snake needs much less food, than a warmblooded animal of the same size.
Template Toolkit 2 has a whole section on sustenance, including a box on "Scale and Food" (all on page 25).

But a short answer is Increased Life Support would require more than would be obvious for a given SM, while Increased / Reduced Consumption would require more or less food.

Unfortunately, there's no one place that ties all these things (Size Modifier, Increased/Reduced Consumption, Cold blooded, Aquatic, Increased Life Support, etc.) into how they affect mechanical life support needs on a space ship.
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Old 03-15-2021, 07:09 PM   #10
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Default Re: [Space] Carrying capacity not connected to size of species?

Quote:
Originally Posted by David Johansen View Post
You could ball park it at carrying capacity is in average humans and humans average 150 lbs. So a 1500 lbs race would need 10x the carrying capacity.
The basic idea is plausible. But the nutritional requirements of a living organism are proportional, not to its mass, but to its surface area. You can better approximate this by having its food requirements vary with its Basic Lift (Basic Lift goes as the 2/3 power of body weight).
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