GURPS Spaceships Power Plants

[Langy]

That's just an inconsistency between Ultra-Tech and Spaceships. In Ultra-Tech, you need to use more power to make a Graser do as much damage as a UV Laser. In Spaceships, you don't.

Personally, I think Spaceships might be the more believable of the two options.

[Fred Brackin]

Originally Posted by Langy

That's just an inconsistency between Ultra-Tech and Spaceships. In Ultra-Tech, you need to use more power to make a Graser do as much damage as a UV Laser. In Spaceships, you don't.

Actually in UT, UV lasers do half as much damage as Grasers. The big deal though is the armor divisor. The net result of that is that grasers give 10x the armor penetration. You think you get that for free?

I don't see what the great strain of disbelief is. You all know that a PP isn't the same unit for ships of different sizes (SMs to be specific) even at the same TL.

You also know (or should by now) a PP is unit of constant output (like a kilowatt) over any time period rather than fixed quantity of energy like a kilojoule. That's the only reason PP use doesn't go up with Turn length.

Given that PP is already so flexible and arbitrary, why are you all so sure that they're the same unit over multiple TLs?

[Ulzgoroth]

I'm aware of the bits that suggest higher TL powercells have more power. I ignore them deliberately because:

-They're just bad. You can't make low-TL power sources provide the output of high-TL power sources? In what physics? You might need a backpack full of electronics to replace a AA battery sized device, but I won't believe you can't do it. Similarly, putting a high-TL cell in a low-TL device might be a problem, if you do it stupidly, but building an adapter should not be hard.

-They're unusably vague. Maybe a higher-TL power cell is supposed to make your gadget work longer...too bad nothing provides a hint of how much longer.

-They imply that future people can't see any reason to refine a proven, efficient technology rather than (or even as well as) roll out questionable, grossly inefficient successors.

-Waste heat doesn't magically go away. Thermodynamics does not work like that! (Unless you use a black hole for a heat sink.)

Originally Posted by Fred Brackin

Actually in UT, UV lasers do half as much damage as Grasers. The big deal though is the armor divisor. The net result of that is that grasers give 10x the armor penetration. You think you get that for free?

Actually, yes. I think you get that for free from putting out your energy in a very different wavelength. And I think you achieve that wavelength at low-to-no cost by virtue of having a 3 TL advantage.

Hum. UT and SS seem to have...problems with regards to lasers. At TL9, Spaceships gives us a laser weighing under half a ton that does 30d(2). UT gives us a laser with that output weighing 4 tons. At TL10 you can get the Spaceships 3kj laser...but the space fighters have already been using them for decades? Similarly, UT thinks, for some reason, that neutral particle beam weapons are TL11/12. Spaceships thinks they're TL10, and the size ranges overlap.

Originally Posted by Fred Brackin

I don't see what the great strain of disbelief is. You all know that a PP isn't the same unit for ships of different sizes (SMs to be specific) even at the same TL.

You also know (or should by now) a PP is unit of constant output (like a kilowatt) over any time period rather than fixed quantity of energy like a kilojoule. That's the only reason PP use doesn't go up with Turn length.

Given that PP is already so flexible and arbitrary, why are you all so sure that they're the same unit over multiple TLs?

What's flexible and arbitrary about the above? PP are ship-specific...naturally they change with SM. One tank of fuel is a lot more mass for a bigger ship, but I'd hardly call it flexible or arbitrary. Nor do I see anything either flexible or arbitrary about a Power Point being a unit of power. You know, energy over time.

But the big one, of course, is that mixing TLs is in no way discouraged, and rather may be mandated since many components apparently don't improve with TL. So if you want to tell me that at TL12 I need to spend...more than four times as much energy to power an ion drive, I have a problem. For that matter, if you want to tell me that in addition to their improved endurance, my fuel cells are generating several times more power at TL11-12, I have a problem.

[Fred Brackin]

Originally Posted by Ulzgoroth

I'm aware of the bits that suggest higher TL powercells have more power.

Well, you ranted about one of them anyway, You ignored the Exploding Power Cells and the Plasma Explosives.

[Ulzgoroth]

I just tried to run the math for the fuel cell systems. If I did it right, it looks like it's thermodynamically impossible for them to work if a power point is more than 0.75 MW/ton. Which suggests the laser efficiency figure may need to be shifted a bit to the higher range.

Also seems like it says bad things about the feasibility of PP scaling with TL, unless chemical power is secretly not supposed to be used at higher TLs.

Originally Posted by Fred Brackin

Well, you ranted about one of them anyway, You ignored the Exploding Power Cells and the Plasma Explosives.

You can try to back-calculate a scale for variable power cells from those if so inclined, yes. Though I think (belying my claim that "nothing provides a hint", I suppose) you shouldn't do that below TL11, because the performance figures for assorted devices tend to double each TL, when they have improvement listed.

[Fred Brackin]

Originally Posted by Ulzgoroth

You can try to back-calculate a scale for variable power cells from those if so inclined, yes. Though I think (belying my claim that "nothing provides a hint", I suppose) you shouldn't do that below TL11, because the performance figures for assorted devices tend to double each TL, when they have improvement listed.

Just being thorough, but Exploding Power Cells applies before TL11.

As an observation, 4e's numberphobia for UT devices can be a real pain in the but sometimes. 3e really was clearer on this sort of thing.

[Ulzgoroth]

Originally Posted by Fred Brackin

Just being thorough, but Exploding Power Cells applies before TL11.

It does, but I would not assume that the REF and the total energy content of the power cell necessarily move identically. Batteries don't explode very well even for their energy content, but hypothetical high-density energy storage options can be much more volatile. The factors of 4 in REF from TL 9 to 10 to 11 run well ahead of the factor-of-two performance improvements.

Originally Posted by Fred Brackin

As an observation, 4e's numberphobia for UT devices can be a real pain in the but sometimes. 3e really was clearer on this sort of thing.

I never saw 3e, but I agree wholeheartedly with the first part.