Where does GURPS derive these formulas?

[premature_backpain]

New poster here, so if I mess anything up or do something wrong, please let me know.

I've been digging through the Basic Set, and I've noticed that the formulas for determining the hit-points of artifacts or structures seems kind of arbitrary; specifically, the formula [HP = 100 x (cube root of building's empty weight in tons)] for structures, and [HP = 4 x (cube root of weight in lbs)] or [HP = 8 x (cube root of weight in lbs)] for artifacts. Is there any scientific basis for these formulas, or are these just an arbitrary way of converting real world materials and structures into GURPs hit-points? And are there any articles or resources that detail how real-world things are converted into GURPs-playable statistics? All replies are appreciated, thanks in advance.

[RyanW]

HP are just kind of an arbitrary game number, but due to the way damage scales with energy (as most visible in guns), it should scale with the cube root of weight. Everything else shakes out from "average adult human has HP 10" and assumptions about the relative resilience of biological, mechanical, and solid objects.

[seycyrus]

Just going by the "feel" of the equation ... seems like it is making an assumption on density and pulling in a cube root due to volume.

[Ulzgoroth]

Originally Posted by premature_backpain

New poster here, so if I mess anything up or do something wrong, please let me know.

I've been digging through the Basic Set, and I've noticed that the formulas for determining the hit-points of artifacts or structures seems kind of arbitrary; specifically, the formula [HP = 100 x (cube root of building's empty weight in tons)] for structures, and [HP = 4 x (cube root of weight in lbs)] or [HP = 8 x (cube root of weight in lbs)] for artifacts. Is there any scientific basis for these formulas, or are these just an arbitrary way of converting real world materials and structures into GURPs hit-points? And are there any articles or resources that detail how real-world things are converted into GURPs-playable statistics? All replies are appreciated, thanks in advance.

HP scales with cube root mass. That's how GURPS 4e does it. 'Derive' would be overstating it, it's more 'define'.

HP = 2/4/8x cube root of mass in pounds are the fundamental assignments for living, unliving, and homogeneous objects.

100x cube root of mass in tons is approximately the same calculation as 8x cube root of mass in pounds. (8 times cube root 2000 is 100.8.)