but there's empty space inside both a C152 AND a B747. The question is, is there proportionately more or less empty space in either. I suspect, to a first approximation, it's about the same.
Let's compare:
B747
length: 230ft (span 210ft)
wing area 6000ft^2
MTOW 900,000lb
C152
length: 22ft (span 33ft)
wing area: 160ft^2
weight: 1600lb
So the lengths are in a 8:1 ratio (roughly), the areas about 40:1 and the weights about 600:1. I agree it's not 10:100:1000, but it's not THAT far off. I'm not a weights conceptual design guy, but it looks like overall average density isn't far off constant.... (if you assumed the nominal dimension of a C152 was 27ft, and the B747 was 220ft [average of length and span] you'd predict a B747 weighed [220/27]^3 = 541 times a C152 - in other words, 865,000lbs. Not a bad guess.
