[quote]red04 wrote:
[quote]Silyak wrote:
[quote]csulli wrote:
I had a very difficult time with the theory behind how much a giant of a certain height would reasonably weigh given a normal person’s proportions. BMI starts breaking down very quickly before you really even hit the 7 foot mark. So I’m really unsure of exactly how tall I would need to be.
Anyway I can tell you I would want to weigh at least 20,000lbs. I estimate that my height would need to be at least 30ft, but as I said, I had trouble with the mathematics of my answer.
Regardless, in this way I would be the most powerful terrestrial organism alive today. Things such as hippos, rhinos, and elephants would be to me as dogs are now.[/quote]
Simply preserving proportionalities, a 30 foot person is 5 times taller than a 6 foot man. Since mass is related to volume, you would expect him to weigh 125 times more (5 cubed). So if the average 6 foot man is 200lbs, a 30 foot man would be 25000lbs.
However, proportionalities don’t work because your bones would be crushed for the same reason that a spider would crush itself if blown up to human size. Basically, the strength of your bones and muscles is proportional to their cross sectional area while their mass is proportional to their volume. So, basically you would need legs, arms, and a torso that would be proportionally thicker just to remain functional. So to account for the difference between volume and area, you’d probably have to increase that 125 multiplier to the power of 3/2. So a 30 foot human would probably be about 1400 times heavier than a 6 foot human or about 280,000 lbs.
So doing the math, if our model is a 6 foot 200 lb human, you would only need to be about 16.7 feet tall in order to weigh 20,000 lbs. That’s all theoretical but, for reference, African elephants stand up to 13 feet tall and weigh up to 15,000 lbs. Elephants are quadripeds, so giants would be expected to be a little more vertical. Your core and legs have to be really thick to support all of that mass, so you’re going to be huge. If you don’t like the image of a blob, you could also imagine that your bones and muscles are just much denser than an average human so proportionally you look the same. As far as elephants being dog sized, at 17 feet you’re already pretty much there with the biggest elephants being smaller and lighter than you. [/quote]
280,000 lbs just sounds like it can’t possibly be correct. That’s double the mass of all but the absolute largest sauropods ever. It could be totally possible and I’m just woefully understating the girth increase that a man would undergo to become 30ft tall.
I’ve actually been to the Giants of the Mesozoic exhibit at the museum in Atlanta, so I’ve seen the (estimated) restoration of the Argentinosaurus skeleton, even knowing that the proposed human would be significantly taller(by 7 or so feet), I just can’t imagine anything more massive on the whole.[/quote]
It’s an extrapolation that probably breaks down when talking about a giant 5-6 times bigger than the average human. The human proportions would obviously cease to work at 30 feet tall because your legs would probably be wider than they would be long. If you instead just assume that giants have much denser bones and muscles (which are accordingly much stronger), then it might work.
280,000 lbs may be on the high side, but the problem really becomes that we run out of terrestrial beings to compare with. A 3 story structure is probably going to weigh a couple hundred thousand pounds, and it will be about 30 feet tall. Overall, the point is that in order to get taller, your support structures grow in either size or strength more quickly than you grow in height. I still think that if you want to be 20,000 lbs, 15-20 feet is probably a reasonable height target.