Comments on: All-Star Superman Biological Review: The Square-Cube Law

By: mutuelles

mutuelles — Tue, 29 Dec 2009 11:24:24 +0000

Well, there are real-world, Terran, examples of weightlessness’ “escape” from the square-cube law. Aquatic animals often run much larger than terrestrial critters in similar ecological niches, precisely because supporting their own weight is almost a non-issue. Of course, food/energy supplies are still an issue

By: Charles Taylor

Charles Taylor — Thu, 17 Sep 2009 21:56:33 +0000

I vaguely remember from biology many years ago that the square cube law had special meaning for warm-blooded animals. Increasing mass required increased surface area for the transfer of internally generated heat. Since mass increased faster than surface area, this placed an upper limit on growth. This was supposedly reflected in the size of an elephant’s ears, providing extra surface area. Dinosaurs being cold-blooded avoided the limit, as did whales living in water which conducts heat more efficiently.

Is all this still accepted as true?

By: Andreas

Andreas — Mon, 26 Jan 2009 11:00:48 +0000

Great post thanks.

“Similar points are made in Larry Niven’s science fiction books The Smoke Ring and The Integral Trees.”

When I read that I decided to bookmark your page. Niven is one of my all time favorite authors, and you quote two of his lesser known works! Speaking of Niven in regards to Superman, did you read “Man of Steel, Woman of Kleenex”?

By: Chris Arndt

Chris Arndt — Fri, 02 Dec 2005 18:21:42 +0000

Canonically speaking, the blood-and-air thing has been an issue for Hank Pym, and for the most part the only issue.

On the other hand, ionically-powered and ionically-consisted size changers don’t have the same problem.

So Goliath can and did beat the shite out of Giant Man just because Giant Man’s powers are limited by how much oxygen he can circulate.

Surface area is not an issue nor is mass per se. It’s just that thanks to respitory restrictions he is not capable of doing much in giant form.

By: M

Thu, 01 Dec 2005 03:40:53 +0000

If you run a man thru an enlarger that just scales him up then the surface area of the lungs and intestines will only increase at x-squared rate versus the x-cubed rate of his mass and most energy needs. But if you grow a person to giant proportions the development program would probably maintain it’s fractal nature resulting in an increase in exchange capacity more proportionate to the increased needs. Of course his skin surface would only increase at the slower rate so he’d be liable to overheat unless changes were made to the lower the basal metabolic rate of heat production or provide enhanced cooling. Of course being entirely anaerobic and using liquid nitrogen for blood indicates what you might quantify as big-ass changes to the metabolism.

Two things about liquid nitrogen:

1) It’s very cold so you’d need a different set of chemical reactions for a lifeform that’s supposed to live at the same pace we do. Our biological rxns are practically stopped entirely at such temperatures, conversely they’d, well explode at ours.

2) It’s non-polar, unlike water or ammonia, so solvation and protein (or whatever) folding rules would be radically different than those our biology is based on two. So on that account kind of a you can’t get there from here aspect to the idea of converting human metabolism into something like that.

By: Carl

Carl — Wed, 30 Nov 2005 23:51:24 +0000

Actually I meant “by inspection”. Drat.

By: Carl

Carl — Wed, 30 Nov 2005 23:50:36 +0000

Scott, about surface area, note that I didn't say the area of the lungs would increase as the cube. It would be closer to the cube than to the square, but some of the volume would be wasted on non-respiratory areas for what amounts to tubing. For us that would be the familiar bronchii and bronchioles. If the chest were just packed with alveoli, then area would increase as the cube, as you should be able to see by evaluation (as my old calc teacher used to say).

By: David Harmon

David Harmon — Wed, 30 Nov 2005 17:34:19 +0000

Well, there are real-world, Terran, examples of weightlessness’ “escape” from the square-cube law. Aquatic animals often run much larger than terrestrial critters in similar ecological niches, precisely because supporting their own weight is almost a non-issue. Of course, food/energy supplies are still an issue — note that the largest modern animal, the blue whale, is a filter feeder that feeds on krill, way down the food chain and therefore plentiful. As noted above, gas and nutrient exchange are typically handled by structural involution.

Regarding Giant-Man, the Marvel universe implies (though IIRC never explicitly states) a “dualistic” justification for super-strength and the survival of such “enlarged” creatures. Lifeforms in general, and especially humans, are supposed to have a non-corporeal “energy field”, which can tap into “cosmic” (that is, external) energy sources to provide the energy implied by most super-powers. There are also hints of “morphogenetic fields” in their handling of some shape-changers.

By: Scott

Scott — Wed, 30 Nov 2005 16:57:48 +0000

Carl:

I’ll grant you that there were some giant bipeds in the distant past, but as you point out, they had evolutionary adaptations to support their weight. Plus they had big freakin’ tails.

I will disagree about membrane transfer. Humans (and other mammals [and maybe other classes too]) have developed anatomic strategies to increase the surface area of their organs (such as alveoli in the lungs and villi and microvilli in the intestines)precisely because surface area is so important. Convoluted or not, it still all comes down to surface area; these convoutions exist only to allow the body to maximize surface area. As such, it won’t increase to the same extent that volume will when enlarging the organism and a mis-match will occur.

MsCongeniality:
Similar points are made in Larry Niven’s science fiction books The Smoke Ring and The Integral Trees.

By: MsCongeniality

MsCongeniality — Wed, 30 Nov 2005 16:40:05 +0000

The manga/anime Planetes deals with the idea of the limitations of the human body in a weightless or reduced gravity environment quite well. One of the ’subplot’ stories revolves around a girl who is one of only a handful of people born and raised on the moon. At the age of twelve, she appears to have reached full ‘adult’ size (unlike your average anime 12 year old, usually drawn as appearing much younger) and is constantly being studied by doctors and researchers trying to figure out both her current physiology and potential limits. If I recall, they don’t believe she will ever be allowed to go to Earth, because her bones are not sufficiently developed to be able to stand the stress of full gravity.