by Quentin Long ©2009 Quentin Long 


The furry community is truly a manysplendored thing: While every fur accepts the fundamental animalswithhumancharacteristics premise, there is rather less agreement about specific details over and above that basic premise. For some, furry is about anthropomorphic cartoons (i.e., characters like Bugs Bunny); for others, it’s a spiritual thing (i.e., totem spirits and suchlike); for still others, it’s about dissatisfaction with their personal reality (i.e., folks such as ‘otherkin’); and so on, and so forth.
In short, furdom can be thought of as the proverbial ‘big tent’—which goes double (triple, fourple, etc) for that particular segment of the community which focuses on socalled ‘macrofurs’. As the name implies, a macrofur is a very large anthropomorphized critter, typically not less than 10 meters tall. It’s a timehonored concept of very ancient pedigree (tales of economysized monsters go back as far as storytelling itself, as best I can see), but at the same time, there are some practical problems with being Very Large Indeed.
A large part (sorry) of these problems are directly due to the sheer size, in and of itself. Not just because that size makes it impractical for a macrofur to interact with other people of normal height, but also because of the brute facts of physical existence. To begin with, there’s the socalled ‘square/cube law’: If you expand the size of something by a factor of X, its surface area gets multiplied by X^{2}, and its volume goes up by X^{3}.
Now at this point, some of you may be saying to yourselves, “Okay, square/cube law, fine. How is that a problem for macrofurs?” Well, consider two cubes sitting on the ground, both made of solid iron, identical in every way except that one of them has 1inchlong edges, and the other, 10inchlong edges. Because one of the cubes is 10 times larger than the other, the bigger cube has (10^{2} =) 100 times more surface area than the smaller cube, and (10^{3} =) 1,000 times more volume.
Now, the density of iron is a bit more than 4.5 ounces—a quarter of a pound—per cubic inch. Multiply this percubicinch figure by the volume of each cube, and you find that the smaller cube weighs about a quarter of a pound, and the larger cube weighs about 284 pounds. Now divide the weight by the surface area of the face on which the cube is resting: For the 1inch smaller cube, this works out to about 4.5 ounces per square inch… but for the 10inch larger cube, it’s 45.5 ounces (2.84 pounds) per square inch.
In other words: When one object is 10 times larger than another, the bigger object is subject to 10 times more physical stress than the smaller one just because it is 10 times larger. Which means that the skeleton of a 60foottall macrofur needs to be 10 times stronger than that of a 6foot normalsized fur, lest the big guy’s femurs snap in two (or worse!) when he stands up.
Now do you see why macrofurs should worry about the square/cube law?
Another area of concern: Oxygen supply. Normal lungs consist of a vast quantity of tiny airsacs called ‘alveoli’, which are thickly lined with capillary blood vessels; oxygen diffuses through the walls of these airsacs into the capillaries, after which the O2 molecules get distributed all throughout the body. For purposes of this editorial, the key point is that the amount of oxygen you can pump into the blood is dependent on the total surface area of these arsacs. So if you take a 6foottall fur and expand him by a factor of 10, so he ends up 60 feet tall, that big boy has a problem: While the total surface area of his alveoli got boosted by a factor of 100, the total volume of living body which needs to be supplied by oxygen has gone up by a factor of 1,000. Which means that his lungs will only provide 1/10 as much oxygen as he really needs!
Heat buildup is also a problem, because how much heat can radiate away from a body in a given time is dependent on how much surface area the body has to radiate heat away from itself. Let’s go back to our pair of iron cubes: The smaller cube has (6 * 1^{2} =) 6 square inches of area, and (1^{3} =) 1 cubic inch of volume; thus, each cubic inch of the smaller cube has 6 square inches of area through which to dissipate heat. The larger cube, contrariwise, has (6 * 10^{2} =) 600 square inches of area, and (10^{3} =) 1,000 cubic inches of volume, so each cubic inch of the larger cube has (600/1,000 =) six tenths of a square inch of area through which to dissipate heat—significantly less than what the smaller cube has to work with. 10* less, in fact…
A macrofur has it worse than our iron cubes; unlike the inert metal from which the cubes are made, the macrofur’s living body actively generates heat. And if our macrofur is N* the size of a normal fur, its surfacetovolume ratio will be 1/N that of the smaller fur—which, in turn, means that its innate ability to radiate body heat will be 1/N that of the smaller fur. And since this 1/N reduction in heat dispersal is accompanied by an N^{3} increase in heat generation… well, let’s just say that warmblooded macrofurs may be in imminent danger of cooking themselves, from the inside out, with their own body heat!
Next: Human nerve impulses travel at a rate of about 100 feet per second. This is plenty fast enough for a normalsized body; but if your corpus happenss to be significantly larger than normal, your nerve impulses will have N times more distance to cover, hence your Ntimesbigger body is going to have an innate reaction time that’s N* worse than the little people around you. No wonder giants are commonly regarded as slow and clumsy!
Excretion is another thing that macrofurs may need to worry about. With an N* bigger body, you’ve got N^{3} times more waste to deal with, but that waste exits your body through orifices that only have N^{2} as much ‘throughput’. See the problem?
I could go on, but this is as good a stopping place as any. The important part is that all the above issues, and many more, are customarily ignored by furries of the macro variety. This is a pity, because working out solutions to problems of this sort can be fun and interesting—and apart from the fun factor, having ‘real’ answers for questions like “so how come you don’t fry in your own body heat?” can only enhance the verisimilitude of an economysized fursona.