Small Internet / The right size (zaibatsu), 04/03/2019
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You've hopefully read about spring's Small Internet[1], in
the original post, and in the various responses speckled
across gopherspace. It's an important and interesting
subject.

I came across the following old paper today, and it made me
think of the Small Internet. It's especially interesting, I
think, in light of thoughts and ideas on making gopher
better[2][3]. It may very well be that Haldane's ideas on
scalability don't apply to gopher & http, I don't know.
Something tells me there are some ideas to be had in here.

Full text follows:


On Being the Right Size
J. B. S. Haldane
March 1926

The most obvious differences between different animals are
differences of size, but for some reason the zoologists have
paid singularly little attentionto them. In a large textbook
of zoology before me I find no indication that the eagle is
larger than the sparrow, or the hippopotamus bigger than the
hare, though some grudging admissions are made in the case
of the mouse and the whale. But yet it is easy to show that
a hare could not be as large as a hippopotamus or a whale as
small as a herring. For every type of animal there is a most
convenient size, and a large change in size inevitably
carrieswith it a change of form.

Let us take the most obvious of possible cases, and consider
a giant mansixty feet high - about the height of Giant Pope
and Giant Pagan in the illustrated Pilgrim’s Progress of my
childhood. These monsters were notonly ten times as high as
Christian, but ten times as wide and ten times asthick, so
that their total weight was a thousand times his, or about
eighty to ninety tons. Unfortunately the cross sections of
their bones were only a hundred times those of Christian, so
that every square inch of giant bone had to support ten
times the weight borne by a square inch of human bone. As
the human thigh-bone breaks under about ten times the human
weight, Pope and Pagan would have broken their thighs every
time they took a step. This was doubtless why they were
sitting down in the picture I remember. But it lessens ones
respect for Christian and Jack the Giant Killer.

To turn to zoology, suppose that a gazelle, a graceful
little creature with long thin legs, is to become large, it
will break its bones unless it does one of two things. It
may make its legs short and thick, like the rhinoceros, so
that every pound of weight has still about the same area of
bone to support it. Or it can compress its body and stretch
out its legs obliquely to gain stability, like the giraffe.
I mention these two beasts because they happen to belong
to the same order as the gazelle, and both are quite
successful mechanically, being remarkably fast runners.

Gravity, a mere nuisance to Christian, was a terror to Pope,
Pagan, and Despair. To the mouse and any smaller animal it
presents practically no dangers. You can drop a mouse down
a thousand-yard mine shaft; and, on arriving at the bottom
it gets a slight shock and walks away, provided that the
ground is fairly soft. A rat is killed, a man is broken, a
horse splashes. For the resistance presented to movement by
the air is proportional to the surface of the moving object.
Divide an animal’s length, breadth, and heighteach by ten;
its weight is reduced to a thousandth, but its surface only
a hundredth. So the resistance to falling in the case of
the small animal is relatively ten times greater than the
driving force.

An insect, therefore, is not afraid of gravity; it can fall
without danger,and can cling to the ceiling with remarkably
little trouble. It can go in for elegant and fantastic forms
of support like that of the daddy-longlegs.But there is a
force which is as formidable to an insect as gravitation to
amammal. This is surface tension. A man coming out of a bath
carries with him a film of water about one-fiftieth of an
inch in thickness. This weighsroughly a pound. A wet mouse
has to carry about its own weight of water.A wet fly has to
lift many times its own weight and, as everyone knows, a
fly once wetted by water or any other liquid is in a very
serious position indeed.An insect going for a drink is in a
great danger as man leaning out over aprecipice in search of
food. If it once falls into the grip of the surface
tension of the water -that is to say, gets wet - it is
likely to remain so until it downs.A few insects, such as
water-beetles, contrive to be unwettable; the majoritykeep
well away from their drink by means of a long proboscis.

Of course tall land animals have other difficulties. They
have to pump their blood to greater heights than a man, and,
therefore, require a larger blood pressure and tougher
blood-vessels. A great many men die from burst arteries,
greater for an elephant or a giraffe. But animals of all
kinds find difficulties in size for the following reason. A
typical small animal, say a microscopic worm of rotifer,
has a smooth skin through which all the oxygenit requires
can soak in, a straight gut with sufficient surface
to absorb its food, and a single kidney. Increase its
dimensions tenfold in every direction, and its weight is
increased a thousand times, so that if it to use its
muscles as efficiently as its miniature counterpart, it will
need a thousand times asmuch food and oxygen per day and
will excrete a thousand times as much ofwaste products.

Now if its shape is unaltered its surface will be
increased only a hun-dredfold, and ten times as much
oxygen must enter per minute through eachsquare millimeter
of skin, ten time as much food through each square
mil-limeter of intestine. When a limit is reached to their
absorptive powers theirsurface has to be increased by some
special device. For example, a part of theskin may be drawn
out into tufts to make gills or pushed in to make lungs,thus
increasing the oxygen-absorbing surface in proportion to the
animal’sbulk. A man, for example, has a hundred square
yards of lung. Similarly,the gut, instead of being smooth
and straight, becomes coiled and developsa velvety
surface, and other organs increase in complication.
The higher animals are not larger than the lower because
they are more complicated.They are more complicated because
they are larger. Just the same is true of plants. The
simplest plants, such as the green algae growing in
stagnantwater or on the bark of trees, are mere round cells.
The higher plants in-crease their surface by putting out
leaves and roots. Comparative anatomyis largely the story of
the struggle to example, while vertebrates carry the oxygen
from the gills or lungs all over the body in the blood,
insects takeair directly to every part of their body by tiny
blind tubes called tracheaewhich open to the surface at many
different points.  Now, although their breathing movements
they can renew the air in the outer part of the
trachealsystem, the oxygen has to penetrate the
finer branches by means of diffusion.Gases can diffuse
easily through very small distances, not many times
largerthan the average length traveled by a gas molecule
between collisions withother molecules. But when such vast
journeys-from the point of view of amolecule-as a quarter of
an inch have to be made, the process becomes slow.So the
portions of an insect’s body more than a quarter of an inch
from theair would always be short of oxygen. In consequence
hardly any insects aremuch more than half an inch thick.
Land crabs are built on the same generalplan as insects, but
are much clumsier. Yet like ourselves they carry
oxygenaround in their blood, and are therefore able
to grow far larger than anyinsects. If the insects had
hit on a plan for driving air through their tissuesinstead
of letting it soak in, they might well have become as large
as lobsters,though other considerations would have prevented
them from becoming aslarge as man.

Exactly the same difficulties attach to flying. It is an
elementary principleof aeronautics that the minimum
speed needed to keep an aeroplane of agiven shape
in the air varies as the square root of its
length.  If its lineardimensions are increased four
times, it must fly twice as fast. Now the power3
needed for the minimum speed increases more rapidly than the
weight of themachine.  So the larger aeroplane, which
weighs sixty-four times as muchas the smaller, needs one
hundred and twenty-eight times its horsepower tokeep up.
Applying the same principle to the birds, we find that the
limit totheir size is soon reached. An angel whose muscles
developed no more powerweight for weight than those of an
eagle or a pigeon would require a breastprojecting for about
four feet to house the muscles engaged in working itswings,
while to economize in weight, its legs would have
to be reduced tomere stilts. Actually a large bird such
as an eagle or kite does not keep inthe air mainly by moving
its wings. It is generally to be seen soaring, that isto
say balanced on a rising column of air. And even soaring
becomes moreand more difficult with increasing size. Were
this not the case eagles mightbe as large as tigers and as
formidable to man as hostile aeroplanes.

But it is time that we pass to some of the advantages of
size. One of themost obvious is that it enables one to keep
warm. All warm-blooded animalsat rest lose the same
amount of heat from a unit area of skin, for
whichpurpose they need a food-supply proportional to
their surface and not totheir weight. Five thousand
mice weigh as much as a man. Their combinedsurface and food
or oxygen consumption are about seventeen times a man’s.In
fact a mouse eats about one quarter its own weight
of food every day,which is mainly used in keeping it
warm. For the same reason small animalscannot live in cold
countries. In the arctic regions there are no reptiles
oramphibians, and no small mammals. The smallest mammal in
Spitzbergen isthe fox. The small birds fly away in winter,
while the insects die, though theireggs can survive six
months or more of frost. The most successful mammalsare
bears, seals, and walruses.

Similarly, the eye is a rather inefficient organ until it
reaches a large size.The back of the human eye on which an
image of the outside world is thrown,and which corresponds
to the film of a camera, is composed of a mosaic of“rods and
cones” whose diameter is little more than a length of an
averagelight wave. Each eye has about a half a million, and
for two objects to bedistinguishable their images must fall
on separate rods or cones. It is obviousthat with fewer but
larger rods and cones we should see less distinctly. If
theywere twice as broad two points would have to be twice as
far apart before wecould distinguish them at a given
distance. But if their size were diminishedand their number
increased we should see no better. For it is impossible
toform a definite image smaller than a wave-length of light.
Hence a mouse’seye is not a small-scale model of a human
eye. Its rods and cones are not4
much smaller than ours, and therefore there are far fewer of
them. A mousecould not distinguish one human face from
another six feet away. In orderthat they should be of any
use at all the eyes of small animals have to bemuch larger
in proportion to their bodies than our own. Large animals
onthe other hand only require relatively small eyes, and
those of the whale andelephant are little larger than our
own. For rather more recondite reasonsthe same general
principle holds true of the brain. If we compare the
brain-weights of a set of very similar animals such as the
cat, cheetah, leopard, andtiger, we find that as we
quadruple the body-weight the brain-weight is onlydoubled.
The larger animal with proportionately larger bones can
economizeon brain, eyes, and certain other organs.

Such are a very few of the considerations which show that
for every typeof animal there is an optimum size. Yet
although Galileo demonstrated thecontrary more than three
hundred years ago, people still believe that if
aflea were as large as a man it could jump a thousand feet
into the air. Asa matter of fact the height to which
an animal can jump is more nearlyindependent of its
size than proportional to it. A flea can jump about
twofeet, a man about five. To jump a given height, if we
neglect the resistanceof air, requires an expenditure of
energy proportional to the jumper’s weight.But if the
jumping muscles form a constant fraction of the animal’s
body, theenergy developed per ounce of muscle is independent
of the size, provided itcan be developed quickly enough in
the small animal. As a matter of factan insect’s muscles,
although they can contract more quickly than our own,appear
to be less efficient; as otherwise a flea or grasshopper
could rise sixfeet into the air.

And just as there is a best size for every animal, so the
same is true forevery human institution.  In the Greek
type of democracy all the citizenscould listen to a
series of orators and vote directly on questions of
legisla-tion. Hence their philosophers held that a small
city was the largest possibledemocratic state. The English
invention of representative government madea democratic
nation possible, and the possibility was first
realized in theUnited States, and later elsewhere. With
the development of broadcastingit has once more become
possible for every citizen to listen to the politicalviews
of representative orators, and the future may perhaps see
the returnof the national state to the Greek form of
democracy. Even the referendumhas been made possible only
by the institution of daily newspapers.

To the biologist the problem of socialism appears largely as
a problem ofsize. The extreme socialists desire to run
every nation as a single business5
concern.  I do not suppose that Henry Ford would
find much difficulty inrunning Andorra or Luxembourg on a
socialistic basis. He has already moremen on his pay-roll
than their population. It is conceivable that a syndicateof
Fords, if we could find them, would make Belgium Ltd or
Denmark Inc.pay their way. But while nationalization of
certain industries is an obviouspossibility in the largest
of states, I find it no easier to picture a
completelysocialized British Empire or United States than an
elephant turning somer-saults or a hippopotamus jumping a
hedge.

[1] gopher://republic.circumlunar.space:70/0/~spring/phlog/2019-01-16__The_Small_Internet.txt
[2] gopher://zaibatsu.circumlunar.space:70/0/~solderpunk/phlog/pondering-whats-inbetween-gopher-and-the-web.txt
[3] gopher://zaibatsu.circumlunar.space:70/0/~solderpunk/phlog/why-gopher-needs-crypto.txt

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