from My Magazine, May 1918 - No author is credited; I am still trying to determine the copyright status of this article, and it is possible that it will eventually have to be removed, and will not appear on the FF CD-ROM. The illustrations have been considerably reduced in size to save download time in this on-line version.
WHAT THE WORLD MAY COME TO
The School Maps as They May
Be in Millions of Years to Come
WHAT SORT OF PEOPLE WILL LIVE ON THE TETRAHEDRON?
How would you like to live on a tetrahedron? Men say the earth will one day come to that.
Many strange visions men have had of the world since it began. They used to think it a disc floating in water. There are still stupid people who believe it is flat. Every wise child knows that the truth is that the earth is praetically a round ball.
It will not always be like this, however. What we really live on is an oblate spheroid; what the people of the world will live on in millions of years to come will probably be a tetrahedron. It all looks terrible dull, but it is really tremendously interesting.
The world is now the shape of a globe, the shape which gives the biggest possible bulk for its surface, but the inside of the earth is still cooling and condensing, and the internal changes are slowly changing its shape. The surface, already condensed to its utmost, will not change with the core; it cannot reduce its area, but it adapts itself to the shrinking interior by taking a shape which occupies less bulk. So the earth is to become a tetrahedron, a sort of pyramid, the shape which gives the smallest bulk for its surface. Let us think about it all.
THE school books tell us that the earth is a round globe, or, to be more exact, an oblate spheroid - a ball with the ends slightly flattened, as in an orange.
This is, of course, true of the general appearance of the earth as it might be viewed from the moon or from Mars, and we may see it proved more or less by watching the earth's shadow on the lunar surface during an eclipse of the moon. But the earth is slowly but surely changing its shape, and already it is in process of becoming a tetraedron, or a pyramid.
The word tetrahedron is made up of two Greek words meaning four seats or bases, and a tetrahedron is a solid figure bounded by four equilateral triangles. To conjure up a picture of what this means we may say that a tetrahedron is a pyramid with three sides and a base, all of which are equal. Now, men of science who have studied the subject declare that this is really what our earth is becoming.
It is generally agreed that the original form of the earth, when it was a revolving mass of plastic matter, was spherical, and that while it was revolving in this condition the Poles became slightly flattened. The behaviour of a plastic body as it revolves may be proved by experiment, and it is always found that the body tends to bulge at the equator and flatten at the poles.
Remember that the earth consists of two parts, land and water; and when we look at a map or globe we find that the water occupies by far the greater portion. As a matter of fact, 72 per cent., or nearly three-quarters of the earth's surface, is water and only one quarter is land. It is almost entirely the surface of the earth with which we have to do, and its appearance gives us an altogether wrong impression of the earth as a whole. We think of water as forming the greater part of the earth, whereas, taking the earth as a whole, the amount of water is almost infinitesimal.
The solid part of the earth is called the lithosphere, and the water part the hydrosphere; and the total mass of water on the earth, including the oceans and inland waters, is only one 4540th of the lithosphere. In other words, the seas, with an average depth of only just over two miles, form such a thin skin on the earth, in proportion to the total diameter, that they may be compared to the shallow pools and puddles on a roadway after a sharp shower. All they really do is to outline the depressions that occur, which, to a giant viewing the earth from a distance, would be scarcely noticeable. Perhaps nothing will bring home to us more vividly the confused idea which we get of the quantities of land and water than the fact that, while the total mass of solid matter in the earth is 4540 times the mass of water, the volume of water is 13 times as great as the land which shows above the seas.
Before the first great era of geological history, known as the Eozoic, or the Dawn-of-Life Age, the earth was probably an almost perfect sphere, covered by the universal ocean. Then came changes which caused the land to peep out of the waters, there being, as geologists tell us, three land shields protruding in the Northern Hemisphere at nearly equal distances, and three similar shields in the Southern Hemisphere. In the North these land areas were centred about what are now Hudson's Bay, the Baltic Sea, and North-East Siberia, while in the South they were grouped in South America, South Africa, and Australasia.
THE GREAT LAND SURFACES OF THE EARTH WHICH GENTLY SLOPE DOWN TO THE EDGE OF ABYSMAL OCEAN - THIS MAP SHOWS THE LAND AREAS AS THEY WOULD APPEAR IF THE SEA SANK ONE MILE.
The transformation of the earth's original spherical shape went on until, at the close of the Palaeozoic, or second great geological, Era, the protuberances of land had been much enlarged by the growth of sediment around them, and by convulsive movements in the shell of the lithosphere. The result was that the earth now became in shape like two tetrahedrons, cut off at the narrow end and joined together as shown on page 192.
The land surfaces showing above the water were then very different from now, for, instead of great continents running north and south, there were two continents running round east and west, one in the Northern Hemisphere and the other in the Southern, with a mighty ocean between them, to which geologists have given the name of the Ocean of Tethys. Great convulsions took place in the more recent geological eras, during which the Southern Continent disappeared almost entirely, and there was a concentration of the visible land surfaces in the Northern Hemisphere. The remains of the Ocean of Tethys may, however, still be seen in the Caribbean and Mediterranean Seas.
If we take a terrestrial globe and examine it carefully we must be struck by the fact that almost all the large land forms taper to the south, while the great waters narrow towards the north. In other words, the continents are V-shaped and the oceans A-shaped. Look at Africa, Arabia India, Australasia, North America and South America among the lands, and at the North Atlantic, South Atlantic, and Indian Oceans among the seas. What does this mean?
The triangular forms of land and water set geographers thinking, and they came to the conclusion that an arrangement so general could not be the result of accident, but must be governed by some law. Much attention has been given to the matter in recent years, and men of science believe that the theory that best fits facts is that the earth is becoming tetrahedral in shape.
Men of science believe that in millions of years the earth will lose the shape of a globe and become a sort of pyramid or tetrahedron. The earth was formed as a round globe. In cooling down the Poles were flattened and its surface was fixed. But the core is still cooling and shrinking, and the hard unshrinking surface must adjust itself to a smaller bulk. The shape of a globe is the shape that gives the biggest possible surface for its size; but there is another shape that gives the smallest possible surface for its size, and the earth seems likely to assume this shape. It is a sort of pyramid shape, and is called a tetrahedron.
To understand this easily, let us take a piece of plasticine or clay and make a figure such as is shown in the picture above. Now, holding the figure point downwards, imagine the three up-and-down edges to be the great North and South land groups, the first Europe with Africa, the second Asia with Australasia, and the third North and South America. The flat surfaces of the tetrahedron are the Indian Ocean, the Pacific Ocean, and the Atlantic Ocean. We should naturally expect, with a flat surface of the tetrahedron on top and with the point stretching south, that there would be an ocean at the North Pole and a continent at the South; and such is actually the case, as we know from the discoveries of Nansen, Peary, Scott, and Shackleton.
Now, holding our plasticine figure by the side of a terrestrial globe, we shall see how remarkably this theory of a tetrahedral earth fits with the known facts. The terrestrial tetrahedron - that is, the earth on which we live - is not, however, perfectly symmetrical in shape, America being a little too far east to be midway between Asia with Australasia on one side and Europe with Africa on the other. Various causes are thought to have led to this irregularity, arising from the changing rate of the revolution of matter and from differences in its composition. In the main, however, the land surfaces of the earth project where they would be expected to project if the earth's form were changing to a tetrahedron. Another test may be applied. Let us take the plasticine figure and examine it carefully. We shall see that every angle has on the opposite side a flat surface, and vice versa. On the earth, therefore, if the theory is right, we should find that the great land surfaces have water as their antipodes, and this is actually the case. The Antarctic continent has the Arctic Sea as its antipodes, Europe and Africa have the Pacific, Asia and Australasia have the Atlantic, and America has the Indian Ocean.
As a matter of fact, the Tetrahedral Theory is the only one tha explains the three fundamental facts of physical geography - the opposite positions of the continents and seas, the triangular shapes of lands and seas, and the excess of water in the Southern Hemisphere with an elevated continent at the South Pole.
THE EARTH DIVIDED TO SHOW THE GREATEST AREAS OF LAND AND WATER
A SPINNING GLOBE, SHOWING HOW ITS RAPID REVOLUTION FLATTENS ITS POLES
THE TRIANGULAR SHAPES OF LAND AND SEA AREAS
THE EARTH IN ITS EARLIEST AGES - THE FORM IN WHICH THE LAND EMERGED FROM THE UNIVERSAL OCEAN
The question may be asked why the earth in cooling should tend to become a tetrahedron, and an interesting answer is given by men of science. When the earth was first formed it was spherical, and a sphere is the shape which encloses more space for a given surface than any other figure. As the earth began to cool, the surface solidified, and a crust was formed, the core being still hot. But this core continues to lose heat, and as it does so it must necessarily contract and occupy less space. The hardened shell of the earth, however, is unable to contract: being already solidified, it must continue to maintain the same surface area, and the way it accommodates itself to the shrinking interior is to change its shape to one occupying less space for the same surface area.
Now, while the sphere is the figure occupying the greatest space, for a given surface, the tetrahedron occupies the least space for an equal surface, and therefore, mathematically, if the process described goes on, the earth should one day become a tetrahedron.
We may be sorry for the editors and poets in those days. It is pleasant to write of sailing round the globe, or of this spinning ball, but who would not pity the poet who has to write and make his rhymes about some bold Sir Francis Drake's brave journey round the tetrahedron? We hope the League of Nations will rule the Tetrahedron well.