Science
Moho! e
By MAURICE GOLDSMITH I SUPPOSE the next big race will be to the Earth's centre. Whether Britain will be in it is not certain; the Lord President of the Council, the political boss of State science, has not yet set up a steering committee. But the Americans and the Russians already have special bodies in being.
I first heard about the proposal to drill a hole into the Earth's crust in Toronto, in September, 1957—and heard also how AMSOC, a non- existent body, was responsible for this exciting project. At this Toronto meeting the International Union of Geodesy and Geophysics (IUGG) adopted a resolution urging 'the nations of the world and especially those experienced in deep drilling to study the feasibility and cost of an attempt to drill to the Mohorovicic discontinuity at a place where it approaches the surface.' There were some objections to this 'science fiction' approach, but these were silenced when it was pointed out that there were objections on the same grounds when, a few years ago, the IUGG first proposed an investigation into the feasibility of launching an earth satellite.
The earth-scientist has for long been wanting to get a good look at what lies beneath the Earth's crust. As usual, he has been following in the foot- steps of the science-fiction writer. Jules Verne in 1864 had paid a visit to the 'central sea' by making use of a convenient volcano. In 1871 Bulwer Lytton, following on Plato and Dante, described in The Coming Race an escapist Utopia in a well- lighted and well-populated region underground.
More recently Arthur Conan Doyle had Professor Challenger dig a hole eight miles through the shell of the earth. The long drill point that he thrust into the Earth's bottom resulted in a tremendous scream : he was tampering with a living animal, resembling a sea urchin.
Fiction apart, we have had to learn about the composition and structure of the Earth mainly from seismology, the study of earthquakes and man-made explosions; and from measuring various kinds of tremors or waves, seismologists are agreed that the Earth's structure consists of three principal layers.
At the centre, there is a dense core about 4,400 miles in diameter. What it is made of is not clear.
It cannot be solid because it is under such great pressure and heat; but if it is liquid, it is denser than any liquid we know. Around the core is a mantle of solid matter which rises to within twenty or thirty miles of the surface; and above this mantle, a thin surface layer called the crust, with an average thickness of about ten miles. The boundary between the crust and the mantle is called the Mohorovicic discontinuity—obviously : the Moho. And, equally obviously, a hole through the Moho is the Mohole. It would cost a great deal of money—several million pounds. But the scientific benefits could be as eeat as those arising from the space satellite. In the same way as the first samples of the cosmic dust on the Moon will provide us with a history of the Universe, so the samples that will be brought up through the Mohole will give us a picture of the evolution of the Earth through millions of years.
The Mohole came into being—I see from an article in the Scientific American—as an AMSOC undertaking at a wine breakfast in the La Jolla home of Walter Munk, Professor of Oceanography at the University of California, in March, 1957. AMSOC stands for American Miscellaneous Society—a protest against all these alphabetical organisations. It has no corporate being : no con- stitution, no officers, no by-laws, no nothing. It is only a name. Yet today the AMSOC-Mohole Committee is a Committee of the National Academy of Sciences in Washington—compelled to take this form, so that funds could be voted to undertake the preliminary study called for by the IUGG.
A number of cranks, like the American Cyrus Reed Teed, would have regarded the Mohole with peculiar affection. He believed the Earth was hollow and that we were living on the inside. He had a vision one night, and under the name of Koresh (Hebrew for Cyril) he announced in 1870 the discovery of the cosmogonic form. 'All natural life develops and matures in the egg or womb. The Earth therefore is the great womb of natural development, hence we are living in a shell.' Koreshanity actually flourished for a time in the specially-founded town of Estero in Florida. The, Nazis were taken by this idea, and it lives on itt Germany as the Hollow Earth Doctrine.
Teed went back for support to the astronomer Edmund Halley, of Comet fame, who put forward an hypothesis of the structure of the internal parts of the earth' to try to account for changes of the variation of the magnetic needle. Thcre was also Captain John Cleves Symmes, another American crank, who, in 1818, declared that 'the earth is hollow and habitable within; containing a number of concentrick spheres. . . . I pledge my life in support of this truth, and am ready to explore the hollow, if the World will support and aid me in the undertaking.' The World never did, although the Czar of all the Russias invited him to organise an expedition. It came to nothing, but a Soviet scientist said at Toronto two years ago that the Russians were already looking for a place to dig a hole deep into the Earth's crust. 1.
Previous page
