The Day the Universe Changed - James Burke [162]
A drawing from Lyell’s Principles of Geology, 1867, showing the ‘parallel roads’of Glen Roy.
Percival Lowell’s Martian ‘canals’.
By the time a decision has been made that data are to be found within a particular cosmic structure, ordered and moving in a particular way due to mechanisms which operate in modes defined by the structure itself, which also delineates approved forms of research into phenomena that can be properly identified from reputable evidence and examined with instruments designed specifically to examine them - by this time it is the instruments themselves, or the expectations of the researchers, which will give meaning to the data. These data have no ‘objective’meaning, in the sense of representing information about nature which has been discovered by a passive and disinterested process. Every stage of the investigation until this point has been shaped by the preceding stage. Thus, the instrument is constructed to find only one kind of data. The meaning of the data revealed by measurement or observation of the phenomenon is already inferred by everything which has gone before.
Callipers were produced in the later half of the nineteenth century for the purpose of measuring human skulls with great accuracy. In the phrenological structure of human character, the bigger the bump on the skull, the more active the relevant part of the brain. The bigger the bulge in that part of the skull covering the frontal lobes of the cerebral cortex, the greater the genius. Intellect became defined in inches. The myth persists today that a large, domed head and a high forehead are signs of intelligence.
A similar value-loaded interpretation of data occurred in regard to the geological formations known as the ‘parallel roads’of Glen Roy in Scotland, which were explained differently by Darwin and other geologists. According to the chosen geological structure, the strata could reveal that land had been elevated above the sea, or that the sea had receded exposing them, or that they had been formed by glacial lakes, or non-glacial lakes. Without any of these hypotheses with which to interpret the ‘roads’they did not exist at all.
In late nineteenth-century astronomy, both the canals of Mars and the Red Spot on Jupiter were given equal prominence as phenomena which could be measured and whose existence confirmed an entire set of predictions about each planet and about the solar system as a whole. In the case of the Martian canals, the meaning was clear. They showed without doubt the presence at some time of an advanced civilisation on the red planet. Eventually it was found that the canals were artifacts produced by the limitations of the small-aperture telescope.
On some occasions the theory-laden prediction of what the data will show is so strong that absence of the expected results casts doubt not on the theoretical structure but on the observational technique itself. Albert Michelson and Edward Morley failed to find interference fringes produced by the returning split beam of light which they were using to measure the effect of the ether. This result flabbergasted them. Since the model for the behaviour of electromagnetic radiation demanded that there be an ether, through which the radiation could propagate, the possibility that the experiment had been successful in showing that the ether did not exist was out of the question. For Michelson and Morley and many other scientists of the time, the experiment had simply failed because they had used the wrong experimental technique.
The first radiograph, showing a male body. Note the keys in the jacket pockets, the metal sock suspenders and the nails in the shoes.
When the theoretical structure does strongly indicate the need for evidence of a predicted phenomenon, the data will have meaning even if there are no data. In the last decade of the nineteenth century French attempts to decentralise culture and industry had poured millions of francs into provincial capitals such as Nancy, in eastern