Reference

After Galileo had felt the strong hand of the Inquisition, in 1632, he was careful to confine his researches, or at least his publications, to topics that seemed free from theological implications. In doing so he reverted to the field of his earliest studies —namely, the field of mechanics; and the Dialoghi delle Nuove Scienze, which he finished in 1636, and which was printed two years later, attained a celebrity no less than that of the heretical dialogue that had preceded it.

In recent chapters we have seen science come forward with tremendous strides. A new era is obviously at hand. But we shall misconceive the spirit of the times if we fail to understand that in the midst of all this progress there was still room for mediaeval superstition and for the pursuit of fallacious ideals. Two forms of pseudo-science were peculiarly prevalent —alchemy and astrology. Neither of these can with full propriety be called a science, yet both were pursued by many of the greatest scientific workers of the period.

Of the half-dozen surgeons who were prominent in the sixteenth century, Ambroise Pare (1517-1590), called the father of French surgery, is perhaps the most widely known. He rose from the position of a common barber to that of surgeon to three French monarchs, Henry II., Francis II., and Charles IX. Some of his mottoes are still first principles of the medical man.

We saw that in the old Greek days there was no sharp line of demarcation between the field of the philosopher and that of the scientist. In the Hellenistic epoch, however, knowledge became more specialized, and our recent chapters have shown us scientific investigators whose efforts were far enough removed from the intangibilities of the philosopher.

We have now to witness the diversified efforts of a company of men who, working for the most part independently, greatly added to the data of the physical sciences—such men as Boyle, Huygens, Von Gericke, and Hooke. It will be found that the studies of these men covered the whole field of physical sciences as then understood—the field of so-called natural philosophy. We shall best treat these successors of Galileo and precursors of Newton somewhat biographically, pointing out the correspondences and differences between their various accomplishments as we proceed.

Galileo, that giant in physical science of the early seventeenth century, died in 1642. On Christmas day of the same year there was born in England another intellectual giant who was destined to carry forward the work of Copernicus, Kepler, and Galileo to a marvellous consummation through the discovery of the great unifying law in accordance with which the planetary motions are performed. We refer, of course, to the greatest of English physical scientists, Isaac Newton, the Shakespeare of the scientific world.

We come now to the story of what is by common consent the greatest of scientific achievements. The law of universal gravitation is the most far-reaching principle as yet discovered. It has application equally to the minutest particle of matter and to the most distant suns in the universe, yet it is amazing in its very simplicity. As usually phrased, the law is this: That every particle of matter in the universe attracts every other particle with a force that varies directly with the mass of the particles and inversely as the squares of their mutual distance.

We have seen that the third century B.C. was a time when Alexandrian science was at its height, but that the second century produced also in Hipparchus at least one investigator of the very first rank; though, to be sure, Hipparchus can be called an Alexandrian only by courtesy. In the ensuing generations the Greek capital at the mouth of the Nile continued to hold its place as the centre of scientific and philosophical thought.

It is a favorite tenet of the modern historian that history is a continuous stream. The contention has fullest warrant. Sharp lines of demarcation are an evidence of man's analytical propensity rather than the work of nature. Nevertheless it would be absurd to deny that the stream of history presents an ever-varying current. There are times when it seems to rush rapidly on; times when it spreads out into a broad—seemingly static—current; times when its catastrophic changes remind us of nothing but a gigantic cataract.

Syndicate content