A Geohistorical Study of ‘The Rise of Modern Science’: Mapping Scientific Practice Through Urban Networks, 1500–1900

Using data on the ‘career’ paths of one thousand ‘leading scientists’ from 1450 to 1900, what is conventionally called the ‘rise of modern science’ is mapped as a changing geography of scientific practice in urban networks. Four distinctive networks of scientific practice are identified. A primate network centred on Padua and central and northern Italy in the sixteenth century expands across the Alps to become a polycentric network in the seventeenth century, which in turn dissipates into a weak polycentric network in the eighteenth century. The nineteenth century marks a huge change of scale as a primate network centred on Berlin and dominated by German-speaking universities. These geographies are interpreted as core-producing processes in Wallerstein’s modern world-system; the rise of modern scientific practice is central to the development of structures of knowledge that relate to, but do not mirror, material changes in the system.

Light-inadequacy of the ultraviolet theory of ionization in the E-layer

From the reports of the CRPL, average yearly values of h′_E, h′_F1,f °_E and N_F1, for the months of January, March, June, July, September, and December of the years 1944 to 1949 were computed and plotted against the magnetic latitude. Altogether some 25,000 individual records were averaged. Seven curves were plotted. They showed that: (1) all curves are symmetrical with respect to the magnetic equator; (2) the h′_E, h′_F1, f⁰_E and the N_F, curves all swing up and down as the magnetic latitude, north and south, increases; (3) the h′_E is definitely periodic with constant period and constant amplitude; (4) the h′_E curve rises only slightly (on the average) with latitude. These results appear to be inconsistent with the ultraviolet light theory of ionization.     

Future developments in transportation

Nearly all prognostigators, from the fellow who buys a $2 ticket on Blue Boy to the financial policy-makers of government and business, base their final conclusions upon past experience. Properly tempered (and herein lies the success or failure of the prophet), this is a completely logical procedure, and is especially applicable to engineering trends, for most of our technical progress has been achieved through a process of evolution.Thus, one of the best ways to gain an insight as to the direction in which we're going is to note our present position and to review how we reached it.In the preceding discussion, I have tried to cover a few specific phases of our transportation future in just this fashion, in order to emphasize that we can expect tomorrow further applications and extensions of the things we are working with today.     

Frequency-coordinate vector diagram

From the standpoint of circuit synthesis as well as for a fundamental comprehension of circuit behavior, it is desirable to be able to visualize the response of a circuit over an extended frequency range by means of a geometrical construction. Mathematically, the response of a circuit can be expressed with the La Place transform theory as a function of the complex frequency variable, p = α + jωw, in which a is the decrement and ω is the “real” angular frequency. Physically, the nature of the real-frequency response is usually not discernible by casual inspection of the mathematical function. This paper develops a means of visualizing this frequency response readily through the construction of a vector diagram from the response function.     

Committee on science and the arts

In contradiction to results previously reported, it has been found that DNA prepared by a method which utilizes strong NaOH is acted on by the specific nuclease, although at a rate only 20 per cent. of that of DNA prepared by a milder method. The nature of the changes responsible for the low rate of hydrolysis of the alkali-treated DNA are not known.