Newton and Knowledge of the Universe

Like Bacon, Descartes, and Galileo, Newton identified method as the key to discovering truths about the world, and like theirs, Newton’s method conflated induction and deduction in making claims about reality. Against Robert Hooke, Newton claimed that data spoke for themselves, as in his claim that his prism experiments directly proved that sunlight really was a combination of colors. In his theory of light, Newton claimed that his data allowed him to “deduce” that light was made up of corpuscles, against Christiaan Huygens’ claim that light was composed of spherical waves. In Newton’s mechanics, which became the cornerstone of modern mathematical physics, neither his definitions of space, time, matter, and motion nor his famous three laws of motion were deduced from experimental data. In his dismissal of Descartes’ method of reasoning and in his battles with Leibniz over the nature of reality, Newton was forced to confront the logical weakness of his ontological claims.

Measuring electrical properties of the lower troposphere using enhanced meteorological radiosondes

In atmospheric science, measurements above the surface have long been obtained by carrying instrument packages, radiosondes, aloft using balloons. Whilst occasionally used for research, most radiosondes – around one thousand are released daily – only generate data for routine weather forecasting. If meteorological radiosondes are modified to carry additional sensors, of either mass-produced commercial heritage or designed for a specific scientific application, a wide range of new measurements becomes possible. Development of add-on devices for standard radiosondes, whilst retaining the core meteorological use, is described here. Combining diverse sensors on a single radiosonde helps interpretation of findings, and yields economy of equipment, consumables and effort. A self-configuring system has been developed to allow different sensors to be easily combined, enhancing existing weather balloons and providing an emergency monitoring capability for airborne hazards. This research programme was originally pursued to investigate electrical properties of extensive layer clouds, and has expanded to include a wide range of balloon-carried sensors for solar radiation, cloud, turbulence, volcanic ash, radioactivity and space weather. For the layer cloud charge application, multiple soundings in both hemispheres have established that charging of extensive layer clouds is widespread, and likely to be a global phenomenon. This paper summarises the Christiaan Huygens medal lecture given at the 2021 European Geoscience Union meeting.

Newton’s Philosophy of Time

This chapter explains what Isaac Newton means with the phrase “absolute, true, and mathematical time” in order to discuss some of the philosophic issues that it gives rise to. It describes Newton’s thought in light of a number of scientific, technological, and metaphysical issues that arose in seventeenth‐century natural philosophy. The first section discusses some of the relevant context from the history of Galilean, mathematical natural philosophy, especially as exhibited by the work of Christiaan Huygens. The second section offers a close reading of what Newton says about time in the Principia’s Scholium to the definitions. It argues that Newton allows us to conceptually distinguish between “true” and “absolute” time from the vantage point of Newton’s dynamics. The third section, in the context of a brief account of Descartes’ views on time, discusses the material that Newton added to the second edition of the Principia in the General Scholium

“Perspicacity… and a degree of good fortune”: opportunities for revealing the natural world

<p>Experimental science is now more possible and accessible than ever, due to the ready abundance of sensors and recording systems. However, as commercial development of sensors generally follows demand and profitability, most of the options are restricted to devices sensing the most commonly monitored physical quantities. A scientific need can therefore still arise - which Christiaan Huygens would no doubt recognise, and indeed confronted so ably - for an entirely new instrument. As for Huygens’ era, the role of the experimentalist includes seeking and exploiting the best method available for each scientific investigation. This includes modern advances in electronics, materials and production. I will describe some of my own work in atmospheric electricity to try to illustrate the continued value of this approach, in which scientific objectives have driven the design, development and deployment of new instruments for which there were no commercial options. Existing measurement infrastructures, for example surface meteorological observing systems and weather balloon networks, can be enhanced as a result, from embedding and including new sensors, instruments and devices.</p>

Newton’s Laws of Motion

An obstacle to reading the Principia is presuming that the Laws of Motion attributed to Newton in physics textbooks, and the concept of force in them, are the same as those in the book; they are not. This chapter provides an account of his Laws and his conception of force as his contemporaries would have understood them. It does so first by giving the historical background to them in works by Descartes, Christiaan Huygens, John Wallis, and Christopher Wren; and then by reviewing the history of Newton’s own reformulations of them not just in the sequence of manuscripts leading up to the first edition, but extending even to the second edition. In the Principia the Laws serve as the basis for deriving conclusions about forces governing the motions in our planetary system from the motions of the bodies within it “among themselves.” Crucial to their doing so are their six Corollaries, some of them initially formulated as Laws. The history of their development too is covered in parallel with that of the Laws, emphasizing their crucial role in licensing those inferences regarding forces from the observed motions.

Science Fun: Theory of Optics

We, as budding researchers, try to present science in the form of comics. We present the theory of optics by Christiaan Huygens and Sir Isaac Newton in a short comic strip. As we know, the Huygens principle explains that each wavefront can be considered to produce new wavelets or waves with the same wavelength as the previous one. A wavelet can be likened to a wave generated by a rock dropped into the water. The Huygens principle can be used to explain the diffraction of light in small slits. When passing through a small gap, the wavefront will create an infinite number of new wavelets so that the waves do not just flow straight, but spread out. By doing so, Huygens discovered his telescope. In this paper, we then illustrate his telescope through a simple comic.