Forces and Fields: The Concept of Action at a Distance in the History of Physics

by Mary B. Hesse

This history of physics focuses on the question, "How do bodies act on one another across space?" The variety of answers illustrates the function of fundamental analogies or models in physics, as well as the role of so-called unobservable entities. Forces and Fields presents an in-depth look at the science of ancient Greece, and it examines the influence of antique philosophy on seventeenth-century thought. Additional topics embrace many elements of modern physics—the empirical basis of quantum mechanics, wave-particle duality and the uncertainty principle, and the action-at-a-distance theory of Wheeler and Feynman.
The introductory chapter, in which the philosophical view is developed, can be omitted by readers more interested in history. Author Mary B. Hesse examines the use of analogies in primitive scientific explanation, particularly in the works of Aristotle, and contrasts them with latter-day theories such as those of gravitation and relativity. Hesse incorporates studies of the Pre-Socratics initiated by Francis Cornford and continued by contemporary classical historians. Her perspective sheds considerable light on the scientific thinking of antiquity, and it highlights the debt that the seventeenth-century natural philosophers owed to Greek ideas.

Genres: Physics, History, History Of Science, Science

336 pages, Paperback

First published January 1, 1961

Reviews

[J.D. Steens · Rating 3 out of 5]

As best as I can understand this largely inpenetrable book, Hesse explains the basis for action (movement) between objects in the non-organic world. Most interactions between objects are understood mechanically, between one object contacting another in a cause-effect relationship. Gravity challenges this mechanical explanation as there is evident movement between two objects without contact. Beginning with Faraday, the development of field theory provides an explanation for this "action at a distance" by stating that "'matter' is everywhere continuous and that "'atoms' are highly elastic and deformable, mutually penetrable, and," quoting Faraday, "'that matter fills all space, or, at least, all space to which gravitation extends.'" In this way, Hesse appears to be saying that atoms are seamed together, creating the fabric of space, and that it is this field that creates a linkage between two bodies.

While this explanation applies to substantive (such as they are) atoms, it is less clear if Hesse includes photons as part of the field as she writes that "photons can be called 'particles' only in the sense that they are bearers of this energy...but that they have none of the other usual mechanical properties of particles." This, in turn, prompts a question about whether a field in this sense is the same thing as dark energy and dark matter that is said to be space (fill space or space itself?).

Hesse exclusively focuses on inorganic matter, but there are questions about how the field concept might apply to life. She says that fields also operate at the micro level (electricity, magnetism; radiation) and, therefore, within our bodies. Are our bodies held together and moved not just by mechanical linkage (muscles, tendons) but also by fields of interconnected atoms? Is this how we pick up "vibes" from others?