Larry M. Silverberg, North Carolina State University – Why Does the Field Concept in Modern Mechanics Make Sense?

We’re still learning how to understand certain aspects of science and mechanics.

Larry M. Silverberg, professor of mechanical and aerospace engineering at North Carolina State University, discusses one such area of study.

Larry M. Silverberg, born November 5, 1957, is a dynamicist. He writes for The Conversation about basic concepts relating to physical reality that are almost against common sense.

Silverberg attended Virginia Polytechnic and State University (1976-1983). He studied under the dynamicist Leonard Meirovitch from 1977 until receiving the PhD in engineering mechanics in 1983. Silverberg joined the faculty at North Carolina State University in 1984. Over his career, Silverberg is credited with developing applied and theoretical methods that advanced the foundation of ordinary and spacetime dynamics.

Why Does the Field Concept in Modern Mechanics Make Sense?

Modern mechanics is about the broadening of classical mechanics into the realms of electromagnetism and quantum mechanics. The uniting concept is the vector field – a concept that many find obscure. Let us see why it can make a lot of sense.

Think about the force of gravity. In modern mechanics, it is a field that radiates out into space. The field diminishes in strength with distance from its source. It is an action that does not depend on the masses of surrounding bodies.

Classical mechanics is different. It employs a force that interacts with a surrounding body – that depends on the surrounding body’s mass. You’ll see that this difference is precisely why modern mechanics makes more sense.

First, consider Galileo’s leaning tower of Pisa experiment. Two bodies of different mass fall from the top of a tower with the same acceleration. Strange, because in classical mechanics force equals mass times acceleration. One would think that the falling bodies’ masses should play a role.

In modern mechanics, the action force equates to the surrounding body’s acceleration. The surrounding body’s masses are not involved, so one naturally expects their accelerations to be the same.

Now, consider the earth orbiting the sun. In classical mechanics, the interaction forces on the Sun and the Earth are the same. However, the Sun’s mass is huge compared to the Earth’s mass.

In modern mechanics, the Sun’s action force is indeed huge compared to the Earth’s action force – in proportion to their masses – as one would expect. 

Modern mechanics, by how it predicts the accelerations of falling and orbiting bodies is indeed intuitive – even though at one time it was almost against common sense.

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[The Conversation] – Larry M. Silverberg