Organization/School Name

Golda Och Academy

Grade Level Represented

High School



Download Full Text (256 KB)

Document Type



Humanity has a tendency to divide time. The past is distinct from the present which is entirely separate from the future. In supposedly 20-20 vision history is neatly divided into different sections, distinct eras with sharp lines between them. What is present and in the future is always modern. What is past is something else with another name.

Yet time is not divided so neatly. We know this living through it: years and decades blend into one another in a non-uniform progression. To divide human history into separate eras is a necessary simplification, as it helps to ascribe order onto otherwise chaotic chronology. It is still, however, a simplification, and gives incorrect significance to the people and events used to mark beginnings and ends. Rather, the view of history as a constant and uneven progression is more correct.

In a simple definition, modern is “of, relating to, or characteristic of the present or the immediate past.” To be modern is to be in current times, meaning that which is pre-modern is necessarily in the past. If, then, modernity is also defined by the characteristics of the immediate past, what caused that dividing line to fall down between the pre-modern and current eras, so different between one another? What makes modernity?

The field of physics exhibits a sharp divide between modern and classical branches, defined by different theories, each true in different ways. The modern era of physics is commonly defined as beginning in the 20th century, with the classical era, having begun with the works of Galileo Galilei and Isaac Newton in the 16th and 17th centuries respectively, preceding it. “The beginnings of anything like a corrected history of the science which is now called physics may be placed with considerable definiteness about the beginning of the 17th century and associated with the great name of Galileo,” as Henry Andrews Bumstead writes.

1905, the so-called miracle year of Albert Einstein, in which he published revolutionary papers on mass-energy equivalence, brownian motion, and, most importantly, the photoelectric effect and special relativity, is most often used as the sharp dividing line between physics’ past and present. “Modern physics is the physics of the 20th century…” since “the main building blocks, the theory of relativity and quantum mechanics, were developed early in that century.”

Einstein’s breaking down of absolute time and space in his theory of special relativity, a commonly held assumption for millenia beforehand, is what would distinguish the modern from the classical. The aftermath of special relativity is quantum theory, in which strict causality and infinitely divisible space in physics (assumptions from Newton) were also broken down to show that these concepts did not entirely apply at an extremely small scale, namely the atomic and subatomic realms. This concept was also preceded by Einstein’s work, building on that of Max Planck.

Alternatively to a dividing line, physics can also be viewed as a gradual development in which assumptions are constantly broken down and reshaped, a position I will argue for here. Newton demolished the prime mover theory of Aristotle, James Clerk Maxwell reshaped Newtonian concepts with the addition of fields and statistical mechanics, Einstein the absoluteness of space and time, and the great quantum physicists of Planck, Niels Bohr, Erwin Shrodinger, and Werner Heisenberg, along with others, determinism, infinitely divisible space, and orderly mechanics with the discovery of the absolute strangeness of quantum mechanics.

Instead of seeing two eras as completely separate and distinct from one another, with a point in time or event dividing the two, I will argue in this paper that scientific development in physics is always preceded by previous discoveries by looking at the development of modern physics out of the classical. Nothing comes about independently, as some sort of scientific isolate, as I will show in part I. All advances in physics are built upon the shoulders of giants, and mostly come about as a result of developments within the field itself. In part II, I will also focus on how the great revolutions which created what is now commonly referred to as modern physics were the effects of a larger, sociological questioning of authority occurring throughout the Western world at this time. Modern physics’ emergence is notable for occurring at a time and place in human history, the western world at the turn of the 20th century, which was rife with intense social and intellectual upheaval.

Publication/Submission Date

Winter 1-5-2024


Physics, History of Science, Albert Einstein, Quantum Mechanics, Classical Mechanics, Thermodynamics


Atomic, Molecular and Optical Physics | Elementary Particles and Fields and String Theory | History of Science, Technology, and Medicine | Quantum Physics | Statistical, Nonlinear, and Soft Matter Physics

Creative Commons License

Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.

Questioning Reality: The Progressive Development of Modern Physics