Goethe vs. Newton

(Added 18.1.2024)

I have decided to add some background remarks to this study on rainbows from Goethe's point of view, which I started as a blog in 2010.

Johann Wolfgang von Goethe can be characterized as an early phenomenologist in his studies of nature. I will discuss the controversy between Newton and Goethe, their different approaches to prismatic color phenomena and also the sources to which Goethe owed his way of doing science.

I am not suggesting that modern physical science is wrong. From a phenomenological perspective, physical science as physics is correct and a logical and appropriate continuation of what was developed as light theory in the beginning of the seventeenth century, followed by wave theories of light and electromagnetism, all the way up to modern quantum electrodynamics (QED). I am trying to show however, that what Newton presented as evidence for his theory on white sun light being composed of all the colors of the spectrum, can be questioned or even refuted and this was exactly what Goethe did, a hundred years after Newton. This is appropriate because it is still thought that Newton was right in maintaining that his observations were correct despite objections from his contemporaries.

Today we understand that the visible spectrum is that part of the continuous band of electromagnetic radiation that is visible to the human eye. In physics then, this part of electromagnetic radiation is called light. Moreover, in physics it is understood that the spectrum which Newton observed with his prism, and which can be seen by anyone in every prism experiment today, is not the theoretical spectrum of modern wave theory. The visual spectrum is now understood to be a mixture of multiple theoretical wavelengths of electromagnetic radiation. When we talk about the visual spectrum, we talk in terms of colors. When talking about the 'theoretical spectrum', we talk about wavelengths of electromagnetic radiation or light quanta in quantum language. The visual colors in a spectrum are composed of different combinations of electromagnetic radiation wavelengths. Also, the visual spectrum does not contain all the spectral colors that human visual organization can distinguish. Colors such as aniline red for example, is absent in a single visual spectrum because it is thought to be a mixture of different wavelengths, a mixture not found in a continuous spectrum. Colors containing only one wavelength are called monochromatic colors.

How this talk about colors and wavelengths is problematic or crucial to our topic, that I shall discuss in the following.