Before Isaac Newton understood color, he tried to feel it. In one of the more startling footnotes in the history of science, the young Newton pressed a bodkin — a blunt needle — between his eye and the bone of his eye socket, probing whether pressure on the eye would produce the same color effects as light. It did produce colors, as it happens, along with considerable risk to his vision. Newton recorded the experiment in his notebook and moved on, apparently undeterred.
He eventually found a safer method. In a darkened room in 1666, he directed a narrow beam of sunlight through a glass prism and watched it fan out across the wall in a band of color — red, orange, yellow, green, blue, indigo, violet. Then he passed that spectrum through a second prism. The colors did not divide further. They recombined into white light.
Gallery of Isaac Newton and Optics Images for Licensing
With that, Newton established one of the foundational principles of optics: white light is not pure. It is a mixture, and a prism does not add color to light — it reveals the colors already present within it. It was a conclusion so counterintuitive it met immediate resistance. Nevertheless, it remains a cornerstone of physics more than 350 years later.
For publishers, educators, and science communicators building content around the physics of color and light, Newton's prism experiment is one of the most-illustrated moments in the history of science — and one of the most frequently mis-illustrated. At Science Source, our collection spans historical engravings, scientific portraits, and contemporary optics photography, offering imagery that is accurate to both the history and the physics.
Prism demonstrating refraction and reflection effect. © David Parker / Science Source
Newton's Prism Experiment: What Actually Happened
The experiment Newton conducted in 1666 — which he later refined and published in his landmark 1704 work Opticks — was deceptively simple in setup and radical in conclusion. The key elements were:
A darkened room with a small hole in the shutter, admitting a single narrow beam of sunlight
A glass prism positioned to intercept the beam and refract it onto the opposite wall
A second prism used to recombine the dispersed spectrum back into white light
Careful observation that each color refracted at a slightly different angle — what we now call dispersion
The insight Newton drew from this was that different colors of light have different degrees of refrangibility — they bend by different amounts when passing through a medium. Red light bends least; violet bends most. This is why a prism separates white light into a spectrum, and why a rainbow forms when sunlight passes through raindrops. The prism does not create the colors. It unmixes them.
Newton identified seven colors in the spectrum — red, orange, yellow, green, blue, indigo, violet — a number he arrived at partly by observation and partly, historians suspect, by analogy with the seven notes of the musical scale. The decision to include indigo as a distinct color between blue and violet has been debated ever since. Most modern treatments of the visible spectrum treat it as a continuum rather than seven discrete bands, but Newton's seven-color framework remains the one most people learn first.
Isaac Newton and Optics: The Science Behind the Rainbow
A portrait of Sir Isaac Newton, physicist. © Science Source
Newton's color work did not exist in isolation. It was part of a broader investigation into the behavior of light that occupied him for decades and produced some of the most consequential ideas in the history of physics. Understanding what Newton established — and why it was controversial — matters for publishers building accurate educational content around optics and the physics of color.
The central debate of Newton's era was whether light was a wave or a particle. Newton argued for a corpuscular theory — that light was made up of particles — which put him in direct conflict with the wave theories of his contemporaries, including Christiaan Huygens. The wave theory would eventually prevail, and then be complicated further by quantum mechanics in the 20th century, which revealed that light behaves as both. But Newton's corpuscular theory was not simply wrong; it was a productive framework that made accurate predictions about reflection, refraction, and color.
His work on optics also led directly to a practical invention: the reflecting telescope. Frustrated that refracting telescopes produced chromatic aberration — color fringing caused by lenses dispersing light just as prisms do — Newton designed a telescope that used a curved mirror rather than a lens to focus light. The Newtonian reflector remains a standard design in amateur and professional astronomy to this day.
Illustrating the Physics of Light and Color: Stock Images for Publishers and Educators
Newton's prism experiment is among the most-requested subjects in science publishing, appearing in physics textbooks, history of science publications, museum exhibition materials, and digital learning platforms. Publishers working in this space need imagery for various purposes:
Historical context — engravings, portraits, and period illustrations that place Newton in the intellectual landscape of the 17th century
Experimental documentation — accurate depictions of the prism experiment itself, showing apparatus, beam path, and spectral output
Contemporary optics — modern photography of light dispersion, refraction, diffraction, and color phenomena that connect Newton's discoveries to current science
Conceptual and diagrammatic imagery — illustrations of the visible spectrum, wavelength relationships, and the electromagnetic spectrum for educational publishing
At Science Source, our Newton and optics collection spans all four of these categories. Our historical material includes original engravings and portraits from the 17th through 19th centuries — the period when Newton's ideas were being disseminated, debated, and canonized across Europe. Our contemporary optics photography documents the same principles Newton investigated: dispersion, refraction, reflection, diffraction, and the relationship between light and color.
Why Scientific Accuracy in Historical Science Imagery Matters
Historical science imagery carries a particular accuracy burden that generic illustration cannot meet. A depiction of Newton's prism experiment must be correct not just aesthetically but experimentally—the geometry of the prism, the angle of the beam, the order of colors in the spectrum, and the presence of a second prism if the recombination experiment is shown. Errors in these details are not merely aesthetic; in educational publishing, they misrepresent the physics.
License Newton and Optics Images for Physics and History of Science Publishing
Light refraction through a glass of water. © Turtle Rock Scientific / Science Source
The hand-colored engraving that opens this post has served science publishers for nearly two centuries — it is one of the most reproduced images in the history of optics illustration, and for good reason. It captures Newton's experiment with the clarity of a diagram and the richness of a period document, placing the viewer in the darkened room where one of physics' great insights unfolded.
At Science Source, we hold an extensive collection of Newton and optics imagery — historical portraits and engravings, experiment documentation, contemporary light physics photography, and diagrammatic illustrations of the visible spectrum and electromagnetic radiation. Whether you are building a physics textbook, a museum exhibition, a digital learning platform, or a general science publication, our collection is searchable, licensable, and documented for educational and commercial use.
The physics of color has not changed since 1666. The quality of imagery available to illustrate it has.
Browse Science Source's Newton and optics collection at sciencesource.com