Written by Faiz Shaikh
Edited by Claudia Reines
In 2015, a picture of a black and blue dress went viral for sparking passionate disagreements over its appearance. Despite reflecting the same frequencies of light for everyone, the dress appeared as white and gold to many internet users. Unlike most optical illusions, where one can eventually determine an image’s true nature, people could not see the dress for how it actually looked [1].
Our predominant understanding of sight equates the color of an object to the wavelengths/frequencies of electromagnetic radiation it reflects. The human eye can detect wavelengths of light between approximately 400 and 700 nanometers. What people see as red, blue, yellow, or purple is merely a reflected light wave of a particular frequency entering their eyes [2]. When this light passes onto specialized cells known as cones, a signal is sent through the optic nerve to the brain, where it is assigned what we call a color [3].
The dress debate illustrates that the colors the eyes and the brain give to certain objects can vary. Indeed, a proposed explanation for the discrepancy was that those who saw the true color of the dress possessed more blue cones in their eyes. Since cells that detect blue light are already less common, those with fewer blue cones were unable to see the dress’s proper hue [4].
Similar discrepancies arise when people’s brains interpret the eyes’ signals differently. In an experiment with squirrel monkeys that were artificially given red cones (squirrel monkeys typically only possess blue and green cones in their eyes), the animals’ brains didn’t respond to the new color in the same way. The findings suggest that people’s brains may also form different responses to colors, especially at birth [5].
Sight and color aren’t the only phenomena which produce wildly different responses in people. Mutations in olfactory receptor genes cause cilantro to taste like soap for some, though the compounds within it are the same [6]. Likewise, our own voices sound different in recordings than in-person, though the amplitudes and wavelengths of the sound waves are the same.
The story of our senses is one which differs across individuals. Though we can collectively classify certain objects as “red” or “green” (most of the time), we cannot know what kind of “red” or “green” is produced by the precise distribution of cones in each other’s eyes and the exact signals sent in each other’s brains, even if we know what that arrangement of cones or those signals are. Each of us exists in a bubble of perception --- never truly experiencing the world as others do. Philosophers have called our inability to describe subjective experiences like color and especially pain the “Explanatory Gap.” Not all scholars believe that it can’t be bridged [7], but this divide between what goes on in the brain and our experience of reality prevents us from truly describing our perceptions to each other. Hence the question, “Is my red your red?” The answer is that we probably won’t ever know.
Faiz Shaikh ’29 is in the College of Arts and Sciences. He can be reached at fgs32@cornell.edu.
Sources
[2] https://www.datacolor.com/business-solutions/blog/why-we-cant-agree-color-perception/
[3] https://my.clevelandclinic.org/health/articles/21204-vision
[4] https://www.birmingham.ac.uk/research/perspective/the-dress-schofield
[5] https://www.livescience.com/21275-color-red-blue-scientists.html
[6] https://www.britannica.com/story/why-does-cilantro-taste-like-soap-to-some-people
[7] https://www.sciencedirect.com/science/article/pii/S1053810025000649?via%3Dihub
