Some time ago, while doing research for my book, I came across a piece of information that took me by great surprise. In fact, to say that I was shocked by what I found would not be an overstatement. It lead me down a rabbit hole that kept getting deeper and wider. And weirder.
Just writing this post has taken me two weeks, which is just slightly longer than it’s going to take you to read it. That’s a mild exaggeration, you’re looking at ~25 minutes. So make a cup of tea or coffee, and get ready to get your physics on! If the thought of that scares you, get a stiff drink.
You see, I genuinely thought that Stan Lee’s characterization of Matt Murdock’s ability to read print was his own invention. That it was intended as an extension of reading braille, made possible by the fact that the printing technology of the 1960’s left behind letters that were ever so slightly raised above the texture of the paper on which they were printed. Even how it was described in the comics – see the word “imprint” in the featured image, from Daredevil #4 – suggested that this was the case. Framed this way, this seemed like a not entirely implausible superpower, even though I have frequently made fun of the supposed reading speed that Matt could achieve this way.
Little did I know that there had long been stories swirling around about people who could read regular printed text by touch. While “dermo-optical perception” is now considered to be a paranormal phenomenon that I suspect few people today have ever heard of, I was stunned to learn that it was actually taken seriously enough in decades past to be featured in mainstream publications, including this piece in the January 1963 issue of TIME magazine.TIME Jan. 25, 1963, No. 4
Does the timing of this article seem suspicious to you? It sure does to me. It wouldn’t surprise me one bit to learn that Stan Lee, or other people at Marvel, had read this story which came out a year before Daredevil #1 and drawn inspiration from it. Aside from the print reading, the article also alleges that Rosa Kuleshova can describe an image using only her sense of touch, as well as tell colors apart this way. Both are abilities that would appear in the Daredevil comic before being phased out over the decades.
So yes, I have been too hard on Stan Lee in this regard. This doesn’t mean that I give even the slightest bit of credence to the theory that Rose Kuleshova is demonstrating a real ability (more on this below), but I certainly won’t hold it against Stan Lee for not doubting a story that ran in a major news publication. Under the heading of “Neurology” no less!
Debunking eyeless vision
So, what do we make of the claims here then? Well, this story, and subsequent write-ups in other publications, including a 1964 issue of LIFE, served as a major impetus for a 1966 paper published in Science, written by well-known skeptic and science writer Martin Gardner.Gardner, M. (1966). Dermo-optical Perception: A Peek Down the Nose. Science, 151(3711), 654–657. https://doi.org/10.1126/science.151.3711.654 Here’s a quote from the introductory segment.
The Soviet citizen has recently been presented with accounts of fish brought back to life after having been frozen 5000 years, of deep-sea monsters that leave giant tracks across the ocean floor, of absurd perpetual-motion devices, of extraterrestrial scientists who have used a laser beam to blast an enormous crater in Siberia, and scores of similar stories.
By and large, the press in the United States has not taken this genre of Soviet science writing seriously. But in 1963 and 1964 it gave serious attention to a sudden revival, in Russia’s popular press, of ancient claims that certain persons are gifted with the ability to “see” with their fingers.
The revival began with a report, in the summer of 1962, in the Sverdlovsk newspaper Uralsky Rabochy. Isaac Goldberg, of First City Hospital in Lower Tagil, had discovered that an epileptic patient, a 22-year-old girl named Rosa Kuleshova, could read print simply by moving a fingertip over the lines. Rosa went to Moscow for more testing, and sensational articles about her abilities appeared in Izvestia and other newspapers and popular magazines. The first report in the United States was in Time, 25 January 1963.
In the article, Gardner admits to breaking into a “loud guffaw” at the sight of Rosa reading, and introduces the reader to his own interest in magic, and its tricks, before doing a full exposé of the entire field of so-called eyeless vision. It turns out that applying a blindfold that actually prevents anyone so inclined from simply peeking down the nose takes extraordinary care. There will almost invariably be at least a small pinhole for the person to see through.
Magicians and others who have turned this trick into an artform will also use other methods, such as taking a glimpse while pretending to adjust the blindfold, or performing some other gesture to conceal the otherwise conspicuous sniffing posture one must adopt in order to see what is directly below. Committing some of the material to memory is another way of not appearing to look at what you’re “looking” at.
Gardner describes the many other Soviet women who came out of the woodwork, following the publication of Rosa Kuleshova’s story. He also details the further studies that were conducted on Rosa herself:
Experiments on Rosa, [the article in Soviet Life] said, made it unmistakably clear that her fingers were reacting to ordinary light and no to infrared heat rays. Filters were used which could block either light or heat. Rosa was unable to “see” when the light (but not heat) was blocked off. “The fingers have a retina,” biophysicist Mikhail Smirnov is quoted as saying. “The fingers ‘see’ light.”
Accounts of the women also appeared in scientific publications. Goldberg contributed a report on his work with Rosa to Voprossy Psikhologii in 1963. Nyuberg reports that Rosa’s fingers, just like the human eye, are sensitive to three color modes, and that, after special training at the the neurological institute, she succeeded in training her toes to distinguish between black and white.” Other discussions of Rosa’s exploits appeared in Soviet journals of philosophy and psychology.
Not only did Rosa read print with her fingers, she also described pictures in magazines, on cigarette packages, and on postage stamps. A Life correspondent reported that she read his business card by touching it with her elbow. She read print placed under glass and cellophane. […]
As I read this, it was my turn to laugh. I mean, let us first breathe a sigh of relief that neither Stan Lee, nor any of his successors, ever thought to have Matt Murdock pick colors with his toes (or read with his elbows). More importantly though, didn’t any of the scientists studying Rosa find it just a little suspicious that her fingers were unable to “see” in the very same circumstances that would have prevented her eyes from seeing?
There’s just very little about this that makes any sense at all. What “light” are her fingers seeing if she’s pressing her fingers against the reading material or image? Certainly not visible light. On what grounds is Smirnov, the biophysicist, suggesting that the fingers have a retina?
The general function of the actual retina has been known for hundreds of years.See, for instance: https://web.stanford.edu/class/history13/earlysciencelab/body/eyespages/eye.html The four major classes of touch receptors of the skin had been known for many decades at this point, three of them since the 19th century. How curious that no one had happened upon any structure in the skin that looked like a photoreceptor. Even more so considering how numerous and densely packed they would need to be in order to use them to read. Keep in mind that the average human retina has some 4.6 million photoreceptors.Curcio, C. A., Sloan, K. R., Kalina, R. E., & Hendrickson, A. E. (1990). Human photoreceptor topography. The Journal of comparative neurology, 292(4), 497–523. … Continue reading
Needless to say, “finger reading” by some kind of optical process is not a real thing. And, to once again quote Gardner, “It is significant that there are no recent cases of persons known to be totally blind who claim the power to read ordinary print, or even to detect colors, with their fingers, although it would seem that the blind would be the first to discover and develop such talents if they were possible.”
Distinguishing color by touch
Another thing I did find surprising though was that while accounts such as Rosa’s had faded into obscurity, the idea that humans can tell color apart by touch has turned out to be surprisingly long-lived. It has been the subject of at least a handful of studies, scattered over a few decades, that claim to find such an ability in at least some people, some of the time.
As relatively recently as 1992, a Canadian study – funded by the National Research Council of Canada no less – set out to investigate the utility of dermo-optical perception of color as a tool for guiding blind travelers.Passini, R., & Rainville, C. (1992). The Dermo-Optical Perception of Color as an Information Source for Blind Travelers. Perceptual and Motor Skills, 75(3), 995–1010. … Continue reading The authors of the study cite research done in Russia and France – most of the latter by a certain Yvonne Duplessis, described in one obituary as a prominent figure in French metaphysics(!). Their own stance was described in fairly agnostic terms, however:
“The basic assumption underlying the mechanism of dermo-optical perception is cutaneous sensitivity to infrared light emitted by colored surfaces. We know of no research, though, which would have demonstrated this type of perception. We think it is fair to say that we engaged in this research without any strong predispositions concerning the claims or denials of dermo-optical perception.”
So, what’s going on here? Well, first of all, we should maybe quickly mention that this particular study failed miserably, and showed no support for this purported ability in either the blind participants, or the sighted controls. The authors end up dismissing the idea entirely:
A more fundamental question may be imposed at this point of the discussion: is dermo-optical color perception a reliable and measurable phenomenon or is it fictitious? The answer to this question is more difficult. First, it has to be said that we cannot prove in an experiment that dermo-optical perception does not exist. Nevertheless, given the ideal conditions and the various exposures through direct skin contact with the colored boards, the exposure to intensely colored spaces, and the walking experience with high contrasts between colored and white panels, we can argue with some confidence that, if dermo-optical perception existed, we should have been able to measure it in some reliable fashion for some subjects at least.
However, I would be remiss to ignore the surprising credence people have given to the idea that there could be something to this. In one 2019 review of the historical claims of “sightless reading,” where the phenomenon is linked to the 19th century idea of “transposition of the senses,” a distinction is made between the obviously ludicrous idea that people can read print by touch, and the idea that they can tell colors apart in this manner, with the latter being described, briefly, as having to do with thermodynamics.Lundblad, K. (2019). Sightless Reading: Cases of paranormal text consumption. TXT Magazine, 67-78.
This, and the scant collection of other articles that are supportive of the idea, usually all contain references to a 1966 article which proposes a theory for the basis of object discrimination by color.Makous, W. L. (1966). Cutaneous color sensitivity: Explanation and demonstration. Psychological Review, 73(4), 280–294. https://doi.org/10.1037/h0023440. This is actually a pretty serious article, though it’s pretty telling that even this oft-cited defense of color perception by touch makes the following conclusion:
It is difficult to imagine any direct, practical application of this sensory capacity. Even under optimum conditions it is a nearly threshold effect. There is no evidence even of the crudest spatial resolution. Holding the hand perpendicular to the boundary between the reflective and emissive halves of the test plate provides no cues as to which half is which; these cues only arise after the hand is rotated 90 degrees and placed successively over the two halves of the plate.
In fact, the experiment alluded to above didn’t even measure an ability to detect a difference in color between the two surfaces mentioned, as much as a difference in emissivity. However, the author does suggest elsewhere in the article that colors also differ in emissivity. This is a common assertion in the handful of other relevant articles, and one that left me totally perplexed. Because that doesn’t make any sense.
To explain why (and what the heck is meant by “emissivity”), I’m going to have to take a little detour into the world of thermodynamics. For those of you who want to get off the ride here (who can blame you?), here’s a hint about where we are going to end up: My own instincts on this matter end up actually checking out, and this may be the smartest I’ve felt since getting an A on my quantum mechanics exam in college.
In essence: No, you cannot tell colors apart by touch in any situation where color is the only variable separating two objects, and I still stand by what I had to say about this topic in a blog post from over a decade ago. (That one might need to be edited for clarity though.)
Let’s talk about thermodynamics!
I’m going to be honest with you. Thermodynamics is not the easiest subject area to get into. It contains a whole host of terms that we use in daily conversation, but very rarely know the actual definition of. Science communication on this topic can also be sloppy, which I would argue adds to the problem. So for this section, here are some concepts to keep in mind.
Heat is the amount of energy flowing from one body (object) to another spontaneously due to the difference in temperature between them. Heat is not a property of a “system” or object, but more like a process.
To translate this into ordinary language and experiences: When we touch an object we would describe as “hot,” it is not the case that the object “has” heat, but that heat is what flows from the object to our hand. If we touch an object we describe as “cold,” heat flows from our hand to the object. There is no net transfer of heat when the two objects reach thermal equilibrium…
…which conveniently brings us to our next point. When two objects are at thermal equilibrium, they have the same temperature. In order to measure the temperature of an object, we need a thermometer. The temperature, then, is the value (according to whatever temperature scale we choose) at which the thermometer is in thermal equilibrium with the object. This point might seem banal, but underscores the relative nature of the concept.
The temperature of an object is also a measure of its average kinetic energy, that is the average speed of the movements between the particles that make up the object.
“Heat transfer” might sound like a tautology since we already established that heat is defined as an energy flow between objects. However, we still need to establish how heat is transferred. This can happen in one of three ways, though real life processes may, of course, involve more than one.
Conduction takes place within an object, or between solid objects that are in physical contact. Through conduction, heat is transferred by the moving particles bumping into each other, in a kind of bumper car style. How quickly this happens depends on the material. Wood, for instance, is a poor conductor, and metals are very good conductors. This is why a metal objects often feels (briefly) cold to the touch when at room temperature, as the bumper-to-bumper action in our (warmer) hand quickly bumps its way into the metal and cools the skin. Note: “Bumping” is not a scientific term, but what the heck.
Convection is the least interesting for our purposes here, but is the transfer of heat through gases and liquids. Because gases and liquids are poor conductors – the particles they consist of are too far apart to be as good as solids at playing bumper cars with the next-door neighbor – a “larger-scale” process takes over by which there is a flow of particles through a space. Most people are familiar with the idea that hot air rises to “float” on top of colder air. This is because gases expand and become less dense with rising temperature. This creates a mechanism for transferring heat. In reality, though, conduction also contributes since it’s not the case that no conduction is taking place here. The chilling effect of jumping into a cold lake – even though it may be the same temperature as the air! – comes from the fact that water is still a much better conductor than air, and cools you down quickly.
The third way heat can be transferred is one we’ve touched on before, as in my recent critique of the “world on fire” effect, and has to do with “thermal” radiation (usually infrared). I’m putting it under its own heading…
…right here. So, all matter in the universe that has a temperature greater than absolute zero (= when no particles are moving in it) emits thermal radiation. This takes the form of photons. A photon is a sort-of-a-wave-sort-of-a-particle energy packet that underlies all forms of electro-magnetic radiation. We’re talking everything from radio-waves to X-rays, including visible light.
Visible light and infrared radiation are next to each other on the electromagnetic spectrum, with infrared meaning, literally, “below red.” All electromagnetic radiation can move through a vacuum (i.e. nothing at all), which is kind of important to all life on Earth; otherwise the heat from the sun couldn’t reach us.
At the temperatures we normally deal with in everyday life, thermal radiation can be thought of loosely as being more or less synonymous with infrared radiation. However, at higher temperatures, the peak wavelengths of the radiation that is emitted starts to skew higher and higher, with greater proportions being emitted as visible light. This is what happens in the case of glowing hot iron or the flame from a fire. In the latter case, what you’re actually seeing is the glow of tiny soot particles that are really, really hot. Pretty cool, huh? Almost half of the thermal energy that reaches us from the sun is in the visible part of the spectrum, i.e. “light.”
Emission and absorption of thermal radiation
“This is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning.” You didn’t think I was going to quote Churchill, did you? Well, we are actually way past the beginning, so this really does look like the beginning of the end. Either way, we are finally going to look at what all the hoopla about “emissivity” was all about.
Remember how, a few minutes ago, we covered how materials differ in how well they conduct heat? Well, the same goes for surfaces and thermal radiation, and how surfaces differ in how they interact with it.
You see, a surface can either reflect the radiation, transmit it (i.e. simply let it pass through), or absorb it. A perfect example of a surface that does a little bit of each is a glass window.
Think about approaching your car on a sunny day. First, depending on the viewing angle, you see your reflection, so we know at least some of the visible light is reflected. Then you sigh in horror, as you remember you’ve left the car there for an hour and now have to sit in it. Most of the visible radiation has been transmitted by the windshield, which is how you’re able to see through it to begin with. This energy has now been absorbed by the seat and the rest of the interior. Everything from the upholstery to the cupholders are now of a higher temperature than they were when you left the car, which means that these surfaces are now emitting more thermal energy (and doing some “conducting” and “convecting” as well). Since we’re still in your car, and not in an actual furnace, this thermal energy takes the form of infrared, as opposed to visible light. Unfortunately, glass is pretty crap at transmitting infrared, so much of that energy from the sun gets trapped in there, as it is reflected back from the inside of the windshield. Some of the thermal energy is obviously also being absorbed by the glass itself.
If you’re thinking that this sounds an awful lot like how the greenhouse effect works, you are spot on. Same basic principle. You win the Internet today.
Another kind of object, one that behaves very differently from a glass window, is something called a “black body.” In physics, a black body is an idealized imaginary object with a surface that perfectly absorbs and emits thermal radiation at all wavelengths. The reason we think of it as black is simple, albeit somewhat misleading, In our visual world of colors, we register a surface as black if it absorbs all visible light. Surfaces that are white do the exact opposite in that they reflect all incoming light.
A black body defined this way is essentially an abstraction, but we do determine the “emissivity” and “absorbtivity” of real world surfaces based on how closely they conform to the behavior of these extremes, and many surfaces do come pretty close. A black body is defined as having an emissivity of 1 at all frequencies. Real surfaces fall on a scale between 0 to 1 that gives the fraction of how much well they emit thermal radiation compared to a black body.
Okay, back to colors and touch
If you’re still with me, give yourself a pat on the back! I’m impressed. So, to remind ourselves of how we ended up here, we have to remember on what grounds the case for color perception by touch was made. To once again quote that Canadian article from 1992: “The basic assumption underlying the mechanism of dermo-optical perception is cutaneous sensitivity to infrared light emitted by colored surfaces.”
The suggestion here seems to be that differently colored surfaces interact differently in contact with the skin depending only on a difference in color. There are several problems with this line of reasoning. First of all, we are not dealing some exchange of visible light of a particular wavelength, which could legitimately be said to be of a particular color, but with an exchange of infrared radiation between human skin and various objects.
The skin obviously emits (and receives) thermal radiation in the infrared portion of the electromagnetic spectrum, and is actually a very good emitter (and absorber) with an emissivity of roughly 0.98. In case you’re curious, skin color does not appear to factor into this at all. Whether most of your ancestors hail from Ireland or Uganda makes no difference when it comes to the infrared radiation your body emits.
What about these colored objects that we’re touching? Well, they may differ in any number of ways, including what causes them to appear to be a particular color. A tomato and red lipstick are both red, but they can be red for very different reasons. What they have in common is that, when illuminated by visible light, something about their material makeup preferentially reflects the portion of the spectrum of visible light we call red, and preferentially absorbs other wavelengths. In tomatoes, the substance that makes it look red is lycopene. In a lipstick, it can be any number of natural or synthetic pigments that may chemically be very different from lycopene. How these different pigments interact with infrared has nothing to do with how they visibly appear to us.
Surfaces that look very similar to our eyes can act very differently through the lens of an infrared camera, and vice versa. This is also where emissivity can make a big difference if you’re using infrared to gauge temperature, as the neat correlation between the temperature of an object and how much thermal radiation it emits breaks down somewhat when you factor in that objects have different emissivities. The video below provides a great demonstration of this, and also brings home the point about how color does not affect emissivity (at least not independently of other variables).
One final thing to keep in mind is that when we are touching a material at or around room temperature, there is not only the exchange of thermal radiation to contend with, but the arguably bigger factor of conductivity. In that 1966 experiment where people learned to tell the difference between the low and high emissivity surfaces, they were holding their hands slightly above the surface, making thermal radiation virtually the only way heat is transferred between the skin and the surface. This is not the case when the hand and surface touch so that kinetic energy can also move between them. As was noted in the video above, the temperature of an object remains the same regardless of emissivity. The accuracy of an infrared thermometer does not.
Learning about all the obscure reporting that was previously completely unknown to me has certainly made me much more forgiving of some of the sillier stuff that Stan Lee came up with. It also gave me a great reason to revisit thermodynamics as a field, and I’m relieved that my scientific instincts are still reasonably sharp.
However, one of the reasons it was worth it to really dig into this stuff was to show that color perception by touch is not merely a matter of the sensitivity of the fingers to heat, but a matter of basic physics. The argument that Matt Murdock would be able to distinguish between different colors if his sense of touch (or, more accurately, “hot and cold”) were better than that of an ordinary human, simply doesn’t hold up.
What about the tales of people who have allegedly been able to make distinctions between materials of different colors? We don’t even have to rule all of that out, if we are talking about the experiments that are not obviously fraudulent. Materials of different colors can certainly differ in ways that that can be detected by touch, by whatever mechanism, but it is very difficult to control for the situation where the color difference doesn’t stem from some other difference, such as the presence or absence of particular pigment. And, even in the best of circumstances, we are talking about people who are distinguishing between pairs (usually) of materials and objects in highly controlled situations. There is no single quality connected to any color that makes it possible to identify it in isolation through touch alone. None.
This post started with the extreme case of reading (print) by touch, and how these highly publicized cases may have inspired Stan Lee and others. This is impossible to prove, especially after Stan’s passing, but the timing is suspect. Finding this link, though, has made me more convinced than ever before that it would be a good idea to retire print reading entirely. I’m relieved the show did so, even if it happened inadvertently, but a modern take on the character would do well to remove itself from Cold War era pseudo-science while simultaneously making a stronger case for braille.
|↑1||TIME Jan. 25, 1963, No. 4|
|↑2||Gardner, M. (1966). Dermo-optical Perception: A Peek Down the Nose. Science, 151(3711), 654–657. https://doi.org/10.1126/science.151.3711.654|
|↑3||See, for instance: https://web.stanford.edu/class/history13/earlysciencelab/body/eyespages/eye.html|
|↑4||Curcio, C. A., Sloan, K. R., Kalina, R. E., & Hendrickson, A. E. (1990). Human photoreceptor topography. The Journal of comparative neurology, 292(4), 497–523. https://doi.org/10.1002/cne.902920402|
|↑5||Passini, R., & Rainville, C. (1992). The Dermo-Optical Perception of Color as an Information Source for Blind Travelers. Perceptual and Motor Skills, 75(3), 995–1010. https://doi.org/10.2466/pms.19220.127.116.115|
|↑6||Lundblad, K. (2019). Sightless Reading: Cases of paranormal text consumption. TXT Magazine, 67-78.|
|↑7||Makous, W. L. (1966). Cutaneous color sensitivity: Explanation and demonstration. Psychological Review, 73(4), 280–294. https://doi.org/10.1037/h0023440.|