This is the first post of of the three I mentioned in my “science week” introductory post a couple of days ago. Here we’ll be taking a look at some of the numbers put forth by the writers of the Marvel Universe Handbook (specifically the 2004 edition). I’m also going to take the opportunity to play around with some concepts that might be good to keep in mind for posts two and three. First, some basics…
Daredevil science as a thought experiment
I mention this again because it bears repeating. I attack this whole subject from a “what if?” perspective, and while I feel very strongly that there are more and less realistic ways of writing Daredevil, I should make it clear that in real life:
People who lose a sense don’t find their other senses actually getting better. Being blind doesn’t make your ears more sensitive and being deaf doesn’t heighten your visual acuity. However, people are very good at adapting to novel situations and the human brain is remarkable in its ability to find new uses for areas that are suddenly finding themselves without a job. If you lose a sense, you may find yourself becoming better at using your remaining senses, but this is due to your brain being efficient and not due to changes to the sensory organs themselves.
Contrary to what Silver Age comic book science tells you, ionizing radiation from radioactive compounds is not good for you. If the dose is not high enough to kill you (immediately or over the course of a few agonizing days or weeks), all it will do is damage your DNA. If you’re lucky, nothing bad will come of this. If you’re not so lucky, you may find yourself at a heightened risk of getting cancer or passing along some nasty mutation to your offspring. What is absolutely guaranteed not to happen is the emergence of large-scale enhancements to any part of your anatomy.
If we pretend for a moment that having a nasty accident would actually heighten four of your senses, there is no way this could happen the way Stan Lee describes it (which I’m sure must come as a shock to all). It has always been suggested in the Daredevil comic that Matt’s senses are heightened due to changes in his brain. In reality, this wouldn’t be even nearly enough to explain his abilities.
The brain can only act on the information presented to it, and the real bottle neck here are the sensory organs themselves. In order to hear better, your inner ear would have to go through some pretty extreme anatomical changes, for enhanced smell the olfactory bulb would have to grow substantially more nerve ending protruding into the nasal cavity, and in order to have more sensitive touch, your skin would have to grow more – and possibly novel – touch receptors.
For the purposes of this and subsequent posts, we are going to suspend our disbelief to the point of accepting that all the required changes to Matt Murdock’s anatomy are in fact possible, and that the only limiting factor are the laws of physics themselves along with a healthy dose of common sense. With that out of the way, let’s go straight to…
“Daredevil’s sense of smell is so acute that he can distinguish between identical twins at twenty feet by minute differences in smell. He can detect odors of an atmospheric concentration of thirty parts per million. […] he can focus upon a single person’s smell and follow it through a crowd of people at a distance of fifty feet.”
– The Marvel Universe Handbook (2004)
My comments: The sense of smell is perhaps the most underused of Daredevil’s senses, or at least it was until Frank Miller came along. Rather than have Matt recognize people by the way they smell (which is what many animals do), someone came up with the idea of “heartbeat signatures.” The idea of hearing heartbeats is not that crazy, but distinguishing between people on this basis seems like a case of, as we say in Sweden, crossing the river to fetch water. “Smelling people apart” makes perfect sense and is not that much of a stretch of the imagination. Your dog can do it (and so can you, actually), it’s not rocket science.
As for the numbers suggested by the MUH, they seem arbitrary to me. If Daredevil can tell twins apart – which he should be able to do – why stop at twenty feet? This shouldn’t be a matter of any fixed distance but by how strong the particular odor is, what other odors are present, whether they are indoor or outside and, in the case of the latter, which way the wind is blowing.
The MUH also states that the concentration of an odor has to be 30 parts per million which is quite clearly just a number someone came up with. The concentration required to elicit a response to an odor varies widely depending on the nature of that odor and there are many scents that you and I can detect at concentrations much lower than 30 parts per million. So, what is required for us, Matt Murdock or your dog to be able to smell something?
In order to detect a scent, it has to be able to get into your nose. You don’t actually smell the buffet table fifty feet away when you walk into a restaurant. What you smell are the molecules origination from that buffet table that managed to disperse through the air and travel up your nostrils.
Not all compounds or molecules are have this tendency to vaporize, that is not all are what chemists call “volatile.” Compounds that don’t vaporize under normal conditions don’t have a smell. Did you know, for instance, that metals have no smell? The smell that we associate with metals comes from the compounds that form when handling metals due to a reaction between the metals and oils from the skin.
Getting into the nose is not enough, however. The nerve endings in the back of the nose that you use for the detection of odors are dancing around in a layer of mucus. In order to get to the nerve endings and trigger a response, the molecule in question needs to be water soluble. Some substances dissolve more easily than others and some are insoluble.
Up to this point, having a super sense of smell doesn’t help much. If a substance can’t 1) get into your nose and 2) get to where the nerves are, it’s not going to register. However, if you increase the number of nerves and optimize the “smelling environment” (there’s a reason dogs have those big and moist noses) you can shift the threshold so that you need a lower concentration of a particular scent in order to detect it.
The so-called olfactory epithelium of dogs is much more densely innervated that that of humans, and much larger as well, and dogs have senses of smell many times better than humans*. Since Matt Murdock doesn’t look like a dog (though he’s occasionally been accused of being one), a more “realistic” assessment for a super-smelling human would be that he might fall somewhere in between.
The third step in triggering a response is that the shape of the molecule swimming around in the mucus covering the olfactory epithelium has to find a matching receptor. The nerves in the nose have different kinds of receptors that bind to different kinds of molecules. We have roughly a thousand olfactory receptor genes but only about 350 of them actually work. Still, with only these 350 receptors, most of us are able to distinguish between around 10,000 different smells. The most common theory of how we do this is that most scents are detected by more than one kind of receptor, and that most receptors can detect more than one kind of scent. This would mean that each unique scent would activate a pattern of receptors, which by itself is unique, in the same way we can use only 26 letters to spell out millions of words.
In conclusion: Well, the MUH makes very modest assumptions about what would be possible for Daredevil even though the human sense of smell – although better than most people realize – leaves plenty of room for improvement. I would suggest that Matt would have the same number of functioning olfactory receptor genes as any other human, thus making him less able than a dog to differentiate between very large numbers of scents, but that he’d have a much higher density of nerves in his nose, thus being able to detect scents at much smaller concentrations than normal. But hey, just my two cents. 😉
“Daredevil’s sense of hearing enables him to detect an acoustic pressure change of 1 decibel at a pressure level of 7 decibels (whereas the lowest human hearing is 20 decibels). […] Through practice, Daredevil is able to control his hearing acuity, mentally blocking out specific sounds like his own breathing and heartbeat, all ambient sounds to a normal human level of perception, or all sounds but a particular sound he is concentrating upon. If taken by surprise, Daredevil can suffer more distress from a painfully loud sound than an ordinary human would. Also, beyond a certain size, crowds of people create too many sensory impressions for him to easily sort through”
– The Marvel Universe Handbook (2004)
My comments: The hearing section of Daredevil’s MUH bio is a complete mess. The normal human hearing threshold is not 20 dB (decibels), but 0 dB – and even a little below that for most people – in the most sensitive frequency range, somewhere between 3,000-4,000 Hz. As for being able to detect a change in sound pressure of 1 dB, this actually describes the average dynamic resolution (i.e. the smallest difference needed to be able to differentiate between sounds differing only in their intensity) of normal humans. Judging by the MUH, Matt actually has a hearing problem, albeit a very mild one. It most certainly doesn’t explain how he can hear the the things he does.
However, rather than just complaining about this, I’m going to help the editors out by actually presenting a model for what super-hearing could theoretically look like. Of course, this would require a huge stretch of human physiology, but it at least abides by the laws of physics. What’s this about the laws of physics, you ask? Well, here’s the thing; there’s a very strict physical limit to sound that no amount of super-hearing can get around. At some point sounds get so faint that they simply cease to exist or at least become irrelevant. It’s sort of like throwing a rock in a pond and watching the rings on the surface spread, only to become smaller and smaller and eventually disappear into the “background noise” of the water itself.
Sound is really a pressure disturbance that propagates through the air, setting molecules in motion. But it’s not as if the air molecules are naturally at rest and any motion constitutes a sound. The air molecules actually bounce around randomly due the kinetic energy they have – a phenomenon known as “random thermal motion” – and this can be looked at as a sort of background noise.
When air molecules are set in motion by some kind of mechanical disturbance, say hitting a drum, the motion will spread to neighboring molecules as the sound travels away from the source, and the intensity of the sound will gradually decrease the farther away you get. This is due to friction as well as simple geometry. Eventually, you get to a point where the intensity of the sound is so low that the size of the oscillations are no bigger than the random movements of air molecules. At this point, the sound has physically ceased to exist. At room temperature, these movements correspond to a sound pressure level of -23 dB.
Keeping this theoretical limit in mind, here’s my own idea of what super-hearing might look like. Geeky, I know. As for what this little model would allow someone to do, you’re going to have to wait until parts 2 and 3 of this little series.
In conclusion: The MUH tells us nothing, but physical science does set limits for what biology, even the super-enhanced by radioactivity kind, will allow. However, if we allow for some bending and stretching of normal human anatomy, there are significant gains to be made. I’ll have reason to return to this point when we talk about echolocation (part 2) and just which of Daredevil’s abilities actually pass the laws of physics test (part 3).
“Daredevil can also sense the proximity and arrangement of objects about himself. According to one theory, Daredevil’s “radar sense” functions via his brain’s generation of energy within a certain portion of the electromagnetic spectrum. The signal emanates from sending regions of his brains, after which it travels outward, bounces off objects around him, and returns to receiving regions of his brain. Another theory is that this sense functions more closely to sonar in which Daredevil hears the faint echoes of sounds as they bounce off nearby objects. His sense may operate by a combination of these techniques or by other, unknown, means. His “radar sense” varies from the “proximity sense” of Stick and the Chaste, which is more of a mystical discipline.
In any event, via this ability, Daredevil synthesizes a very close analogue of three-dimensional human sight. Its resolution is not very fine, probably on the order of several feet at a distance of one hundred feet. By repositioning his head and adding input from his other senses, Daredevil is able to resolve the image of an average flagpole (three inch cylinder) at a distance of over 80 feet.
– The Marvel Universe Handbook (2004)
My comments: This passage sums up pretty well what I’ve tried to demonstrate in my A history of the radar sense series; that is, no one knows what it’s supposed to be and most writers seem to picture it in different ways. The old idea of the radar being an actual radar is still out there, but as I’ll argue in my next post, it doesn’t need to be.
What I find interesting about this passage, however, is that it tries to quantify the accuracy of the radar sense, and where there are numbers, there’s an answer to be had. I won’t actually show you the math here, but being able to just barely discern an object three inches wide at, say 85 feet translates into a visual acuity of slightly worse than 20/100 or just below one fifth of normal acuity. The suggestion that this feat is accomplished partly by inference after relying on his other senses, and the mention of “its resolution is not very fine, probably on the order of several feet at a distance of one hundred feet” suggests that 20/100 might actually be optimistic. Of course, as with every other number mentioned in the MUH, this one is probably just something the writer came up with on the spot. The. question is: Is it reasonable?
While keeping in mind that we’re dealing with a fictional sense that no one has clearly defined and which has been interpreted in a myriad of ways by both writers and artists, I’d say that it does make some kind of sense. The definition of legal blindness is an acuity of 20/200 or worse, but the idea that Matt may not “see” much better than this is not as preposterous as it might sound. Dogs see no better than 20/70 and cats do even worse with estimates ranging from 20/100 to 20/200 (i.e. one fifth to one tenth of human visual acuity). Cats, whether big or small, are known to be skilled hunters and capable of daring, but precise, leaps and bounds (though my own cat is completely worthless in these regards) so it’s quite obvious that seeing the world in a relative blur may not be a problem so long as the ability to judge distance is preserved.
Most artist, when attempting to recreate the radar experience on the page, tend to draw it as slightly blurred and ill-defined and few writers have suggested that the radar sense rivals human sight when it comes to visual acuity. In the case of Matt Murdock, he can’t read at a distance anyway, nor can he “see” the kind of detail that people normally utilize color perception for, so there really wouldn’t be that much to gain from “seeing” better. Since everything is only one color, he’d still be more dependent than you or me on his other senses regardless of how sharp that one-color experience is.
Touch and Taste
Much remains to be said about these topics, but it makes more sense to deal with them in post number 3, so I will have the opportunity to return to the burning questions of whether you actually can count the number of grains of salt on a pretzel and whether reading print by touch is actually physically plausible. We’ll also look at what having heightened senses might be able to do for your fighting skills. If you’ve made it this far, reward yourself with a stiff drink and join me back here for part 2.
*) Note: In recent years, more and more research is indicating that humans have a much better sense of smell than previously thought, and that dogs and other mammals are not as superior as was once believed. In terms of the scent threshold for many substances, humans can in fact rival dogs. However, there seems to be a deficit in human awareness of scent that I will have reason to return to.