A Neat Surprise — We Cannot Sense Temperature — That’s an Illusion
A Neat Surprise — We Cannot Sense Temperature — That’s an Illusion
Human Body Thermodynamics of Heat Transfer in Convection, Conduction, and Radiative Heating (plus Bonuses on Humidity, Personal Hydration, and Body Weight)
Surprises in the Sciences are Refreshing
It’s a matter of playing with ideas, and enjoying some of the wonderful ways of natural processes in science and nature: our world and nearby. It’s better not to lay out a bunch of rules and behaviors, but to go exploring something, getting to support the effort with some considerations, calculations, and side notes, all along the way. Working and manipulating the ideas toward some ends is a joy. Reciting lists for science exams is a drag, in contrast, with nothing much to explore or develop.
I Write These “Science Surprises” for Fun
When I write “science surprises” I err heavily toward doing it all lightheartedly, and so happy to humbly and playfully ramble on about features and elements of sciences I was long ago taught in the sciences and in engineering. For me, some of these sorts of things are plain fun. I do try not to bore my readers, however.
Science Tidbits Sometimes Can Redeem Nature
It’s too big to grasp, when so very many nice touches come into play, just from getting highly excited to do the calculations and discover something new, and which also happens to be a fresh angle to some very heartening reflections on the nature of it all. The nature of it all includes the ugliest things in life to the prettiest things, all inclusive, so sometimes these heartening reflections on “all” of the universe and nature, holding no biases, results in a beautiful uplifting of absolutely everything, including anything lodged negatively in our hearts from ever most recently having disappointed us or seemed too ugly to our former mental review of it all.
Science Sometimes Can Be Free of Agenda
It’s an even greater nice touch that often there’s some imbued continual and undeniable beauty to the way these scientific or natural processes behave, indicating much that complements and flatters anything and everything, and without having to elevate anything too much or belabor something downbeat either. This can be very uniquely refreshing and infrequent to come upon.
Science Exploration and Projects Can Engage Us
To some enthusiasts, automobile operating principles are so very fascinating and fun, in a way that fills their lives nicely and adds great character to the days. And in another whimsical way, someone might find that music synthesizer inner workings could be a great way to expend hours of fully optional effort — brushing up on expertise, that gladly has no requirements attached, nor any need to serve a serious purpose. This can engage us nicely as well.
Thermodynamics for Entertainment and Refresher
This is a concept and idea ride into counterintuitive thermodynamics, to intentionally challenge ourselves with that which might make secondary sense to us, in a derivative way, but while surely not feeling like it in raw sensation, to any of us.
The Flexible and Thickly Spread Sense of Touch
Our sense of heat transfer is keen. Gladly, nature is smarter than many meteorologists and feeling heat transfer is far more beneficial to any animal than some fictitious and unreal sense of temperature would be. Heat transfer is all there is to the game regarding energies flowing through nature that carry molecular vibration “heat” by conduction (simple solid to solid touch) or by convection (touch with gaseous air flowing by at speed, having a “conveyor belt” effect of replacing newly heated up air, with reinforcements still cool), and is what warm bodies care about to maintain comfort and health. Temperature is a different sort of measure, and does not understand differences. Thermodynamics is all about differences, or deltas. But I digress, and I won’t diverge or derail…
Differences Between Drive Our Warming or Cooling, and Not Average Scales Like Temperature
When we think to ourselves that a coat or jacket, or maybe a sweater, feels cozy, we are totally fooled as to the temperature of it. The entire garment has a temperature distribution below body temperature, and is cooler in temperature than it seems in standard healthy illusion, but with the trusty sense of touch feeling heat transfer stabilities and “comfort zones” very astutely and sensitively, and while wisely caring less for belaboring temperature. What matters are material composition, such as solid, liquid, and gaseous. What also matters is airspace interspersed in layered air/gaseous gap in clothing. What also matters is the wicking principle, which uses the change of state from liquid to gaseous of evaporation to dissipate heat energy via transfer mechanisms, capable even of improving comfort on a hot sweaty afternoon without temperature decrease, or even in the face of small temperature increase (it being the change of material state that carries with it to unbalancing the budget of finding a comfortable heat loss/transfer rate.) A comfortable heat loss transfer rate is always the case for human bodies. The 98.6°F minus 72.0°F gap is nearly approximately 27°F below body temperature as being our human no-wind, low-humidity comfort zone to be in, on species average for a healthy adult or child. That doesn’t seem like much, but in some lights it is quite a lot. After all: 72°F is only 40°F above freezing, and another 27°F above that is our body temperature. It’s amazing that we feel so comfortable when in dry calm air nearly halfway down the thermometer toward freezing, from our hot core body temperatures.
If it seems erroneously but compelling to the reader that we can in fact sense temperature, rather than the overall heat transfer slope to feel, then maybe remember that a semi-cold wooden dowel if picked up on a winter day would feel much less “cold” (an expression of transfer loss being high, not of temperature) than a steel alloy metal rod would feel on that same winter day. The only rationale for such a difference in the sensation of the two differing, even if at same temperature, is that the whole game is a feeling of either transfer heat loss too high of rate (“cold” feeling) or too small of rate (“hot” feeling), or of course the comfortable spans in between the two states. In this case, the metal object has greater properties of “conduction” “conduciveness” than a wooden object possesses, explaining the illusory difference to us.
Moisture, Humidity, Hydration, and Weight Get Wrapped up too, Similarly but Differently Felt
When heat transfers to or from our bodies (or between body parts) and when humidity or moisture is sensed by us, these two sensitivities are rolled up together in the human animal sense of touch. (Sense of weight and encumbrance is oddly also left to touch integration, so you can begin to see how complex and messy it can be.) Further, in some ways the touch sense’s capabilities in measurement refinement and spectrum are somewhat unrefined and limited, or a bit numbed, but like with many other matters of biology, it does seem to work particularly well that way. Expect nothing from the sense of touch but to give us plenty of what we need to sense, but to do it in a sort of sloppy and inaccurate seeming way, getting the job done but with sensations not matching up to visual inspection! So most often our feel for heat transfer and moisture content are presenting us with keen senses, but at other times, or only in unique extreme weather or clothing, these feelings and senses come off seeming borderline erroneous or maybe even backwards to us, after maybe attempting to extrapolate and judge too quickly. Sensed moisture, heat transfer, hydration, and body weight factors are notoriously unwieldy to estimate by feel alone.
Bonus Advanced Material for the Curious, Brave, or Bored
Exercise: Understanding Hydration Lost While Asleep
When most of us were children, we learned to work those blankets so that the upper edge of insulation wasn’t parked over our mouths, reflecting back into our sensitive faces: both lung-released heat transfer outbound, and lung-released humidity via dehydration outbound from our bodies cores, presenting each child with an irritating situation of “humidity index” developing inconveniently right around the exhaling mouth, which really could ruin comfortable heat transfer mechanisms, especially for sleep.
Further, if the reader has ever weighed himself or herself on a scale in the bathroom at creative times, and compared notes, he or she might have learned some neat things about how our body weight fluctuates. Yet that’s likely to have only been performed by a few readers, and for the rest of you this might be quite new: that we lose a lot more weight through long-sleeping dehydration via lungs and skin than we do by way of dieting just for one day. It can be calculated and measured to some extent, by comparing before and after retiring/waking weights on the scales to the next result. That next result is done by drinking cup by cup of liquid early in the morning, to see how many tall beverage cups it takes to make up for the difference, and exactly match numbers.
Exercise: Understanding Weight Loss Differences Between Defecation and Urination
Comparing notes while being creative as to when and how to weigh oneself at the scales can also be very enlightening as to relative weights of things: especially urine as compared to feces. We are terrible at sensing this weight difference. Chunkiness and size we pay too much heed to, and we forget how lightweight the canine feces was to pick up for disposal the last time we walked a dog outdoors. Truly the urine is much heavier than the feces, with some variation but not much. To perform the checks is only a matter of weighing before urination, then after urination, and likewise the same about when feeling the time to defecate.
I’m hoping you enjoyed reading some of this, just for the heck of it and toward no truly useful purpose, as that’s the spirit of it! I’ve written some interesting things for you to read, and I’ve been very elucidative in my disfavor of oversimplification. But as I didn’t want to bore heavily the reader, I haven’t quite been rigorously complete to thermodynamics standards. That can be painful to attempt, and this is no place for textbook rigor.
A Neat Surprise — We Cannot Sense Temperature — That’s an Illusion was originally published in Humen Facets Techniques (Mastery Meny Sciences) on Medium, where people are continuing the conversation by highlighting and responding to this story.