Do you think you can tell the temperature of something just by touching it? I’ll bet you can’t. Here’s why:
As was hopefully clear from the video above, what we typically perceive as a relative temperature difference between two objects can actually be a difference in thermal conductivity. This is not to say that you can’t tell whether an ice-cube is cold or a stove is hot, but that we can misjudge the temperature of things that are objectively the same temperature.
In physics, the thermal conductivity of a material is the ability of that material to transfer heat. Heat transfer across materials of high thermal conductivity occurs at a higher rate than across materials of low thermal conductivity. This is why the ice-cube in the video above melted faster on the aluminum (higher conductivity) than on the plastic (lower conductivity), even though both were at the same temperature.
So why would our body be sensitive enough to thermal conductivity that we could mistake the temperature of two similarly heated objects? To speculate, perhaps it was evolutionarily beneficial for our ancestors to be able to tell how fast they were losing heat. As we branched out from Africa and lost our fur (relatively speaking), the conservation of heat would become very important in less hospitable environments. Being able to sense how much heat your body is losing then becomes an advantage. Today, this results in us hopping off a bathroom floor and onto a floor mat after a shower because the floor seems “colder.” Or, at a day at the local pool, 70 degree water on a 70 degree day still feels colder because spending any amount of time in the water will sap our precious heat. Or maybe our sensitivity to thermal conductivity is simply a quirk of our tactile senses and how our brain interprets relative temperature. But again, this is speculation on my part.
Even though my evolutionary explanation could certainly be wrong, it still stands that we are not very accurate reporters of reality. It takes something objective, like science, to shake us free of this subjectivity. And it is always fascinating.
I love smashing through our common sense with science.
As an engineer, that was one of the most painful videos to watch. I wanted to scream at these people! I couldn’t make it through without skipping through the video.
Also as an engineer, after Demetrius, above, specifically a Chartered Engineer, my first thoughts on seeing the book and hard drive, along with the temperature question involved two words, “thermal mass”. I am not sure how the thermal capacities of the two items compare, dependent on mass of materials as well as the thermal capacity of that particular material, of course, and it is a very long time since I did any serious thermal related calculations. However, it was clearly, at least from my point of view, a matter of heat sink and heat flow comparison. Sorry if that spoils your “story”.
“Even though my evolutionary explanation could certainly be wrong, it still stands that we are not very accurate reporters of reality.”
You are a “skeptic”, “of science” and you could actually be wrong?! (I am not into “smileys” but I assume you will take that the right way, given the arrogance of “skeptics” in general, though not necessarily present company, or at least not as bad.)
On the other hand I agree “that we are not very accurate reporters of reality”, though, having read a few of your blogs, I cannot imagine you getting your head round the understanding of realities that many of us who are not of your persuasion can handle with ease. Actually the “with ease”, in my case, is from about 1994 onwards, the previous few years having been a remembering process, which is, partly, why the use of “remembering” in the title of my book is so apt – currently finalising the manuscript. My understandings in other physical lifetimes (only about twenty-five back and a few forward remembered, so far) have varied but that is normal and as it should be.
“It takes something objective, like science, to shake us free of this subjectivity. And it is always fascinating.”
The “objectivity” of science is an illusion. That so-called objectivity is totally dependent on the founding assumptions of science, which are subjective. If those assumptions are not subjective then they need to be objectively proven. If that is done using science it comes down to the equivalent of someone pulling like mad on their bootstraps and trying to convince everyone else, as well as themselves, that they are flying.
“I love smashing through our common sense with science.”
Then to a large extent you are kidding yourself because science, as with any scientific experiment, is only as good, at best, as the starting assumptions.
Science has its limitations and it is as well to recognise them. Try, for example, “smashing through” any “common sense” related to how an aerofoil works; even after over a century of successful use of various forms of that extremely common device its functioning is still not properly understood and there is no common agreement on exactly how it works.
I was past the “science has all the answers, or can find them” stage by my early to mid teens. By my early twenties I had an inkling of more than science, at its present level, can handle and by my mid forties essentially knew there was more.
There are many things we do in engineering that may defy “common sense” at times, certainly some of our concepts and proposals do as far as many people are concerned. There are also many things in engineering that are not “scientifically proven” and some that have been compared to a form of magic. We do not get “hung up” on science, certainly not in the mainstream way, that it is the only way, we cannot afford to. We have our own ways, own body of knowledge and own experience. What is amusing is that, while mainstreamers decry that which is not scientific, or scientifically proven, that are more than happy to make use of such things, albeit that they do is down to ignorance of the ways of engineers.