Paradox?: Three Apparently Different Systems Produce One Observed Temperature
Written by Jerry L Krause PhD
Principia Scientific International (PSI) is ostensibly a scientific news site which allows readers to comment upon what they read. But if you read what it is about, its objective is to return the practice of science to that founded by Galileo with the support of Tycho Brahe and Johannes Kepler.
And to that of Sir Isaac Newton who built on the new intellectual foundation prepared by the efforts of these three men. But before Galileo there was Nicholaus Copernicus who dared question the wisdom of Aristotle which had been accepted for nearly 2000 years.
Isaac Newton was a member of a group of men, the Royal Society, with an interest in better understanding the world in which they lived. These men shared their thoughts with each other and supported the intellectual efforts of each other. It was they who published Newton’s The Principia or The Mathematical Principles of Natural Philosophy.
I am not sure how many current scientists have read Galileo Galilei’s forbidden book—Dialogues Concerning Two New Sciences. It was last translated from Italian to English by Henry Crew and Alfonso de Salvio and published in 1914. I do know that I, who studied science at university level for 10 years and then practiced science and taught science (chemistry) for more than two decades, did not read this book until I was near the end of my employment as a chemistry instructor, say about 1992 (I do not remember even the year). So I did not know, until that late date, that the publisher, Elzevir, had written that a common saying in 1638 was: “intuitive knowledge keeps pace with accurate definition”.
System is a common word. But in physical science it has a very specific definition that I expect is not commonly known. So, in the context of this article it needs to be defined. Walter J. Moore in Physical Chemistry 2nd Ed. page 5 wrote:
“The ordinary subjects for chemical experimentation are not individual particles of any sort but more complex systems, which may contain solids, liquids, and gases. A system is a part of the world isolated from the rest of the world by definite boundaries. The experiments that we perform on a system are said to measure its properties, these being the attributes that enable us to describe it with all requisite completeness. This complete description is said to define the state of the system.
“The idea of predictability enters here; having once measured the properties of a system, we expect to be able to predict the behavior of a second system with the same set of properties from our knowledge of the behavior of the original. This is, in general, possible only when the system has attained a state called equilibrium. A system is said to have attained a state of equilibrium when it shows no further tendency to change its properties with time.”
In these two brief, concise, paragraphs, Moore has not only defined the scientific word—system—but also the fundamental scientific words—state and equilibrium.
Of the three systems referred to in the title, one is a natural system and two are of invented devices being used to observe our natural world. And temperature is a property used to define an equilibrium state of each individual system.
The natural system is the lunar surface. Which has a maximum measured temperature (at the equator) of 390K (117oC, 240oF) and a minimum observed temperature of 90K (–183oC, –290oF). This extreme difference between the maximum and minimum observed day-night temperatures is understood to be due to the long diurnal period of the moon (about 27 earth days) and its surface’s dust layer which has an extremely excellent insulating property. This in part because the moon is observed to have basically no atmosphere. So energy cannot be thermally conducted, by the random motions of gas molecules, from one point to another point as is the case on the earth, which has an atmosphere. (see Moon Fact Sheet below)
One of the invented systemsw is the de Saussure device. Which has been described and discussed in the PSI article–http://principia-scientific.org/the-horace-de-saussure-hot-box/. This condensed statement from Wikipedia summarizes the device and the observation:
“He [Horace] had constructed the first known Western solar oven in 1767, trying several designs before determining that a well-insulated box with three layers of glass to trap outgoing thermal radiation created the … highest temperature—230°F.”
In the PSI article several critical factors relative to Horace’s device are reviewed. One is that a property of glass is that it strongly absorbs much of the longwave infrared (I)R radiation being emitted by a condensed matter (liquid or solid) surface at a temperature of 230oF.
Another, critically important, is the physical principle that such a smooth, surface which strongly absorbs radiation is also a good reflector of that radiation. This somewhat contradictory principle is explained to be because the radiation cannot penetrate significantly into the ‘opaque’ (strongly absorbing) matter.
However, as noted in the PSI article, glass also absorbs a portion of solar radiation’s IR component with the result that the surface of a glass pane becomes too hot to comfortably touch when solar radiation is directly incident upon it at midday.
So it is observed that only a portion of the solar radiation incident upon the de Saussure device is transmitted through the three panes of glass to its interior where it must be absorbed by the walls and bottom. Then it is converted into sensible heat (increased temperature), with the result that de Saussure observed that the interior of his device was warmed to the maximum temperature of 230°F. Which, this high temperature, de Saussure considered was the result that the glass ‘trapped’ the radiation being emitted from the interior surfaces of his device.
The other invented system is an insulated box much like the de Saussure device, except the three glass panes were replaced with two very thin films of polyethylene (plastic warp) which does not significantly absorb any solar radiation or that being emitted by a surface at a high temperature near the maximum temperatures observed in the cases of the lunar surface and the de Saussure device.
I had constructed this device, using extruded Styrofoam as the insulating, structural, component of the device according to the simple design of Suomi, Staley, Kuhn (SSK) net radiometer. (see: Quarterly Journal of the Royal Meteorological Society, vol. 84, No. 360, Apr 1958, pp. 134-141) The SSK device was an instrument that was never intended to be used during the daytime to measure the intensity of solar radiation.
It was invented to measure the upwelling and downwelling long-wave IR radiation at increasing altitudes of the atmosphere as it was lifted by a weather sounding balloon from the surface. And this instrument became obsolete shortly after possibly its first test which is described in the article cited. This was because shortly after this test, the USA placed a satellite into an orbit about the earth and radiation studies of the atmosphere were almost immediately moved to observation being made from these satellites in space.
However, an unknown author saw something in a figure of the SSK article which the authors did not mention. It was that the temperature of the instruments upward facing absorbing-emitting (a-e) surface was consistently 10oC less than that of the atmosphere only about a centimeter away (the space between the two polyethylene films) as the instrument was lifted by the balloon through the atmosphere.
So, I constructed a modified radiometer (the top half of the SSK net radiometer) to see if the temperature of it’s a-e surface could be observed to cool 10oC below the ambient temperature of the atmosphere only a centimeter distant. And on rare occasions it did. But, given apparently cloudless sky, the observed temperature of the a-e surface was always significant lower than that of the ambient atmosphere.
However, the issue of this article is not this lower temperature, it is about the much greater temperature I observed when I, because of curiosity, used the instrument during the daytime to see how hot the a-e surface would become. Initially I did not point the radiometer toward the sun, I only set it on a level surface as I had during the nighttime. And its temperature rose to at least 212oC at midday near the summer solstice. And my latitude was 45oN. And when I pointed it toward the sun, the Styrofoam surface under the a-e surface (a thin aluminum foil painted black) melted. When the Styrofoam melted I remember that the maximum temperature I observed was 220oC or possibly a degree or two greater.
But at the time these high temperatures had no significant significance to me. This because I only became aware of the 1776 de Saussure device June 1, 2016. And it took me month or so to see the existence of a paradox, of what I still question is a paradox. For obviously one invention ‘traps’ radiation and the other does not, yet the same approximate maximum temperatures are observed in both cases (systems). And the observed maximum temperatures of these two invented systems are near the maximum temperature of the third natural system, which is different because there is no atmosphere involved.
I find I question if these cases constitute a paradox because I have not considered the definition of the word—paradox. Which I find is: “A tenet contrary to received opinion; also, an assertion or sentiment seemingly contradictory, or opposed to common sense, but that yet may be true in fact.” (Webster’s New Collegiate Dictionary) The temperatures clearly are observed facts. However, also a fact is that each of the two invented systems have a feature that is clearly the opposite of the other.
Now, I consider the systems of the lunar surface and my SSK radiometer are similar in that both do not limit the transmission of radiation emitted from an absorbing-emitting surface. From this, can I consider the presence, or absence, of an atmosphere is not a factor? Well, I do consider this. So, I consider there is no paradox between these two systems as nothing is inconsistent if atmosphere is not a factor. Why should atmosphere be a factor? Well, you see there is this theory that atmosphere should be a factor. Could this theory be wrong because it is known that human theories have been wrong before?
Clearly, the third system, the de Saussure device and its observed maximum temperature near those of the two other systems, is a bit of a contradiction (to understate the obvious). Or, is it the other two which are a contradictions to the de Saussure device’s observed maximum temperature? Either way, it seems there exists a paradox which needs an explanation. I will further consider this paradox and its possible consequences in a separate article. In the meantime, you (the reader) can take opportunity to explain it for me and others by making a comment to this article.