Guest Posting by

Jerry L Krause   2017

First we need to review a bit of history from the pen of the one who founded this thing we now term physical science.  But before we review what Galileo wrote in Dialogues Concerning Two New Sciences, we need to consider what the publishers (Elzevir) of his book wrote in their preface to the reader.  According to the common saying, sight can teach more and with greater certainty in a single day than can precept even though repeated a thousand times. (as translated by Henry Crew and Alfonso de Salvio, 1914)

Many of us have been taught that Galileo refuted a long accepted general idea—that bodies twice as heavy fell twice as fast—of the Greek philosopher Aristotle by dropping, at the same time, bodies of significantly different masses (weights) from high places and observing that they struck the ground at basically the same time.  However, it seems Galileo efforts of demonstration were not readily accepted by everyone.

For Galileo had his character Simplicio state:  Your discussion is really admirable; yet I do not find it easy to believe that a bird-shot falls as a cannon ball.  To which Galielo had the character Salviati reply:  Why not say a grain of sand as rapidly as grindstone?  But, Simplicio, I trust you will not follow the example of many others who divert the discussion from its main intent and fasten upon some statement of mine which lacks a hair’s-breath of the truth and, under this hair, hide the fault of another which is as big as a ship’s cable.  Several pages Simplicio stated:  The previous experiments, in my opinion, left something to be desired: but now I am fully satisfied.  Even after Simplicio accepted that Aristotle’s idea was false, it seems it was not the demonstration which convinced him.  What was it that convinced Simplicio?

Immediately after Simplicio’s concession, Salviati replied:  The facts set forth by me up to this point and, in particular, the one which shows that difference of weight, even when very great, is without effect in changing the speed of falling bodies, so that as far as weight is concerned they all fall with equal speed: this idea is, I say, so new, and at first glance so remote from fact, that if we do not have the means of making it just as clear as sunlight, it had better not be mentioned; but having once allowed it to pass my lips I must neglect no experiment or argument to establish it.  Herein lies the possible answer to what convinced Simplicio.  If we remove no experiment from Saviati’s last statement, we are left with:  I must neglect no argument to establish it.

I have read that Galileo refused to accept the result (that the planets’ orbits about the sun were ellipses) of Tycho Brahe’s very careful naked-eye astronomical observations and Johannes Kepler’s very careful mathematical analysis of Brahe’s observational data.  I have read that Galileo did this because he considered a circle to be a more perfect figure than an ellipse.  Whatever his reason, the observed fact is he was wrong about the ‘shape’ of the planet’s orbit.  Because of some argument he had with himself?

Relative to Saliviati’s previous reply, I question what was so new, and at first glance so remote from fact.  What was the fact that Galileo’s new idea was so remote from?  I have pondered this question and have concluded the fact was the result of this experiment (experience):  hold a ten-pound bag of sugar in one hand and a one-pound package of butter in the other.

But Galileo was not done, after Salviati’s comment, he had his third character, Sagredo, immediately state:  Not only this but also many other of your views are so far removed from the commonly accepted opinions and doctrines that if you were to publish them you would stir up a large number of antagonists; for human nature is such that men do not look with favor upon discoveries—either of truth or fallacy—in their own field, when made by others than themselves.  A bit later Sagredo added:  In this manner he has, as I have learned from various sources, given occasion to a highly esteemed professor for undervaluing his discoveries on the ground that they are commonplace, and established upon a mean and vulgar basis; as if it were not a most admirable and praiseworthy feature of demonstrative science that it springs from and grows out of principles well-known, understood and conceded by all.

The title of this essay is this essay’s sole purpose.  So as I bring measurements (observations) to your attention, we will only consider the observed facts which apply to this purpose.

It is an undebatable fact that certain atmospheric gases have been observed, by instruments, to absorb certain portions of the invisible, to human eyes, infrared (IR) radiation being continuously emitted by the earth’s surface.  And there are many undebatable cases that when radiation is absorbed by matter it is observed to be transformed into a sensible heat (an increase in temperature) of that matter.  So based upon these cases and a radiation balance calculation, it has been long accepted that the result of this absorption of the IR radiation is that the earth’s average surface temperature would need to be about 33 degrees Celsius (33C) less if not for the presence of these certain atmospheric gases.  This is the claimed greenhouse effect (GHE).

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