Democratic Sentinel, Volume 2, Number 35, Rensselaer, Jasper County, 11 October 1878 — Heat of the Sun. [ARTICLE]

Heat of the Sun.

We can measure the quantity of heat that the sun constantly emits, because we can measure the amount received by our earth, which intercepts about the 2,300,000,000 th part of all the light and heat emitted by the sun. We thus find that, in every second of time, the sun emits as much heat as would result from the combustion of 11,600,000,000,000 tons of coal. In passing, it may be convenient to notice that each portion of the sun’s surface as large as our earth emits as much heat per second as would result from the combustion of 1,000,000,000 tons of coal—a simple and easily-remem-bered relation. Now it is easily calculated from this that if the sun’s whole mass consisted of coal, and could burn right out to the last ton, maintaining till then the present rate of emission, the supply would not last more than 5,000 years. As the sun has most certainly been emitting light and heat for a far longer period than this, the idea that the solar fire is thus maintained is, of course, altogether untenable. There are, however, many other reasons for rejecting the idea that the sun is composed of burning matter, using the word “ burning ” in its proper sense, according to which a piece of coal in a fire is burning, whereas a piece of red-hot iron is not burning, though burning hot. In like manner we find ourselves compelled to reject the belief that the sun may be a body raised at some remote epoch to an intense heat throughout its entire mass, and gradually cooling. For we find that in the course of a few thousands of years such a mass would cool far more than the sun has cooled (if he has cooled appreciably, at all) even within the historic period, and we have evidence that he has poured his heat on the earth during periods compared with which the duration of the human race is but as a second amid centuries, while the duration of historic races is utterly lost by comparison.— Cornhill Magazine.