--- title: Improvement Era description: Monthly periodical of the Mormon church, 1897 onward. This library holds the issues of November 1897 to December 1930. authors: - Widtsoe, John A. collections: - periodicals tags: - magazine - improvement-era periodical: Improvement Era volume: 4 number: 5 published: 1901-03 publisher: Young Men’s Mutual Improvement Associations publisher_place: Salt Lake City language: en type: magazine reference: 'John A. Widtsoe, "Sunshine," *Improvement Era* 4, no. 5 (March 1901): 371–376.' source: url: https://archive.org/details/improvementera0405unse transcription: Transcribed from the Internet Archive scan of each issue (the item for each issue is named in the issue's own source); unnumbered advertising leaves are omitted, printed page numbers are kept as page markers. identifier: improvementera0405unse start_page: 371 end_page: 376 rights: status: public-domain basis: US publication 1930 or earlier (published 1901-03) source: https://archive.org/details/improvementera0405unse publication_year: 1901 note: The Internet Archive item metadata carries a blanket "© Copyright by Intellectual Reserve, Inc." notice. The library owner judged it inapplicable because this issue was published in 1901, before 1931; a scan-level notice does not restore copyright. --- # Sunshine SUNSHINE. BY DR. JOHN A WIDTSOE, DIRECTOR EXPERIMENT STATION, UTAH STATE AGRICULTURAL COLLEGE, LOGAN. The nature of the sun has puzzled the wisest heads for many centuries; it puzzles them now. Some have said that the sun is a fiery ball of vapor; others that it is a gigantic ball of burning charcoal; others again that it is a ball of molten or solid material, that is contracting, and, in so doing, giving out heat. Today, we are as much in doubt concerning the true nature of the sun as men were four thousand years ago. Hypotheses may be made, but they are no more than fanciful guesses; the mystery of the sun has hitherto shown itself impenetrable. Nevertheless, of some facts concerning the sun, we are reasonably sure. We know, for instance, that the sun gives out light and heat; that is, that it shines upon us. We know also that the sunshine is indispensable to the well being of the earth; that without the privilege of basking in the sun's influence, all things upon the earth would die, and the earth itself would become a frozen, lifeless mass. The beauty and glory of the sun are often spoken about, but the limitless power that it wields over human existence and progress, is often forgotten, or not understood. To understand more fully the relationship -between the sun and the earth, we need to know something of the modern theories concerning the nature of light and heat. Scientists assume that all space is filled with a substance of remarkable properties, known as the lutniniferous ether. This ether, besides filling all inter- planetary space, fills, also, the space between the elementary particles of all known materials. Oar bodies are penetrated by this 372 IMPROVEMENT ERA. substance; so are rocks, wood, air, the things we eat and the things we wear. Now, heat and light are believed to be produced by very rapid movements of the molecules, or elementary particles, that constitute the body that gives out heat or light. The fact that the sun gives out light shows that the particles constituting it are in rapid motion. As the molecules move back and forth, they strike upon the ether that fills the intermolecular spaces, and waves are set up, somewhat like the waves that are produced on a pond when a rock is thrown into it. These ether waves travel with extraordinary rapidity in all directions from the particle that originated them, and some of them strike our earth and give it heat. The difference between heat and light depends only on the difference in the size of the ether waves. Heat waves are long; light waves are short. . Our eyes are so constituted that ether waves of a certain smallness give us the sensation of seeing; while the long waves make no impression on the eye beyond heating it. Sunshine, then, is nothing more than countless millions of ether waves striking upon the materials of which this earth is built, — the short waves we call sunlight; the long ones we call sun-heat. Neither sunlight nor sun-heat is made up of one kind of waves only. White light, as it comes from the sun, is composed of short waves of various sizes. If the shortest waves found, be separated and then allowed to fall upon the eye, they would appear violet; the next longer waves will look violet-blue; and as the wave lengths increase, the colors change from blue, green, yellow and orange to red. Ether waves that are longer than the red waves cannot be seen, and are rated as heat. By letting a beam of sunlight pass through a triangular prism of glass, or an inclined tumbler half full of water, it will be broken up into its prismatic colors. This has been observed by everyone. When these colors are judiciously mixed, white light is produced again. The possibility of colors depends on the existence of these facts. Some things, roses for instance, have the power of absorbing all kinds of light waves except those that give the sensation of red. These are reflected from the rose, and produce tjie sensation in the eye that the mind interprets as red. Other substances will absorb all rays except the blue ones, which will be SUNSHINE. 373 reflected, and the thing appears blue. From this knowledge, it has become a but true saying, that any substance has every trite color except the one it appears to have. Things that are white absorb no light, but send it all out; they are really black. Black things absorb all the light that falls upon them, and reflect none; they should really be called white. These are the very elements of the science of color. There is, however, one relationship to human welfare in which sunshine is all important. To grasp it, we must consider a bit of plant physiology. If a plant leaf beexamined with a magnifying glass, it will be found that its underside is covered with little slitlike openings that lead into theinterior of the leaf. The stems and the upper side of the leaves also contain some of these slits or stomata; but the number is very small compared with the number on the under side of the leaves. It has been estimated that the number of these openings, found on the under side of most leaves amounts to nearly forty thousand to the square inch. Around these openings, within the leaf, are grouped cells, that contain grains or granules, green in color, that are called chlorophyll, or leaf-green. The gases found in the air pass through these stomata and come into contact with the chlorophyll and then undergo remarkable changes. The air, it must be remembered, contains several gases of which oxygen, nitrogen and carbon dioxide are the most important. Carbon dioxide consists of carbon, one form of which is ordinary charcoal, and oxygen. Whenever organic substances are burned, the carbon in them escapes in the form of carbon dioxide. When this gas passes through the stomata into the leaf, it is immediately seized by the cells containing chlorophyll, and torn asunder into carbon and oxygen. The oxygen is allowed to go back into the air, but the carbon is retained within the leaf, and from it are made starch, sugar, plant acids, and many other things found in all plants, that are sent from the leaves to other parts of the plant. It is thus that a plant takes up the material necessary for growth. If a plant be deprived of chlorophyll, this taking up of carbon from carbon dioxide cannot occur. This has been shown in many ways, and thus, the fundamental nature of chlorophyll for the 374 IMPROVEMENT ERA. growth of plants has been established. A question arises here, that furnishes the text for this whole writing. The carbon and oxygen in carbon dioxide are held together very firmly; whence comes the work necessary to pull them apart? The answer to this question was found when the conditions under which chlorophyll can exist were established. It was early determined that plants placed in cellars or other dark places lost their color, and became nearly white. By means of the microscope, it was shown that in the dark, the granules of the chlorophyll disappeared from the plant, and that thus, no carbon could be taken from the atmosphere. It was further learned that, in the presence of direct sunlight, the chlorophyll grains became very abundant, and the assimilation of carbon from the air grew very active. The indispensable condition under which chlorophyll can exert its peculiar power, is, then, in addition to moisture and the carbon dioxide in the air, the presence of direct sunlight. Since sunlight is due to matter of some kind in motion, it must, therefore, possess energy, or the power to do work. Sunlight falling upon a leaf is taken up by the chlorophyll, and changed into one kind of light, very much like the red, and this light is of such a nature that when it beats upon the particles of carbon dioxide, they are broken up and the carbon is deposited in the leaf. By this means the sun's energy, transmitted to us over many millions of miles of ether, is taken up by the plant and stored within its structure. Bearing on this fact is the common experience that with sunny weather crops make more rapid growth than on cloudy days. When it is recalled that animals cannot Jive if all plant food be taken away from the earth, it is apparent what direct importance sunshine has for our daily lives. Every loaf of bread or every piece of meat served upon our tables, represents a certain amount of work done for us by the sunshine. The preceding paragraphs have already shown that a growing plant heaps up the energy of much sunshine within itself. Thus the plant acquires a power to do work, as is shown when the plant is burned and heat is given out. Wherever plants grow, this heaping up of energy occurs; and as this process has gone on SUNSHINE. 375 ever since the world began, a tremendous lot of energy from sunshine must have been stored away for the future. It is of this that I want to write. Since the earth was young, many periods of time ago, it has undergone numerous changes, and has had many different climates. During the earth's history, mountains have been changed into sea bottoms, and sea bottoms have been raised up to form mountains. The cold countries of the north have, at different times in the past, been covered with palms and tropical vegetation; then, at other times, gigantic ice sheets have crept far south, far beyond the present limits of the region of perpetual ice. In geological time, there is an era called the carboniferous. At that time, the atmosphere was moist, and it contained a much greater proportion of carbon dioxide than it does at the present. The climate was warm— the world was drowsy and languid. Under such conditions, a peculiar and luxuriant vegetation flourished. Plants of low orders, that now grow a few feet high, flourished then and became trees, scores of feet high, and with proportionate girths. Under the influence of the sunshine, through the intervention of chlorophyll, the mighty, dense, carboniferous forests drew from the heavily laden atmosphere large quantities of the carbon dioxide that it contained. In time, these gigantic tree3 fell, and others sprang up beside them. In their turn, these latter fell also, and other generations grew up. This went on for ages, and the forest floor became a mass of rotting remains of earlier forests. Then a change came upon parts of the earth; a forest, perhaps, began to sink, and soon became a sea bottom. The rivers washed down into the sea, clay and sand and other rock fragments, and this debris covered the former forest floor. When this had gone on for some more ages, another change occurred, and the sea bottom was brought up, and, it may be, made into a mountain. Under the influence of great pressure and heat, the sediment of the sea bottom was changed into rock, and the fallen logs of the forests became converted into a seam of coal. In this manner — many of the well known coal beds were made, not necessarily during the carboniferous era only, but at other times when the climatic conditions favored the rapid and large growth of vegetation. Thus, then, it happens, when we sit of an evening before a 376 IMPROVEMENT ERA. cozy coal fire, that the warmth which plays upon us was taken from the sunshine many, many ages ago, by the trees of mighty prehistoric forests, through the wonderful and mysterious action of the green coloring matter, the chlorophyll of living plants. Thus, too, it happens, when we travel on the railroad from place to place, that the work of drawing the cars is done by the energy of sunshine that fell upon the earth perhaps millions of years before Adam came. When, in our houses we light the gas burner or the coaloil lamp, the light given us is the light that fell upon the earth in the far-away, misty, early days, that was imprisoned by the waving leaves of the forest. Though the time may be near at hand when our houses shall be warmed by electricity, and our railroads and ships propelled by electric forces, and our only source of illumination be the electric light, we shall yet have to fall back on sunshine for the source of the heat, the power and the light. For, in that coal-less age, the electric currents will be generated by falling water; and the water comes from the clouds; and the clouds came from the mists rising from lakes and oceans; and the mists came from the ether waves of the sunshine beating upon the water molecules and changing them into water vapor. In any case, behind it all , is sunshine as the active first cause. And it may be that in the future, we shall use neither coal fires, nor waterfalls, but great machines that will take the sunshine, directly, and convert it into the forms of energy that we may desire. And should that happen, we should understand better than we do now, the backing of sunshine that every earthly action possesses. However, that may be, let the young readers of the Era, for whom this has been written, no longer look upon a leaf playing in the sunshine, or a pond glittering with sunbeams, as simply a growing leaf or a bit of water that is being vaporized. Look deeper, and recall the work of the tiny laboratories of the leaf, where new substances are made, and where the energy of the sunshine is stored away, against future use; or look in among the molecules of the water and see how they move faster and faster as they rob the sunlight of its energy, until they fly into the air as vapor, laden with the power to do work as they are changed back into water, and seek their home in the lake or ocean. When a for-