A YELLOW WORLD.

Auckland Star, Volume LVIII, Issue 208, 3 September 1927, Page 27

A YELLOW WORLD.

i failed. - jTxmur or humanity. , - Oir EQUATOR'S FRINGE. H-ttemn were suddenly extinguished Jib:* candle, leaving the earth in perprißalnight and increasing eold, humanfy,agd all other forms of life could only - • few days. . . Speculation along these lines is unpro#^llSp^/CTCs.'we can conceive of no poe--which could put out the sun $: On the other hand, it to suppose that the sun I. day be extinguished, slowly, ' J*®*; "any centuries to achieve com- > jp» «tin«tion. We may with reason the consequences of this slow lllteiwould be. - humanity adapt itself to the £ "Bfochanging conditions, or would it battle from the very be- ■ the decline of the sun's power ? Slbmanity would concentrate at the v • • . effective temperature of .'22** is 10,000deg. Fahrenheit, and a | «*ta»lation shows that before § -*gK|*Kthre temperature of the sun had OOOOdeg.- the average tempera-ttw-'year at the equator would > below freezing point, i know that the human race in comfort above latitude in regions like Scandian equable temperature ia Stream) unless with food from lower latitudes. 1 'JfiL. Armageddon, that by the time the 2^— temperature had dropped to | there would only be a . remnant left, inhabiting a narrow *"° the equator, its whole energy p on obtaining food. Jfy very hardiest races could posi J®*™' ®t a S e » and their would not be long extinction would follow the for food. temperature became lower over earth we should find hi our that the years of poor wheatbecome more frequent, though ®till be intervening years crops, but in time the lean .;W°uld become so frequent, and **l«i 80 Sequent, that it would ttei l *•* P ro ®table to grow wheat ija At the same time, the °f the wheat-growing zone * further suuth, and until re ached the equator there S;sS^E^fV\i. n0 B€ " ous diminution in the . ' surface over which tWt. j. d 1,6 grown. It is probable i Ciitt stage regions of the J"* W<rtti are now un P o P u l a ted would by the nations of higher

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The same process would take place with other crops, and the inevitable consequence would be that humanity would drift slowly towards the equator, into regions where food was obtainable, and where less clothing was required to keep it warm. In time the food supply would become insufficient, and nation would war with nation, literally for a place in the sun. A Yellow World. There would be no sun, no blue sky— only a clear-cut yellow world. If. the sun becam£ steadily cooler the sun's rays would first lose their ultraviolet light, then the violet, indigo, blue, green, yellow and orange, , in turn, leav-. ing it a dull-red cdour., TVn-u xurtber cooling it would cease to be visible, though it would continue to send us the invisible heat rays of the inf. ".-red type. The distant horizon would appear clear-cut, the blue haze we now see having disappeared. The blue colour of the sky would have paled away, being replaced by a very faint greenish yellow, and the clouds and the icefields would appear a faint yellow. It is in such a world that we imagine the last struggles of humanity against famine and cold. Winds would cease when the heat died away. The most obvious effect of the sun's rays on the earth is the heating of the earth's surface, and of the air. This heating is greatest in the tropics, where the sun is nearly overhead, and is least in the polar regions, where the sun only shines during a part of the year. It is the difference between the temperatures at equator and pole .which 'provides the motive force for the circulation of the winds' in our atmosphere. Warm winds from the tropics carry heat to higher latitud— and cold winds from the.. jlar regions carry cold air towards rwer latitudes, and so the winds, act as distributors of heat over the surface of the earth. A single example may help to make this clear. Whether a mid-winter day in the British Isles will be warm or cold depends, not eo much on whether the sun is stiining or net, as upon whether the wind is southerly or norti-_.ly. A cloudy day With a south-westerly wind is generally much warmer in winter thftn a sunny day. with a nor«,..erly wind. ' Stagnant Seas. fro rains and stagnant seas would be another phase when the sun ceased to shine. ~ . < . . , Some of the heat from the sun is used up in evaporating water from the oceans. The water vapour which the atmosphere cains in this way is carried by the winds, and eventually dropped as rain. Though the amounts of rain which fall upon different regions of the earth differ considerably, the rainfall of each region keeps within reasonable distance of a constant average value. _ With the progressive cooling of the sun, and the consequent decrease m the amount of light and heat reaching the earth, there would be a general lowering of temperature over the whole of the earth, and a decrease in the oj temperature over the equator and which would in turn slow down the winds and the ocean currents. The

polar caps of ice and snow would increase and advance slowly towards the equator, and the area of the frozen polar oceans would increase slowly but surely. Vegetation would gradually shrink until it disappeared. Let us consider how the sun helps in the growth of plants. Most of the familiar plants require heat, light, and moisture to enable them to thrive. The heat and light are supplied by the sun, and the moisture by rainfall. Most plants can survive under conditions which fall short of the ideal, but there is a limit to their adaptability, as shown by the fact that each one grows only in a limited zone of the earth, obviously in the zone which affords the most favourable conditions of heat, light and moisture. The last phafee—a frozen waste with disease and famine triumphant. We can to some extent picture what the earth would look like at this stage. The polar caps of snow and ice would have encroached over most of the earth's surface, leaving a narrow belt around the equator in which day and night would bring alternate thaw and frost. The light of day, though still intense enough for clear vision, would have lost the ultra-violet which keep men strong and which destroy many forms of bacteria, so that humanity's final stage would be not only a struggle with famine, but also with disease.

We may conclude with the comforting thought that the final stage we have pictured is a glimpse into a very distant future. For, though the views of scientists to-day concerning the Course of evolution of the sun and the stars are in the melting pot, we can emphatically state that they are all agreed that the sun can go on radiating at its present rate for many millions of years without any appreciable diminution in the rate of supply. The final catastrophe, therefore, is by no means imminent.