THE FORCE THAT DRIVES THE WORLD

Nelson Evening Mail, Volume XLVI, Issue XLVI, 24 June 1911, Page 5

THE FORCE THAT DRIVES THE WORLD

THE ASTONISHING POWER THAT POURS D.OWiN' UPO:N OUiR . STREETS. How is it that wo can' eco the sunbeam's? How is it that we can seo.tlio stars? Professor J. ,T. Thooxiigoai Jvaa been explaining a,t the. Royal Instituti-an in a series -of charming lectures on' the.' sun ; the miarveliLous' force froirn winch ill life an<i power come. Wo see tlhe sunbeams and the sunlight because the sun gives out -an en-prmous quantity of what we call radiant ener-;' gy. All iho.'d'ies of a temperature afoovo the absolute zero give out radiiaait cnei"-. gy, but tbab energy cannot be .detected by' the eye until the teratperatiu'e/ has' reached 400 or 500. deg. The stars ate enormously hot, so we can, see their light, but they are such, unthinkable distances away that only an indefinitely refined instrument called the radiometer. (invenited by Sir William Crooiks)* oan detect their heat. ; TJi© energy given' off by the ©liri is vaster than anythiiig else itihlat we imagine. ■ When it is ®hini.ng Ujpop eanth, the sun is emitting enei'gy. eqyqjl to 7000 horse-power am acne. If >vo opjala colledt this .energy,' we should (pftvi?ea - enough to do all the mechanical work oiE tihe • ' . How .hot, then, is the sun ? Various calculations 'have been made, tout Pjn>7 fessor Thomson states t'hat the taoat 'accurate is 'that which places the tempera.ture at 6,000,00deg. To thkiik what thai means, we have only to remember' that tlhe average heat of'the Kuman-'-body "ft 98deg. If we iget much hotter l3ia.h we are said to have a high t(OT]DerattyiMEtj and if we readh 105de<g. our lives/aire'JJi grave danger. ' ' ' y',\; If the heat of tlhe sun, on reaching the earth, is equal to 7000 horse-power an acre, what must be the energy in the sun itself? This calculktiicai ,too, -pTof-. Thomson has woited out for u§: It' is equal to 45,000 horse-power a square inch. Our sunlight is <Joole4' fojr '-usV' Every sunbeam that dances tli-rough o:ur. window has travelled over' 90,000,000'. first through airless space, tlten through our cool, vaporous atmosphere. ■ ;. Now that all tihe world- 'knows of vadium and usaniutm, -which gives'offbeat and light without any noticeable decline, many (people fancy that.the' sun must he composed of these. -elements. But, long as they last, tlheir tiLme 'is short in; comiparison with the vast 'age 'of the sun. The only theory' on this point witih which Prof. Thomson can' agree is that the sun derives its hec'.t by shrinking i n upon itself . \ .