Why does the sun shine? How does the star work? Why is it mostly plasma,not gas? Green gives us the latest mind-stretching facts, and tells the story of the heroes of solar scienceWe rarely search for directly at it but we miss it when we can’t see it. If it wasn’t there at all, or we’d be gone too. It delivers the food we eat,the air we breathe, the clothes we wear. We read by its light – on a screen, or on paper,indoors or out – because it is the ultimate energy source: indeed, the only energy source. It powered the primeval forests of carboniferous ferns and conifers that became our fossil fuel just as it drives the winds for the electrical turbines that must one day replace coal and oil. Even the radioactive elements whose decay and fission maintain the planet alive and self-renewing are stellar confections: fragments first forged in, or then recycled by supernovae,exploding giant suns.
That lucky aged sun, the great Louis Armstrong sang, and “has nothing to do but roll around heaven all day”. In fact,it is the only thing in the solar system that really works tough: every moment it converts 600m tonnes of hydrogen to 596m tonnes of helium and those lost 4m tonnes become the energy released by the thermonuclear reaction: a bonus of electromagnetic radiation distributed across the entire solar system.
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Source: theguardian.com