25 October 2008
What if the Sun shuts down?
In today's life, light and heat generated by the Sun is one of the primary sources responsible for the existence of many living beings. After huge initiatives against global warming, in fact the dependency on the Sun is increasing as industrial and domestic equipments increase the use of solar energy as alternative energy sources. Even if Sun simply shuts off, the Earth would stay warm—at least compared with the space surrounding it—for a few million years.
Within a week, the average global surface temperature would drop below 0°F. In a year, it would dip to (–100°). The top layers of the oceans would freeze over, but ice would insulate the deep water below and prevent the oceans from freezing solid for hundreds of thousands of years. Millions of years after that, our planet would reach a stable (–400°), the temperature at which the heat radiating from the planet’s core would equal the heat that the Earth radiates into space, explains David Stevenson, a professor of planetary science at the California Institute of Technology.
Although some microorganisms living in the Earth’s crust would survive, the majority of life would enjoy only a brief post-sun existence. Photosynthesis would halt immediately, and most plants would die in a few weeks. Large trees, however, could survive for several decades, thanks to slow metabolism and substantial sugar stores. With the food chain’s bottom tier knocked out, most animals would die off quickly, but scavengers picking over the dead remains could last until the cold killed them.
Humans may not feel the threat immediately as humans would take measures to combat it. Humans could live in submarines in the deepest and warmest parts of the ocean, but a more attractive option might be nuclear- or geothermal-powered habitats, says astronomy professor Eric Blackman of the University of Rochester, people could continue harnessing volcanic heat for hundreds of years.