Monday, March 18, 2013

Weather Channel's "Forecasting the End" to air March 21; mostly available now: Gamma ray burst, rogue planet

On Thursday, March 21, 2013 the Weather Channel will broadcast a documentary “Forecasting the End”.  But most of the film seems to be available now in video clips on the Weather Channel website when you go to it.

The two biggest risks discussed here are “Gamma Ray Burst” and “Rogue Planet”.

We would not know that a gamma ray burst was going to happen until it arrived, because it would travel at the speed of light.  It is thought that the Earth has experienced several bursts in its history, some resulting in mass extinctions (the most recent, 450 million years ago). 

A burst from a supernova 6000 light years away (it’s 27000 light years to the center of our Galaxy) would appear as a sudden bight flash in the sky, perhaps cause temporary or even permanent blindness, and severely damage the Earth’s ozone layer and magnetic field.  It might produce an effect on the power grid similar to an EMP (electromagnetic pulse) blast.  And there is no way to know in advance that it is about to happen.
The rogue planet hypothesis, actually explored in a couple of sci-fi films in the 1950s, is based on the idea that there may be about two hundred billion such bodies in our galaxy, ejected from their original solar system.  A direct hit with Earth would obliterate it, as in the 2011 film by Lars Van Trier, “Melancholia” (Movies blog, Nov. 11, 2011).  This is even more cataclysmic than a hit by an asteroid and could not be stopped with human technology.  Much more likely is that the planet would perturb the orbits of the larger planets as it passed through the solar system without hitting anything.  (Suppose it collides with Jupiter?)  The end result could be a gradual elongation of the Earth’s orbit, taking it as close to the Sun as Venus and as far away as Mars.  Gradually, over some number of years and centuries, the climate on Earth would develop far greater extremes than it has today.  Imagine the sociological effects.  Would people simply stop having children because the future is so finite?

There is a web extra, “Measuring gamma radiation”.  

No comments: