How the world might end

How might the world end?  St. John in the Apocalypse prophecies a rather ghastly end to the world, but with the consolation that at least the good will be transported to a better place to live in peace and harmony.

But scientists also ask how our earth, our galaxy, and even the universe might end.  Their hypotheses don’t have “And they lived happily ever after” endings either, but at least  up to now most of the possibilities lie comfortably millions of years in the future:

The sun won’t burn out for another four billion years and by that time, if  descendants of Homo sapiens are still around, they might have established some outposts in other galaxies.

The universe might expand into infinity, or it might collapse back into an infinitessimally tiny dot of energy, it might keep expanding and contracting forever, or it might reach an equilbrium and stay just the way it is.

Today, however, the papers are featuring two “the-end-of-life-on-earth possibilities that are a little less distant.

The first is the possibility of a supernovae explosion in our neighbourhood that would destroy earth’s ozone layer.  Astronomers from Villanova University in Pennsylvania said the International Ultraviolet Explorer satellite shows a white dwarf star that is sucking in gas and steadily growing.  In the process, it has released small blasts of energy called novas every 20 years or so.   These burps stopped in 1967.  But when the star reaches a critical mass the star will blow up in asupernova blast.   The star is over 3,000 light years away, but the blast could destroy earth’s protective ozone cover, exposing it to deadly radiation.  As one writer put it, “it would frazzle the earth.”

At the moment, although scientists say it could happen “soon,” “soon” in galactic terms does not seem to mean this week.  They aren’t suggesting we all run for radiation cover for another million years or so.

The second end-of-the-world scenario covered in the news today is the possibility of a huge methane explosion that could devastate earth’s oxygen supply.  Methane is a greenhouse gas that is 20 times more warming than carbon.  Huge amounts of it are stored in bogs, in the seabed and ice caps.

The melting ice caps could be the problem where the release of methane has accelerated.  The rates of release are not lethal at this point, but there is cautious concern that a vicious circle could accelerate:  as methane is released with global warming, global warming is thereby increased, leading to faster methane releases leading to… etc.

A mega-methane explosion has been fingered as the cause of at least one of the five major extinctions that we know have taken place on the planet.  Major extinctions are catastrophes not to be taken light.  They usually last millions of years and each have wiped out between 75 and 95% of all the species living anywhere on the planet.

Unlike the supernova explosion, we might be able to actually do something to reduce the possibility that this worst-case-scenario will occur.

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About Terry Sissons

Terry Sissons is the author of The Big Bang to Now: All of Time in Six Chunks, and this blog is a dialogue about the universe and what’s happened in the last 13 billions years.
This entry was posted in mega-catastrophes, saving our home - thoughts about global warming, Uncategorized. Bookmark the permalink.

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