The world is ending ... but how?

These are good times for pessimists, if that even makes sense. Everywhere you look, you can find ways the world is going to hell in a handbasket. Between the Taliban and swine flu and the financial crisis, there is enough material to keep your grumpy neighborhood pessimist going for a while. 'Smile', as the guy said, 'tomorrow will be worse.'

I was reading a hyped-up version of some such 'armageddon' when I started thinking about the book I recently completed and blogged about, Bill Bryson's A Short History of Nearly Everthing. There, the cheerful Mr. Bryson lays out not one, not two, but many different ways the earth could literally come to an end. And when you start speaking in a truly cosmic sense, the sky could literally fall, the earth could literally erupt in a ball of fire. There are real armegeddons out there, my friends, and they would literally be it. The end. Finito. So long, and thanks for all the fish, as Douglas Adams might say.

So, how might we die, you ask? Let me count the ways.

First up, an ice age. Here is what A Short History has to say on the matter. 'For most of its history until fairly recent times the general pattern for Earth was to be hot with no permanent ice anywhere. The current ice age - ice epoch really - started about 40 million years ago, and has ranged from murderously bad to not bad at all. Ice ages tend to wipe out evidence of earlier ice ages, so the further back you go the more sketchy the picture grows, but it appears that we have had at least seventeen severe glacial episodes in the last 2.5 million years or so.' ... 'About fifty more glacial episodes can be expected, each lasting a hundred thousand years or so, before we can hope for a really long thaw.'

And just in case you think we have a lot of time to get ready for a long winter, Bryson helpfully adds, 'Previous inter-glacials have lasted as little as eight thousand years. Our own has already passed its ten thousandth anniversary.' Sweet.

Next up - asteroids. 'It is thought, based on extrapolating from cratering rates on the moon, that some two thousand asteroids big enough to imperil civilized existence regularly cross our orbit. But even a small asteroid - the size of a house say - could destroy a city. The number of these relative tiddlers in Earth-crossing orbits is almost certainly in the hundreds of thousands and possibly in the millions. ... The first one wasn't spotted until 1991, and that was after it had already gone by.' So what would happen if an asteroid decided to come by to visit? Well, at the speeds at which these asteroids travel, our atmospheric air would get compressed and heated to a temperature of about 60,000 K, or ten times the surface temperature of the sun. Everything in the path of the meteorite of course would vaporize. It would hit earth 1 second after entering our atmosphere. The blast would blow out a thousand cubic kilometers of rock, earth and superheated gases. The shock would radiate out at the speed of light. 'It has been estimated', Bryson informs us calmly , that at least a billion and a half people would be dead by the end of the first day.'

Here is my question - who are the manic depressives estimating this stuff? Thay have to get a life!

Want some more? Let's talk about recurring viruses. Nobel laureate Peter Medawar defined a virus as 'a piece of nucleic acid surrounded by bad news'. He wasn't kidding. Viruses aren't themselves alive, but introduce them into a suitable host, and they burst into life. 'They reproduce in a fanatical manner, then burst out in search of more cells to invade. ... They also have the unnerving capacity to burst upon the world in some new and startling form and then to vanish again as quickly as they came.'

Bryson goes on to discuss (I kid you not) the Great Swine Flu epidemic of 1918. 550,000 people in America died, and the global toll is estimated at between 20 million and 50 million. 'A disagreeable Russian virus known as H1N1 caused severe outbreraks over wide areas in 1933, then again in the 1950s, and yet again in the 1970s. Where it went in the meantime each time is uncertain ... No one can rule out the possibility that the Great Swine Flu epidemic might once again rear its head.'

Just in case you aren't the type to be afraid of pig stuff recurring, Bryson optimistically adds - 'If it doesn't, others well might. New and frightening viruses crop up all the time.' Like that little thing called HIV.

I could go on. But I think you get the picture. There is some really scary stuff out there. Stuff that could kill us, and eventually will. So the next time the S&P falls 300 points, and you feel like jumping off a cliff after looking at your 401k statement, remember: An asteroid could have crashed into us yesterday. But it didn't. Party-time!