Time And Space

A Danish scientist, one who actually appears not to be a raving lunatic, by the way, has actually done a study on why aliens haven't found the Earth yet. His conclusion? There simply hasn't been enough time.

Using a computer simulation of our own galaxy, the Milky Way, Rasmus Bjork, a physicist at the Niels Bohr institute in Copenhagen, proposed that a single civilisation might build eight intergalactic probes and launch them on missions to search for life. Once on their way each probe would send out eight more mini-probes, which would head for the nearest stars and look for habitable planets.

Mr Bjork confined the probes to search only solar systems in what is called the "galactic habitable zone" of the Milky Way, where solar systems are close enough to the centre to have the right elements necessary to form rocky, life-sustaining planets, but are far enough out to avoid being struck by asteroids, seared by stars or frazzled by bursts of radiation.

He found that even if the alien ships could hurtle through space at a tenth of the speed of light, or 30,000km a second, - Nasa's current Cassini mission to Saturn is plodding along at 32km a second - it would take 10bn years, roughly half the age of the universe, to explore just 4% of the galaxy. His study is reported in New Scientist today.

Bjork says that a discovery of the Earth by aliens will not occur in our lifetimes. Which is, of course, patently absurd. Aliens are already here bombarding New Jersey, even though it is hard to tell. But Bjork is Danish and may not have heard of that event. But there is another example closer to his home. If aliens have not visited Earth, how do you explain George Galloway?