Day: June 4, 2008

Thank God for Evolution?

Christianity is many things to many people – something I learnt the hard way after becoming a Christian, then a fundamentalist, a liberal, an agnostic/atheist and finally a believer in something a bit broader than the easy categories I used to see the world in. So what happens when a Pentecostal preacher falls in love with an atheist biologist? You get evolutionary evangelism…

Thank God for Evolution

…the Reverend Michael Dowd and his wife travel the USA preaching the Gospel, as updated by evolutionary biology. I’m no expert but personally I think it’s about time too, that someone embraced the commonalities between the Christian myth and the tale of creation told by evolution. While that might sound odd to you, consider the idea of “original sin” or “the flesh”, then consider the concept of “selfish genes” – either conceptual group implies some innate selfishness/imperfection within human beings, all creatures in fact, which works against the higher ethics we’re called to by ideals or God or group demands.

I’m yet to read the good Reverend’s book, but the few bits available online seem less theistic than most Christians would be comfortable with. Most aren’t easy with the idea of an impersonal cosmic process as “God” – and cosmic creativity, what Dowd wants badged as “God”, is usually seen as impersonal. Does it have to be? Well read Michael’s book and find out.

The New Milky Way

The latest view of our Galaxy, the Milky Way, can be found at the Spitzer Infra-Red Space Telescope’s newspages here…

The New Galaxy

…seems we’re now officially a few galactic arms short – two arms based on old hydrogen-based maps aren’t evidenced by actual star-counts and thus were an artefact of the limitations of hydrogen-based radio astronomy. The Galaxy is still a BIG place, but it looks more like a pretty barred spiral galaxy than a relatively dull “grand-design” flocculent spiral like it did in the old maps.

But why are spiral arms the way they are? It’s a puzzle, but one astrophysicists have no end of good ideas about – and then along come some new surprises, like this one…

Black Hole Mass determines tightness of the Spiral

…seems the heftier the central Black Hole, the tighter the spiral arms. In our Local Group there are three big Spirals – ours, M31 (in Andromeda) and M33 (in Triangulum) – and the central Black Hole masses 4 million Solar masses (for the Milky Way), 180 million for M31, and just 1,500 for M33. M33 is a pretty loose spiral, though pretty. Andromeda’s M31 is tightly wound, from what we can see as M31 is tilted away from us. SO the Milky Way is somewhere between the two.

But why the correlation? Dark Matter? Weird gravity lanes? Something in hyperspace? Who knows? And that’s why astronomy is both fun and worth doing…