Tuesday, March 27, 2012

webspotting 26 - the crisis

As published in the Apr/May 2012 issue of SCOPE, the newsletter of the RASC Toronto Centre. Republished here with permission.


I stumbled across the Dark Matter Crisis discussion bloggy site articles while searching for a simple and clear definition of dark matter. Ha! I had never before seen it worded that way per se, that we're experiencing a "crisis," but it struck me as appropriate. It really is a big problem for scientists and cosmologists. The overarching theme? None of the current theories are working well.

I don't pretend to have a valid theory. I wouldn't even know where to begin. But I cannot shake this inkling, this feeling, deep down, that our current beliefs, the whole approach, might be wrong. I have this inescapable feeling that we can't get there from here. I keep wondering if we need a rethink. To back up. Start again. Re-examine our data. Develop some new premises. 

It also seems to me that a unified or common rule will apply. For a long time I've thought there's an eerie similarity to things microscopic and macroscopic. The eddies in a babbling stream remind me of huge spinning galaxies. The clumps and clusters of galaxy groups, connected by ethereal threads, remind me of the lattice trabecular structure inside our bones. Surely there's a simple way to describe all this, without dozens or hundreds of exceptions.

Actually, I myself might need to rethink the eddie-galaxy metaphor... It may not be a good fit. And therein lies one of the Great Mysteries. It has been observed for some time now that the material near the hub of a spiral galaxy is spinning at an angular (not linear) rate that matches the systems and stars and gas in the outer arms. This is the opposite of what generally happens in solar systems: inner planets orbit faster than outer. It was Kepler who revealed why and posited an elegant, simple mathematical theory for planetary motion. In a galaxy it's almost like the inner and outer sections are connected, like spokes on a bicycle wheel. The Band-Aid applied to our current theories is that there must be a big chunk of mass "locking" all this material together... But where is it? Why can’t we see it? Why can't we measure it?

I have to be careful here. It's tempting to explore this tantalising subject further but, obviously, it is a huge topic which would take hundreds of SCOPE articles to tackle!

Back to my main point. The theories, discussions, points, counter-points, arguments, observations (very limited observations), are fascinating to me. And when I find clear, lively, interesting discussions on these complex subjects, I'm all in. I've enjoyed reading criticisms of the Lambda-Cold Dark Matter during our long, dark winter evenings. 



Updated address: http://www.scilogs.com/the-dark-matter-crisis/

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