15.2.06

lambda



For years now I've been haunted by a heresy. One I can't get out of my mind. It's that I don't believe in the Big Bang. Once, in the audience at a literary festival being addressed by an Eminent Philosopher, I put up my hand in question time and suggested that the Big Bang was an appropriate cosmological metaphor for a civilization that had invented the atomic bomb and was gratified when the Eminent Philosopher's jaw dropped. But only for a moment; she soon consigned the notion to the reject pile of loopy ideas and went on to other things.

Anyway ... have just read an article by Neil DeGrasse Tyson called Gravity in Reverse (in The Best American Science Writing 2004) which gives the clearest explanation I've yet come across of the Cosmological Constant (= lambda), Dark Matter and Dark Energy. I won't (can't) go into the details but the statistics are extraordinary and the (possible) conclusion genuinely uncanny: the cosmos is (they say) 73% Dark Energy, 23% Dark Matter and 4% ordinary stuff. It's the Dark Energy, which appears to arise out of a vacuum, that seems to be driving expansion:

As a consequence, anything not gravitationally bound to the neighbourhood of the Milky Way will move away from us at ever-increasing speed ... Galaxies now visible will disappear beyond an unreachable horizon ... beyond the starry night will lie an endless void, without form ... darkness upon the face of the deep.

So far so good. But what about this -

Dark energy, a fundamental property of the cosmos will, in the end, undermine the ability of later generations to comprehend their universe. Unless contemporary astrophysicists across the galaxy keep remarkable records, or bury an awesome time capsule, future astrophysicists will know nothing of external galaxies - the principal form of organisation for matter in our cosmos. Dark energy will deny them access to entire chapters from the book of the universe.

Here, then, is my recurring nightmare: Are we, too, missing some basic pieces of the universe that once was? What part of our cosmic saga has been erased? What remains absent from our theories and equations that ought to be there, leaving us groping for answers we will never find?


On the other hand, there's nothing here that doesn't accord with our experience of life as she is lived.

(the image is a picture of globular cluster M13)

No comments: