Monday, October 18, 2010

Into The Darkness

Next week Professor Warrick Couch will be visiting us here in Wellington. Don't be alarmed by the words Dark Energy. Couch is a real astrophysicist, and leader of the almost complete WiggleZ Dark Energy Survey. This project observes a large range of galaxies, over one thousand square degrees in the sky, through a redshift range of $z = 0.25$ back to $z = 1.00$. As indicated in the figure, this is the first galaxy redshift survey to take us through the magic $z = 0.6$ mark.

WiggleZ considers the acoustic oscillations imprinted on the CMB, assumed to define the characteristic length scale that is known to be favoured in galaxy clustering. This standard candle complements supernovae data and CMB fits to show that dark matter forms around $27$ percent of the universal energy budget, as measured by $\Omega_{m}$.


  1. Don't know if you're notified of comments on old posts, so I'll put it here.

    Re the quark factor of 1.76 (vs. sqrt(2) for leptons); geometrically, the precise value is 1.76028383... if the lepton triangle "nests" inside the up-type quark triangle. See these 3 pictures for a layout of the geometry...


  2. That's very interesting, Dave! I will take a look ...

    By the way, it is better not to log in as Anonymous, because those comments tend to get eaten without me reading them.


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