14 March 2002

Cosmology: Cosmic Doppler effect

Central to our view of the Universe is the idea that the 2.7 K cosmic microwave background (CMB) radiation originated as the Universe cooled after the Big Bang and matter and radiation became decoupled. Current cosmological models would be invalidated if the CMB was in fact generated locally. One test for a cosmic origin would be the confirmation of a Doppler effect. As the Earth moves towards and away from distant radio galaxies the number count of galaxies should show the same directionality as the CMB and at the predicted amplitude. This test has now been carried out using data from the Very Large Array sky survey of distant radio sources, and a cosmic origin is confirmed.

A velocity dipole in the distribution of radio galaxies
CHRIS BLAKE & JASPER WALL
Nature 416, 150–152 (14 March 2002)
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Cosmology: Maintaining the standard
GEORGE F. R. ELLIS
Cosmologists continue to probe for weaknesses in the 'standard model' for explaining the structure of the Universe. Happily, the model passes the latest observational test of its consistency.
Nature 416, 132–133 (14 March 2002)
| Full Text | PDF (126 K) |