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Science Frontiers ONLINE No. 112: Jul-Aug 1997 |
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A TWISTED COSMOS?
An astronomer really risks his or her reputation if he or she suggests that the universe has a preferred direction. A core belief in cosmology maintains that no point or direction in the cosmos is in any way "special."
So, B. Nodland and J.P. Ralston stirred up a hornets' nest this past spring when they published a paper that began with this paragraph:
"Polarized electromagnetic radiation propagating across the Universe has its plane of polarization rotated by the Faraday effect. We report findings of an additional rotation, remaining after Faraday rotation is extracted, which may represent evidence for cosmological anisotropy on a vast scale." (Ref. 1)
Most inflammatory was their claim that the plane of polarization of the radio waves rotated more along a particular direction [axis?]; specifically, along a line connecting the constellations Aquila and Sextans. (Ref. 2)
Only a few days after the NodlandRalston paper was published, it was blasted in Science. The major complaint was that their data were old and incomplete, since they derived mainly from observations made prior to 1980. (Ref. 3)
Indeed, a similar study using more recent measurements but fewer radiation sources seems to refute the NodlandRalston claim of a preferred direction in the cosmos. (Ref. 4)
Nodland and Ralston disagree with the charges and the implications of the other study. It will be a while before this is all sorted out. The paradigm that Nodland and Ralston are challenging is deeply entrenched and of great philosophical import. (There's nothing "special" in the cosmos, especially humans!)
References
Ref. 1. Nodland, Borge, and Ralston, John P.; "Indication of Anisotropy in Electromagnetic Propagation over Cosmological Distances," Physical Review Letters, 78:3043, 1997. Cr. K. Partain.
Ref. 2. Cowen, R.; "Does the Cosmos Have a Direction?" Science News, 151:252, 1997.
Ref. 3. Glanz, James; "Doubts Greet Claim of Cosmic Axis," Science, 276: 530, 1997.
Ref. 4. Anonymous; "Do the Twist," New Scientist, p. 13, April 26, 1997.