Monday, May 17, 2010

Whimsical Science

Mel Acheson: Whimsical Science.

The Sculptor Wall itself is an artifact of assuming that a galaxy’s redshift (z) is a measure of its distance. With that assumption, the Wall stretches across the universe from near to far. The raw data, of course, only indicates that it stretches from low-z to high-z. With Arp’s assumption that high-z objects are ejected from low-z ones and evolve toward low-z themselves, the Wall is a family grouping of relatively nearby galaxies.

The newly discovered material between the galaxies has been named WHIM (Warm Hot Intergalactic Medium). There’s an already existing name for it—plasma—but the invention of a new name helps to obscure the electrical implications. The artist’s license also permits the WHIM to be drawn as a fog bank rather than the more likely filamentary cell.

Electrically discharging galaxies embedded in cells of plasma is a phenomenon that can be studied (on a smaller scale) in plasma labs on Earth. Such a study would take astronomy a giant step toward becoming a science and away from whimsical artistry.

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