Explanations That Don’t Explain

The planetary nebula Fleming 1 seen with ESO’s Very Large Telescope Credit: ESO/H. Boffin

The planetary nebula Fleming 1 seen with ESO’s Very Large Telescope
Credit: ESO/H. Boffin

 

May 16, 2013

“Planetary nebulae are glowing shells of gas around white dwarfs,” according to the standard explanation. This is a better description of dogma than of the image.

“Astronomers have long debated how these symmetric jets could be created,” the press release continues. “Stars are spherical”; the jets not so much. In fact, not at all. But astronomy has a long history of not letting facts get in the way of good explanations.

The nebula is “likely to have…two white dwarfs at its centre…. As the stars aged, they expanded…, one…sucking material from its companion. This material [formed] an accretion disc.” Gravitational interaction with the binaries caused the disc to precess, or wobble, and the wobbling disc then shaped the jets into knotted twists. The observations “combined…with existing computer modeling to explain in detail for the first time how these bizarre shapes came about.”

Fascinating. But the question was “how these symmetric jets could be created.” How could a spherical star that “blows off its outer shells” create not just collimated jets but bipolar bubbles as well? Gravity doesn’t do that. This Question of the Century is passed over with a specious excuse for later morphological minutiae. The elephant trumpeting in the living room is answered with talk about dirt on the carpet.

“This study now confirms that precessing accretion discs within binary systems cause the stunningly symmetric patterns around planetary nebulae….” Rather, it confirms that modern astronomy is adept at distracting attention with computer games.

By this logic, an electricity-free meteorology could explain lightning by modeling the gravitational interaction of the discharge channel with wobbling clouds. That wouldn’t explain what caused lightning, but the concentration of effort on computer simulations would allow meteorologists to forget about the troubling larger question of how lightning—both terrestrial and galactic—is created.

Mel Acheson

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