STRUGGLING WITH TYCHO'S SPHERES:
A RETRACTION AND A SUPPLEMENT
Commentary on Margolis on Cognitive-Illusion

Abstract

In my commentary, "Margolis's Delusion" (Topper, 1998), I argued that Tycho's system of planetary motion would not work as a system of nested physical spheres -- contrary to Margolis's assertion (Margolis, 1998a,b) that it would. I now think I may have been wrong; that I "deluded" myself. Hence the "retraction" of the subtitle. But this is more than a retraction. As I also show, Margolis's argument is still insufficient for explaining how the Tychonic model may work as a physical system. True, he displays how the system would work from a geometrical viewpoint. But a physical system entails certain constraints that must be taken into account for the planets and the sun to rotate as expected. This Margolis does not do. Hence I see my argument as perhaps a supplement to his original discovery.

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References

• Gingerich, O. (1998) The Tycho Illusion: Performing the Cutout Correctly. PSYCOLOQUY 9(52) ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1998.volume.9/psyc.98.9.52.cognitive-illusion.11.gingerich
• Margolis, H. (1998a) Tycho's Illusion: How It Lasted 400 Years, and What That Implies About Human Cognition. PSYCOLOQUY 9 (32) ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1998.volume.9/psyc.98.9.32.cognitive-illusion.1.margolis
• Margolis (1998b) A "Delusion" Defended. PSYCOLOQUY 9(45) ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1998.volume.9/psyc.98.45.cognitive-illusion.10.margolis
• Topper, D. (1998) Margolis's Delusion: a Critique of "tycho's Illusion". PSYCOLOQUY 9(42) ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1998.volume.9/psyc.98.9.42.cognitive-illusion.7.topper