Hollow threats? (Letters).Researcher Mark Goodwin's conclusion that a hollow base to an animal's horn greatly diminishes its strength, and hence its utility in defense or dueling The fighting of two persons, one against the other, at an appointed time and place, due to an earlier quarrel. If death results, the crime is murder. It differs from an affray in this, that the latter occurs on a sudden quarrel, while the former is always the result of design. , begs for an engineering analysis ("How did Triceratops Triceratops (trīsĕr`ətŏps) [Gr., = three-horn face], genus of ornithischian quadruped dinosaurs of the late Cretaceous period. grow its horns?" SN: 10/20/01, p. 248). In tension, compression, and torsion torsion, stress on a body when external forces tend to twist it about an axis. See strength of materials. about the axis of symmetry (Geom.) any line in a plane figure which divides the figure into two such parts that one part, when folded over along the axis, shall coincide with the other part. (Geom.) See under Axis. See also: Axis Symmetry , most of the strength of a cylindrical cyl·in·dri·cal adj. Of, relating to, or having the shape of a cylinder, especially of a circular cylinder. structure comes from the walls, not the interior. If the sides of the horn were subject to blows perpendicular to the horn's axis of symmetry, a hollow interior could signify relative weakness. It all depends on the particular assaults that the hollow section might have encountered. Certainly, the statistical frequency of damaged horns in Triceratops fossils must also be considered. Unless and until such analysis is done, the conclusions about Triceratops' use of their horns ought to remain pending. Mike Roberts Waikoloa, Hawaii Goodwin notes that the fossil record doesn't include evidence for duel-induced horn damage in Triceratops. He agrees that a detailed engineering analysis of the structures could help scientists understand what the animals' horns may have been used for. --S. Perkins |
|
||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion