University's Physics Students Present Papers at Conference

Texas A&M International University physics students Raymundo Castillo Jr. and Maximo Salazar each presented papers in San Antonio recently at the 1998 Meeting of the Texas Section of The American Physical Society (APS).

Castillo's paper, "The Retrograde Rotation of the Planet Venus: A Numerical Model," attempted to explain why the rotation rate of Venus is extremely slow and opposite to its orbital motion. Castillo developed a numerical model to consider the effects of a major impact in two distinct cases with similar results, a large reduction in the angular velocity past zero with an eventual reversal of rotation, and a large net torque producing a flip of the rotation axis with an accompanying loss in angular velocity.

Castillo coauthored the paper with Dr. Juan Homero Hinojosa, associate professor of physics and chair of the department of natural science at A&M International, and Omar Ariel Gonzalez, instructor and lab technician in the department of natural science.

Castillo, a graduate of Martin High School, is majoring in math and minoring in physics. He will graduate in May 1999 and will pursue a graduate degree.

Salazar's paper, titled "A Computational Study of the Axial Tilt of the Planet Uranus," presented an investigation of the previously proposed theory that Uranus' unusual tilt was caused by a catastrophic impact from a planet-sized body. Using numerical modeling, he calculated two cases, a single-body impact and multiple-body impacts analogous to the recent impacts on Jupiter from the fragmented Comet Shoemaker-Levy 9. Salazar coauthored the paper with Dr. Hinojosa and Gonzalez.

Salazar, a graduate of Nixon High School, will graduate from A&M International in 1999 with a major in math and minor in physics. He plans to pursue a graduate degree in computational physics.

Abstracts of both papers are available on the World Wide Web through The American Physical Society Home Page, The abstracts will also be published in the June 1998 Transactions issue of the APS Bulletin.

The papers were based on research conducted by the students with the assistance of Hinojosa and Gonzalez. They are currently developing more complex computer models of their work.

For more information on the papers presented by Castillo and Salazar, please contact Dr. Hinojosa at 326-2595 or by email at

Additional information on Physics courses at A&M International may be obtained from the University's Home Page on the World Wide Web.

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