Interactions and mergers of galaxies

When two galaxies approach each other, we can witness the effects of the tidal forces on a gigantic scale. Peculiar features like galactic bridges and galactic tails may form, or the two galaxies may even merge into each other and form a single system. Merger of two spiral galaxies leads to the formation of an elliptical galaxy. The interaction of gas during such galaxy encounters triggers star formation and activity of the nucleus. It is generally being accepted that galaxy interactions and mergers play a vital role in galactic evolution. S M Alladin is a retired Professor of Astronomy, Osmania University, Hyderabad. He specialized in dynamical astronomy and did research on dynamics of colliding and merging galaxies. He is also interested in interaction between religion and science. S N Hasan is an Assistant Professor of Astronomy, Osmania University, Hyderabad. His field of specialization is celestial mechanics. His research interests include the three body problem, stellar and galactic dynamics.     

Dynamics of the Sun-Earth-Moon system

The dynamics of the Sun-Earth-Moon system is discussed with special attention to the effects of Sun’s perturbations on the Moon’s orbit around the Earth. Important secular effects are the regression of the nodes, the advance of the perigee and the increase in the Moon’s mean longitude. We discuss the relationship of the first with the occurrence of eclipses, the second with the fluctuations in the moon’s synodic period, and the third with the slowing down of the Earth’s rotation due to tidal friction. The Sun-Earth-Moon system is compared with other triple celestial systems with regard to the intensity of tidal effects. S M Alladin is a retired professor of Astronomy, Osmania University, Hyderabad. He specialized in dynamical astronomy and did research on the dynamics of colliding and merging galaxies. He is interested in the interaction between religion and science. G M Ballabh is a retired professor of Astronomy, Osmania University, Hyderabad. His field of research includes dynamical astronomy and positional astronomy. At present he is the Chairman of the Standing Advisory Committee for the Positional Astronomy Centre, Kolkata     

INTERNATIONAL CO‐OPERATION IN HIGHER EDUCATION: THE GLOBALIZATION OF UNIVERSITIES

This article begins by posing some fundamental questions about global co‐operation and why co‐operation among nations is necessary. Co‐operation in higher education can foster global understanding and bridge cultural gaps. What is therefore called for is the globalization of universities. For positive international co‐operation in education to occur, the following initiatives are required: global perspectives in the curriculum, foreign students as learning resources, the globalization of universities and colleges, and the disengagement of educational policy from foreign policy.