Science Briefs

LBT mirror

Scientists at the UA's Mirror Laboratory began the next phase in recasting the largest mirror in the world Ð the 8.4-meter Large Binocular Telescope Ð Thursday after heating it for the past five weeks in preparation for the recasting.

Scientists rotated a furnace, which contains the LBT mirror, in order to "flash heat" the surface to bring the temperature to 1,180 degrees Celsius (2,165 degrees Fahrenheit).

This rise in temperature was maintained for about an hour, causing the 2.1 tons of glass added in April to melt and thicken the faceplate of the mirror.

The mirror continued to rotate for a day and a half while it cooled to a temperature of about 650 degrees Celsius (1,193 degrees Fahrenheit).

The furnace will now continue to spin at 6.8 rotations per minute until the second week of September, when the mirror is expected to return to room temperature.

The LBT mirror, weighing 17 tons, is being recast after 10 percent of its total surface turned out to be too thin for use.

The next step will be to polish the mirror at the UA Mirror Lab.

The recasting process is not expected to delay the completion of the LBT or any other mirror castings already scheduled for the future.

The LBT mirror was originally cast in January in the rotating furnace, which holds 1,662 cores made of a material similar to the heat shield tiles on the space shuttle.

The hollow cells give the mirror its unique, lightweight "honeycomb" structure, designed by Roger Angel, UA regents professor of astronomy.

The molten glass flows around the cores while the furnace assembly spins at 6.8 rotations per minute, giving the mirror its parabolic shape, much like swirling water in a bottle.

Germany scholarship

A UA mechanical engineering senior is one of 60 Americans recently awarded a scholarship to study and work for one year in Germany.

John Struble is participating in the 1997-98 Congress-Bundestag Youth Exchange for Young Professional Agriculturalists.

During his year abroad, Struble will take a two-month intensive German language course, spend four months studying at a German professional or technical school and spend six months in an internship at a German business or organization.

The program begins in July and most students stay with a German host family for the duration of the year.

The 14-year-old exchange program began as part of President Reagan's Youth Exchange Initiative to honor the 300th anniversary of German immigration to the United States.

It is financially supported by the Bureau of Educational and Cultural Affairs of the U.S. Information Agency and German Bundestag.

The program's goal is to strengthen the ties between the younger generations of the United States and Germany and is achieved through a reciprocal exchange of 80 young German participants from technical, professional and agricultural backgrounds.