[FOUNTAIN]Political shock wavesIn March 2000 in the Bahamas, 18 whales, which should be in the deep ocean, “landed” on shore. Among them, seven were unable to return to the ocean and died. In September last year, a similar thing happened in the Canary Islands. A group of 10 whales came ashore only to meet death. Why did they show such odd collective behavior? Scientists concluded that it was due to a sound navigation ranging (sonar) test offshore by the navy. The ultrasonic waves confused the whales and caused their collective aberration.
An ultrasonic wave is a sound with a frequency exceeding 20,000 Hertz, which is inaudible to human ears. Because its wavelength is short, an ultrasonic wave rebounds after hitting a barrier or produces a strong vibration. Since a French physicist used it to detect submarines at the end of World War I, ultrasonic technology has made great progress. For one thing, there is ultrasonic liposuction, a plastic surgery to remove abdominal fat. By applying ultrasonic rods to the fatty area and producing a strong vibration, fat cells are melted and then vacuumed out of the body. Ultrasonic waves are also used to remove chemicals from agricultural products or stains from pipes.
The most widespread use is by the military. A representative case is “active sonar,” which measures the existence, direction and distance of a target through the rebound of sound from the object. This equipment, attached to a ship or helicopter, can locate the position of an enemy’s submarines and weapons. A new type of equipment has recently been developed to detect underwater objects located 100 miles away. The problem is that the ultrasonic wave from this equipment is so strong that it may threaten the life of marine mammals. The waves can paralyze their hearing ability and cause abnormal blood circulation.
The U.S. Navy recently announced that it would limit the deployment of the new-type sonar in some regions, accepting the views of international environmentalists. But since Korea and other Asian countries are excluded from the restricted area, domestic environmental groups have begun to rebel.
Some day, ultrasonic weapons may be developed to aim not at whales but at human lives. But we may not need to worry too much. Isn’t Korean society already trained for such shock waves, produced every day by the shocking remarks of politicians?
by Lee Kyu-youn
The writer is a deputy city news editor of the JoongAng Ilbo.