A worker stands inside one of the Metro tunnels under construction in New Delhi, India, in preparation for the Commonwealth Games this October. To overcome the challenges of a tight three-and-a-half-year schedule and construction underneath a densely populated city, engineers used 14 tunnel-boring machines (TBMs) to dig the underground thoroughfare.
A video shot on the floor of a subway car in Kobe, Japan, shows paperclips standing on end whenever the train accelerates or decelerates. The electromagnetism that drives the train's motors leaks through the floor and excites the clips.
Medicine: Ultrasound waves are more than loud enough to rouse a sleeping fetus.
By Gunjan SinhaPosted 01.31.2002 at 3:54 pm 0 Comments
Nothing thrills expectant parents like an ultrasound vision of their developing fetus. But Mostafa Fatemi of Minnesota's Mayo Clinic wondered why such fetuses always seem to move and stretch while their picture is taken. He found out by placing a tiny hydrophone inside a woman's uterus during the procedure. The device registered up to nearly 100 decibels -- as loud as a subway train.