When the Three Gorges Dam was built, 39 trillion kilograms of water from the Yangtze River built up behind it to 175 meters above sea level. This altered the Earth’s moment of inertia changed ever so slightly, causing the rotation to move more slowly. This is the same principle behind why figure skaters tuck in their arms to spin faster.
NASA has calculated that the dam only slows the rotation by 0.06 microseconds, which is six hundredths of a millionth of a second. Our planet’s rotation speed actually fluctuates fairly often, as it can be influenced by earthquakes, the moon, and the climate change-induced movement of the North Pole.
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Screws made from 100% silk have been used to repair broken bones.
This research that could transform surgery, with metal fixtures being potentially replaced with those made from the natural fibre, which eventually dissolves in the body. Once used to make sutures, silk has recently been used in modern medical implants.
Lead researcher, Dr David Kaplan of Tufts University, MA, USA, commented – ‘we envision a whole set of orthopaedic devices for repair based on this – from plates and screws to almost any kind of device you can think of where you don’t want hardware left in the body’.
The screws were made using medical-graded silk by a group of researchers at the University. The silk material was cut in to the desired size on a machine and implanted in to the hind limbs of rats. The silk began to dissolve by the end of the study.
The silk screws have not interfered with X-rays, haven’t set off alarms or caused sensitivity to cold. So far the technique has only been tested on rodents.
Image credit: norgan_picsoflife