Zhongshan (中山) is a city in the south of the Pearl River[?] Delta in Guangdongprovince in China. The city was originally a county named in honour of Dr. Sun Zhongshan. Dr. Sun was born Sun Yat-sen in Cuiheng Village (翠亨村) of this place.
... emitting diodes powered by a little generator embedded in the gyroscope.
The physics of this device looks confusing at first sight, but is surprisingly simple. It can ...