..... Stumper Index
How Good Is Your Science KQ?
Bicycling home from school in the early darkness of long ago winter afternoons, I would light my way, and alert others to my presence, with white front and red rear lights mounted on the bike frame. My steady pedaling not only turned the wheels to propel the bike, but also caused the rear wheel to rub against the knurled knob of a 'dynamo.' The dynamo generated sufficient electricity to power the lights and at the time I took this technological phenomenon for granted. I know now that the knurled knob rotated very fast when it rubbed against the wheel, and in the dynamo it caused a magnet to spin inside a coil of copper wire. This action created (as discovered by Faraday in 1831) an electric current which heated up the light bulbs' filaments causing them to glow brightly.
Since those days the world has become more dependent upon electrical power and scientist-inventors have devised many marvelous techniques and technologies for generating electricity. A basic requirement is to keep the system moving using either a natural power source or a fuel. Nowadays we are particularly concerned that this power source should be renewable and, like the energy from my legs as I pedaled my bike, replaced by natural processes. So, the current challenge is to devise electricity generating systems maintained using such unlimited sources of power as wind, solar energy, wave or tidal movement, 'biomass', hydro and geothermal energies.
In Britain, a new cutting-edge method of energy generation showing great promise uses a natural source of energy to bounce a device called the "Snapper." It uses magnets and wire coils like my bicycle dynamo but in a very different context and with much more effect. The Snapper is not yet in commercial production, but a different system developed in Scotland to use the same natural source is being implemented in Portugal. It consists of several 150-metre long articulated tubes called "Pelamis energy converters" and is to be connected to the local grid this summer.Stumper Questions: 1. 1. What natural source of power is used by the Snapper and Pelamis energy converters?
Clue: the "Pelamis" is named after a carnivorous snake that chews poison into the fish it catches.
2. What fuel was used in the first electrical power plants of the late 1800's?
Send feedback to
Explorit Science Center, P.O. Box 1288, Davis, CA 95617, USA
Phone: (530)756-0191 Fax: (530)756-1227