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| Sunday, 17 October 2004 |
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Junior Observer |  |
| News Business Features Editorial
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Having fun with your bicycle Bicycles are a great way to get around. They are fun to ride, especially down hills. And, as you whiz along the road, you might also think of ways in which you could improve your bike - make it safer, more efficient, more comfortable, or more versatile. In fact, the two-wheeled machines make for some cool science projects. This year's Intel International Science and Engineering Fair (ISEF), held in Cleveland, USA featured three bicycle projects from three countries. Like many of the other experiments presented at ISEF, the bike projects showed that some of the most interesting scientific research often begins by taking a closer look at things you care about. Electricity bike Renato Angulo Chu had grand ambitions. The 12th-grader from Lima, Peru, wanted to address some of his country's economic troubles. "I see a problem in my country," Renato said. "If you go to the forests in Peru, in some places you cannot find electricity. If you go with my bicycle, you can turn on the lights." Renato, 16, spent three years designing his special Multibike. The contraption looks like a stationary (not moving) exercise bike. It has wires strung along the frame and a blender strapped to the back. Turning the pedals operates the blender. The same principle can be used to sharpen knives or sweep city streets.The Multibike can work either as a stationary bike or as a bicycle able to travel city streets and country roads. Ronak Tak and Anish Menon, two high school seniors from Jaipur, India, just wanted to find a more efficient way to get around. "In our country, 95 per cent of people use bicycles as their main means of transportation," said Anish, who rides his bike about four kilometres to school every day. Ronak added: "We wanted to do an experiment that was... beneficial for the common man". So, the 17-year-olds invented a chainless bicycle. A bicycle's chain creates problems, the students said. Without regular oiling, it can rust, reducing the bike's efficiency. When it is oiled, there is the nuisance of stains when hands or clothing touch the chain. Ronak and Anish started by removing the chain assembly from an ordinary bike. Then, they used rods (or shafts) to connect the pedals and the wheel. Their new axle-rod assembly resembled that found in trucks and buses. When the pedals rotate, the rod moves, which in turn rotates the bicycle's wheel. The result is much more efficient than a regular bike, Anish said. "It feels more comfortable. The stress on your legs is reduced. You can go a much longer distance using the same number of pedals". Ronak added: "It is compact. It is durable. You don't have to worry about getting grease on your pants". Ronak and Anish did laboratory tests to compare their chainless prototype with a regular bike. They applied equal amounts of force to both bikes in rotating the pedals one full time around. Using an instrument called a tachometer, they measured how fast the rear wheel spun. In test after test, the chainless bike outperformed the chain-equipped bike. Without the resistance of a chain, the back wheel rotated an average of 66 times in a 30-second trial. Racing wheels Winning is exactly what Mackenzie LaRoe likes to do. The 15-year-old triathlete from Eustis, Fla., is ranked seventh in the country in the Junior Elite division of her rigorous sport, which combines running, swimming, and cycling. The high school freshman is also an aspiring scientist who made it to ISEF with an experiment designed to identify the fastest wheels for her bike. She tested three types: a regular set of wheels; a set of racing wheels with fewer spokes; and a set of specialty wheels with a spokeless disk for a rear wheel and only three wide spokes in the front wheel. For each wheel set, Mackenzie did six trials. She used the same bicycle, wore the same clothes, and held the same body position. In each trial, she coasted down the same hill for about half a mile. The only variable was the wind. Results matched her expectations: The fastest wheels were the ones with the fewest spokes. Science for Kids
Toys from the past Lately, the Thames River in London, England has been looking a lot like a toy store. That is because people with metal detectors have been exploring the riverbank. They have found toys that date back to as early as the 1200s. And these toys are changing the way historians view medieval kids' lives. Before the discoveries, many historians thought that "there was not really such a thing as childhood in the Middle Ages," said Hazel Forsyth of the Museum of London. The Middle Ages, or medieval times, lasted in Europe from about the year 500 to the year 1500. Historians thought that parents did not pay much attention to their kids, because families were often very large. Plus, many kids died when they were young. At the time, everyone - kids and adults - had fairly poor healthcare and diets. Children who did survive were often sent to work at the age of six. Finding the medieval toys has caused some historians to change their minds. "Some medieval parents were very devoted to their children and gave them every luxury and pleasure they could afford," Forsyth said. Toys like the ones found in the Thames River are very rare. Most of these toys are made of pewter, a metal that decays very easily. But the stinky mud on the Thames riverbank has very little oxygen. This lack of oxygen prevents decay and helped preserve the toys. The medieval toys are touring Britain as part of an exhibition called 'Buried Treasure: Finding Our Past'. These treasures are not silver or gold. But according to Richard Hobbs of the British Museum, true treasures are those that shed light on the past. National Geographic Kids News |
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