Innholdsfortegnelse for July/August 2017 i Ask Science and Arts Magazine for Kids and Children

At first glance, bikes and cities might seem like a bad mix. There’s so much traffic! Everyone is in such a hurry! Not to mention all those trucks and buses. But for many city people, getting around by bike makes a lot of sense. Bikes are small, cheap, and easy to park. Biking is fun and good exercise. In cities around the world, more and more people are riding bikes—and cities are finding ways to help them share the road. Ways to Go One of the simplest ways cities can help bikers is to make bike lanes. This is a traffic lane just for cyclists. Just like lanes for cars, bike lanes are marked with painted lines. Symbols and colors say, “No cars allowed!” Some cities put barriers between bike…

A bike with square wheels sounds like a crazy idea. On a flat road, you’d thump up and down. But if the road has just the right shape, you can get a smooth ride. To ride smoothly, you want to keep the same distance between the rider and the road—no up-and-down bumps. On a flat road, a round wheel does just that. But what about on a bumpy road? If the bumps exactly match the shape of the wheel—you can still get an even ride. A square wheel can roll smoothly if it travels over bumps with a special curved shape, called a catenary. This is the shape a chain or rope takes when it hangs loose. Turn that curve upside down, and you have the road for a square-wheeled…

Is there anything more beautiful than a bike? How about a bike with streamers, sparkles, flowers, flags, or fangs? For this month’s contest, come up with some bike decorations that will make your bike the star of the parade. Send us a photo of your decked-out bike, or draw us your amazing plans (especially if they are just too amazing for reality), and we’ll post a parade of the most wonderful wheels in an upcoming issue of Ask. Contest Rules: 1. Your contest entry must be your very own work. Ideas and words should not be copied. 2. Be sure to include your name, age, and address on your entry. 3. Only one entry per person, please. 4. If you want your work returned, enclose a self-addressed, stamped envelope. 5.…

1818 How did bikes get started? A German forest ranger named Karl von Drais wanted a faster way to roam around the woods. His contraption, called a draisienne (he named it after himself, of course), didn’t have pedals. It was more like a sit-on scooter. Special schools sprang up to teach people how to ride these “hobbyhorses,” but only the rich could afford them. And the dirt roads, meant for real horses, were too rough for comfortable riding. 1821 The hobbyhorse needed more oomph, but people didn’t believe you could balance on two wheels without your feet touching the ground. One solution was a hobbyhorse with a handlebar you pulled to make the front wheel spin faster. These awkward machines were not a hit with anyone but mail carriers, who…

Gears The toothed circle around the rear hub is the gear ring. Gears catch the chain to make your bike move. If your bike has several gear rings on the back and a shifter on the handlebars, it means your bike has different speeds. What speed is best? Low gears (low numbers, bigger gear rings) are easier to pedal, but you need to pedal faster. They’re good for starting out and climbing hills. Higher gears (high numbers, small gear rings) move the back wheel more each time you pedal. They are good for going fast once you’re already moving. Rear hub Why don’t you go backward when you pedal backward? Inside the gear rings on the rear wheel is a clever part called a ratchet. Your bike chain moves the…

In the 1890s, a new bicycle was taking the world by storm. This bike had two wheels the same size, gears, and air-filled tires. “Safety bikes” were the first to look like the bikes we ride today. They were speedy, comfortable, and fun. Everyone wanted one. Even the army! Steeds of Steel Why would the army be interested in bikes? Back in the 1890s, there were no cars. To get somewhere, you walked, took a train, or rode a horse. But bikes were cheaper than horses. You didn’t have to feed them, brush them, or keep them warm at night. A bike never got sick, bit you, or ran away. You could hide a bike easily, and they were hard to track. Some armies in Europe were already using bicycles…

Hazel L., age 10, Oregon Pull string, spoon goes up, which flings a rock, that tips the scale, swinging stone to hit gong, which scares a cat, who climbs plant, tipping it over, to flip on the light switch. Amanda M., age 8, California Mouse takes cheese. Cat attacks mouse. Owner puts cat in litter, tipping scale, sending ball up. Batter hits ball. Ball breaks window and triggers rocket, which hits bird, causing flock to squawk, waking up neighbor. Toast by Siri C., age 10, New York Push the button to turn peanuts. This attracts skateboarding elephant. Skateboard pulls match box, lighting match attached to mouse. Mouse runs up string, lighting candle under bread rotating on a stick, toasting the bread! Santhana S., age 8, New York A. Puppy grabs…