Category Kids Queries

Crowded airports, delays, jet lag – travel by plane can be a real pain. Imagine zipping to Hawaii for a surf session, then zapping to Italy for a slice of pizza, all in the time that it takes some planes to taxi for takeoff. Believe it or not, teleporting technology already exists, but it isn’t quite the crew-beaming transporter from Star Trek.

Using a process called quantum teleportation, scientists have figured out how to transfer the characteristics of one atom (the basic unit of matter) to a distant atom. The technology might eventually be used to transmit objects across the solar system. Teleporting people, however, is a trickier matter. The object being “teleported” is essentially destroyed at its point of origin and duplicated at its destination.

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Science fiction from the last century predicted we’d all be zipping through the sky in the family car by now, so why are we still stuck on the ground in highway traffic? Inventors have developed many flying car prototypes – such as the Moller Skycar and the Terrafugia Transition – over the decades, but these flying machines are still too tricky for the average driver to operate without a pilot’s license. They also often involve time-consuming transformations – wings that fold, propellers that tuck away, and the like – to get airborne, making them more like planes that can drive on the road than true flying cars. And then there’s the safety factor. Drivers in malfunctioning cars can simply pull over to the side of the road. Pilots in malfunctioning flying cars better have a parachute.

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Seeing a sailboat travel downwind makes sense even to landlubbers. The wind pushes the sails and the boat moves forward. But seeing a sailboat travel upwind is baffling – especially once you learn that the wind is “pulling” the boat. How is that possible? Simple physics!

It might not look like it, but a sailboat’s sails – especially modern triangular sails – are really just giant wings. Like an airplane wing, each sail is shaped so that air moves faster over one side than it does over the other. This creates lift on the surface of the sail facing the wind, which “pulls” the sail (and the boat to which it’s attached) forward at an angle against the wind even as the wind pushes the boat away in the in the downwind direction. This downwind slippage – known as leeway – is counteracted by a wing that you can’t see: a heavy fin called a keel that runs down the center of the boat underwater. The keel’s weight and shape counteract the force of the wind striking the sail above the water, keeping the boat from sliding downwind or being pushed over by the force of the wind (which is why you often see sailboats leaning over; the weight of the keel is keeping the boat from capsizing).

By controlling the angle of the sails, a captain can chart a course against the wind. Sailing directly into the wind is impossible, however, because the captain always needs to keep the wind at the correct angle to pull the sails forward. By sailing a series of zigzags – or “tacking” – across the wind, the captain can chart course to destinations that lie completely upwind.

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You can neither see it nor feel it, but the air around you is both crucial to your survival and actually weighs something (which is why scuba and oxygen tanks are lighter when they’re empty). Air is thickest and heaviest at sea level, where humans have evolved to live. Planes, on the other hand, fly faster and more smoothly at high altitudes, around 35,000 feet (11 km). Way up there, the air is thin and frigid. Fly this high without your own air supply and you’d pass out from lack of oxygen. So, using a complex mechanical system that takes air from the engines, airplane cabins are “pressurized” to maintain the air pressure of an altitude that the passengers and pilots find comfortable.

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It hits you like a speed bump out of thin air – literally. The plane lurches, your orange juice sloshes on the tray table, and the “Fasten Seat Belt” light illuminates overhead. Turbulence – aka chop or bad air – is as much a part of air travel as bagged pretzels and bad in-flight movies. It’s the reason pilots wear their seat belts at all times, although it’s not dangerous (planes are built to withstand even the most severe turbulence). Thunderstorms and pockets of warm air called updrafts create turbulence, but pilots can usually spot these areas of bad air and steer clear. What pilots can’t see are jet streams, fast-moving rivers of air that course through the atmosphere at altitudes that planes fly. Flying “upstream” in these rivers or skimming along the banks can make even the largest passenger planes rock. If it happens on your flight, don’t panic!

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To land the plane, the pilot lines it up with the runway many miles from the airport. Then he or she slowly reduces engine power, in turn reduces thrust and slows the plane down. With less air moving over the wings, the plane gradually loses lift and descends closer to the ground. Pilots carefully time the reduction in thrust and lift so that the plane touches down gently at the start of the runway (although in passenger planes, a computer-controlled autopilot typically handles the landing).

Picture Credit : Google