고등영어 독해와 작문 능률 양현권 3과 본문 변형문제 GPS: Born from a Change in Perspective

GPS: Born from a Change in Perspective

For thousands of years, humans had difficulty ____________ to figure out where they were.

So, they devoted a great deal of time and effort to ____________ this problem.

They drew complicated maps, constructed great landmarks to keep ____________ on the right path, and even learned to navigate by looking up at the stars.

Nowadays, it is much easier to find out where you are and which way to go _______________ you have one of the world's greatest inventions at your fingertips.

As long as you have a Global Positioning System (GPS) receiver, you never have to _____________ about taking a wrong turn.

Your GPS receiver can tell you your exact location and give you directions to any place you need to go, no matter ___________ you are on the planet!

But how ________ this amazing technology invented?

The story begins in 1957, when the Soviet Union _____________ the world by announcing that it had launched Sputnik 1―the world's first man-made satellite―into orbit.

In particular, two researchers at Johns Hopkins University's Applied Physics Laboratory, William Guier and George Weiffenbach, _______________ by this achievement.

____________ with curiosity, they built a listening station the following year, and they began to closely monitor Sputnik 1's radio signal.

While listening to the persistent sound from the satellite, they noticed _____________________: its radio frequency repeatedly became higher and lower.

This was happening because the frequency of a radio signal rises and falls ____________ on whether the satellite is moving toward or away from the listener.

By keeping track of these changes, Guier and Weiffenbach were able to ______________ the satellite's precise location.

Although Guier and Weiffenbach ______________ this fascinating, tracking satellites was not exactly part of their duties.

Their director, Frank McClure, called them into his office, suspecting that they had been ____________ their time.

He asked them _____________ the thing they had been working on.

As Guier and Weiffenbach explained themselves, an idea ____________ through McClure's mind.

"If we can figure out where the satellite is", McClure said, "then can't we do the opposite and ________ the satellite to figure out where we are?"

This _____________ out to be a revolutionary insight.

Not only __________________ be measured to track a satellite from the ground, but by measuring the distance from the satellite to the receiver, the receiver's precise location could be determined as well.

This is the _______________ concept behind modern GPS.

Satellites ____________ to transmit signals, and any device with a GPS receiver can use these signals to calculate where you are, how high you are, and even how fast you are moving.

McClure was able to come up with this brilliant insight by taking the idea Guier and Weiffenbach had been researching ― finding __________________ from a known location ― and turning it on its head.

Likewise, we can produce extraordinary inventions and ideas by _______________ our perspective.

The real act of discovery, it _________ been said, consists not in seeking new lands, but in seeing things with new eyes!