What is geodesy?

Geodesy is the science of measuring and monitoring the size and shape of the Earth and the location of points on its surface. NOAA's National Geodetic Survey (NGS) in the US is responsible for the development and maintenance of a national geodetic data system that is used for navigation, communication systems, and mapping and charting.

Building roads and bridges, conducting land surveys, and making maps are some of the important activities that depend on a spatial reference system. For example, if you build a bridge, you need to know where to start on both sides of the river. If you do not, your bridge may not meet in the middle.

As positioning and navigation have become fundamental to the functions of society, geodesy has become increasingly important. Geodesy helps the transportation industry ensure safety and reliability, while reducing costs. Without geodesy, planes might land next to rather than at airports, and ships could crash onto land. Geodesy also helps shipping companies save time and money by shortening their ship and airplane routes and reducing fuel consumption. Geologists, oceanographers, meteorologists, and even paleontologists use geodesy to understand physical processes on, above, and within the Earth. Because geodesy makes extremely accurate measurements (to the centimeter level), scientists can use its results to determine exactly how much of the Earth's surface has changed over very short and very long periods of time.

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Skyscrapers

People started building skyscrapers not only because of new technological discoveries, but also because they are needed to effectively utilize expensive land and have office workers close to each other. The steel frame developed with several buildings in New York and Chicago advancing the technology, which allowed the steel frame to carry a building on its own. Suddenly, it was possible to live and work in colossal towers, hundreds of feet above the ground. People didn't construct many buildings made of bricks and mortar more than 10 stories tall until the late 1800s. The main technological advancement that made skyscrapers possible was the development of mass iron and steel production. Skyscrapers were then erected in the growing American metropolitan centers, most notably Chicago. Steel, which is even lighter and stronger than iron, made it possible to build even taller buildings. Many skyscrapers are built almost entirely of steel and glass, giving the occupants a spectacular view of their city.

The skyscraper race is far from over. There are more than 50 proposed buildings that would break the current record. According to some engineering experts, the real limitation is money, not technology.

Experts are divided about how high we can really go in the near future. Some say we could build a mile-high (5,280 ft, or 1,609 m) building with existing technology, while others say we would need to develop lighter, stronger materials, faster elevators and advanced sway dampers before these buildings were feasible. Speaking only hypothetically, most engineers will not impose an upper limit. Future technology advances could lead to sky-high cities, many experts say, housing a million people or more.

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