Why do structures stand

It is no wonder that modern efforts of preservation such as the Global Seed Vault, nuclear waste repositories and archives are all built beneath the surface. This article is part of a BBC Future series about the long view of humanity , which aims to stand back from the daily news cycle and widen the lens of our current place in time.

There is, however, one serious drawback to trying to preserve things underground — water. I have visited nuclear waste sites in the US and Europe, the Global Seed Vault, and the Mormon Genealogical Archive — and in every case they are fighting a losing battle to keep water out.

Over centuries and millennia, water will always find a way in. The only successful mitigations of water I have seen are when it is redirected rather than blocked. The ancient rice paddies of Asia are a testament to the effectiveness of carefully directing water over thousands of years. Building the 10, Year Clock underground is important not only for preservation, but for timekeeping as well.

Temperature change causes metals to expand and contract, requiring clever and imperfect schemes to keep devices like pendulums at the same length, and therefore keep regular time. The less temperature change a mechanical clock experiences, , the more accurate it will be. However, after witnessing the struggles with water at nearly every underground site I have visited, we had to think very carefully about how we tackle it. Our underground site is built at the top of a mountain in order to minimise the area of drainage that can collect water, but we still assume that water will get in.

To address this eventuality, we angled every underground surface away from the clock and made sure that water would not be trapped anywhere and could escape at the bottom of the site. When we imagine materials that may last for thousands of years, most people think of stone or precious metals like gold — because they don't oxidise readily. But even bodies can be preserved for millennia if stored in the right chemical environment, as the mummies of Egypt demonstrate. Not long ago a perfectly preserved leather shoe was found in Armenia dating from over 5, years ago.

The longevity of a material is often less about the object itself, but much more about the environment it is in. In the case of the leather shoe, it was buried in a cave and sealed in by sheep dung, thereby creating the perfect anaerobic, stable temperature environment. A 5,year moccasin said to be the world's oldest leather shoe Credit: Getty Images. But to build objects and machines that people interact with over thousands of years, we have limited ability to control that environment.

People breathe the same oxygen that degrades materials, and they bring in dust on their clothes, and oil on their skin. To build a working machine that people can visit for 10, years, the materials themselves must be long-lasting. Probably the best example of this are the bearings that we are using for the clock. All the rotating parts in the clock require some sort of bearing surface in order to smoothly roll with minimal friction.

However, there are several problems with traditional bearings, which are usually made of a row of hard steel balls between specially-ground tracks called races. Steel or even stainless steel bearings will simply weld together if left for long periods of time, and they also undergo another process called galvanic corrosion if they are separating two metals with different electrical potential. If you have ever seen the way a penny corrodes when left on another metal surface, this is galvanic corrosion.

The Great Pyramid was constructed in 2, BC using 2. If you ever get to write a detailed essay about this ancient wonder, make sure that you take help from Writing Ocean to score big on your paper. Image Credits. A gigantic aqueduct bridge that towers over people at a maximum height of While the actual length of the construct is more than 15 kilometers long, it begins to show its splendor when it enters the inner parts of the city near Azoguejo Plaza.

The aqueduct was primarily used for supplying water to the different parts of the city and constitutes both double and single arches that are supported with magnificent pillars. On a particular evening, the sun and the structure create a dance of shadows and light that are bound take your breath away.

It has over arches in total. Popular belief and recent studies show that it was constructed under the authority of Emperor Domitian in AD 81 and was completed seventeen years later in AD Another megalithic grave mound making our list is the Tumulus of St. Michel located in Brittany, France and is also considerably the largest of its kind within Europe.

The structure dates back to BC. It has been classified as a National Heritage Site since On the summit, you can find the chapel of St Michel standing on top. With a height of 10 meters, 50 meters of width, and a length of meters, there is a central chamber that was discovered in the 19th century. Public access to the site is strictly prohibited during times of historical research and other work-related events.

Centre des Monuments Nationaux, a French government body runs the site to preserve and restore its glory. A well-preserved facility for bathing use during ancient Roman times, this large imperial bath complex is located in the city of Bath, Somerset, England. The bathing complex dates back to 60 AD.

Due to its overwhelming presence, the Roman Baths contributed towards the development of many other urban settlements such as the Aquae Sulis.

It is reputedly considered as a major tourist attraction with more than 1. Over the past two decades, Dubai has become a virtual playground for architects who want to put their wildest dreams to the test. And perhaps no architect has explored the potential curve of an angle more than the late Zaha Hadid.

The firm that still bears her name, Zaha Hadid Architects, ZHA , will soon complete a building that will surely stand out in a city chock-full of head-turning architecture. The Opus, as the building is being called, will house a hotel, 12 restaurants, a rooftop bar, and 56, square feet of office space. The structure miraculously has a gaping hole in the middle of it, continuing the firm's lengthy tradition of designing objects that seem to perform a dance with the same trio: gravity, space, and voids.

One of those techniques was heating pieces of glass in temperatures as high as 1, degrees Fahrenheit before molding and quickly cooling them to increase their breaking strength.

Designing a skyscraper in New York is an experience unlike building in nearly any other city in the world. The combination of architectural history, coupled with the sheer volume of foot traffic walking past and flying above buildings in the Big Apple, makes their presence a vital part of the city's identity.

Slated to be completed in , Central Park Tower will be a shocking 1, feet tall, making it the second-tallest skyscraper in the United States and the Western Hemisphere behind One World Trade Center , the 15th-tallest building in the world, and the tallest residential building in the world.

Yet, unlike those aforementioned locations, no matter the height, building in New York brings on a whole new host of challenges. Understanding that and trying to design a building that will retain its own stature within that context has been a great opportunity. The location, on 57th Street between Columbus Circle and the Plaza District, means occupants will have uninhibited views of Central Park to the north.

In the past, travelers arrived to New York by car and air would be greeted by dominating structures such as the Statue of Liberty and the Empire State Building. Now we can add Central Park Tower to that exclusive list of buildings that stand out upon first experience. Paris is a city steeped in classical architecture. Led by the Chinese-born virtuoso Ma Yansong, the residential structure will be located within the verdant setting of Martin Luther King Park. Playing off this theme, Yansong's undulating design is meant to blur the line between building and nature.

The story building is tall enough so that at the top floors, homeowners will have clear views of the Eiffel Tower located to the southwest of the new residential building. Attached to MAD Architects' sleek structure will be an adjacent public housing project, as well as direct access to major metro and bus stops. While this is the Chinese firm's first residential project in Europe, we have a strong feeling it won't be the last.

So, why do we need skyscrapers? The simple answer: more room for more workers, or in the residential frame, more residents. In line with rising population density, and advancements in engineering, height limits around the world are being revisited and revised to maximise space for commercial and residential growth. In theory, skyscrapers maximize land use, increase urban density, and lead to lower energy use.

For instance, skyscrapers tend to be built further apart than low-rise buildings. In addition to being resistant to high winds, skyscrapers have a unique opportunity to take advantage of them as a sustainable energy source. The Bahrain World Trade Center, built by multinational engineering company Atkins, includes stylish-yet-practical wind turbines in its design.

A team of researchers at MIT has designed one of the strongest lightweight materials known, by compressing and fusing flakes of graphene, a two-dimensional form of carbon. The new material, a sponge-like configuration with a density of just 5 percent, can have a strength 10 times that of steel. Begin typing your search term above and press enter to search. Press ESC to cancel. Skip to content Home Social studies What factors make structures strong and stable? Social studies.

Ben Davis October 13, What factors make structures strong and stable?