Infrared light shows the deepest view of distant galaxies ever photographed. JWST Photo: NASA Public Domain
Overview
The question of extraterrestrial life on other worlds has baffled even the foremost scientists for millennia. With the Hubble telescope and now, the James Webb telescope floating in the cosmos a million miles from Earth, we are finding more and more life-sustaining planets on a frequent virtual basis.
This is different from space observatories, which can determine the existence of exoplanets by spectrum analysis, calculating their gravitational pull from their sun, or using the transit method—an observational process whereby a star changes in brightness when a planet is seen orbiting around it. The JWST’s advanced technology surpassed those methods by taking pictures of these exoplanets. This is the first time this has ever been done!
Exoplanets with Life? Maybe!
In 2013, a team of astronomers led by Dr. Duncan Wright from the University of New South Wales discovered the Wolf 1061 System using the HARPS spectrograph, part of the European Southern Observatory’s telescope in La Salla, Chile.
This solar system contains an inactive red dwarf star, orbited by possibly seven planets, including three super-Earths. These planets may be capable of supporting life as we know it, as they have a low enough mass to be potentially rocky with a solid surface.
The most interesting of the three planets is Wolf 1061c. At four times the size of the Earth, it is the closest habitable planet outside our solar system. It also sits in the Goldilocks Zone, close enough to its sun to contain liquid water and support life with its mild temperatures.
Artist’s impression of the planetary system around Wolf 1061. Photo: Wikipedia Public Domain
Based on these readings, scientists speculate that iron deposits, as well as silicates (elements that contain the minerals silicon and oxygen), may exist on the planet, which are very common.
Still, with the hope of Wolf 1061c sitting right next door, scientists are now hopeful that they can test the planet’s atmosphere in more detail once it passes across the face of its star, making the not-so-lone Wolf planet easier to study and determine if it has the potential to sustain life.
Even though rocky planets similar to our own and multi-planet systems are known to be abundant in our galaxy, most of the ones discovered are hundreds, if not thousands, of light years away. They are too far for us to reach using current technology.
Life is Out There
Photo: iStock
Here, we list a sampling of just a few exoplanets that could sustain life.
WASP-39 b
In 2022, the James Webb Telescope discovered a planet called WASP-39 b in the Virgo constellation. Known as ‘Bocaprins’, the planet orbits a star about 700 light-years from Earth. Scientists were surprised to see that this planet’s atomic structure resembles water and carbon – two of the essential ingredients of universal life.
Kepler-186f
But that’s not all. Planets such as Kepler-186fare among those astronomers say have a perfect chance of potential life relative to the hundreds of other planets discovered outside our solar system. Kepler-186f is the first exoplanet found to be in the habitable zone. Slightly larger than Earth, it is 490 light-years away, which is not too far.
Kepler-22b
Another close neighbor in the habitable zone is Kepler-22b. This body is about 150 light-years further away than Kepler-186 but has the promise of life just the same. It is about 15% closer to its sun than our Earth is to our sun, but its sun is smaller than ours, so there is a compensation effect where these two factors cancel each other out.
Subsequently, it still allows the planet to remain in the habitable zone. Kepler-22b has a surface temperature of 72℉. This sounds like a good vacation spot when we get to that point of space travel. For Star Trek fans, you can envision the beautiful planets the crew visited when on shore leave. Well, not so fast.
Kepler-22b might be more on its axis than Earth, meaning half of the planet may have all sunlight 24×7, and the other half may be in complete darkness for every (of that) planet’s six months. Further studies have revealed that the planet may be 90% ocean or more, compensating for seasonal issues.
Additionally, Kepler-22b has been calculated to have a much stronger gravitational pull than our planet, so walking on this planet may be as hard as walking briskly through the water at the same speed as walking on land.
But if there are creatures on this planet, intelligent or not, natural evolution may cause these beings to look much different from us. Due to the planet’s strong gravitational pull, the aliens may have budging feet full of muscles that would make the strongest man in the world look like a stick figure. They may have more than just two or four legs. Additionally, their internal organs would have to be naturally engineered to handle the physical stresses of the planet’s strong gravity, such as an overly large heart.
The Day the Earth May Stand Still
If Kepler-22b is life-sustaining, it would take astronauts 635 years to get there. Since that is out of the question for us, if intelligent life exists there or on other planets, their technology might provide a quicker way to visit us. But is that what we would want?
From tragedy to triumph, a tower soars 104 stories, 1,776 feet high, representing the year the Declaration of Independence was signed.
One World Trade Center (AKA The Freedom Tower) opened to businesses on November 3, 2014, and the three-story observatory, which opened on May 29, 2015, invites visitors to a spectacular view of the New York skyline.
Skidmore, Owings & Merrill, famous for designing some of the most notable modern tall buildings throughout the world, were the primary architects, under the supervision of designer David Childs. The firm, also known as SOM, was the architect of the Burj Khalifa and Chicago’s Willis Tower (formerly the Sears Tower).
The Preliminaries
Soon after the tragic destruction of the original World Trade Center (Twin Towers), the Lower Manhattan Development Corporation initiated proposals for the reconstruction of a new tower, as well as a plan to memorialize the victims of the September 11 attacks.
When the public rejected the first round of designs, a second, more open competition took place in December 2002, in which a blueprint by Daniel Libeskind was selected as the winner. This design went through many revisions, mainly because of disagreements with developer Larry Silverstein, who held the lease to the World Trade Center at that time.
Construction began on April 27, 2006, but not after continuous delays and ongoing bureaucracy, including disputes between the Port Authority of New York and New Jersey and the developer Tishman Realty & Construction. The Tishman construction firm was famous for its participation in building some of the tallest buildings in New York City, including the original World Trade Center complex and the John Hancock Center in Chicago. John Tishman died on February 6, 2016.
No doubt that security was a prominent concern in the design and construction of this tower, and terrorism was indeed a major consideration.
No one was more concerned than the NYPD, and after many debates and delays, the final proposal for the Freedom Tower 11-Year was approved and shown to the public on June 28, 2005, with a 187-foot base of concrete added.
Additionally, the building had installed stainless steel panels and blast-resistant glass. The Freedom Tower is designed to withstand earthquakes and has an elaborate security facility integrated within it.
In addition to 24×7 monitoring, there is a high-tech security system that includes video analysis in which computers would alert security personnel to abnormal situations automatically.
There are additional security apparatuses that have been installed, but their actual function has not been made public. What is known is that there are radiation detectors abound in lower Manhattan and the NYPD Hercules Team is ready at a moment’s notice.
Building the Skyscraper
On November 18, 2006, 400 cubic yards of concrete were poured onto the building’s foundation.
On December 17, 2006, a ceremony was held in Battery Park City, with the public invited to sign a 30-foot (9.1 m) steel beam. The beam was welded onto the building’s base on December 19, 2006. Construction was slow but continuous.
One World Trade Center (Freedom Tower) under construcion. (L-R) March 2010 and November 2011. Photo SMS
In 2012, workers installed the steel framework at the top of the tower to support the 408-foot spire. The spire was fabricated as 16 separate sections at a factory near Montreal, Quebec, and was transported by barge to New York City in mid-November of that year.
On May 10, 2013, the final component of the skyscraper’s spire was installed, making the building, including its spire, reach a total height of 1,776 feet, representing the date of the Declaration of Independence.
Negotiating the Wind Forces
Optimizing One World Trade Center for high winds was unique as the tower’s design included a geometrical shape that helps reduce exposure to wind loads.
Additionally, the core has reinforced concrete which provides the main support against resistance to the wind forces and other forces of nature.
The One World Trade Center observatory opened on May 29, 2015, and is currently the highest of the four observatories in the city at 1,268 feet.
There are three floors, including exhibits and a restaurant.
The most convenient way to purchase tickets would be to purchase them online.
Surrounding Area
World Trade Center North Tower Reflecting Pool. Photo: Wikimedia Public Domain
Visitors who come to the Freedom Tower should also visit the 911 Memorial, which is a tribute to the 3,000 people who were lost, including the first responders.
The memorial contains the footprints of the former Twin Towers. It has continuous running water over two one-acre pools, one for each of the towers, called “Reflecting Absence“, signifying the physical void left by those who were lost.
Skyscrapers are defined as being at least 330 feet (100 meters) high with supertalls classified as 984 feet (300 meters) and mega tall at 1,968 feet (600 meters) or higher.
From the Burj Khalifa in Dubai to the Shanghai Tower in China and the Empire State Building in New York, there is no doubt that these structures are a marvel of modern engineering and they stand as a testament to human ingenuity and perseverance. For architects and engineers, the challenge to design them is complex.
From the foundation to the roof, they are carefully planned and executed by scivi engineers, which might take years to complete before even one brick is laid down. Considerations towards building codes, structural stability, aesthetics, and of course economics are primary factors to be studied.
Exploring the making of skyscrapers is an exciting journey for anyone interested in how tall buildings are constructed. This article is a credit to the dedication to the architects and engineers who build them.
Enter the Forces of Nature
Burj Khalifa, Dubai, UAE – Tallest Building in the World. Photo by Wael Hneini on Unsplash
Wind loads (wind forces) that hit the buildings can cause them to sway. The higher the building is, the more wind it will be subject to.
Skyscrapers will sway and can easily move several feet in either direction.
To reinforce the structure to withstand these winds, there are several options that engineers will use.
Empire State Building – A Prime Example of Mitigating Wind Forces
Before we delve into the engineering specifics, let’s get familiar with the general idea of how buildings suppress wind forces and what better example to use than the famous Empire State Building?
Most tall buildings use multiple methods to mitigate strong winds, so let’s take a look at what engineers have done with this 1,472-foot-high iconic structure.
Streamlined shape: The building has a tapered shape that reduces wind resistance and helps to distribute wind forces evenly across the building. More commonly known as setbacks.
Wind bracing: The building has a series of steel braces that run diagonally between the exterior columns, which helps to provide additional support and stability against wind forces.
Corner columns: The building’s corner columns are larger and stronger than the interior columns, which helps to distribute wind forces more evenly throughout the building.
Tuned mass damper: The building has a large pendulum-like device called a tuned mass damper located on the 58th floor. The damper helps to counteract wind-induced building oscillations by moving in the opposite direction of the building’s sway, effectively damping out the oscillations.
Now let’s take a look at the process from start to finish.
Designing the Structure
3D rendering with construction specifications using CAD software. Photo: iStock
Economics always comes into play, so whatever the planned design is, it must be within the developer’s budget. Architects use computer-aided design (CAD) software to create 3D models of a building.
Usually created on networked desktop computers, CAD is used primarily for analyzing and optimizing a building’s design.
Of course with skyscrapers, there may be hundreds of CAD diagrams that would be needed. The software includes the building codes that they must follow.
It should go without saying that structural stability is of the utmost importance and the foundation is the first step in helping to buttress the building from the forces of nature to which these buildings may be subject.
Beginning with the foundation, engineers must determine if the soil below the building is strong enough to support the structure. A good example is in New York City where there is solid bedrock that makes it perfect for the construction of skyscrapers.
Steel and concrete are the most commonly used materials for foundations. Concrete is strong under compression, but not as strong under tension, and in its pure form, it is unsuitable to withstand the stresses of the wind forces and vibrations,
To compensate for this lack of tensile strength, workers pour a liquid concrete mixture into a wire mesh steel frame, called rebar or reinforcing bar, which strengthens the tension component of the concrete. Together, the product is known as reinforced concrete and forms a strong solid foundation to support any tall building.
Strong Internal Cores
One of the most popular methods for mitigating wind forces is the ability to build strong cores in the center of the building. Usually constructed around the elevators are solid steel and/or concrete trusses, braced by steel beams.
Most of the tall buildings of the 20th century use this method and it is still going strong into the 21st century, but usually, there are more obstacles to the wind added, especially if the building is of the super or mega tall variety.
Corner Softening
Taipei 101 in Taiwan China uses corner softening to dampen the winds
This is a style that softens the edges of tall buildings to reduce the vortices (strong winds) that these structures are subject to.
The 1,667-foot Taipei 101 in Taiwan uses this method which is very effective in controlling high winds.
But that’s not all Taipei 101 uses against wind vortices as we will see below.
In 1916, due to the shadow effect that tall buildings would leave on the sidewalks of New York, specifically, the 555-foot tall Equitable Building that was completed a year before, a new zoning law was enacted that would force developers to apply setbacks to all tall buildings.
New York City’s Empire State Building and Chrysler Building are excellent examples of setback design, as well as examples of the esthetic beauty of the art deco structures of that time.
Not only were setbacks desirable but, from an engineering point of view, they helped to diminish the harsh winds that tall buildings were subjected to.
Twisting
Shanghai Tower (right). Photo by qi xna on Unsplash
Spiraling skyscrapers are becoming more popular. Not just for their aesthetic appeal, but also because of their ability to reduce wind vortexes by up to 24%.
For the Shangai Tower, this resulted in a reduction of $58 million that the developers did not have to add to buttress the building.
Even more, aesthetically pleasing is the 1,417-foot tall Diamond Tower in Jeddah, Saudi Arabia. If that’s not intriguing enough, there is the 1,273-foot Dubai Tower that not only twists but also rotates 360 degrees. Built by Italian/Israeli architect David Fisher of Dynamic Architecture, the building gives spectators and residents alike an ever-changing view of the Dubai skyline.
The Willis Tower in Chicago is an excellent example of a building that employs the tubular method for addressing wind forces.
This super tall consists of a collection of nine tubes supporting each other, subsequently buttressing the building to fight off the winds more than if it was just one straight up-and-down structure.
Additionally, since they level off at different heights, the wind forces are inherently disrupted.
Cutout
A less used method but efficient nonetheless. The wind is allowed to pass through specific areas of a building. which reduces the wind loads on the building. Below is an animation demonstrating how the building negotiates the wind forces using cutouts on various floors.
When employing the cutout wind method, other methods of wind optimization are used along with it. New York’s 432 Park Ave makes use of this system. Additionally, the building uses the tuned mass damper system as described in the next section.
Tuned Mass Damper (TMD) (AKA harmonic absorber)
Tuned Mass Damper illustration for Taipei 101
Large, heavy dampers, usually near the top of the building compensate for building vibrations, such as high winds. Similar to a pendulum that sways back and forth, these dampers will move against the wind thereby stabilizing the building.
In technical terms, the mass damper is designed to work in harmony with the oscillation frequency of the building from the wind, thereby reducing the overall sway of the structure.
Combination of the Above
Many times, a multiple of these strategies are used to tackle the vortices, and in so doing, they can be very effective in taming the wind.
Constructing the Superstructure
The superstructure is the actual building, more specifically, it is the framework that connects the foundation to the roof, and this is where the CAD model is pertinent. The CAD model will help to identify the best location for the support columns, known as the centroid.
Engineers will select the most economical material and size of steel for these columns. They must also ensure that the columns are spaced far enough to resist both wind and potential seismic forces. Consideration will go into the type of concrete material and the size of the floor slabs, based on how much weight the slabs must support.
They must also consider the thickness of the slabs based on the amount of deflection allowed by the building codes, but we’ll leave the details of these considerations to another article that provides the specifics of these components.
Structural Engineering in a Nutshell
Watch this video which lays out the concepts of the engineering techniques required to build a tall building.
Summary
The engineering behind the making of skyscrapers is a complex and lengthy journey. When engineers design a supertall, they must consider many different aspects of the project. They must select materials that can withstand the forces of nature such as high winds, heavy precipitation, and even earthquakes.
They must also ensure that the building is structurally sound. In today’s skyscrapers, you can rest assured that the hard work and dedication that was put into each of these buildings by the architects, engineers, and construction workers make these buildings sound and secure.
