Cosmic Megastructures
As far as humankind has dreamt of the stars, we have never actually considered it achievable to live amongst what lies past our own stratosphere. However, there are no bounds to the imagination, allowing us to infinitely invent new possibilities for ourselves in the form of theoretical megastructures. Megastructures, in terms of astrology, exist primarily in theory. They interact with the bounds of space in unimaginable feats incomprehensible to most astrophysicists of the past. Original ideas of cosmic megastructures scale anywhere from scraping the edges of our orbital boundaries to interstellar satellites that dwarf the size of even some stars. Exploring the world of these spatial behemoths is only the beginning of our journey into truly living amongst the stars.
Space Elevator
At first glance, megastructures seem daunting, but some can actually soon be achieved with today’s technology. Consider the concept of the space elevator. Conceived as an idea first in 1895, it was intended to be a tether to a structure in low orbit that could be accessed from ground level on Earth. With the intent of efficient transportation into space, the space elevator resembled almost that of a modern day skyscraper which extended beyond the atmosphere. In comparison the world's current tallest artificial structure only reaches about 830 meters in height, whilst the space elevator is conceptualized to be 42,000,000 (42,000 Km) meters. Being over 50,600 times taller than that of what humankind has achieved so far, the space elevator also must be made up of material which would need to withstand greater and more extreme conditions in comparison to what resides in our troposphere (10,000 m or 10 Km in height). Considering that this structure extends almost quadruple the length of the highest recorded part of our atmosphere, (exosphere at 10,000 Km) it has to be made of material strong enough to withstand the apex of speed given from Earth’s rotation for its height. It also must be able to withstand extreme temperatures. With Earth rotating at over 460 meters per second and with merely the exosphere reaching extreme temperatures of 0 to 1700 degrees celsius, it’s difficult to imagine that this is the most achievable megastructure at this given time in human history. If humans were to travel through these conditions we would most likely feel greater G-forces (forces of gravity) with the amount of increased height. To put into perspective, fighter pilots face around 9 Gs of force at a height of 15,500 meters, and a speed of 7,200 kilometers per hour. Given that the force of Gs will increase proportionally with height, humans traveling through the space elevator will be traveling at a height of 400,000 meters with a speed of 1656 Kilometers per hour before reaching the edge of Earth’s gravitational pull. With extreme conditions that are enough to induce frostbite or or boil the water within one’s body. Much to say there is a lot of thought and considerable care that would have to go into making these structures plausible. Using metals like tungsten which can withstand the extreme heat of space and proper protective equipment and training, humans will actually most likely be able to use megastructures like the space elevator sooner than we may think. Considering that the apex of humankind’s endurance is now, most likely humans will soon be able to use this as a viable means of space transportation.
Dyson Sphere
In our universe today, the planets revolve around a massive star, known to many as the sun. Every planet relies on it as a source of energy and life. However, the rays of energy that are widely dispersed throughout the solar system, harnessing the energy at its full potential is all but possible. Even the small amount of energy that is directed towards Earth is greatly reduced by our atmosphere, and as civilizations begin to grow, energy requirements will naturally grow alongside it. This means as time passes, one must think of better methods to be able to capture and use more energy to help sustain the ever increasing population on Earth.
Introduce the Dyson Sphere, a theoretical design that completely encompasses a star and captures a major portion of its energy output. This megastructure has the capability to harness the entirety of the energy of a star much more efficiently as the rays of energy can be directly captured and used in the encompassing sphere. The idea came to fruition from Freeman J. Dyson in 1960 where Dyson imagined the system could be used not for humans but for unknown advanced civilizations to discover and utilize thereafter. Sprouting from this, many scientists in recent years have searched the galaxy in hopes of finding a star with a Dyson Sphere, possibly leading ourselves to hidden advanced civilizations as opposed to them finding us. Although called a sphere, Dyson envisioned the megastructure to start out as a ring of objects independently orbiting a star. From there, more rings could be put out into orbit, increasing the gain of energy from the star until it is fully encapsulated by these rings, forming the originally envisioned Dyson Sphere. With the increased capability to secure much more energy, countless possibilities are opened up. One such utilization is in the Matrioshka Brain, a computer system initially theorized by Robert J Bradbury. The Matrioshka Brain would use the power gained through multiple Dyson Spheres, built from Mercury all the way to Neptune and emitting outwards the excess energy gained to outer Spheres, to run the greatest computer in the entire Universe. Its name comes from the Matryoshka doll, a series of smaller dolls nested within larger dolls that originates from Russia, seen in how the Dyson Spheres would be nested within each other similarly to these dolls. The Matrioshka Brain is the most powerful computer, it could be used to upload a human's consciousness to be run inside of a virtual reality or even create an entire alternate reality/universe within the system.
O'Neill Cylinder
What if humans were able to live in space? One of the biggest questions on our Earth, American Gerard K. O’Neill tackled this great question with his 1976 novel, The High Frontier: Human Colonies in Space. In the novel, O’Neill theorized the plans the United States could come up with after their successful Apollo Program which brought humanity to the moon for the first time. The main plan of this novel was how humanity could discover a method to allow living in space, and O’Neill believed this plan to look like a cylinder: more specifically, his O’Neill Cylinder.
Thanks to 3D-printing technology, as well as the natural materials from the moon and nearby asteroids, the resources needed for the cylinder are possible to acquire. The megastructure, in its entirety, is made up of two cylinders with diameters of 4 miles, lengths of 200 miles, and areas of 500 square miles. The O’Neill Cylinder also has the capabilities of having even larger dimensions with diameters of 15 miles, lengths of 75 miles, and areas of 7,000 square miles (that’s half the size of Switzerland!). To stop the megastructure from drifting away into space, the 2 cylinders will be connected and forced to rotate in the opposite direction of one another. The rotation of it would also provide an earth-like gravity inside the habitat. Additionally, the habitat is split up into 6 different strips, half for land/living and the other half that is used for windows. Inside these windows, mirrors will be able to move across them and create a day and night cycle.
However, one of the biggest problems in making the O’Neill Cylinders is making it manageable to create and safe for organic habitation. One such problem is dealing with waste. As space within the cylinder is quite limited and there is no other place to throw away trash other than inside the habitat, trash could build up very quickly. Thus, habitants should be sure to recycle properly to avoid removing this trash in costly manners. Also, when the cylinder is being made in a specific place, the designers of the structure must keep track of nearby asteroids floating or shooting through space. Similar to the asteroid that wiped out the dinosaurs about 65 million years ago, if an asteroid were to hit the habitat, immeasurable damage could be dealt, putting at risk hundreds of thousands to even millions of lives in grave danger.
Sources:
Byrd, Deborah. “What Is a Dyson Sphere?: Human World.” EarthSky, 30 Aug. 2018, earthsky.org/space/what-is-a-dyson-sphere/.
Hadhazy, Adam. “How We Could Actually Build a Space Colony.” Popular Mechanics, Popular Mechanics, 14 Nov. 2017, www.popularmechanics.com/space/deep-space/a11351/how-we-could-actually-build-a-space-colony-17268252/.
Tirion, Wil. “The History of Uranography, or Celestial Cartography.” Popular Astronomy, 8 July 2018, popularastronomy.technicacuriosa.com/2017/03/06/the-history-of-uranography-or-celestial-cartography/.
E=mc2
Minutephysics, director. E=mc² Is Incomplete. YouTube, YouTube, 28 Oct. 2012, www.youtube.com/watch?v=NnMIhxWRGNw.
Minutephysics, director. Einstein's Proof of E=mc². YouTube, YouTube, 29 Mar. 2012, www.youtube.com/watch?v=hW7DW9NIO9M.