Ybytyara

— Hypothetical Essays on Ybymarian Technology —

    1. Initial concepts

    Ybytyara (contraction of Ybytyaparasá-Iuacauara, Ybytyiereuá-Iuakauara, or Yby-tyamu-Iacauara, which means something like “inverted mountain that is in the sky”) is a huge cone-shaped floating balloon with the largest surface facing upwards. It is decorated in such a way that, to anyone looking from below, it provides the impression that it is an upside-down mountain. It has a radius of 4000 feet and a height of 5200, and its surface may be between 10,000 and 12,000 feet above sea level.

    2. Ybytyara internal structure

    The structure is basically a flat surface on which a counterweight is ‘suspended’ by numerous cables. The counterweight at the bottom must be of sufficient mass so that the center of gravity of the structure is below the midline to provide a minimum of passive stability. Let’s do an initial calculation to get an idea of the total mass that Ybytyara could have.

    The interior of the balloon-island is filled with helium. The buoyancy of this gas is about 0.069 pounds per cubic foot (lb/ft³) at sea level. To find the total buoyancy, you need to know the balloon’s volume, which is roughly:

    V = 1/3 π.r².h ⇒ 1/3 × 3.14 × 4000² × 5200 = 87,082,666,666 ft³

    Using these data, the total thrust can be calculated:

    87,082,666,666 yd³ × 0.069 lb/ft³ = 6,008,704,000 lbm

    Let’s round to 6,000,000,000 lb. This is the total mass that Ybytyara can have to allow the balloon to float. But, for it to be minimally stable, most of it needs to be at the lower end to shift the center of gravity below the midline of the cone. Let’s then arbitrate 3,500,000,000 lb for the apex of the cone and 2,000,000,000 lb for the surface, leaving 500,000,000 lb for the rest of the structure, which are adequate values to obtain an idea of how Ybytyara could float.

    The vertex of the cone must be filled with heavy and abundant material. Perhaps granite could be used for this function. The average density of granite is 170 lb/ft³; then, a volume of approximately:

    3,500,000,000 lb ÷ 170 ≈ 20,500,000 ft³

    This will occupy a height of about 315 feet and a radius of 250 feet in a conical volume at the bottom of the structure:

    V = 1/3 π.r².h ⇒ 1/3 × 3.14 × 250² × 300 = 20,606,250 ft³

    The center of gravity will be about 2,000 feet above the apex of the cone and about 600 feet below the midline. This will provide a minimum of passive stability that must be complemented with additional active stabilization devices.

    One of the ways to improve stability is to divide the lower mass into a slightly larger area. Thus, from the midline, something can be hung that, when camouflaged, will look like a kind of stalactite. Look at the illustration on the next page:

    These ‘stalactites’ must be mobile to provide dynamic stability. This improves the overall stability of the structure by better counterbalancing with the surface, even when the counterweight mass remains unchanged.

    The surface of the balloon is about

    V = π.r² ⇒ 3.14 × 4000 × 4000 ≈ 50,240,000 ft²

    The surface mass should be concentrically uniform, preferably accumulating in the central area to improve stability. On average, in each ft², we can place:

    2,000,000,000 ÷ 50,240,000 ≈ 39.80 ≈ 40 lb of mass each ft².

    We assume that the density of the material covering the surface is 100 lb/ft³. So we can put around:

    40 lb ÷ 100 lb/ft³ ≈ 0.4 ft

    This produces coverage of just 0.4 ft, or 5 inches, on average. The structures will have to be hollow. If lighter materials are used, the covering may be thicker. In addition to the passive thrust of helium, active thrust can also be added, such as propellers or turbines, which would allow the mass volume of the surface to be increased.

    3. Dynamic stabilization

    The mobile “stalactites” that help stabilize the structure must be fixed just below the surface at a mobile displacement point, but the large dimensions involved make rigid structures unfeasible. Therefore, they must be hung with a fixation at at least three interconnected points. The assembly must move synchronously to allow the counterweight to change position smoothly. A possible mechanism for such an arrangement is illustrated below:

    4. Energy

    To make better use of the surface, it is advisable to opt for alternative energy sources to solar (photocollectors and photocells). The energy source for the systems could be a fusion reactor. Since hydrogen fusion produces helium, this process can help replace the helium inside the balloon.

    It is important to note that most of the energy produced will be used to stabilize the structure and maintain its integrity.

    5. Uiraitás

    The Uiraitás are large robotic birds that sit on the edge around Ybytyara. They serve as guardians to catch people and objects that may fall from the island and bring them back. Their name comes from the fact that they are camouflaged as stone birds when they are perched.

    6. Oxygen

    Ybytyara’s surface should be at a height where oxygen remains abundant enough for most people. To prevent unpleasant effects on unaccustomed visitors, oxygen release points can be installed along the surface that will help increase its concentration.