Iron Imperative
Building has lighter-than-air, gas-filled skin and comprises of a 
string of vertical capsules, tethered to Earth.
Calliarthon Thalli is made up of porous material and its structure has articulations which keep the macro-alga upright and flexible.

Problem Statement
Two structural challenges increase dramatically with increase in the height of tall building.
1. Distribution of load to the ground. Building needs to taper down as it goes up in order to remain planted firmly.
2. Flexibility. The building should be flexible enough to withstand high magnitude of lateral forces which cause building sway.
Design concepts which were once considered theoretical like F. L. Wright’s Mile-High Skyscraper, are being materialized now as our new conceptual limits go beyond Earth atmosphere.  The edge where atmosphere meets space is only a man-made construct. So how can we design an ultimate tall building?
Nature Review
A set of forces similar to those acting on high-rise, are found in deep sea. Lateral movement of currents exert tremendous pressure on a coralline macro-alga (Calliarthon Thalli). Its structure has following two important qualities:
1. It has calcified fronds which provide a constant buoyancy. This internally embedded, permanent upward force keeps the fronds vertical and upward.
2. Its only flexible parts are the joints between its segments. These joints (genicula) provide all the tensile strength it needs to sustain lateral forces.
Technology Review
After studying a number of case studies and comparing construction technology of the macro-alga with high-rise typology, it becomes evident that our structural requisites for tall building (tapering and flexibility) become obsolete. A new design paradigm is required.

Row1Column1: A Closeup of Coralline Macro-algae
Row1Column2: Viscoelastic Joints of Coralline Macro-Algae
Row1Column3: Size, Strength and Allometry of Joints of Coralline Macro-algae
Row1Column4: Bending of Coralline Macro-algae
Row2Column1: Tube Structures
Row2Column2: Comparison of Tallest Buildings of the World
Row2Column3: Bigelow Expandable Activity Module (BEAM)
Row2Column4: A Conceptual Image of the NASA Transhab
Row3Column1: Inflatable Modular Space Habitat
Row3Column2: Concept of a Spacescraper Hung from an asteroid
Row3Column3: Space Elevator
Row3Column4: Analysis of (Conceptual) 20-Mile Long Spacescraper
Row4Column1: Inflatable Kevlar Tube Concept
Row4Column2: Helium Balloon Tower Concept
Row4Column3: An Example of Biotensegrity
Row4Column4: Filamentosa- An Ultra-Lightweight Skyscraper

Nature Gadget
The new structural system follows two principles:
A. It is designed for an upward force (1) instead of downward gravity. Helium structures (14) and space-grade inflatable architecture (16) give valuable insight on that account.
B. Structural system of the proposed spacescraper has a discrete mode of flexibility (7). That is, its compression (29,32) and tension-based (38-41) structural components are separate from each other, unlike in our conventional system of construction where these two elements intertwine and reinforce each other. Lateral movements are tolerated only at the intermediary layer (9) between two habitat segments.

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