On the Moon with One-Sixth Gravity, is it possible to build buildings taller than on Earth?

Humanity's construction technology has constantly challenged height. To overcome the limited space on the Earth's surface, high-rise buildings have become an essential choice, and now the gaze is turning beyond Earth toward the Moon. Is it truly possible to build buildings much taller than on Earth on the Moon, where gravity is only one-sixth of Earth's? According to a 'Gwahageulboda' video, this is not simply a matter of gravity, but a complex issue involving atmospheric pressure and structural stability.

The Magic of Gravity and Physical Limits: The Trap of 6x Height

If approached purely from a physics standpoint, construction on the Moon seems much more advantageous than on Earth. In terms of 'load,' where a building withstands its own weight, it can be expected that one could theoretically build buildings six times taller than on Earth because gravity is reduced to one-sixth. However, the presenter in the video points out that one should not consider only the load. This is because the strength to resist when a building tilts sideways, namely the bending strength, is proportional to the cube root of gravity. Calculations show that if gravity becomes six times weaker, the height limit considering bending strength would be approximately 1.8 times.

Furthermore, there is the issue of structural efficiency in super-tall buildings. The video explains that typical high-rise buildings are most efficient when they are between 35 and 50 floors. If they go higher than that, the area occupied by elevator shafts increases exponentially, leading to significant waste of space. To solve this, methods such as transferring elevators at intermediate floors are sometimes used, but this adds to the complexity of the design. In fact, because super-tall buildings use a large amount of central area for elevators to pass through, designs are introduced to increase efficiency, such as having passengers transfer elevators above the floor where the hotel front desk is located.

The limits of construction materials are also a constraining factor for height. Currently, steel is the strongest material in construction, but reinforced concrete is widely used due to cost issues. Reinforced concrete has the advantage of preventing corrosion by having concrete encase the steel to block exposure to oxygen. The video cites the case of the world's tallest building, Burj Khalifa, mentioning that the fact this building was built on a reinforced concrete base rather than a steel structure (such as H-beams) is a very remarkable technical achievement. Burj Khalifa adopted a design that narrows as it goes up for structural stability, and considering the characteristics of desert areas, it used an ingenious method of using a 'Tension' structure—a core principle of tents—to hold it from the outside with cables. This is a point of differentiation from general construction methods that primarily use compressive force.

The Lunar Environment: No Wind, but a Massive Wall Called 'Pressure Difference'

The environment on the Moon is vastly different from Earth. The biggest difference is the lack of an atmosphere. The biggest factor threatening super-tall buildings on Earth is 'wind (wind force).' Withstanding the vibration and pressure caused by wind is a key challenge in high-rise construction. On the other hand, since there is no atmosphere on the Moon, there is almost no influence from wind. However, a more fatal problem awaits. It is the 'pressure difference.'

A lunar base must maintain an internal state of 1 atmosphere so that humans can breathe. However, the external environment of the Moon is close to 0 atmospheres. The video mentions this extreme pressure difference and emphasizes that if windows are made, they must be manufactured to be extremely sturdy. Even in high-rise buildings on Earth, phenomena occur where elevator doors do not close well or airlocks are needed due to pressure differences, because the force of the internal air trying to burst outward is much stronger on the Moon. In super-tall buildings on Earth, problems also occur where elevator doors do not close well due to being pushed by pressure, even though they should open with weak force due to the pressure difference. In short, construction on the Moon is highly likely to be a 'fight against pressure' rather than a 'fight against wind.'

Additionally, the lunar environment provides another variable compared to Earth. Because there is no atmosphere, the risk of meteorite impacts is very high, and earthquakes also exist. If a base is constructed on the Moon, maintaining the internal 1 atmosphere while enduring the external vacuum state will be the core challenge of construction.

The Future of Construction: Expansion of Space and Limits of Materials

The reason humanity continues to go higher is ultimately in the 'expansion of space.' In past agricultural societies, the land on the Earth's surface was the only space, but as the population grew, people began to utilize aerial space through high-rise buildings. The video analyzes that the end of this spatial expansion is ultimately leading to 'internet virtual space.' This means digital space is replacing the limits of physical space. Humans have progressed by finding new spaces whenever physical space becomes insufficient.

In terms of physical construction, the limits of materials are clear. Two key factors that determine height in physics are the 'pressure' the material can withstand and the 'density' of the material. The lighter a material is while also being able to withstand pressure well, the higher it can be stacked. However, until now, it has been very difficult to find a material that is light enough to overwhelm reinforced concrete while also being strong. Ultimately, future super-tall construction depends on the discovery of new advanced materials that can surpass current reinforced concrete or steel, being lighter yet better at withstanding pressure.