How High Can We Build?
Based on Vsauce's video on YouTube. If you like this content, support the original creators by watching, liking and subscribing to their content.
A “building” is defined here as a structure where at least 50% of its height comes from habitable floor plates; otherwise it’s treated as a tower.
Briefing
Humanity’s tallest-built record has repeatedly shifted—not because people suddenly mastered higher buildings, but because the definition of “tallest” kept changing. For nearly 4,000 years, the Great Pyramid of Giza held the height crown at 147 meters, until England’s Lincoln Cathedral finally surpassed it in the 1300s. After that, a run of landmark structures followed: the Eiffel Tower became the tallest for about four decades, then the Chrysler Building took over, and the Empire State Building pushed the record further. The Empire State Building also introduced a striking physics milestone: if someone jumped from its top, they’d reach terminal velocity before hitting the ground, meaning the fall would stop accelerating and instead proceed at the fastest speed their body can sustain.
By the mid-1950s, the height race took a turn. Radio and TV towers could be far taller than habitable buildings because they didn’t need to be designed for people to live and work inside. That shift explains why modern icons—like the Petronas Towers, Taipei 101, the World Trade Center, and the Willis Tower—have never held the overall “tallest thing” title for long. Somewhere nearby, a radio or TV mast was always taller. The record then moved to extreme, non-building structures, culminating in the Warsaw radio mast in Poland, which stood as the tallest until a 1991 failure: workers mishandled guy-wires, the mast bent, and it snapped in the middle.
After the Warsaw mast fell, the KVLY-TV mast in North Dakota became the tallest standing human-made structure. But the conversation about height eventually returned to buildings, with the Burj Khalifa in Dubai becoming the current benchmark. Its scale isn’t just visual; it changes daily experience. Because the top is far enough above the base, the sunset timing differs so much that Dubai’s Islamic Affairs department issued Ramadan rules: people above floor 80 must wait 2–3 minutes after those at ground level to start eating, since the sun hasn’t set for them yet. The episode then uses the Burj Khalifa as a springboard to a broader idea: you can “double” sunrise or sunset by standing higher, even at the beach, and the timing difference can be used to estimate Earth’s radius.
The ultimate ceiling, however, isn’t a skyscraper—it’s space. As structures grow taller, they must support their own weight, but beyond a certain altitude the physics changes: at geostationary-orbit height, a new outward centrifugal effect appears alongside gravity. In principle, a structure that tall could be stable under tension and reach more than 35,000 km, forming a “Space Elevator.” The obstacle is materials: no known substance is strong enough for a feasible Earth-to-space tether, though carbon nanotubes or boron-nitrate nanotubes are discussed as potential candidates. The episode closes with why such a system matters: launching a pound into orbit costs roughly $11,000 today, but a space elevator could reduce that to about $100—an advantage so large that Philip Ragan argues the first country to deploy one could gain a 95% cost edge and potentially dominate space-related activity.
Cornell Notes
Tallness records shift depending on what counts as a “building.” Habitable structures dominated early history, with the Great Pyramid of Giza (147 m) holding the record for nearly 4,000 years. Once radio and TV towers arrived in the mid-1950s, non-habitable masts could surpass buildings, keeping the “tallest thing” title moving—until failures like the 1991 Warsaw radio mast collapse. The Burj Khalifa brought the focus back to buildings, even affecting Ramadan timing because sunset occurs minutes later at higher floors. Looking beyond skyscrapers, a space elevator could, in theory, be stable at geostationary altitude via tension, but it depends on materials strong enough to build a tether over 35,000 km.
Why did the “tallest” record stop belonging to habitable buildings after the mid-1950s?
What physical milestone is tied to the Empire State Building’s height?
What happened to the Warsaw radio mast in 1991, and why does it matter for the height story?
How does the Burj Khalifa create a real-world timing difference for sunset?
How can a person at a beach “double” a sunset, and what does that enable mathematically?
Why is a space elevator theoretically stable, and what blocks it in practice?
Review Questions
- How does changing the definition of “tallest” (habitable building vs. non-habitable mast) alter which structures hold records over time?
- What role do tension and terminal velocity play in the story of extreme height, and where does each concept apply?
- Why does a space elevator require both a specific altitude regime and unusually strong materials?
Key Points
- 1
A “building” is defined here as a structure where at least 50% of its height comes from habitable floor plates; otherwise it’s treated as a tower.
- 2
The mid-1950s height race shifted toward radio and TV towers because they didn’t need to be habitable, letting them outgrow traditional buildings.
- 3
The Empire State Building’s height is high enough that a fall from the top would reach terminal velocity before impact.
- 4
The Warsaw radio mast collapse in 1991 highlights how failures in tension systems like guy-wires can bring down extremely tall structures.
- 5
The Burj Khalifa’s height is sufficient to change sunset timing by minutes, leading to Ramadan rules for when people on higher floors can start eating.
- 6
A space elevator is theoretically stable at geostationary altitude due to a balance between gravity and centrifugal effects, but it depends on materials strong enough to span more than 35,000 km.
- 7
A space elevator is framed as a major cost reducer for launching mass into orbit, potentially dropping per-pound costs from about $11,000 to about $100.