{
  "id": 1008571,
  "title": "388 years ago, Galileo worked out why human giants can't exist—and explained a law of nature",
  "url": "https://urgent.news/2026/08/15/388-years-ago-galileo-worked-out-why-human-giants-cant-exist-and",
  "topic": "science",
  "section": "Science",
  "published": "2026-08-15T10:00:00.000Z",
  "source": {
    "name": "Scientific American",
    "slug": "scientific-american",
    "url": "https://www.scientificamerican.com/article/388-years-ago-galileo-worked-out-why-human-giants-cant-exist-and-explained-a-law-of-nature/"
  },
  "original_language": "en",
  "account": "Four hundred and eighty years ago, Galileo Galilei unraveled the mystery behind why human giants remain a figment of human imagination, and in doing so, elucidated a fundamental law of physics. Giants have been a recurring theme in literature and folklore, from the Cyclops in Homer’s Odyssey to King Arthur’s \"Jack the Giant Killer.\" These mythical beings, with their towering stature, typically engage in human activities—walking, running, and even climbing ladders.\n\nHowever, Galileo’s 1638 treatise \"Dialogues Concerning Two New Sciences\" suggests that such humanoid giants couldn't exist in reality. To support his argument, Galileo posed a thought experiment involving a beam of oak, a material known for its strength and durability. He envisioned a larger beam, scaled up proportionally to the original. The larger beam, though thicker, wouldn't be able to bear a similarly scaled-up load. This is because the load-bearing capacity of a beam depends on its cross-sectional area, which scales with the square of its linear dimensions, while the weight of the load is proportional to its volume, which scales with the cube of the linear dimensions.\n\nFor instance, if a beam is made 10 times larger, its cross-sectional area becomes 100 times greater, making it 100 times stronger in load-bearing capacity. However, the weight of the load increases a thousandfold due to the cubic scaling. Thus, a 10-times larger beam would only be able to support one-tenth of the load it originally supported. Applying this principle to giants, their bones, much like structural beams, wouldn’t be able to support their own mass if scaled up proportionally to humans.\n\nGalileo further extrapolated this principle to other aspects of these mythical giants. Scaled-up versions of everyday tools and structures—such as ladders, swords, armor, and even chairs—would be either too heavy for their users or unable to bear the weight of the giant. This line of reasoning not only explains why human giants cannot exist but also sheds light on the existence of larger animals in the natural world. Animals like elephants, with their thick, sturdy limbs, can be understood through the same principle. Their bones are proportionally thicker to support their massive bodies, a concept Galileo’s argument elegantly illustrates.",
  "summary": "Giants have featured in stories for millennia, but the reason why they don't exist helps explain the natural world",
  "key_points": [
    "Galileo Galilei explained why human giants can't exist in 1638",
    "Larger beams can't support scaled-up loads due to cross-sectional area vs volume",
    "Principle applies to giant-sized tools, structures, and larger animals"
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}