What If You Never Stopped Growing? The Science of Giants

What if you never stopped growing? At the pace you grew as a baby, you'd be more than ten metres tall by forty. So why do we stop growing? The answer is hidden in your growth plates, and the hormone behind it isn't the one you'd guess. We follow Galileo's crushed giant, Robert Wadlow, the tallest man ever, who was still growing at twenty-two, and the doctors who stopped Sultan Kösen's growth. Then we open up the growth plates to find the countdown that ends your growth, and the surprise hormone that runs it, in men too. Plus why lobsters and cod never stop, why big dogs age faster, and two myths about your height and your ears. Chapters: 00:00 What if you never stopped growing? 00:49 Growth plates: where your bones get longer 01:43 The square-cube law and Galileo's giant 02:38 Robert Wadlow, the tallest man ever 03:45 Gigantism, acromegaly and growth hormone 04:57 Why growth plates close: the countdown 05:27 The hormone that stops your growth 06:26 Why lobsters and fish never stop growing 07:00 The cost of size: big dogs, height and cancer 08:05 Evolution's deal with growth 08:29 Myths: daily height and growing ears 09:24 Your skeleton never stops rebuilding Sources: WHO Child Growth Standards, length-for-age: https://www.who.int/tools/child-growt... Smith et al. 1994, estrogen resistance in a man (NEJM): https://pubmed.ncbi.nlm.nih.gov/8090165/ Nilsson & Baron 2004, growth plate senescence: https://pubmed.ncbi.nlm.nih.gov/15380... Nilsson et al. 2014, estrogen depletes resting zone cells: https://pubmed.ncbi.nlm.nih.gov/24708... Cooper et al. 2013, chondrocyte enlargement (Nature): https://pmc.ncbi.nlm.nih.gov/articles... NIDDK, Acromegaly: https://www.niddk.nih.gov/health-info... Galileo, Two New Sciences (1638), Crew & de Salvio translation: https://en.wikisource.org/wiki/Page:D... Guinness World Records, Robert Wadlow: https://www.guinnessworldrecords.com/... Foot ulcers in the tallest patients with gigantism (review): https://pmc.ncbi.nlm.nih.gov/articles... Guinness World Records, Sultan Kösen: https://www.guinnessworldrecords.com/... Barneche et al. 2018, fish reproductive output (Science): https://pubmed.ncbi.nlm.nih.gov/29748... Kraus et al. 2013, why large dogs die young: https://pubmed.ncbi.nlm.nih.gov/23535... Green et al. 2011, height and cancer, Million Women Study: https://pmc.ncbi.nlm.nih.gov/articles... Guevara-Aguirre et al. 2011, growth hormone receptor deficiency: https://pubmed.ncbi.nlm.nih.gov/21325... Reilly et al. 1984, daily variation in height: https://pubmed.ncbi.nlm.nih.gov/6600017/ Heathcote 1995, ear length and age (BMJ): https://www.bmj.com/content/311/7021/... Surgeon General 2004, bone remodelling: https://www.ncbi.nlm.nih.gov/books/NB... Narration voice: Qwen3-TTS (synthetic). All animation, music and sound are original. This video explains physiology and is not medical advice. #growthplates #skeleton #humanbody