{"id":36,"date":"2025-12-15T20:04:17","date_gmt":"2025-12-15T20:04:17","guid":{"rendered":"http:\/\/localhost\/thedigitaldraft\/?p=36"},"modified":"2025-12-15T20:04:17","modified_gmt":"2025-12-15T20:04:17","slug":"we-fell-for-the-oldest-lie-on-the-internet","status":"publish","type":"post","link":"https:\/\/www.iamtiksha.com\/blog\/we-fell-for-the-oldest-lie-on-the-internet\/","title":{"rendered":"We Fell for the Oldest Lie on the Internet : The 100,000 km Myth"},"content":{"rendered":"\n

You\u2019ve probably heard this one before:
\u201cIf you laid out all the blood vessels in your body end to end, they\u2019d stretch 100,000 kilometres – enough to circle the Earth twice.\u201d<\/p>\n\n\n\n

Sounds amazing, doesn\u2019t it?
It\u2019s also completely wrong.<\/p>\n\n\n\n

In their video \u201cWe Fell For The Oldest Lie On The Internet,\u201d<\/em> the team at Kurzgesagt – In a Nutshell<\/strong> spent a year chasing down the origins of this so-called \u201cfun fact.\u201d What they found was a perfect case study in how misinformation can quietly take root – even in science.<\/p>\n\n\n\n

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The Investigation Begins<\/h3>\n\n\n\n

The 100,000 km claim is everywhere<\/em> – textbooks, websites, even classrooms. But when Kurzgesagt tried to find where it came from, they hit a dead end.<\/p>\n\n\n\n

No research papers.
No original measurements.
Just endless repetition.<\/p>\n\n\n\n

When they checked medical databases like PubMed, the number didn\u2019t appear in a single scientific study. That was their first big clue: something wasn\u2019t right.<\/p>\n\n\n\n

Digging further, they found references to the claim in the 1990s, in works by science writers David Suzuki<\/strong> and Steven Vogel<\/strong>. But when they reached out to Suzuki, he couldn\u2019t even remember where he\u2019d first seen the number – despite publishing it over 30 years ago.<\/p>\n\n\n\n

So the team went through all 93 references<\/strong> in Vogel\u2019s book. And that\u2019s when they got \u201cstupidly lucky.\u201d<\/p>\n\n\n\n

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The Real Source of the Myth<\/h3>\n\n\n\n

Their search finally led to a 1959 Scientific American<\/strong> article – which in turn cited a 1922 book<\/strong> called The Anatomy and Physiology of Capillaries<\/em> by August Krogh<\/strong>, a Nobel Prize\u2013winning physiologist.<\/p>\n\n\n\n

Here\u2019s the twist:
Krogh wasn\u2019t estimating all<\/em> blood vessels. He was only talking about capillaries<\/strong>, and his total came to roughly 100,000 kilometres.<\/p>\n\n\n\n

But there were two problems:<\/p>\n\n\n\n

    \n
  1. His estimate was based on a 50 kg body made entirely of muscle.<\/li>\n\n\n\n
  2. Later studies found his assumptions about capillary density were way off.<\/li>\n<\/ol>\n\n\n\n

    In other words, what began as a rough guess from a respected scientist turned into a \u201cscientific fact\u201d that no one ever bothered to question – for nearly a century.<\/p>\n\n\n\n

    \n\n\n\n

    So What\u2019s the Real Number?<\/h3>\n\n\n\n

    While Kurzgesagt was working on their video, a new study came out with a far more realistic estimate:<\/p>\n\n\n\n

    \ud83e\uddec The total length of all capillaries<\/strong> in the human body is between 9,000 and 19,000 kilometres<\/strong> – not 100,000.<\/p>\n\n\n\n

    That\u2019s still mind-blowing, but it\u2019s nowhere near enough to wrap around the Earth.<\/p>\n\n\n\n

    \n\n\n\n

    Why the Myth Survived<\/h3>\n\n\n\n

    The video ends with a reminder of why this false \u201cfact\u201d lasted so long:<\/p>\n\n\n\n