Key insights

• 🧐 The search for the original source of a scientific claim leads to dead ends, old textbooks, and a letter to a renowned science communicator.
• 📚 Unable to find the original source of a scientific claim about blood vessels length, Searched through PubMed, scientific papers, and biology textbooks with no luck, Discovered two books from the 1990s with the claim, authored by Dr. Suzuki, Attempted to contact Dr. Suzuki for the original source, Resorted to writing a letter to Dr. Suzuki to resolve the issue
• 🔍 After a long search and following various leads, the original source was finally found in a book by August Krogh, a Nobel Prize winner for Medicine.
• 💡 August Krogh made a pioneering estimate of the total length of capillaries in the human body based on muscle weight and capillary density., Krogh's assumptions about capillary density and muscle mass were later found to be inaccurate., The incorrect estimate gained widespread acceptance in scientific papers and became detached from its original source, leading to its perpetuation for over a century.
• ⚙️ New accurate estimate of the length of all capillaries in a human is 9000-19000 km, Challenges in debunking misinformation due to time and effort required, Misinformation can persist due to its appeal and ease of repetition, Efforts to correct misinformation and provide accurate scientific information
• 🌟 Explore fulfilling careers that make a positive impact with free advice from 80,000 hours. Sign up for their newsletter to get an in-depth career guide.
• 💼 80,000 hours offers free career advice for impactful careers, Research shows there are many paths to make a big difference in the world, Time spent on a career is a significant opportunity to have an impact, Support from patrons allows for thorough and reliable content creation

Q&A

• What career advice is offered by 80,000 hours?

  80,000 hours provides free career advice for impactful careers that make a positive impact. Research shows that there are numerous paths to make a significant difference in the world, and time spent on a career is a valuable opportunity to have a positive influence.

• Why do scientists struggle to debunk and correct misinformation?

  Debunking and correcting misinformation demands significant time and effort. Additionally, misinformation can persist due to its appeal and ease of repetition, posing challenges for scientists striving to provide accurate scientific information.

• What was the issue with the century-old estimate about capillary length?

  The estimate, based on inaccurate assumptions by August Krogh, gained widespread acceptance in scientific papers despite its inaccuracy. Krogh's assumptions about capillary density and muscle mass were later found to be inaccurate, leading to the perpetuation of the incorrect estimate for over a century.

• How was the original source finally discovered?

  After an extensive search, the original source was found in a 1959 Scientific American article, which referenced a 1922 book by August Krogh, a Nobel Prize winner for Medicine. This discovery resolved the mystery of the claim's origin.

• What were the challenges faced during the search for the original source?

  The search encountered dead ends, inconsistencies, and a lack of proper citation in various publications and sources. Despite efforts to contact the author of the claim, Dr. Suzuki, the original source remained elusive.

• What was the year-long search for the original source about?

  The year-long search aimed to determine the origin of the claim that blood vessels, taken together, add up to 100,000 kilometers. It involved exploring various publications and sources to find the accurate citation for the claim.

• 00:00 The video explores the journey to determine the origin of the fact that blood vessels, taken together, add up to 100,000 kilometers. The search for the original source led to inconsistencies and a lack of proper citation in various publications and sources.
• 02:12 The search for the original source of a scientific claim leads to dead ends, old textbooks, and a letter to a renowned science communicator. 🧐
• 04:20 After a long search and following various leads, the original source was finally found in a book by August Krogh, a Nobel Prize winner for Medicine.
• 06:28 A century-old estimate about the length of capillaries in the human body, based on inaccurate assumptions, was widely used in scientific papers despite being incorrect.
• 08:33 Scientists struggle to debunk and correct misinformation due to the time and energy required; misinformation can persist due to its appeal and ease of repetition.
• 10:40 Explore fulfilling careers that make a positive impact with free advice from 80,000 hours. Sign up for their newsletter to get an in-depth career guide.