How Things Work

Trace the history of passports to find out why we need these documents and what challenges travelers face within this system. -- Passports are not the first form of travel documents: in Ancient Egypt, travelers carried “letters of safe conduct” issued by rulers; in Han China and Tudor England, foreigners were issued travel passes. However, for much of human history, borders have been relatively fluid, and travel lacked bureaucratic requirements. So, what changed? Kristin Surak details the history of the passport system. Lesson by Kristin Surak, directed by Tomás Pichardo-Espaillat. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: http://bit.ly/TEDEdPatreon Check out our merch: http://bit.ly/TEDEDShop ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Follow us on Facebook: http://bit.ly/TEDEdFacebook Find us on Twi

Trace the history of passports to find out why we need these documents and what challenges travelers face within this system. -- Passports are not the first form of travel documents: in Ancient Egypt, travelers carried “letters of safe conduct” issued by rulers; in Han China and Tudor England, foreigners were issued travel passes. However, for much of human history, borders have been relatively fluid, and travel lacked bureaucratic requirements. So, what changed? Kristin Surak details the history of the passport system. Lesson by Kristin Surak, directed by Tomás Pichardo-Espaillat. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: http://bit.ly/TEDEdPatreon Check out our merch: http://bit.ly/TEDEDShop ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Follow us on Facebook: http://bit.ly/TEDEdFacebook Find us on Twi

Trace the history of passports to find out why we need these documents and what challenges travelers face within this system. -- Passports are not the first form of travel documents: in Ancient Egypt, travelers carried “letters of safe conduct” issued by rulers; in Han China and Tudor England, foreigners were issued travel passes. However, for much of human history, borders have been relatively fluid, and travel lacked bureaucratic requirements. So, what changed? Kristin Surak details the history of the passport system. Lesson by Kristin Surak, directed by Tomás Pichardo-Espaillat. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: http://bit.ly/TEDEdPatreon Check out our merch: http://bit.ly/TEDEDShop ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Follow us on Facebook: http://bit.ly/TEDEdFacebook Find us on Twi

Trace the history of passports to find out why we need these documents and what challenges travelers face within this system. -- Passports are not the first form of travel documents: in Ancient Egypt, travelers carried “letters of safe conduct” issued by rulers; in Han China and Tudor England, foreigners were issued travel passes. However, for much of human history, borders have been relatively fluid, and travel lacked bureaucratic requirements. So, what changed? Kristin Surak details the history of the passport system. Lesson by Kristin Surak, directed by Tomás Pichardo-Espaillat. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: http://bit.ly/TEDEdPatreon Check out our merch: http://bit.ly/TEDEDShop ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Follow us on Facebook: http://bit.ly/TEDEdFacebook Find us on Twi

Explore the incredible systems that create breathable air in space, and how we can adapt that process for future expeditions. -- For over 25 years, the International Space Station’s air supply systems have revolutionized space missions. Yet the need for regular maintenance, repairs, and upgrades has pushed engineers to develop even more reliable systems for future spacecraft. How do we create breathable air in space? And what does that look like for longer expeditions? Alvaro Romero-Calvo and Theo St Francis investigate. Lesson by Alvaro Romero-Calvo and Theo St Francis, directed by Lazy Chief. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: http://bit.ly/TEDEdPatreon Check out our merch: http://bit.ly/TEDEDShop ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Follow us on Facebook: http://bit.ly/TEDEdFacebook F

Explore the incredible systems that create breathable air in space, and how we can adapt that process for future expeditions. -- For over 25 years, the International Space Station’s air supply systems have revolutionized space missions. Yet the need for regular maintenance, repairs, and upgrades has pushed engineers to develop even more reliable systems for future spacecraft. How do we create breathable air in space? And what does that look like for longer expeditions? Alvaro Romero-Calvo and Theo St Francis investigate. Lesson by Alvaro Romero-Calvo and Theo St Francis, directed by Lazy Chief. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: http://bit.ly/TEDEdPatreon Check out our merch: http://bit.ly/TEDEDShop ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Follow us on Facebook: http://bit.ly/TEDEdFacebook F

Explore the incredible systems that create breathable air in space, and how we can adapt that process for future expeditions. -- For over 25 years, the International Space Station’s air supply systems have revolutionized space missions. Yet the need for regular maintenance, repairs, and upgrades has pushed engineers to develop even more reliable systems for future spacecraft. How do we create breathable air in space? And what does that look like for longer expeditions? Alvaro Romero-Calvo and Theo St Francis investigate. Lesson by Alvaro Romero-Calvo and Theo St Francis, directed by Lazy Chief. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: http://bit.ly/TEDEdPatreon Check out our merch: http://bit.ly/TEDEDShop ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Follow us on Facebook: http://bit.ly/TEDEdFacebook F

Explore the incredible systems that create breathable air in space, and how we can adapt that process for future expeditions. -- For over 25 years, the International Space Station’s air supply systems have revolutionized space missions. Yet the need for regular maintenance, repairs, and upgrades has pushed engineers to develop even more reliable systems for future spacecraft. How do we create breathable air in space? And what does that look like for longer expeditions? Alvaro Romero-Calvo and Theo St Francis investigate. Lesson by Alvaro Romero-Calvo and Theo St Francis, directed by Lazy Chief. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: http://bit.ly/TEDEdPatreon Check out our merch: http://bit.ly/TEDEDShop ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Follow us on Facebook: http://bit.ly/TEDEdFacebook F

Explore the three conditions needed to trigger an avalanche, and what makes these natural disasters so hard to survive. -- Avalanches are the rapid descent of snow, ice, rock, or a combination of these down a slope. They can be destructive natural disasters and personal tragedies: killing an average of 27 people annually in the US. These alpine nightmares don’t just awaken out of nowhere; they need three specific conditions. So, what causes an avalanche? And is there any way to survive? Simon Trautman investigates. Lesson by Simon Trautman, directed by Denys Spolitak. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: http://bit.ly/TEDEdPatreon Check out our merch: http://bit.ly/TEDEDShop ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Follow us on Facebook: http://bit.ly/TEDEdFacebook Find us on Twitter: http://b

Explore the three conditions needed to trigger an avalanche, and what makes these natural disasters so hard to survive. -- Avalanches are the rapid descent of snow, ice, rock, or a combination of these down a slope. They can be destructive natural disasters and personal tragedies: killing an average of 27 people annually in the US. These alpine nightmares don’t just awaken out of nowhere; they need three specific conditions. So, what causes an avalanche? And is there any way to survive? Simon Trautman investigates. Lesson by Simon Trautman, directed by Denys Spolitak. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: http://bit.ly/TEDEdPatreon Check out our merch: http://bit.ly/TEDEDShop ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: http://bit.ly/TEDEdNewsletter Follow us on Facebook: http://bit.ly/TEDEdFacebook Find us on Twitter: http://b