The world's tallest mountain just got a little taller — here's why. ✉️ Sign up for our newsletter: vox.com/video-newsletter In December of 2020, China and Nepal made a joint announcement about a new measurement for Mount Everest: 8,849 meters. This is just the latest of several different surveys of Everest since the first measurement was taken in 1855. The reasons why the height has fluctuated have to do with surveying methodology, challenges in determining sea level, and the people who have historically been able to measure Everest. We mention this NOAA post in the end tag of the video, which addresses another way to measure the height of mountains: oceanservice.noaa.gov/facts/highestpoint.html NOAA has more information about the geoid here: oceanservice.noaa.gov/facts/geoid.html More reading: npr.org/2020/11/24/938736955/how-tall-is-mount-everest-hint-its-changing nytimes.com/2020/12/08/world/asia/mount-everest-china-nepal.h...