Lecture 3 - Why Are Mountains So Small? Is it possible to escape gravity? Tune in to find out... The first time Mark got into the harness to defy gravity it was unfortunately too tight in key places! The Ri is on Twitter: http://twitter.com/ri_science and Facebook: http://www.facebook.com/royalinstitution and Tumblr: http://ri-science.tumblr.com/ Our editorial policy: http://www.rigb.org/home/editorial-policy Subscribe for the latest science videos: http://bit.ly/RiNewsletter