From coccolithophores to the White Cliffs of Dover, physicist Helen Czerski explains the amazing cycle that makes Calcium her favourite element. Each day in December, we'll publish a new video revealing the elements that really excite and inspire people. 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