The cloud chamber is an incredible piece of equipment that allows us to visualise ionising radiation. Watch the full lecture: http://www.rigb.org/christmas-lectures/watch/1993/the-cosmic-onion/to-the-centre-of-the-sun?utm_source=youtube&utm_medium=social&utm_term=description Frank Close gave the 1993 lectures "The Cosmic Onion" tracing a hundred years of discovery and invention. In his second lecture, Frank Close looks at how atomic nuclei form, behave and change. Watch the full series: http://www.rigb.org/christmas-lectures/watch/1993/the-cosmic-onion?utm_source=youtube&utm_medium=social&utm_term=description 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