Professor Ian Chapman joins Saiful Islam to explain how fusion reactors’– Michael Faraday – addressed in the very first Christmas Lectures – energy. In his first lecture, Saiful investigates one of the most important challenges facing humankind – how to generate energy without destroying the planet in the process. As part of the celebrations, Saiful invites former Christmas Lecturers to join him on stage, and repeats some of the most exciting (and dangerous) experiments and demonstrations from the past. Saiful begins his lecture by being plunged into darkness. Armed initially with nothing but a single candle, his challenge is to go back to first principles and bring back the power in the energy-hungry lecture theatre. Along the way he explains what energy is, how we can transform it from one form to another, and how we harness it to power the modern world. A fascinating and stimulating celebration of the stuff that quite literally makes the universe tick –- the weird and wonderful world of energy. Thanks to our major supporter, Lloyd's Register Foundation, and whole community of supporters: http://www.rigb.org/about/news/autumn-2016/our-2016-christmas-lectures-supporters 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