A review of the DVD edition of fter the centenary of Albert Einstein's annus mirabilis, 1905, there surely can't be too many readers who'd fail to recognise his best-known equation, E=mc². But do we know what it means? It's this question American author David Bodanis addressed in his book, E=mc², on which this film is based. The method is simple: look at each of the four key elements of the equation (E, m, c, and the square rule), and trace our understanding of them in the years before Einstein's discovery.

After the centenary of Albert Einstein's annus mirabilis, 1905, there surely can't be too many readers who'd fail to recognise his best-known equation, E=mc². But do we know what it means? It's this question American author David Bodanis addressed in his book, E=mc², on which this film is based. The method is simple: look at each of the four key elements of the equation (E, m, c, and the square rule), and trace our understanding of them in the years before Einstein's discovery.

We learn, for example, through Michael Faraday that different forms of energy are related and watch as he transforms chemical energy to electrical energy and finally to kinetic energy. Next we see Antoine-Laurent de Lavoisier proposing that the universe is a closed system in which matter can be neither created nor destroyed but simply changed.

Next comes Einstein himself, often in conversation with his first wife, Mileva Maric, or his fellow students in Bern, and the process of evolving some of the ideas that led to his astonishing output in 1905 and particularly to Special Relativity (General Relativity is not celebrated in this film).

The whole journey culminates in the proof of the equation, discovered by German physicist Lise Meitner (whose Nobel Prize was snatched from her by the Nazis - she was Jewish), who observed a loss of nuclear mass during small-scale fission experiments. It's but a small step from there to see the entire universe as a nuclear laboratory and Einstein's face in the stars.

If you still find Einstein a daunting figure, E=mc² might just be for you. Join the Einsteins as they try to understand just what goes on when you're travelling at the speed of light.