Lightspeed: the greatest revelation in modern science

7.00pm to 8.30pm, Wednesday 11 March

The Theatre

The Royal Institution of Great Britain GB United Kingdom W1S 4BS 21 Albemarle Street London

This event has already taken place

  • Credit: FelixMittermeier via pixabay


Standard £16


Concession £10


Ri Members and Ri Patrons £7

Event description

How have physicists from the ancient Greeks to Einstein tackled the problem of how light travels and what discoveries did it lead them to along the way?

This talk explores how the fact that light travels at the same speed in all frames of reference is one of the greatest revelations of modern science. It led 20th Century physics to amazing, world-changing discoveries from E=mc2 to nuclear weapons.

Join John Spence as he tells the stories of some of the greatest experimental scientists in history as they searched in vain for the mysterious 'aether' and a frame of absolute rest in the universe.

About the speakers

Prof John C.H. Spence is a Fellow of the Royal Society and the Richard Snell Professor of Physics and a Regents Professor at Arizona State University. He is also the director of science for the NSF BioXFEL Science and Technology Center on the application of X-Ray Free-electron lasers to structural biology. 

John completed a doctorate in physics at Melbourne University in 1972,  followed by a postdoctoral fellowships at Oxford. He received the Distinguished Scientist Award of the Microscopy Society of America for 2006, the Buerger Award of the American Crystallographic Society in 2012, the J.M. Cowley Medal of the International Federation of Societies of  Microscopy for 2014, the Burton Medal of MSA and a Humbolt Senior Scientist Award.


The doors will open at approximately 6.30pm, with a prompt start at 7.00pm. There will be time for questions after the talk.

Latecomers will be admitted into the gallery.

Book signing

Copies of John's book, 'Lightspeed: The Ghostly Aether and the Race to Measure the Speed of Light', will be available for purchase and signing after the talk. 


This event will be filmed and on the Ri's YouTube channel within a few months. Subscribe for free to hear when new videos are released.


The theatre is on the first floor and there is step-free access from the street via lift.

The closest underground station is Green Park, which is step-free.

There is space at floor level in the theatre for wheelchair users.

Seating is usually unreserved for our events. If you and your group require seating reservations, please do let us know by email and we’ll be more than happy to help. Email:

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Our theatre is equipped with an Audio Induction Loop. 

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