The Large Hadron Collider (LHC) was switched on to great acclaim on Wednesday. Andrew Marr was there to mark the moment for Radio 4 – and produced these sketches.
"These are very fast, done on the wing between broadcasting," the presenter said.
Prof Sir Chris Llewellyn Smith is a theoretical physicist – and was director general of Cern for five years. There were anxious – and proud - moments as the LHC began to work.
"I think you can tell a lot about people by looking at them from behind: Lyn [Evans] with his hands plunged into his trousers was finally wallowing in success: some of the faces came from earlier, tenser moments," Andrew Marr explains.
"The contol room was boring to draw - like a school sports hall filled with computers. The other sketch is of the three things essential for radio - mike, headphones and water!"