TV scientist Johnny Ball delighted young and old at a Huddersfield school.
The celebrity was at Shelley College to mark its achievement of gaining specialist science college status.
And his wacky experiments and joke-filled lectures went down a storm.
The college threw open its doors to students from other schools and colleges to join in the special science day.
Students joined in workshops run by the scientists working on the 43-foot Starchaser rocket, which was another special feature of the visit.
Ball ran a series of maths and science workshops for Year 9 students, with many practical experiments.
"There was no shortage of willing volunteers," said assistant head Mrs Debbie Lumb.
"Johnny Ball captivated everyone with his lectures and his stories of how great scientists like Galileo, Archimedes and Einstein were ordinary people, enthused by science."
Later in the day, 250 invited guests -including councillors, governors, sponsors and parents - enjoyed another lecture from Mr Ball.
* Presenter of more than 20 TV shows
* Won Bafta award and Emmy nomination
* TV show Think Of A Number inspired a roadshow which ran for 13 weeks
* Comedian in the 1960s, appearing with Val Doonican and Harry Secombe
* Father of Zoe - best known as Radio 1 presenter