I have successfully defended by Ph.D. titled 'Cooling & sensing using whispering gallery mode resonators'.
My internal examiner was Prof. John Morton and my external examiner Prof. Gilberto Brambila (Southampton Univ) who were both extremely pleasant during the 3 hr exam!
In the UK, Ph.D.s are awarded upon passing a private viva exam with 2 examiners - this is quite different to the public defence in some areas of Europe. Vivas can last between 1 hr to 6 hrs defending on the subject and tenacity of the examiners - experimentalists often talk the most!
Yay I'm a Dr. now!