Thanks both for confirming my suspicions. Appreciate the responses.

Hi. I'm currently working in the UK as an engineer and my employer offers career breaks of up to 5 years. I'm hatching a plan to go to Australia to do a PhD (I was born there, so I've got dual-nationality) but how I go about doing this is currently evading me. Everyone I know who has done or is currently doing a PhD knew their supervisor personally beforehand. Is the best approach to find some research groups whose work looks interesting and contact them directly? My ignorance is appalling but I clearly don't understand the process particularly well - I always assumed that PhDs were generally advertised like jobs. I'm coming to the conclusion now that the reality may be slightly more complicated...

Just to be specific (in case it's somehow relevant), it's research in space engineering that I'm angling towards. Otherwise, robotics or cryogenics or something related. My motivation is two-fold. Firstly, I considered research immediately after graduation but it just didn't feel the right thing to do at the time. After 4 years in employment though, the prospect has become much more attractive and it might represent an opportunity to shift my career progression in a more favourable direction. Secondly, I desperately want a reason to get out of the UK for a while...