If you're interested in academia or scientific research, there is scope to work on open source projects there. My full time job is working on a particle physic

If you're interested in academia or scientific research, there is scope to work on open source projects there. My full time job is working on a particle physics data analysis program, which is entirely open sourced. You won't necessarily have to do a scientific project either - other people who work at the same research facility work on configuration management systems, or databases. Note that this doesn't have to involve doing a PhD or actually being an academic - it's more a providing the tools that enable academics to do successful research kind of thing.