How does Stephen Hawking conduct his research? I've recently watched The Theory of Everything and it got me thinking. How does a researcher with a serious physical impediment, such as Stephen Hawking, conduct his research?

Academic life usually involves studying, staying up to date with current literature, attending or giving conferences, teaching some classes, etc. Each of those activities presents serious challenges. For instance, how does he do math? Everything is done in his mind or does he scribble some notes on software? Or maybe in Latex? I'm assuming he has people helping him, too.

I'm not sure if this is on topic here, so I apologize if it's inappropriate.
Have you read his article in the Wikipedia? I believe most of your questions are answered there. 

As for students and researchers with disabilities in general: Every disability is different and different things can be done to help, from extra time on homeworks and exams, to special reading / blackboard viewing devices, hearing aids, keyboards that require very little finger strength, to having another person take notes for the disabled student / researcher. I'm sure I forgot lots of other tools. 

The most important tool for research is the mind and with a keen mind most obstacles can be overcome.