The day I thought we'd unplugged Stephen Hawking - BBC News
Our science correspondent Pallab Ghosh remembers his many interviews with the great physicist.
I was lucky enough to meet Prof Stephen Hawking several times. Each time it was a joy.

There was a marvellous twinkle in his eye and always a mischievous sense of humour.

It was these qualities and his determination not to allow his disability to prevent him from contributing to research that made him so famous and indeed so loved by people all across the world.

I first went to interview Prof Hawking in 2004 at his office in Cambridge.

I felt a mixture of awe and excitement as I waited for the man who for years had been my idol. He seemed to smile at me as he entered the room which immediately put me at my ease.

The camera operator I was with wanted to make a last minute adjustment to his lighting and so he asked Prof Hawking's staff if he could pull out one of the plugs in the office so that he could use the socket for his equipment.

Without waiting for a response he pulled the plug and the room was filled with a deafening siren.

Prof Hawking then slouched forward and I feared that my colleague had inadvertently unplugged a vital piece of life-support equipment.

Fortunately, it was the alarm to the uninterruptable power supply to his office computer and he was slouched forward with mirth at our incompetence.

Thankfully, he invited me to interview him many times after that.

We talked a lot about his science of course. But what I remember most was his humanity.

As well as his own work he would often talk about the social implications of research and the responsibility scientists had to make sure that their work was used for the benefit of society.

And it was for this that he became the world's most famous scientist.

He reached people not normally interested in science because of his compassion as well as his genius.

And that wicked sense of humour.

When I asked him how we could test his belief that radiation emerged from black holes, he told me that he did not wish to get too close to a black hole for fear of falling in - but he did agree that it would be a wonderful way to go.