Q. Speaking of space: Earlier this week, your daughter, Lucy, and Paul Davies, the Arizona State University physicist, sent a message into space from an Arizona schoolchild to potential extraterrestrials out there in the universe. Now, you’ve said elsewhere that you think it’s a bad idea for humans to make contact with other forms of life. Given this, did you suggest to Lucy that she not do it? Hypothetically, let’s say as a fantasy, if you were to send such a message into space, how would it read?

A. Previously I have said it would be a bad idea to contact aliens because they might be so greatly advanced compared to us, that our civilization might not survive the experience. The “Dear Aliens” competition is based on a different premise.

It assumes that an intelligent extraterrestrial life form has already made contact with us and we need to formulate a reply. The competition asks school-age students to think creatively and scientifically in order to find a way to explain human life on this planet to some inquisitive aliens. I have no doubt that if we are ever contacted by such beings, we would want to respond.

I also think it is an interesting question to pose to young people as it requires them to think about the human race and our planet as a whole. It asks students to define who we are and what we have done.

Q. I don’t mean to ask this disrespectfully, but there are some experts on A.L.S. who insist that you can’t possibly suffer from the condition. They say you’ve done far too well, in their opinion. How do you respond to this kind of speculation?

A. Maybe I don’t have the most common kind of motor neuron disease, which usually kills in two or three years. It has certainly helped that I have had a job and that I have been looked after so well.

I don’t have much positive to say about motor neuron disease. But it taught me not to pity myself, because others were worse off and to get on with what I still could do. I’m happier now than before I developed the condition. I am lucky to be working in theoretical physics, one of the few areas in which disability is not a serious handicap.