The conversation started with a famous physicist and wound around the garden path in a wheel chair until it ended up with a famous baseball player and a debilitating disease they share.
Lou Gehrig, for whom the motor nurone disease Amyotrophic lateral sclerosis is named, died in 1941 from complications of the affliction.
As you can see from the links in the last paragraph, I have been following a train of thought around Wikipedia.
An excerpt from Lou Gehrig's retirement speech lifted from Ken Burns' Baseball (damn fine documentary) cuts out most of what he had to say, so I'll lift it from Wikepedia and recount it here for you to appreciate:
Fans, for the past two weeks you have been reading about the bad break I got. Yet today I consider myself the luckiest man on the face of the earth. I have been in ballparks for seventeen years and have never received anything but kindness and encouragement from you fans.
Look at these grand men. Which of you wouldn’t consider it the highlight of his career just to associate with them for even one day? Sure, I’m lucky. Who wouldn’t consider it an honor to have known Jacob Ruppert? Also, the builder of baseball’s greatest empire, Ed Barrow? To have spent six years with that wonderful little fellow, Miller Huggins? Then to have spent the next nine years with that outstanding leader, that smart student of psychology, the best manager in baseball today, Joe McCarthy? Sure, I'm lucky.
When the New York Giants, a team you would give your right arm to beat, and vice versa, sends you a gift — that’s something. When everybody down to the groundskeepers and those boys in white coats remember you with trophies — that’s something. When you have a wonderful mother-in-law who takes sides with you in squabbles with her own daughter — that's something. When you have a father and a mother who work all their lives so that you can have an education and build your body — it's a blessing. When you have a wife who has been a tower of strength and shown more courage than you dreamed existed — that's the finest I know.
So I close in saying that I might have been given a bad break, but I've got an awful lot to live for. Thank you.
Lou Gehrig at Yankee Stadium, July 4, 1939