How is it physically possible for Stephen King to write so many books?

An endless well of imagination. As a King fan for life, even though I've missed some recent ones, and even though some of his stories are misses, the man is a wealth of genious and hilarious scariness. I should have 1/10th the career as he's had. And he overcame cocaine and alcohol addiction.

Energy, darling, energy and a great deal of talent.

They have amazing equipment available now.
(Like DragonSpeak)
But I get your drift. Stephen King has a certain style, like most writers, and they don't often change that style. Did you know that his wife is also a writer? (hmm)

He writes much the same book time after time after time. The trick is dressing them up so that nobody notices.

A guy by the name of Trollop (spelling?) has written over 500 (no, that wasn't a miss-type) books. I don't know how good they were...but King believes it had to do with his ability to schedule out his writing time.

He's not very good. Anyone could put out that trash at that rate for that money, and most would. He happened onto a venue, that's all. The good writers will be around after they've been dead a long time.

Well King no longer physically "writes" anything anymore. He just stands there and recites them while someone listens and types it out for him, so that saves plenty of time, for one thing.
As for him being a genius, I certainly agree, but most of his stories run on the same sorta concept, which doesn't seem all that complicated to weave, especially when he found an avenue that sticks.
(The Stand-Cell, IT,-Dreamcatcher.)
He's also super rich now, and no longer needs to frantically write books in hopes that they'll catch-they'll always catch, and he said it himself, he's passed the point of concern to provide for his family.

He could stop writing books right now and never work again and be comfortable, so with all that free time, he writes books.

I do agree. But the man is a fucking genius, he would find a way.

The answer is most likely: massive amounts of cocaine.
Sorry, but the secret had to come out sometime.

Coffee. Lots of it.

He's a professional. He works at it every day.

Voice-recognition software for sure.

He definitely has a gift. Some people just have that kind of creative mind and are able to spin out stories quickly. In addition, it is possible that he is writing more than one story at a time.

He's been writing for a very long time and has a deep imagination and people like his work. He gets enough money from writing that he has free time to keep writing.