Sci-fi pre-1985 children's(ish?) book series about a boy who lived next door to an old scientist

Question

When I say this series has been haunting me for a couple of decades, it's an understatement. I remember loving this series, but I also remember it being a bit weird, and maybe even a bit science heavy for kids.

There were a number of books in it (I believe), and all I can remember is this young kid would go over to his neighbor's house, and the neighbor was an eccentric, old, scientist. I -feel- like they'd go to alternate dimensions and that sort of thing.

But the books themselves seemed old in 1986, so they might've been from the 70s?

Answer 1

Aside from the living arrangement, this seems very much like the Danny Dunn books by Jay Williams and Raymond Abrashkin. They were published from the mid-1950s until the late 1960s.

Danny's mother was the (live-in, with separate quarters) housekeeper for Professor Bullfinch, and Danny (along with his friend Joe and sometimes another friend, a girl whose name I've forgotten) would always get involved with the Professor's inventions. The Professor had a frenemy (a term which hadn't been invented yet when the books were written), Professor Grimes. The two would sometimes make music together; Bullfinch (a large, portly man) played a piccolo, while Grimes, a skeletal fellow, played a "bull fiddle" (a bowed upright bass).

There were about a dozen books in the series, with Danny and friends dealing with a supercomputer, a cryogenic thermocouple device, a high powered laser, a submarine -- and other stuff I've forgotten.