The original source for that “58%” poll is Tipler’s The Physics of Immortality, where it’s cited (chapter V, note 6) as “Raub 1991 (unpublished)”. (I know nothing about the pollster, L. David Raub, except that he corresponded with Everett in 1980.) Tipler says that Feynman, Hawking, and Gell-Mann answered “Yes, I think the MWI is true”, and he lists Weinberg as another believer. But Gell-Mann’s latest paper is a one-history paper, Weinberg’s latest paper is about objective collapse, and Feynman somehow never managed to go on record anywhere else about his belief in MWI.
The original source for that “58%” poll is Tipler’s The Physics of Immortality, where it’s cited (chapter V, note 6) as “Raub 1991 (unpublished)”. (I know nothing about the pollster, L. David Raub, except that he corresponded with Everett in 1980.) Tipler says that Feynman, Hawking, and Gell-Mann answered “Yes, I think the MWI is true”, and he lists Weinberg as another believer. But Gell-Mann’s latest paper is a one-history paper, Weinberg’s latest paper is about objective collapse, and Feynman somehow never managed to go on record anywhere else about his belief in MWI.
I trust Tipler as far as I can throw his book.
(It’s a large book, and I’m not very strong.)