# Where do Feynman Diagrams Appear for the first time?

Do they formally appear in any book? Or his Lectures?

• I think it appears in this paper. journals.aps.org/pr/abstract/10.1103/PhysRev.76.749 – Sayan Mandal Oct 6 '17 at 1:01
• I'm voting to close this question as off-topic because it is about historic events rather than actual physics. – Qmechanic Oct 6 '17 at 4:06
• That's fine, I'm just thinking about somebody else looking for this answer, which I was not able to find anywhere else. – Carlos Oct 6 '17 at 16:13
• @Qmechanic Hm, I actually thought the question was fine. This is the sort of thing the specific-reference tag was made for. – David Z Oct 6 '17 at 18:35
• IIRC, Stückelberg was using diagrams to compute perturbative expansions long before Feynman. Can anyone confirm this? – AccidentalFourierTransform Oct 6 '17 at 19:04

As for the context in which Feynman diagrams appear: Imagine you want to know how a particle travels from $A$ to $B$. You can split up the time evolution operator $\text{e}^{-\text{i} Ht}$ into many small steps and integrate over every possible position, that the particle could go to at every infinitesimal step.