First off, my apologies if this is the wrong sub to post in. I'll post it in /r/hinduism if that's better, it just seems like this sub is the most active. The interest in this stems from J. Robert Oppenheimer's speaking of this quote during the atomic bomb test. My question is, for someone who doesn't understand Hinduism all that well, why was this originally said by Vishnu if his role is more so the "protector"? Shouldn't this be more appropriate for the "destroyer" Shiva to say? Or are Vishnu and Shiva just different forms the same deity can take?
Thanks in advance! Let me know if this is a more fitting question for a different sub.
In the actual Gita, it is Krishna, not Vishnu, who says the quote. Oppenheimer misattributes it. (Krishna is an avatar of Vishnu, but whatever.)
Anyway. The quote is not about destruction, per se, it is about the inevitability of death. Oppenheimer's own translation is idiosyncratic. It is Krishna saying to Arjuna (a human prince who doesn't want to fight): look, you don't want to kill all those people, but guess what: they're going to die anyway. It's not up to you whether they live or die. It's up to me, your God. Now do your duty.
Understanding this makes Oppenheimer's invocation of the quote make more sense. He's not identifying with Krishna. He's identifying with Arjuna, the one being told that death is going to come to his victims whether he wants them to or not. If anyone is Krishna, it is the bomb itself — the revelation of secret, deadly power that surpasses the individual, and compels them to act.
I have written about this at some length here, with other translations (including that of Arthur Ryder, Oppenheimer's Sanskrit teacher) offered up as well.
/u/restricteddata's piece on the duality of Kenneth Bainbridge's response of "Now we're all son of bitches" is just as, if not more interesting than Oppie's initial statement.