Manhattan project for aligned AI

As I understand, theory of atomic bomb was considerably more advanced at the beginning of Manhattan project compared to our understanding of theory of aligned AGI.

To somewhat simplify, there were two unknown parameters. The critical mass of uranium-235, and the rate of uranium isotope separation. Given these two parameters, you could calculate how long it would take by simple division. Remember Little Boy was not tested at all: theory was that solid. Success was basically guaranteed if you had enough time, although success in 100 years would have been rightfully considered failure.

What about nuclear reactor, plutonium, and implosion device? Those were gambles to speed things up, because they thought it would take too long. (They were right: war in Europe ended first.) But Manhattan project would have succeeded without them, in the sense of producing fission weapons.

Another thing they tried to speed things up was better isotope separation. Electromagnetic separation was well understood and basically worked as designed. They gambled on developing gaseous diffusion, and it ended up more efficient, but development took too long so it didn't shorten the timeline at all.

In retrospect, they should have gambled on centrifuges, which is the current preferred method. What was missing was a clever innovation, not an advanced material or other things of that nature. Manhattan project could have been finished a lot faster if only they had known about Zippe centrifuge.

In fact there is an alternate history novel based on this, The Berlin Project by Gregory Benford (recommended). The author's estimate, which seemed reasonable to me, is that centrifuge would have shorten the timeline by one year, finishing in 1944. As a result, as the title suggests, atomic bomb is dropped on Berlin.

So, let me answer the question. I will define success as producing fission weapons before the end of war in Europe. (This is reasonable interpretation of statements by scientists who worked on Manhattan project.) The real world Manhattan project failed.

No one could predict anything before the necessary experiments were done to figure out the critical mass. Rough estimates varied by one order of magnitude, implying one to ten years. Once critical mass was figured out, electromagnetic separation implied three years (1942~1945), which was felt to be about 50% success rate based on guesses about how war would progress. They tried hard to speed things up and shorten the timeline, but they failed. Choosing centrifuge would have led to success in 1944 but there was no reasonable way to know that and unlucky choice was made.

I'm not sure I understand the motivation behind question. How much of my modern knowledge am I supposed to throw away? Note I am not in fact an atomic theorist who has the state of knowledge of atomic theory in 1942 so it's hard to know what I'd think, but I can imagine assigning somewhere between 5% and 95% depending on how informed of an atomic theorist I actually was and what it was actually like in 1942. Maybe I could give a better answer if you clarify the motivation behind the question?

I downvoted this, because I think it showa a common mistake: I think that people view quantum things as magic that is necessary to do X, and I think that's a huge mistaje.

Don't get me wrong, reliable, scalable and general quantum computers especially once you get to be able to perform computation out of black holes, would be instantly the #1 invention in all of history, and would make my views around takeoff shift to way foomier models, maybe almost agreeing with Eliezer's tskeoff views.