
Transcript of Conversations among German Nuclear Physicists at Farm Hall (1945) [pdf] - jackgavigan
http://germanhistorydocs.ghi-dc.org/pdf/eng/English101.pdf
======
Animats
The Farm Hall transcripts are well known. There's much more of this, including
where they discuss how the Americans might have done it.[1] Hahn says to
Heisenberg: "If the Americans have the uranium bomb you're all second-raters.
Poor old Heisenberg".

Heisenberg had made a big miscalculation. He thought it would take 2 tons of
enriched uranium to make a bomb. In fact, it's about 52Kg for a dumb bomb, and
and maybe 5Kg with a good design. Oops.

[1]
[https://books.google.com/books?id=_qVgeP_UGqsC&pg=PA64&lpg=P...](https://books.google.com/books?id=_qVgeP_UGqsC&pg=PA64&lpg=PA64&dq=Farm+Hall+transcripts+"second+raters")

------
meowface
Hahn comes across very sympathetically throughout this.

>HAHN: I must honestly say that I would have sabotaged the war if I had been
in a position to do so.

>HAHN replied that he too loved his country and that, strange as it might
appear, it was for this reason that he had hoped for her defeat.

~~~
tptacek
Otto Hahn is well known for his opposition to Nazism and to nuclear weapons.

~~~
hga
And he matched that by action, delivering the results of his radio-chemistry
masterpiece (e.g. getting results from just a few thousand atoms!) first to
his exiled colleague Lise Meitner, which follows a very straight line to the
scientific success of the Manhattan project through her nephew, who did his
Christmas vacation with her when she got them, and then in England with
Peierls figured out the fast fission path to a practical device, and then on
to America.

------
KON_Air
>GERLACH: If Germany had had a weapon which would have won the war, then
Germany would have been in the right and the others in the wrong, and whether
conditions in Germany are better now than they would have been after a HITLER
victory –

>HEISENBERG: I don't think so. On the other hand, the days of small countries
are over. Suppose HITLER had succeeded in producing his EUROPE and there had
been no uranium in EUROPE.

This is now my favourite political quote.

~~~
Jugurtha
Or this one:

> _HARTECK: Who is to blame?_

> _(?) VOICE: HAHN is to blame._

> _WEIZSÄCKER: I think it 's dreadful of the Americans to have done it. I
> think it is madness on their part._

> _HEISENBERG: One can 't say that. One could equally well say "That's the
> quickest way of ending the war.”_

> _HAHN: That 's what consoles me._

Sharp.

~~~
hga
His "fault" a _very_ direct way:
[https://news.ycombinator.com/item?id=12568722](https://news.ycombinator.com/item?id=12568722)

~~~
Jugurtha
I was talking about Heisenberg being sharp. You can see through his comments
he can talk with detachment about issues and offer perspective as would a
complete outsider. He talks casually, almost as a commentator in a
documentary.

>HEISENBERG: _There is a great difference between discoveries and inventions.
With discoveries one can always be skeptical and many surprises can take
place. In the case of inventions, surprises can really only occur for people
who have not had anything to do with it. It 's a bit odd after we have been
working on it for five years._

It seems like they're talking about the issues at hand, and he's just sitting
there thinking about all of this in an abstract way, like it doesn't matter.

~~~
sesqu
Heisenberg is remembered for his theorem on quantum observation being
necessarily incomplete. It's not terribly surprising to find he had a
perspective-seeking approach in other matters.

~~~
Jugurtha
Pardon me but, can you elaborate? What do you mean by "Heisenberg is
__remembered for his theorem on quantum observation being necessarily
incomplete __"?

And how does that make him a "perspective-seeker"?

~~~
sesqu
I was referring to Heisenberg's uncertainty principle, which states that there
is an upper limit to the combined precision of a particle's position and
momentum. Bohr's take on this was that the limit is due to these concepts
being a poor approximation of actual quantum mechanics, which would fit the
scientific eminence co-existing with devout religious beliefs in Heisenberg.

I am no physicist, nor am I well versed in Heisenberg's life, but the quotes
in the link suggest to me that he has spent a large amount of time pondering
ethics, unseen causality, and attributed intent. That is what I meant by
seeking perspective.

~~~
Jugurtha
>I was referring to Heisenberg's uncertainty principle

Now I see.. I only took a few physics courses and mostly associate his name
when using the inequality, i.e what I think of when I read " _uncertainty_
principle" (also, doing time-frequency signal processing/analysis). I was
thrown off by the expression "quantum _observation_ " because I thought you
were talking about the _observer effect_ , something that didn't really make
me think of him.

Maybe we can chalk it up to cultural differences, but we've never called it
like that here (it was always "Heisenberg's uncertainty principle").

>the quotes in the link suggest to me that he has spent a large amount of time
pondering ethics, unseen causality, and attributed intent. That is what I
meant by seeking perspective.

Indeed. I also think this is the case for the others, too. What's impressive
was his almost forensic approach. His remarks read more like an autopsy than
someone being in the situation he was in.

~~~
sesqu
> I was thrown off by the expression "quantum observation" because I thought
> you were talking about the observer effect

I admit that the observer effect was the first thing that sprang to mind when
I was thinking of how the uncertainty principle was stated. That's probably
why I worded it so poorly.

> His remarks read more like an autopsy than someone being in the situation he
> was in.

Seeing as how all this took place soon after the war, I imagine he may have
considered it something of a post-mortem.

------
GnarfGnarf
One of the most telling remarks:

 _That shows at any rate that the Americans are capable of real cooperation on
a tremendous scale. That would have been impossible in Germany. Each one said
that the other was unimportant._

Organization & management were key to winning.

~~~
hga
Indeed, this I believe is _the_ key insight into the stunning success of the
Manhattan project. The scientists worked pretty hard as soon as uranium
fission and it's details were discovered, Frisch and Peierls critically got
all the fast fission concepts right in 1940, see
([https://en.wikipedia.org/wiki/Frisch%E2%80%93Peierls_memoran...](https://en.wikipedia.org/wiki/Frisch%E2%80%93Peierls_memorandum)
And Frisch's story is particularly interesting, see Rhodes' book, doing
Christmas vacation with his aunt, who just happened to be the first physicist
her back in Germany colleague sent his results to right then.... Vs., for
example, again from Rhodes' book, a clerical mixup ruining the saving throw
for the German effort, the Nazi political types got invitations for the wrong
seminar, one on very technical stuff instead of the pitch for atomic stuff
(which, if they'd done _everything_ right, they _could_ have pulled off, I
think).

But it took a long time to light a fire under the American authorities, and it
wasn't until the absolutely critical replacement of his name is a footnote in
history with Groves that things really got rolling, on the industrial scale
needed, and the scientists and engineers sufficiently focused on the design
and execution of the bombs themselves (which for various reasons didn't end up
being the afterthought some expected). And he of course picked Oppenheimer to
lead that effort, which was opposed by most, albeit he was one of the few
uncommitted physicists capable at that level.

These two men organized more than 100,000 people for the industrial production
of the required fissionables (90% of the work per Wikipedia), and Grove's
drive got those ready in time to forestall Operation Downfall. Heck, they went
from the first real test to putting metal on target in 21 and 24 days....

And the design and fabrication of "the bomb" turned out to be massively harder
than they expected due to weapons grade plutonium not being suitable for a gun
assembly bomb (which is also grossly wasteful of fissionable, if the Little
Boy is any guide, as I recall it had 3x critical mass, and a fair amount if it
wasn't as pure U-235 as they'd have wanted). Making the implosion concept work
was _hard_ , and they got it right the first time....

Read Rhode's book, especially the latter half after the nuclear physics
discoveries take a back seat ([https://www.amazon.com/Making-Atomic-Bomb-25th-
Anniversary/d...](https://www.amazon.com/Making-Atomic-Bomb-25th-
Anniversary/dp/1451677618)) and Grove's autobiography
([https://www.amazon.com/Now-Can-Be-Told-
Manhattan/dp/03068018...](https://www.amazon.com/Now-Can-Be-Told-
Manhattan/dp/0306801892/)) to learn the organization and management details,
they're amazing.

And had much wider effects on the world at large, that we could indeed do such
things led to the Apollo program, and of course to too much conceit that "If
we can put a man on the moon, why can't we [do something very different and a
lot more intractable, probably without even a clearly defined goal]?"

------
pdm55
"The Atom Soldier" [https://www.youtube.com/watch?v=CthmRe-
IU_Y](https://www.youtube.com/watch?v=CthmRe-IU_Y) This episode of the United
States Army's "The Big Picture" details the tests conducted at Frenchman's
Flat, Nevada, in January of 1955. The Army, based at Camp Desert Rock,
utilized thousands of ground troops in an effort to establish the proper
coordination between the foot soldier and the atomic blast.

------
zerooneinfinity
Some of them seemed relieved the war was going to be over. It was also
interesting they weren't that interested in winning.

HEISENBERG: One can't say that. One could equally well say "That's the
quickest way of ending the war.” HAHN: That's what consoles me

WEIZSÄCKER: I believe the reason we didn't do it was because all the
physicists didn't want to do it, on principle. If we had all wanted Germany to
win the war we would have succeeded.

~~~
whoopdedo
Might they have known or suspected that they were being recorded? Their words
may have been chosen to make them sound good were they to be brought before a
tribunal.

~~~
meowface
Especially considering they were very familiar with an oppressive regime known
for its secret police and intelligence gathering from various agencies.

------
kmonad
> WEIZSÄCKER: One can say it might have been a much greater tragedy for the
> world if Germany had had the uranium bomb. Just imagine, if we had destroyed
> LONDON with uranium bombs it would not have ended the war, and when the war
> did end, it is still doubtful whether it would have been a good thing

I believe this should be "...and if it _did_ end the war, it is still
doubtful..."?

~~~
dragonwriter
No, I think its exactly right. The war _would_ have ended eventually, somehow,
and its doubtful that the change to how it would have wrought by the German
use of the A-bomb would have a good one.

------
blackflame7000
Very cool Article! For all the political discord going on in this day and age,
reading this transcript really does make me feel proud to be an American.

~~~
davesque
I actually agree. It seems there was no other time in recent history when we
were truly in the right about so many things. I believe there are some
passages in this document that touch on this:

"HAHN: I must honestly say that I would have sabotaged the war if I had been
in a position to do so."

"...They then went on to discuss the feelings of the British and American
scientists who had perfected the bomb and HEISENBERG said he felt it was a
different matter in their case as they considered HITLER a criminal..."

"WEIZSÄCKER: Our strength is now the fact that we are 'un–Nazi'."

Many of the physicists mentioned here expressed doubts about the Nazi regime.
Perhaps it could be said that they didn't achieve the bomb because, in many
ways, they didn't want their leaders to possess it. So there was a kernel of
doubt preventing them from doing so. On the other hand, the Americans did not
have that problem since they "considered Hitler a criminal" and viewed it as
imperative that they win the war at any cost. Maybe this made the moral
question of whether or not to achieve the bomb less of an obstacle for them.
That gave a psychological benefit which facilitated the work they were doing.

~~~
blackflame7000
Yes that is an excellent point! Moral superiority and the imparitive to act
are highly motivating factors. What's interesting is that when faced with the
opposite senario, humans tend to default to inaction rather than be a
whistleblower. Moral superiority is only motivating if the majority is on your
side.

~~~
hga
Perhaps the single most curious things in Rhode's book is what put them off
the path of graphite moderated natural uranium reactors, the work of a single
unreliable scientist who, as it happened, was not using pure enough graphite
(too many neutron poisons, it was quite a challenge for us to get graphite
pure enough). That pretty much dead ended their efforts on the science front,
heavy water natural uranium reactors are quite possible
([https://en.wikipedia.org/wiki/CANDU_reactor](https://en.wikipedia.org/wiki/CANDU_reactor)
although I remember reading somewhere the Canadians had access to extra rich
in U-235 uranium), but definitely not trivial, especially when we were zapping
their supplies of heavy water from Norway.

------
chillacy
> HEISENBERG replied that had they produced and dropped such a bomb they would
> certainly have been executed as War Criminals having made the "most devilish
> thing imaginable"

Heh. There's a little piece of truth to how war crimes are prosecuted.

~~~
jrockway
I still don't understand why Japan gives us a pass for nuking two of their
cities.

~~~
67726e
Because they started it and would have killed and estimated million of our own
(millions of their own!!!) invading the home islands. Why does this happen
every damn time it comes up on HN. We didn't just say "hey, fuck those nips".
It was the best option for everyone involved.

~~~
Cyph0n
It's not as clear cut as you make it out to be in my opinion. Please think
twice and look at the aftermath and devastation that resulted from using
nuclear bombs on a civilian population.

Both sides were at fault, but to say that the U.S. was _objectively_ right is
an oversimplification.

~~~
tptacek
The invasion of Okinawa killed something like 140,000 civilians, in addition
to the horrific military casualties. That's _just Okinawa._

~~~
Cyph0n
Holy shit, that's insane...

~~~
tptacek
The civilian death toll just in ETO Belgium is higher than that of Nagasaki.
War is fucked up.

------
sandworm101
Careful. Start talking about the US defeating Germany and the Russians will
have something to say. There is good reason why in the US it is called WWII
and in Russia "The Great Patriotic War". The walk from Moscow to Berlin was
much longer than from France.

~~~
blackflame7000
It's not so much the Americans defeating the Germans that makes me proud, but
rather the immense technical achievement that was done in such little time out
of necessity. It is a perfect example of the American ingenuitive ideal. It's
shouldn't be taken as a slight to other nations but rather as admiration for
the accomplishments of those who came before me

~~~
sandworm101
But don't forget that Manhattan was a three-country effort. Don't forget where
the uranium came from, or the number of scientists brought in from all over
the allied nations.

[https://en.wikipedia.org/wiki/Manhattan_Project](https://en.wikipedia.org/wiki/Manhattan_Project)

~~~
blackflame7000
Almost all of the enrichment process was done at oak ridge in Tennessee. It
even says so in the Wikipedia page you posted.

~~~
hga
On the other hand, we were handed on a silver platter a huge supply of hand
sorted pitchblende from the Belgium Congo, with an _average_ uranium content
of 60-65% (!!!), without that we wouldn't have finished in time to finish the
war.

All due to one foresighted Belgium who had learned would be a _very_ bad idea
to let the Nazis get their hands on it, and arranged shipment of a lot of it
to America. Where it sat in a warehouse until Grove's men showed up and were
actually serious about buying the stuff, after e.g. the State Department and
everyone else he'd contacted had blown him off, this is
[https://en.wikipedia.org/wiki/Edgar_Sengier](https://en.wikipedia.org/wiki/Edgar_Sengier)
but the greater story can be found in Rhodes' and Groves' books.

~~~
blackflame7000
Its not the Uranium content that matters, it's the ability to extract U235
from U238.

~~~
hga
It counted because we had enough raw uranium to, indeed, separate one bomb's
worth of U-235 in time, but more importantly to fuel the natural uranium
reactors in which we bred plutonium, which got into high gear faster than the
former.

By comparison, in the link I included is the statement that " _To illustrate
the uniqueness of Sengier’s stockpile, after the war the MED and the AEC
considered ore containing three-tenths of 1 percent as a good find._ ", which
comports with my memory.

