
The Day Feynman Worked Out Black-Hole Radiation on My Blackboard - dnetesn
http://nautil.us/blog/the-day-feynman-worked-out-black_hole-radiation-on-my-blackboard
======
Mugwort
This is not at all unusual. Poincare discovered special relativity before
Einstein, Hilbert found the correct equations for General relativity one week
before Einstein, Hamilton almost discovered quantum mechanics decades before
everyone else. Newton found solutions to major mathematical problems and never
published them. Gauss discovered hyperbolic geometry before Bolyai and
Lobachevski and never bothered publishing his results. I can go on and on in
the fields of physics and mathematics which I know best. Certainly, the same
thing is true in chemistry, biology, etc. I wouldn't doubt someone got there
before even Feynman did. Still in every case, the recognized discoverer not
only made their discoveries independently but also managed to convince their
communities of their merit, something which is FAR harder to do.

This smells like classic Feynman. He did more things than people realize even
coming up with his own ideas about the Riemann hypothesis even though he
wasn't a mathematician at all. In a certain sense Feynman didn't discover a
single physical law. (arguable) . This little anecdote if true would be
Feynman's "single" discovery of an actual new physic law (which happens to not
have experimental verification).

Feynman was brilliant. If you have a physics PhD you can still benefit
enormously by reading Feynman's lectures on physics. His work on statistical
mechanics is essential reading too especially if you already know everything.

~~~
stcredzero
_This smells like classic Feynman. He did more things than people realize..._

He used to be ribbing Danny Hillis all the time, saying that he came up with
just about all of Computer Science during the Manhattan Project. "Just what is
it that you do again?"

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comboy
This just says he came to the conclusion that there should be spontaneous
emission and estimated it. Coming up with how it actually happens (particle-
antiparticle pair) is another story, so it seems a bit unfair to Hawking to
say that Feynman got it first.

~~~
coldtea
What other thing could be the emission?

Besides, isn't particle-antiparticle pair obvious, if one knows about their
spontaneous appearance?

~~~
mannykannot
I am always skeptical of retrospective claims of obviousness (partly from the
number of times I have seen it made in math textbooks.)

~~~
JadeNB
> I am always skeptical of retrospective claims of obviousness (partly from
> the number of times I have seen it made in math textbooks.)

I agree with you about your claim, but not about your justification. I believe
that "historically obvious" things ("that's the first thing I would have
thought of in that situation; how did it take them so long?") are usually
subject to considerable _ex post facto_ bias.

On the other hand, when a mathematics textbook says that something is obvious,
it means, or should mean: we've specifically set up the presentation to this
point so that there's a unique best way to assemble the material so far, and
that unique best way will accomplish the next step. This isn't always true
when it's claimed, but it _is_ possible in textbooks in a way that it isn't
(or that has only a small probability) in history, since textbooks are
consciously organised and history isn't.

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nihil75
Do cleaning staff actually wipe blackboards at Caltec?

Makes me question the authenticity of the story.

~~~
nabla9
I think Lightman uses artistic license a lot and has rehearsed the story
mulitple times in his mind. Lightman is a writer who wrote 'Einstein's
Dreams'. This article is basically transcript of the interview from 2014.
[http://nautil.us/blog/why-hawking-radiation-was-almost-
feynm...](http://nautil.us/blog/why-hawking-radiation-was-almost-feynman-
radiation)

Another weird think in the interview is Lightman saying that he don't think
Feynman didn't have a big ego.

Feynman loved Feynman stories and was very intellectually very competitive
with his peers. His reputation and those stories were not completely
spontaneous. His breakup with Gell-Mann came because he sometimes forgot that
it was not he who invented all those ideas they came up together.

I think one of the things that makes Feynman a bigger than life characters are
his quirks and personality. There is no need to clean up his image into some
king of humble guy.

~~~
gumby
> Another weird think in the interview is Lightman saying that he don't think
> Feynman didn't have a big ego.

I only got to know him pretty late in his life (when he was in Boston) and
FWIW, compared to many folks around MIT he was not especially or showily
egotistical and he had the time to talk to random students about interesting
things. He was more patient than most of the MIT faculty.

I can't say I was some sort of pal or anything so perhaps I got the benefit of
a more edited persona?

~~~
nabla9
Assuming Feynman's identity and self worth were tied around his intellect,
accomplishments and reputation. I don't think his identity was challenged in
day-to-day encounters with his students and colleges. Only people like Gell-
Mann might be able to push his buttons. If I remember correctly the stories,
the two were always trying to one-up each other even in trivial matters. That
kind of mutual challenging was probably beneficial.

Ego is weird word because it can mean opposite things in common use. "Weak
ego" \- person is easily upset when their identity is challenged. "Strong ego"
or "big ego" \- used as positive thing, opposite of weak ego. "big ego" \-
used negatively as synonym for egoistic, selfish or self centered. "egotistic"
\- excessive and objectionable reference to oneself in conversation or
writing; conceit; boastfulness, selfishness

~~~
gumby
Insightful theory. Impossible for me to have tested as I am not, and have
never been, in the Gell-Mann zone!

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neilv
I don't think I'll ever get tired of Feynman stories.

~~~
mrmondo
You and I both, if you haven’t already - read ‘Surely you must be joking, Mr
Feynman!”

~~~
neilv
Some other good ones on the 'net:

"Richard Feynman and the Connection Machine"
[http://longnow.org/essays/richard-feynman-connection-
machine...](http://longnow.org/essays/richard-feynman-connection-machine/) and
a smaller TEDx talk on the same topic by Danny Hillis:
[https://www.youtube.com/watch?v=8CKW4A6jnJA](https://www.youtube.com/watch?v=8CKW4A6jnJA)

"Los Alamos from Below" [https://www.youtube.com/watch?v=_aKM-
MeDMSI](https://www.youtube.com/watch?v=_aKM-MeDMSI)

~~~
mrmondo
Thanks for those, I don’t think I’ve seen the TED talk :)

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bjornsing
Sounds credible, up to the point about the cleaning lady... If he realized
their importance, why would he not be able to work out the equations again,
possibly with Feynman’s help?

~~~
huhtenberg
Precisely!

Violating the sanctity of one's blackboards is one of the worst possible
offenses in the academic world. Cleaning staff sure knows better than even
glancing in their approximate direction.

~~~
JoeAltmaier
Was that true in the 1050's? 1960's? Back then, the upper-class folk who
inhabited offices would not think of emptying a wastepaper basket, clearing a
desk, cleaning a floor. They may have had different expectations about who's
job it was to erase the chalkboard as well.

~~~
mannykannot
I would guess the cleaners would clean off the board only if the author had
made it very clear, some time beforehand, that this is what he wanted and
expected.

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vanderZwan
> _But when I got back to my office in the morning, the cleaning lady had
> wiped the blackboard clean._

Didn't something that happen to the notes of a very famous mathematician as
well? That they were burned by the person cleaning up his belongings after he
died?

~~~
reallymental
Perhaps you're thinking of Fermat[0], who famously remarked "I have discovered
a truly remarkable proof of this theorem which this margin is too small to
contain.", and promptly proceeded to take the solution with him to the other
side.

I doubt anyone burned his manuscripts however, but I seem to recall an article
where they mentioned that everyone searched for the solution (or for his
approach) in every one of his notebooks, but couldn't find it.

[0]
[https://en.wikiquote.org/wiki/Pierre_de_Fermat](https://en.wikiquote.org/wiki/Pierre_de_Fermat)

~~~
tragomaskhalos
Isn't the accepted version of this that Fermat _thought_ he had an elegant
solution, but had actually made some simple logical error in his reasoning?
And Andrew Wiles' solution is certainly not simple. However it is very
seductive to imagine that Fermat was correct, and it's just that no-one since
has had the insight to rediscover it.

~~~
anacleto
Very seductive but highly unrealistic. Wiles' proof required math techniques
undiscovered at the time Fermat made this famous statement.

~~~
whatshisface
Just because our proof is complicated does not mean Fermat's proof couldn't
have been simple, as no exhaustive search of all possible short proofs has
ever been carried out. Vanishingly unlikely yes, but not proven false, and
after all it is exceedingly romantic. ;)

~~~
anacleto
> and after all it is exceedingly romantic.

Agree on that part. (:

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lostmsu
AFAIK, Hawking got the idea of black hole radiation from Zeldovich. See
[https://en.m.wikipedia.org/wiki/Hawking_radiation#Discovery](https://en.m.wikipedia.org/wiki/Hawking_radiation#Discovery)

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CalChris
The article doesn't explain why light would bounce off a rotating black hole
and that doesn't make intuitive sense to me. I think of light as bouncing off
of surfaces and I think of a black hole as being an event horizon and stuff
inside. Does anyone have an explanation for this?

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paulpauper
there are multiple derivations. my guess is he used the simpler of the two
that does not require the field equation:
[https://en.wikipedia.org/wiki/Hawking_radiation](https://en.wikipedia.org/wiki/Hawking_radiation)

~~~
mannykannot
Feynman's argument is made from a phenomenon predicted for rotating black
holes, that is analogous to stimulated emission. I believe Hawking radiation
is predicted for all black holes, whether rotating or not, so I am wondering
if there is a phenomenon analogous to stimulated emission from non-rotating
black holes? (I am making an analogy of analogies here: if the original
phenomenon is like stimulated emission from rotating black holes, and Hawking
radiation is the corresponding spontaneous emission, then is Hawking radiation
from stationary black holes also like spontaneous emission, and if so, what is
the corresponding stimulated emission?)

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StopClickBait
This story may or may not be true, either way it encapsulates what a scientist
should be: distracted by reality and allowing other smart people to play their
roles. Feynman had his own things to work on, and clearly there were more
people needed for humans to advance.

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zeristor
This made me wonder if Rick Sanchez was based on Richard Feynman?

~~~
Retra
I thought it was well-known he was based on Doc Brown, and transitively,
Albert Einstein.

~~~
zeristor
I know that, but Feynman seems more fitting

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anacleto
Kinda reminds of me Fermat's equation though.

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foobarbecue
`Feynman said that what Bill and Saul were describing sounded like simulated
emission...`

Proof we live in a simulation! (presumably this is a typo)

