June 16, 1929
There was no time in the rush of getting off to answer your good letter. Thank you,
and thank you for returning the photograph. Of course, we're all sorry you decided
not to come. But we understand very well you wanting to stay in Pasadena, and we are
not a bit mad about it. If I had been in your place, I think I would have done the
same thing. You have probably heard by now that my decision was to stay at Harvard.
Financially, and in some other ways, Princeton was more attractive. But it does seem
to me that things at Harvard are much more strategically fixed for the developments
of the next few years in physics, and the advantages of Princeton ill do seem made
up at Harvard anyway. I have decided, even more definitely than when you were in
Cambridge that the thing for me to do is to get into very much the stuff you are in
- applying the principles of quantum theory to the structure of matter in to more
ordinary [unintelligible]. It seems to me that there must be
one of the great finds, for a good while to come. I am planning, while I am in
Europe, to get ideas together and write a rather general paper on applying wave
mechanics to many-atom problems; trying to go at it in a more fundamental and
general way than, for example, the people who write on math using said specialty
models and methods. Bridgman is highly enthusiastic about giving in strongly for
that time. We are going to cooperate definitely on some problems in orbits, and gas
under high pressure. And we are planning some much more efficient training for
graduate students along the lines of properties of matter than we have had before
a graduate students course, with everything from high pressure to X-ray crystal
analysis, and more carefully planned and coveted research job. One finds that we are
going to work into it that of the optical properties of solids – both math and
non-math. One of Lyman’s students this year has been measuring reflect power of
[metals?] in the extreme ultraviolet, and we hope to extend his method so as to get
all the [unintelligible] constants. These, it seems to me,
should be of great use in investigating the energy level sets of free and formal
electrons in solids – I am very hopeful about the way things are going, and every
one else seems to be too.
My complex spectrum paper is done. I am taking an extra copy with me, to show to
[unintelligible]. I may want to see it in the next few
weeks, but I hope to be able to get that copy, or another, to you before very long.
I hope to use the same part of method I have employed in this paper in the more [unintelligible] many-atom problems.
One question that very much interests me is this: the calculation of good atomic
models to use in problems of [unintelligible]. As far as I
know, you and [unintelligible] and Fermis are the principle
men who have been, and are, calculating along its time. Two of our men, Zena and
Suilleman, who will be in Europe this year, are also taking a turn at it, [unintelligible] method. I have set a student working out
multiple equations, according[?] to my paper, and this will lead to the completion
of exchange integral between electrons in an atom. Kimble is also interested in the
problem. Now with so many of us working at it, it seems too bad to do it in an
entirely disconnected[?] way. You and Hartman, for example, have different methods.
But it seems to me entirely likely that you must, [unintelligible], I intended it, and [unintelligible] of shielded constant is by far the best and right for the
inner electron, with his methods, vary [unintelligible] more
accurate for outer electrons, with Fermis’s scheme certainly will be profitably[?]
used if general orientation of orbitals with bond. We at Harvard would be very glad
to take the initiative in exchanging ideas about the best methods, and in [unintelligible] and emerging results. I hope to see Hartman
in England, and see if he has useful ideas on the subject. It seems to me a plan
where some suggestion would both save a good deal of time and lead to better
results. I would be very glad of your ideas. We naturally want atomic models
ourselves, but I hesitate to set anybody direct works on them, since it will be too
much like competition. I hope to do some more things in the subject of the best
method, myself, before the year is over.
Best wishes for your work at Pasadena. We are, so far, having a tine trip – started
last Sunday, and land in Scottland [sic] Tuesday (after considerable delay from
fog). I hope to see Darwin, Fraler, Hartman, and perhaps one or two others, in
England, Kramers in Holland, and then go to Zurich. Helen sends her best wishes.
John C. Slater
Address: 90 Baring Bros & Co., Ltd, 8 Bishopsgate, London.