MAR 1 6 1970

MATHEMATISCH INSTITUUT
DER RUKSUNIVERSITEIT TE UTRECHT

utrecHt, March 12, 1970
Universiteliscentrum De Uithof

Budapestlaan
Tel. (030) 5114 11

Professor Joshua Lederberg

Stanford University School of Medicine
Department of Genetics

STANFORD (Calif) 94305 USA

Dear Lederberg,

It is not the first time you show your keen interest in Lincos.

I do not remember about the fine structure constant, but I am
not sure whether transmitting any dimensionless physical
constant would adequately be understood. Dimensionless constants
may be computed differently in civilizations with a different
historical background. For instance, the fine-structure
constant could have a factor 27 more or less in one or the
other culture withdut impairing its usefulness. Even purely
mathematical constants are not, too trustworthy. Maybe in an-

other world they prefer using 5- rather than 27, e71 rather

than e, which would not make todmuch difference for mathematics
though it would impair the recognizability of the constant.
Therefore I preferred introducing physical constants in a
broader context where their meaning is explained, even though
they are not dimensionless (as the Rydberg constant).
Describing the hydrogene spectrum is as easy and more convincing),
A list of primeg numbers which may be shot, is more convincingyS
than e or 7. r

3003 SH

LV

I have often bees:aewed about your second question. The
difference with Etruscan and Mayan is, first, that texts in
these old languages are about subjects we are not acquainted
with (it is old religion), second, that Lincos is intentionally
made to be understood. In conferences I often made the
experiment of confronting people with Lincos texts to be
deciphered, and I always succeeded. Of course this is not a _
well controlled experiment, but I am quite convinced that it
would work as well under serious experimental cenditions.

Thank you for your letter.

Yours sincerely,

(H.Freudenthal)