School of Medicine

August 28, 1962
Notes in passing  --

        1. All you've sent me is under serious review.

        2. It would be nice to have a photographic matrix to trace the CitIndex vectors. But it would have to hold something like lO6squared bits. I.E. at 10 µ resolution, it would be 10 meters on each side. (If I recall, the rotating disks that IBM uses for such memories have about 106 bits each.) Someday, we will use an electron microscope to read out nanostorage, but I imagine there is already adequate pressure from computer needs generally to motivate looking for such advances, Actually, since a citation index will be almost empty (about 8,000,000 locations filled among the 1,000,000,000,000 available) it would not make the most economical use of such a memory. (I should add that a cathode ray tube memory has about 1000 x 1000 bits on it, just about enough for the most abbreviated index.)

            3.  AU of which points to the issue I hadn't adequately explained before, about using codes for the references so  citational clusters tend to come together on the tapes, just to shorten the sorting procedures. You probably do this anyhow. I just mean that you take full advantage of what you already know about the citational structure of the literature, e.g. the likelihood of cross- to the same journal, language, discipline, author, in setting up the machine codes. One point about cutting up the total  into disciplines is that the search times in cycling procedures may tend to go as the square of the number of items in the subset, but this may be avoidable.

        4. You might enjoy thinking what the vector representation looks like in polarcoordinates. But you need an equivalence for a radius and a vector angle when a source becomes another' s reference.

        5.  The enclosed should be self-explanatory (Swift is an officer in the new Society for Cell Biology) it is a blind copy to you.

        6. Since you put Harpers into C/C "Social', I dare to ask, as I have long meant whether you could get somebody to index the New Yorker. I have reams of old issues at home that I can' t bear to throw out, but find impossible to locate anything in. And I imagine this is not so for our household.

    Lots more, but must run/

Carmas , IRE-Audio Trans., AU-9 (5) 174 , 1961 has a neat note on the density  of information storage systems. Also in June± 1962 Proc IRE. Which also brings up question, how investigate what market there would be for a semi annual cumulation of C/C. on microcard which any library and many investigators could find a great convenience for lookup, in place of keeping the bulk of a year's past issues.