The kindest cut of all

Uncut pages

Occasionally, I open some dusty tome in the library, only to find that I can't read the pages I want because the pages have never been cut apart. That means that nobody has ever read the page I want to look at (at least in the copy I'm holding in my hands). I always wonder whether this means I'm unusually talented (for finding something interesting that nobody else has discovered) or unusually stupid (for bothering to read something everybody else thinks is dull).

Actually, the proper term for this situation is unopened rather than uncut. Bibliophiles use “cut” only in the sense of “trimmed” — as opposed to deckle edges, for example. When the pages have not been separated at the unbound edges, they are properly said to be “unopened.” But those of us who just read books are likely to say “uncut,” as I did above.

Anyway, a reader's practical problem is to get the pages separated tidily, without tearing their edges. Using a pencil, or your fingers, is guaranteed to produce a mess, ripping the pages irregularly. Don't do that!

Paper cuts

Anyone who has ever suffered a paper cut knows how sharp the edges of modern machine-cut sheets can be. So it's possible, if you're very careful, to use the edge of a new sheet of paper as a sort of knife blade, to saw open the unopened fold. The trick is to insert the paper between the uncut pages obliquely, and then withdraw it slowly, while exerting the right amount of force against the fold, so as to slit the paper cleanly, without tearing.

This is hard to do, because the sheet you're using as a saw will bend if you push it into the fold too hard, and won't cut at all if you don't push enough. It can also be very tricky on old, brittle pages that tear easily: if you push too hard, they may tear crookedly instead of coming apart at the fold. Usually, the older the paper, the less force is needed to do the job.

Often, the edge of a new manilla file folder, or a 3x5-inch file card, has the right combination of thinness, sharpness, and stiffness to serve as a knife for opening unopened pages in books.

Of course, the proper  way to proceed is to take the book to a librarian, and ask to have it opened for you. That way, at least, the librarian is responsible if the job is botched, and not you.

A cutting tale

One of the earliest times I needed to deal with unopened pages in a library was when I was trying to unravel the peculiarities of the Mariner 4 pictures. These were the first spacecraft pictures of Mars, and they showed craters for the first time — a cutting-edge achievement if there ever was one — but they were very peculiar: the craters were barely visible. The Caltech guys who had tried to analyze the pictures had applied Lambert's cosine law to determine slopes, and had come up with slopes of just a couple of degrees — very much shallower than slopes of craters on the Moon.

Having read the literature of both astronomical photometry and planetary science as a graduate student, I knew that (a) Lambert's “law” was invalid and misleading, and (b) this fact had been established back in the 19th Century. All natural surfaces disobey Lambert's “law”. Indeed, even when people have tried to engineer artificial surfaces to be Lambertian, they invariably have failed. As Arthur Searle wrote in 1899:

. . . Lambert's theory, developed in his `Photometria,' had been regarded as almost demonstrably true, while, in fact, it consisted of an ingenious mathematical superstructure on a very insecure foundation.

            — Observatory 22, 310–311 (1899)

I found that if more reasonable assumptions were made about the photometric properties of the surface of Mars, the Mariner 4 pictures could be explained in terms of crater slopes like those on the Moon. This explanation required the Mariner 4 images to be badly contaminated by stray light, however.

It was a rather uphill battle to convince people at JPL and Caltech that this was the case, however. So, to bolster my case, I wanted to quote from the 19th-Century astronomical photometrists who had established the non-Lambertian properties of planetary surfaces in general, and Mars in particular.

I knew where to look — for example, in the publications of the Potsdam Observatory — but needed to see a copy of the original work to cite the exact reference. The library at JPL (where I was working) had no old journals, but the Caltech Astronomy Department library did. I went to the Caltech campus, and found what I was looking for.

But (and here is where we cut back to the original topic) I found the pages were unopened. This meant that nobody at Caltech had ever read the relevant literature. No wonder they ignorantly assumed Lambert's “law” was valid!

And of course I had to open the unopened pages in order to find the passage I needed.

A cutting paper

In writing up my work for publication, I of course cited the various 19th-Century references mentioned above, knowing that the information they contained would be news to the Caltech folks. I put together the best arguments I could; but before I could submit the paper to a journal for publication, the manuscript had to be approved by people at JPL, where I was a junior staff member at the time.

My boss realized they didn't have the expertise required to judge such esoteric matters at JPL, so I was told I could submit the paper for publication if Robert Leighton (a Caltech physicist who had been deeply involved in the Mariner 4 TV experiment) would agree to it. So I was sent to his office to discuss it with him.

I'd sent him a copy of my manuscript in advance, so we could discuss it in detail. We had some straightforward discussion of various small points, and then came to the Lambert business.

“Well,” said Leighton, “in this paragraph, you make it sound as if anyone should know better than to use Lambert's law.” He said this in a half-jocular of-course-you-don't-really-mean-that tone of voice.

“Yes, that's right,” I replied brightly.

He looked quite taken aback. “Well,” he said finally, “I'll approve the paper for publication if you take out that paragraph.”

I figured half a loaf was better than none, so I made the requested cut. The paper was published in Icarus 11, 1–23 (1969). Carl Sagan, who was then the editor of Icarus, told me that he particularly liked it “because of the David and Goliath aspect.”

From my own point of view, it was more like shooting fish in a barrel. Or maybe I should say I viewed the whole affair as Leighton shooting himself in the foot: in science, ignorance of the facts will get you in trouble every time.

Leighton eventually retracted his false conclusions in print, and admitted that I had been right.

To cut, or not to cut?

There is a long discussion of the propriety of opening unopened volumes on the Web. The two main points of view expressed are those of

(a) readers who want to read what's in the library, and

(b) curators of “book museums” who insist that unopened pages bear important information about the unopened volumes.

As you can see from my own experience, sometimes the two issues arise simultaneously. I needed to read the old references; but, at the same time, the fact that they were unopened revealed to me that the Caltech people had never read them.

Did I do the right thing? If I'd left the pages unopened, they'd probably still be that way, bearing witness to physicists' ignorance of astronomy . . . .

© 2004, 2005, 2006 Andrew T. Young

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