LtE in CMO #261

From William SHEEHAN

Subject: Re: About Ina

Dear Masatsugu,

As always a tremendous pleasure to hear from you.

I am intrigued by the plans to hold the meeting in the Ina Valley, Nagano, and many thanks for the evocative image. I eagerly await word of this meeting and wish I could join you.

I do hold out realistic hopes of visiting Japan next summer, on the way to New Zealand. It would give me inexpressible delight to meet you and other members of the CMO and to observe Mars together. We could scout out some of the sites associated with Percival Lowell's visit to Japan -- his visit is, obviously, as your comments underscore, still fresh in memory.

I'm intrigued by Lowell's reputation as an alpinist. As you know, the Lowell abilities in such fields as literature and mathematics have run very true, and it may interest you that the current Lowell Observatory Sole Trustee, Bill Putnam, has been an avid alpinist. I recall he has climbed the Matterhorn.

Still on the subject of Lowell, you may find the following of interest.

Tom Dobbins and I recently published in Sky & Telescope an article on Lowell's observations of the spokes of Venus. The latter have long been a puzzle. The article elicited some interesting comments. Sherman Schultz of Macalaster College, in St. Paul, Minnesota, wrote mentioning that as a retired optometrist he wondered whether Lowell's practice of stopping down his big lens to 3 inches or less mightn't, in effect, have produced an instrument similar to one he himself used to map patients' incipient cataracts.

I made some observations of Venus with the Lowell refractor in the summer of 1982, when Venus was a small gibbous, but I must admit, it never even occurred to me to stop down the instrument to only 3 inches. I got quite good views with the aperture diaphragmed to 12 inches -- there was a shading at the terminator and a diffuse dusky band.

After getting Sherm's letter, I realized how singular Lowell's set-up was. I was sufficiently intrigued to write to Andy Young, who's my favorite expert on this kind of optical question.

Here's what he said: "Well, my take on this is that the stopping-down problem produces an exceedingly tiny exit pupil, so that the depth of focus in the eye is greatly increased.

Thus features that are normally out of focus in the vitreous humour could project detectable shadows on the retina. I don't think the cataract explanation is valid. These are features in the lens or the cornea, which are in the same place as the exit pupil of the telescope. As the eye moves, these features would be scanned across the telescope pupil, but would not produce features on the retina. More likely, these are images of blood vessels overlying the retina in Lowell's eye.

"A small exit pupil might work ... by making use of the parallax (small though it is) between the vessels and the retina. As the eye moves ... the angle at which rays arrive at the retina changes, so that features within the eye but a little removed from the retina, such as blood vessels, may cast shifting shadows on the latter and be seen."

This is interesting to me as a former medical student who spent a lot of time looking at fundi -- normal and abnormal -- through an ophthalmoscope.

I did note with interest even at the time that maps of the retinal blood vessels (though they are peculiar to each individual eye) did present a coarse network not unlike Lowell's Venus drawings. If one places an ophthalmoscope image of the fundus of an eye (such as, conveniently, that in Richard L. Gregory's Eye and Brain: the psychology of seeing) next to Lowell's map of Venus, the resemblance is, in my view, uncanny. The fovea is in the position of Lowell's "subsolar spot."

So my conclusion is that Lowell was actually using his telescope as a kind of ophthalmoscope and mapping not Venus but the fundus of his eye.

Arthur C. Clarke's comment, that Lowell was "the man with the tesselated eyeball," takes on new meaning.

I can't resist mentioning that Lowell died of an intracerebral hemorrhage. The usual cause of this is extreme hypertension, which often produces changes (such as papilledema -- swelling) in the fundus of the eye.

Lowell didn't make any observations of Venus after 1914 but one does wonder whether, at least in principle, one mightn't have made the diagnosis of hypertension from a careful study of his Venus drawings!!

I was interested to hear that copies of the Japanese translation of Lowell's Noto are still to be found in Japan. I should love to fetch one.

Though unlike Jeff Beish, I don't read or speak Japanese, it would be splendid to have this as a memento of the association of Lowell, Mars, and Japan. If you run into an inexpensive copy please let me know and how I might go about acquiring it.

With my very best and warmest regards,

　　　　　　　　　　　　　　(11 June 2002 email)

I am deeply touched by your kindness in sending me the Japanese translation of Noto -- I shall prize it forever. Meanwhile, I shall look forward to seeing the photographs took during his travels, and hope to compare these scenes with those I shall see when I visit Japan next year, as I am firmly resolved now to do.

My deepest thanks,

　　　(13 June 2002 email)

Thought you might find the following interesting, which I wrote for S&T on the subject of Lowell's "spokes of Venus." There was an article on this long-standing mystery in the July 2002 Sky & Telescope, which elicited some interesting responses.

　　　(13 June 2002 email)

Dear Editors:

It isn't often that one writes an article for a monthly publication about a hundred year old mystery and sees it solved before the next issue is in print. That, however, seems to be the case with "Lowell and the Spokes of Venus," an article that we wrote for the July 2002 issue of Sky & Telescope.

As described there, Lowell's observations have long baffled astronomers and historians of astronomy. However, the crucial factor in explaining what Lowell saw seems to have been his penchant for stopping down the great Clark refractor to 3 inches or so in observing the planet.

Andy Young of San Diego State University, Phil Steffey of Daytona Beach, Florida, and Dale Cruikshank of NASA-Ames all noted that by diaphragming the great refractor to 3 inches or less and using magnifications over 100x, Lowell made the telescope approximately f/120 or greater. This is equivalent to producing a pinhole of diameter less than 0.5 mm, the diameter of the fovea, in front of the eye. This tiny pinhole, when oscillated rapidly against a bright background such as provided by Venus, allows shadows of the blood vessels and other structures in the retina to be seen easily. Steffey suggests that anyone who wishes to can test the hypothesis by using a refractor or long-focus (preferably Newtonian) reflector, using high magnifications, to look at gibbous Venus in a dark steady sky. Another way of seeing the "Lowellian" coarse pattern in the eye is proposed by Andy Young, who suggests looking at a uniform light source (such as a blue sky) through a green interference filter; you just tilt the filter and the features pop into view as you get the transmitted wavelength at the peak absorption of hemoglobin in the spectrum.

The images below, showing Lowell's 1896 map of Venus and the human fundus as viewed through an ophthalmoscope, do suggest that Lowell was effectively using his telescope as an ophthalmoscope! The spokes of Venus correspond to blood vessels, the "subsolar spot" to the fovea. One can see why Lowell was led to believe that Venus had a synchronous rotation; one can even explain the peculiarity, noted by E. M. Antoniadi at the time, that Venus seemed always to keep the same face not toward the Sun but the Earth! Lowell, indeed, accurately recorded what he saw; no one can claim that he did imagined the spokes of Venus. However, he transferred the features of his own tessellated eyeball onto the surface of the distant planet.

I can't resist mentioning that Lowell died of an intracerebral hemorrhage. The usual cause of this is extreme hypertension, which often produces changes (such as edema and swelling, called papilledema) of the fundus of the eye, which can be recognized using an ophthalmoscope. Though Lowell didn't make any observations of Venus after 1914, one must wonder whether, in principle, one mightn't have made the diagnosis of hypertension by carefully studying his Venus drawings!

William Sheehan and Thomas Dobbins

The retinal-shadow explanation of the spoke-like markings on Venus has attracted lots of attention -- it seems so immediately appealing.

Of course, the implication is, further, that such effects might provide a fresh reinterpretation of the rest of the fleeting Lowellian impressions of lines, on the other disks he studied, including Mercury, the Galilean satellites of Jupiter, and even Mars.

Meanwhile, I have just received the following from David Strauss, professor of history at Kalamazoo College, who is retiring this summer (note especially his remarks about the meeting in Japan of the Lowell Society -- do you know of it?). David wrote a recent biography of Percival Lowell published by Harvard University Press. I do hope we can set up a joint Mars/Lowell in Japan conference sometime next summer when Mars is close to the Earth. We could visit the Noto Peninsula with Mars flaring up, and invoking the prose of Lowell's 1895 book Mars: "A great red star ... rises at sunset through the haze about the eastern horizon, and then, mounting higher with the deepening night, blazes forth against the dark background of space with a splendor that outshines Sirius and rivals the giant Jupiter itself" (!) –

(15 June 2002 email)

Here's David Strauss:

I have in hand the Japanese translation of "Noto". It's quite a beautiful edition and I believe that the translator, Masaaki Miyazaki, won a prize for the translation. At any rate, he is a very generous fellow who met me in 1988 and gave me a tour of the Noto Peninsula with stops along the way at appropriate spots. We ended in Anamizu where Lowell spent the night and where they have made something of an industry out of Lowell's brief visit: commemorative markers and a Lowell cake which can be purchased in one of the local bakeries. It's beautifully wrapped and bears the now iconic bora fish observatory as part of the wrapper design. I have some doubts about his identification of the photographs. A couple of them don't square with remarks that Lowell made in his correspondence.

On retirement plans: As soon as Harvard agreed to publish the Lowell biography, I started work on a new and very different research project, "the internationalization of American cuisine after World War II." A very strange aftermath to the Lowell work, but something that has always interested me. Anyway, it has helped me to avoid the letdown which normally follow a big project. In addition, there is a small publishing house in Tokyo which is planning to do an edition of the complete works of Amy and Percival -- at least their works dealing with Japan. I would be responsible for Percival and a Japanese colleague would work on Amy, so that should also keep me busy. Word from Japan is that the Lowell Society will hold its second meeting, this time in conjunction with the Lafcadio Hearn Society

First I wish to thank you for the fascinating piece of Lowelliana -- the Japanese translation of Noto. Of all of Lowell's books on Japan, I have enjoyed Noto the most, and it would be a dream come true to have the opportunity of visiting this lovely landscape. I shall always cherish it, not least for the kindness you have shown in bestowing it on me.

Meanwhile, I am eager to accept, tentatively, the kind offer to visit Japan and present information during the period you suggest, April/May 2004.

We can work out the details later but at the moment it sounds like a perfect solution.

Again, my thanks,

More soon,

(22 June 2002 email)

Bill SHEEHAN (Willmar, Minnesota, USA )

sheehan4@en-tel.net

Back to the LtE Home Page

Jump to the LtE Archives

Back to the CMO Home Page