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Archive for May 23rd, 2008

May
23

On Reading American Prometheus

Posted by jns on May 23, 2008

In truth it was last summer* when I read the book by Kai Bird and Martin J. Sherwin, American Prometheus : The Triumph and Tragedy of J. Robert Oppenheimer (New York : Vintage Books, 2005; 721 pages). It’s only today, however, when I finally got around to assembling my notes into the requisite book note.

It’s a magnificent, informative, and very readable book about a central figure of the last century, the contradictory J. Robert Oppenheimer. Knowing what went on with the Manhattan Project and then the persecution of Oppenheimer may well be required knowledge for good American citizenship; reading this book would be a terrific way to get up to speed on that. (Coupled with Richard Rhodes’The Making of the Atomic Bomb, you can learn virtually all you need to know from two excellent books.)

Guess what? I had some left-over quotations I wanted to excerpt, so there they are.

As Harry Truman moved into the White House, the war in Europe was nearly won. But the war in the Pacific was coming to its bloodiest climax. On the evening of March9–10, 1945, 334 B-29 aircraft dropped tons of jellied gasoline–napalm–and high explosives on Tokyo. The resulting firestorm killed an estimated 100,000 people and completely burned out 15.8 square miles of the city. The fire-bombing raids continued and by July 1945, all but five of Japan’s major cities had been razed and hundreds of 1945, all but five of Japan’s major cities had been razed and hundreds of thousands of Japanese civilians had been killed. This was total warfare, an attack aimed at the destruction of a nation, not just its military targets.

The fire bombings were no secret. Ordinary Americans read about the raids in their newspapers. Thoughtful people understood that strategic bombing of cities raised profound ethical questions. “I remember Mr. Stimson [the secretary of war] saying to me,” Oppenheimer later remarked, “that he thought it appalling that there should be no protest over the air raids which we were conducting against Japan, which in the case of Tokyo led to such extraordinarily heavy loss of life. He didn’t say that the air strikes shouldn’t be carried on, but he did think there was something wrong with a country where no one questioned that….”

On April 30, 1945, Adolf Hitler committed suicide, and eight days later Germany surrendered. When Emilio Segrè heard the news, his first reaction was, “We have been too late.” Like almost everyone at Los Alamos, Segrè thought that defeating Hitler was the sole justification for working on the “gadget.” “How that the bomb could not be used against the Nazis, doubts arose,” he wrote in his memoirs. “Those doubts, even if they do not appear in official reports, were discussed in many private discussions.” [p. 291]

One of the big reasons for developing the Bomb, at least in the minds of the scientists, was to do it before Hitler’s scientists did, lest the world suffer the consequences. The military and the US Government, on the other hand, had a different agenda and insisted on using the bomb on an actual target even thought the Japanese were close to surrender, perhaps as a demonstration to the Soviet Union. The atomic-project scientists felt betrayed and suddenly conflicted as that realization dawned. The whole affair is murky and filled with intrigue.

There was much that Oppenheimer did not know. As he later recalled, “We didn’t know beans about the military situation in Japan. We didn’t know whether they could be caused to surrender by other means or whether the invasion was really inevitable. But in the backs of our minds was the notion that the invasion was inevitable because we had been told that.” Among other things, he was unaware that military intelligence in Washington had intercepted and decoded messages from Japan indicating that the Japanese government understood the war was lost and was seeking acceptable surrender terms.

On May 28, for instance, Assistant Secretary of War John J. McCloy urged Stimson to recommend that the term “unconditional surrender” be dropped from America’s demands on the Japanese. Based on their reading of intercepted Japanese cable traffic (code-named “Magic’). McCloy and many other ranking officials could see that key members of the Tokyo government were trying to find a way to terminate the war, largely on Washington’s terms. On the same day, Acting Secretary of State Joseph C. Grew had a long meeting with President Truman an told him the very same thing. Whatever their other objectives, Japanese government officials had one immutable condition, as Allen Dulles, then an OSS agent in Switzerland, reported to McCloy: “They wanted to keep their emperor and the constitution, fearing that otherwise a military surrender would only mean the collapse of all order and of all discipline.”

On June 18, Truman’s chief of staff, Adm. William D. Leahy, wrote in his diary: “It is my opinion at the present time that a surrender of Japan can be arranged with terms that can be accepted by Japan….” The same day, McCloy told President Truman that he believed the Japanese military position to be so dire as to raise the “question of whether we needed to get Russia in to help us defeat Japan.” He went on to tell Truman that before a final decision was taken to invade the Japanese home islands, or to use the atomic bomb, political steps should be taken that might well secure a full Japanese surrender. The Japanese, he said, should be told that they “would be permitted to retain the Emperor and a form of government of their own choosing.” In addition, he said, “the Japs should be told, furthermore, that we had another and terrifyingly destructive weapon which we would have to use if they did not surrender.”

According to McCloy, Truman seemed receptive to these suggestions. American military superiority was such that by July 17 McCloy was writing in his diary: “The delivery of a warning now would hit them at the moment. It would probably bring what we are after–the successful termination of the war.”

According to Gen. Dwight D. Eisenhower, when he was informed of the existence of the bomb at the Potsdam Conference in July, he told Stimson he thought an atomic bombing was unnecessary to hit them with that awful thing.” Finally, President Truman himself seemed to think that the Japanese were very close to capitulation. Writing in his private, handwritten diary on July 18, 1945, the president referred to a recently intercepted cable quoting the emperor to the Japanese envoy in Moscow as a “telegram from Jap Emperor asking for peace.” The cable said: “Unconditional surrender is the only obstacle to peace….” Truman had extracted a promise from Stalin that he and many of his military planners thought would be decisive. “He’ll [Stalin] be in the Jap war on August 15,” Truman wrote in his diary on July 17. “Fini Japs when that comes about.”

Truman and the men around him knew that the initial invasion of the Japanese home islands was not scheduled to take place until November 1, 1945–at the earliest. And nearly all the president’s advisers believed the war would be over prior to that date. It would surely end with the shock of a Soviet declaration of war–or it might end with the kind of political overture to the Japanese that Grew, McCloy, Leahy and many others envisioned: a clarification of the terms of surrender to specify that the Japanese could keep their emperor. But Truman–and his closest adviser, Secretary of State James F. Byrnes–had decided that the advent of the atomic bomb gave them yet another option. As Byrnes later explained, “…it was ever present in my mind that it was important that we should have an end to the war before the Russians came in.”

Short of a clarification of the terms of surrender–a move Byrnes opposed on domestic political grounds–the war could end prior to August 15 only with the use of the new weapon. Thus, on July 18, Truman noted in his diary, “Believe Japs will fold up before Russia comes in.” Finally, on August 3, Walter Brown, a special assistant to Secretary Byrnes, wrote in his diary: “President, Leahy, JFB [Byrnes] agreed Japs looking for peace. (Leahy had another report from the Pacific.) President afraid they will sue for peace through Russia instead of some country like Sweden.” [pp. 3000--301]

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* In fact it was the book I took with me on our trip in July 2007 to Tuscany. I have fond memories of lying in bed in our hotel room in Pisa reading about Oppenheimer.

May
23

On Satellite Dishes Looking in the Same Direction

Posted by jns on May 23, 2008

I recently finished reading Richard Dawkins’ Climbing Mount Improbable (New York : W.W.Norton & Company, 1996, 340 pages). It wasn’t bad, but it wasn’t his best by any means. All of the little things that irritate me about Dawkins’ writing seemed emphasized in this book. There’s more in my book note, of course.

Dawkins is usually such a careful writer so I was surprised by the brief lapse of analytical perspicacity he exhibits in this passage. He is describing the fascinating compass termites that build tall and surprisingly flat mounds, like thin gravestones.

They are called compass termites because their mounds are always lined up north-south–they can be used as compasses by lost travellers (as can satellite dishes, by the way: in Britain they seem all to face south). [p. 17]

Well, of course they seem to face south–the satellite dishes, I mean–and there’s a very good reason. I can’t believe Dawkins would say something this…well, I can’t think of just the right word to combine unthinking lapses with scientific naiveté, specially since he’s the Charles Simony Professor of the Public Understanding of Science at Oxford. Tsk.

Satellite dishes are reflectors for radio waves transmitted by satellites; the dishes are curved the way they are so that they focus the radio signal at the point in front of the dish where the actual receiver electronics reside, usually at the top of a tripod arrangement of struts. In order to do this effectively the satellite dish must point very precisely towards the satellite whose radio transmitter it is listening to.

If the satellite-radio dish is stationary, as most are, that means that the satellite itself appears stationary. In other words, the satellite of interest always appears at the same, unmoving point in the sky relative to the satellite dish, fixed angle up, fixed angle on the compass.

Such satellites are called “geostationary” for the obvious reason that they appear at stationary spots above the Earth. In order to appear stationary, the satellites must rotate at the same angular velocity as the Earth, and they must appear not to move in northerly or southerly directions.

In order not to appear to move north or south, and to have a stable orbit, the satellites must be positioned directly above the Earth’s equator (i.e., in the plane that passes through the Earth’s equator). In order to have the necessary angular velocity they must be at an altitude of about 35,786 km, but that detail isn’t terribly important for this purpose.

Armed with these facts, we may now consider two simple questions, the answers to which apparently eluded Mr. Dawkins:

  1. For an observer in Great Britain, in what direction is the equator?
  2. If a satellite dish in Great Britain wishes to listen to a geostationary satellite, in which direction will it point?

The answers: 1) south; and 2) southerly.* Now it’s no surprise that (virtually) all satellite dishes in Britain do point south.
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* Yes, there are slight complications having to do with the longitude of the particular satellite, but most of interest to Great Britain will be parked near enough to 0° longitude not to affect the general conclusion.