The Image in the Aperture

I was going to post more excerpts from Hiroshima, but like the blurb on the cover of my paperback copy of the book says (quoting a review from the Saturday Review of Literature), "Everyone able to read should read it."  And if you read it a good while ago, I suggest re-reading it.  I have dog-eared so many pages I'd be posting quotes from here to next week--okay that's beginning in a few hours, technically, so let's say from here to next month, at my current rate--if I excerpted passages from all the pages I marked.  It's a slim book, even with the added 1985 chapter.

Another slim book, slim for a textbook at 200 pages, is one I bought recently through the auspices of Edward R. Hamilton bookseller, called Introduction to the Theory of Coherence and Polarization of Light.  It's written by Emil Wolfe, and contains this as an epigraph for the first chapter:  "...the image that will be formed in a photographic camera--i.e. the distribution of intensity on the sensitive layer--is present in an invisible, mysterious way in the aperture of the lens, where the intensity is equal at all points."  The quote is from Frits Zernike's discussion of the concept of optical coherence in a lecture published in Proceedings of the Physical Society (London), Vol. 61, No. 158, 1948.

Wolf is rather well-known, partly for his research publications in optics and partly due to coauthoring two classic upper level physics textbooks:  Principles of Optics (with Max Born) , and Optical Coherence and Quantum Optics (with Leonard Mandel).  He is on the faculty at The Institute of Optics, U of Rochester. Here's what interests me mainly about the Intro book.  In the preface, and also included in the info about the book in the ERH bookseller catalogue, there's a statement saying it has recently been discovered that coherence and polarization of light "are two aspects of statistical optics which are intimately related and can be treated in a unified manner."  Recently means not long before the book was published in 2007.  Exciting stuff!

Next, or at least sometime soon, we must discuss the idea of superposition in quantum mechanics, before getting back to the cat, the strangeness of which is due to the unavoidability of superposition of states in quantum theory. 

Excerpts from first chapter of Hiroshima

The four chapters of Hiroshima as it was originally published in 1946 are:  A Noiseless Flash, The Fire, Details Are Being Investigated, Panic Grass and Feverfew; the new 1985 chapter is The Aftermath.  The experiences documented in the book are those of Miss Toshinki Sasaki, Dr. Masakazu Fujii, Mrs. Hatsuyo Nakamura, Father Wilhelm Kleinsorge, Dr. Terufumi Sasaki (no relation to Toshinki), and Reverend Mr. Kiyoshi Tanimoto.  Some excerpts from Chapter One:

            As Mrs. Nakamura stood watching her neighbor, everything flashed whiter than any white she had ever seen.  She did not notice what happened to the man next door; the reflex of a mother set her in motion toward her children.  She had taken a single step (the house was 1,350 yards, or three quarters of a mile, from the center of the explosion) when something picked her up and she seemed to fly into the next room over the raised sleeping platform, pursued by parts of her house.

            Timbers fell around her as she landed, and a shower of tiles pommelled her; everything became dark, for she was buried.  The debris did not cover her deeply. She rose up and freed herself.  She heard a child cry, “Mother, help me!,” and saw her youngest—Myeko, the five-year-old—buried up to her breast and unable to move.  As Mrs. Nakamura started frantically to claw her way toward the baby, she could see or hear nothing of her other children.

                                                                  _________________

            Dr.Fujii was the proprietor of a peculiarly Japanese institution: a private, single-doctor hospital.  This building, perched beside and over the water of the Kyo River, and next to the bridge of the same name, contained thirty rooms for thirty patients and their kinfolk—for, according to Japanese custom, when a person falls sick and goes to a hospital, one or more members of his family go and live there with him, to cook for him, bathe, massage, and read to him, and to offer incessant familial sympathy, without which a Japanese patient would be miserable indeed.

                                                                ___________________

            After the terrible flash—which, Father Kleinsorge later realized, reminded him of something he had read as a boy about a large meteor colliding with the earth—he had time (since he was about 1,400 yards from the center) for one thought:  A bomb has fallen directly on us.  Then for a few seconds or minutes, he went out of his mind.

            Father Kleinsorge never knew how he got out of the house.  The next things he was conscious of were that he was wandering around the mission’s vegetable garden in his underwear, bleeding slightly from small cuts along his left flank; that all the buildings round about had fallen down except the Jesuits’ mission house, which had long before been braced and double-braced by a priest named Gropper, who was terrified of earthquakes; that the day had turned dark; and that Murata-san, the housekeeper, was nearby, crying over and over, “Shu Jesusu, awaremi tamai! Our Lord Jesus, have pity on us!”

                                                                  _________________ 

           Dr. Sasaki shouted the name of the chief surgeon and rushed around to the man’s office and found him terribly cut by glass.  The hospital was in horrible confusion:  heavy partitions and ceilings had fallen on patients, beds had overturned, windows had blown in and cut people, blood was spattered on the walls and floors, instruments were everywhere, many of the patients were running about screaming, many more lay dead.  (A colleague working in the laboratory to which Dr. Sasaki had been walking was dead; Dr. Sasaki’s patient, whom he had just left and who a few moments before had been dreadfully afraid of syphilis, was also dead.)  Dr. Sasaki found himself the only doctor in the hospital who was unhurt.

            Dr. Sasaki, who believed that the enemy had hit only the building he was in, got bandages and began to bind the wounds of those inside the hospital; while outside, all over Hiroshima, maimed and dying citizens turned their unsteady steps toward the Red Cross Hospital to begin an invasion that was to make Dr. Sasaki forget his private nightmare for a long, long time.

                                                              ____________________

            Then a tremendous flash of light cut across the sky.  Mr. Tanimoto has a distinct recollection that it traveled from east to west, from the city toward the hills.  It seemed a sheet of sun.  Both he and Mr. Matsuo reacted in terror—and both had time to react (for they were 3,500 yards, or two miles, from the center of the explosion). Mr. Matsuo dashed up the front steps into the house and dived among the bedrolls and buried himself there.  Mr. Tanimoto took four or five steps and threw himself between two big rocks in the garden.  He bellied up very hard against one of them.  As his face was against the stone, he did not see what happened.  He felt a sudden pressure, and then splinters and pieces of board and fragments of tile fell on him.  He heard no roar.

                                                                    ____________________

            … She thought that before she began to make entries in her lists of new employees, discharges, and departures for the Army, she would chat for a moment with the girl on her right.  Just as she turned her head away from the windows, the room was filled with a blinding light.  She was paralyzed by fear, fixed still in her chair for a long moment (the plant was 1,600 yards from the center).

            Everything fell, and Miss Sasaki lost consciousness. The ceiling dropped suddenly and the wooden floor above collapsed in splinters and the people up there came down and the roof above them gave way; but principally and first of all, the bookcases right behind her swooped forward and the contents threw her down, with her left leg horribly twisted and breaking underneath her.  There, in the tin factory, in the first moment of the atomic age, a human being was crushed by books.

A Japanese Doctor's Comments

It's remarkable reading Hiroshima to be reminded of how much the effect of the atomic bomb was like an earthquake:  Buildings are knocked down.  In the case of Hiroshima, after the houses and other buildings were flattened by the bomb's shock wave (or blast effect), various small fires started and resulted in the total conflagration that consumed the city and killed most of the people who died in the bombing.  Others were killed immediately by being hit by flying debris, especially glass, and near the center of the blast by the heat of the bomb.  Others died later from the acute exposure to high levels of gamma rays and from the horrible flash burns that were seen then for the first time.

But in reading the book, there are many descriptions of people being trapped in rubble, of people digging their way out of rubble.  I will post some excerpts from the book later, including excerpts from letters written by the two doctors who are among about the six people John Hersey documents in the book.  First, a letter from a Japanese doctor that was posted as a comment in March on Yahoo's news site, concerning the recent earthquake and tsunami:

Dear friends all over the world

Thank you for your encouraging comments

I am in very neighbor of outrageous disaster of the quake.

And under tremendous fear of spreading nuclear substance from damaged nuclear power plants in Fukushima in Japan.

First thing which I want to say is that this quake and Tunami is unexpected things, besides we surveyed last 300 hundreds years. One can argue it is not enough periods for setting effective countermeasures, but in some town very close to coast set up breakwater over than 10 meters. However, the Tunami very overcame it and swallowed so many people with over than 10.000 casualties. Nightmere.

I must admit that we should have much more careful about managing nuclear plant about huge quake. I am very sorry, but I think that unexpected thing may be happened and, in general, very positive attitude is that help each other and look into real and effective resolution of serious problem. Please give us your talented knowledge and technique to manage deadly consequence of the quale for the appropriate Japanese staff.

We, Japanese, for sure will hang on this problem and would like to welcome all of you to Japan with traditional hospitality as it went before the accident.

With warm regards

Yoshihiko Tomita MD

Meaning of the Japanese word "hibakusha"

In John Hersey's 1985 edition of Hiroshima he included a new chapter, an update on what had happened in the lives of the six people he wrote about in the original version of the book (which was itself published in a single issue of The New Yorker in 1946, filling the issue completely).  In the new chapter, Hersey noted that the Japanese did not call the survivors of the atomic bombings survivors:

In referring to those who went through the Hiroshima and Nagasaki bombings, the Japanese tended to shy away from the term "survivors," because in its focus on being alive it might suggest some slight to the sacred dead.  The class of people to which Nakamura-san belonged came, therefore, to be called by a more neutral name, "hibakusha"--literally, "explosion-affected persons."

In order to renew my slight knowledge of some aspects of Japanese culture, I plan to re-read Hiroshima now that Japan has had another tragedy befall it, one that wasn't of its own making, but one that now also involves nuclear energy release and radioactivity levels above the normal background level.  As far as hibakusha are concerned, the United States has more than its share nowadays, mostly young people who've been seriously and sadly affected physically and mentally by exposure to the shock waves from IEDs and other high explosives in the Iraq and Afghanistan wars.

Alberto V.O. Einstein

It's big Al's birthday, his 132nd.  He wasn't actually that big if the wax figure of him at Madame Tussuad's Wax Museum in London is anatomically correct.  He wasn't that tall I mean.  Penis-wise, well, I don't think his size is in the historical record.  Perhaps one of the numerous women he "slept" with commented on that in her diary.  He wasn't prone to be celibate, nor was he prone to be a faithful husband, but his second wife (who was also a first cousin of his) could live with that.  His first wife, well they were real hot together at first, sorta like in that Steely Dan song "Haitian Divorce" ('so in love/the preacher's face turned red'), but they later drove each other crazy and had the same kind of troubles as separated or divorced people have these days--with money, visitation rights of the kids, demands made on each other. 

Anyway, regarding Uncle Albert's height, in May 1996, my girlfriend at the time took my photo in London (she paid for the trip, God bless her; it was a lot of fun) standing next to Einstein's waxen figure, and at 5' 6" I was slightly taller than Dr. Einstein, whose wax figure looks more like Walter Matthau's Einstein than the real Einstein.*

Here's a recent news release about him, then I gotta get outta this library in Pine Bluff, as closin' time is upon us:

Einstein’s archives to go online

March 14, 2011

JERUSALEM (JTA) -- More than 80,000 of Albert Einstein's documents will go online in the coming months.

The Hebrew University of Jerusalem announced Monday, on what would have been Einstein's 132nd birthday, that it has begun a yearlong project to digitize the documents and make them available on the Albert Einstein Archives website.

The project is being underwritten with a $500,000 grant from the Polonsky Foundation of London.

The Jewish scientist was a founder of Hebrew University in 1918 and sat on its first board of governors. In his will Einstein, who died in 1955, stipulated that his archives go to the university. Along with documents on physics, the archive includes his thoughts on politics and society.
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*actually he was taller than I am, according to most sources: 5' 9" (or in non-USA units, 175 centimeters).

Photographs as observation & measurement

When I took Steven Weinberg's undergrad quantum mechanics class in 1998, he said in the second or third class, "I assume you all know what an electron is, what a proton is."  This chagrined me enough that I immediately spoke up and said, "I don't know what an electron is."

I'd just written a master's thesis, at what's now Texas State Univeristy-San Marcos, questioning the assumption of an electron as a "point" particle, and pointing out that the electron was/is still a mystery.  Weinberg's choice of words was not ideal.  If he'd said something like, "I assume you are all familiar with the properties of electrons and protons," I would not have spoken up.  The endpoint of my classroom conversation with the good professor Weinberg was that I said mainly I was interested in what it means to "find" an electron.

This is one of those peculiar quantum mechanics things that are too often taken for granted:  we talk, for instance, about the wavefunction giving the probability of finding an electron--the square of the wavefuntion is interpreted as a probability density--but we don't say or think much about what the physical process for "finding an electron" is.  In answer to my question, Weinberg mentioned a photographic plate as one method of finding where an electron is (was), and a cloud chamber as another.

The photographic plate or just photographic film can be used as a detector in the so-called two-slit experiment, which is famous for showing the wave nature of electrons and other elementary particles. The set up is like a slide projector and a screen. Electrons go through the closely-spaced, very narrow slits (projector) and hit the faraway photographic plate (screen), leaving little dots where they hit.  Like a microscopic kind of pointillism, and defying all logic, the dots form a wave interference pattern of bright and dark bands on the screen.  Which slit a particular electron went through can't be determined without causing the wavelike property (interference) to disappear. So the observer--the experimenter, or photographer--can observe either property, wave or particle, but not both simultaneouusly, by her choice of experimental set-up. (More than two slits could be used, but the interference pattern is simplest with two.) 

An example of the opposite or complementary case from particles behaving like waves is the photoelectric effect, where ultraviolet light hits a clean metal surface and ejects electrons from the surface. As explained by Einstein in 1905, it's necessary (and sufficient) to imagine a single-energy unit of light, now called a photon, being responsible for the ejection of a single electron. The wave description of light propagation just fails completely here, as does the particle model of an electron in explaining the interference pattern in the two-slit experiment. Which could be called the two-hole experiment if tiny round holes are used instead of slits. 

So, anyway what we have in general on the sub-microscopic scale is the wave-particle duality, while on the large scale of everyday life, we have the love-hate duality in the case of the not-so-elementary psychological-physical-emotional-spiritual entity known as the person (per-SAHN). Hard to figure, also.
  

Today I present photos (below) not of the traces of electrons, but of an alligator gar (small) and a water moccasin (big) that I took last summer from the platform shown in the photo at left.  You have to look carefully to find the snake in the mud (an S shape, bottom photo). Well, the gar too, for that matter (hint: it's horizontal, parallel to my bare foot, not much more than a shadow). 

In my much younger days, the gar and snake would have been targets for shooting with my .22 rifle.  Nowadays the only living thing I shoot is an occasional minnow.  Usually I shoot at a piece of wood or other floating target.  I did shoot a water moccasin once a couple of years ago at the farm, where I built this platform between two large fields (very quiet out there!).  It was unnecessary.  I pulled the trigger "without really thinking about anything at all," like the young man who shoots the monkey at the beginning of Denis Johnson's novel Tree of Smoke.    

Peace.

Measurement vs observation, plus the paradox

All right.  Where were we?  Measurements versus observations, right.

In weighing yourself or reading your speedometer you're observing a measured quantity.  In the case of weighing, you don't have much influence, or not much immediate influence (oh, yeh, long term, sure), and in the case of driving and reading your speedometer you do have immediate influence. On the highway, you need to watch your speed, as they say.

Okay, you're right!  People watch their weight also.  I could surely stand to lose a few pounds, like ten at least.  154 at the doc's office last visit.  (My digital scale in the bathroom, by the way, is inaccurate.  It gives readings to the 10th of a pound [that's called precision--not the same as accuracy], but repeated measurements give different readings by as much as five pounds.  The mechanical scale at the doctor's office--ancient technology--is much more accurate.  A good digital scale, such as I've used in student labs many times, is  both accurate and precise.)

I was going to talk about measuring cups and measuring sticks, both of which require an active role by the measurers, and contrast that with a speedometer reading. But let's just say here that a measurement is a quantitative observation, and leave it at that. No semantical difficulties there.

But sometimes a measurement doesn't give you the quantity you're looking for.  Sometimes you need to make a calculation!  In my very first physics lab, in the excellent year 1974 at the University of Arkansas at Little Rock (as referred to in my Intro post, August 14th), the instructor had us go out to the side of a very busy street, Universty Avenue, and measure the times it took the front bumpers of particular cars to travel a certain distance in order to calculate the speed of the cars.  Rather dangerous.  Probably not done these days.  Anyway, there is a hierachy of observation, measurement and calculation involved in experimental physics. The calculation is not necessarily done by a person, of course.

So where does this leave us with our investigation of Schroedinger's cat?  (Without the two dots on the "o", you're supposed to put in the "e".)  The measurement is more like an observation because it's not obviously quantitative.  But we can call the live state 1 and the dead state 0.  So it's a very simple measurement, the looking in the box part anyway. 

The significant and more complex thing is the meaning of a measurement in quantum mechanics.  Schroedinger, in the cat thought experiment, was trying to show the ridiculous nature of the "measurement creating the reality," which is what the Copenhagen interpretation of quantum measurement says happens. 

This is the same idea as the Einstein-Podolsky-Rosen "paradox," and it was the publication of the EPR paper in 1935 that set Schroedinger to thinking of his cat.  Originally Einstein and Schroedinger corresponded about the wave function (or state vector) of an unexploded keg of gunpowder subject to being exploded by the decay of a radioactive nucleus (one decay from a collection of slow-decaying nuclei, actually) .  Einstein pointed out that the wavefunction would have components for the exploded keg and the unexploded keg.  Schroedinger changed this when he published his paper later that same year to be a cat in a box, and the components become the live cat plus dead cat combination.  The measurement is considered to be performed when the state of the cat is determined.