Cosmology and the Nobel Prize in Physics

After Jim Peebles won the 2019 Nobel Prize in Physics, I've started going through my books and articles to find some good reading. One book that I found is "Origins: The Lives of Modern Cosmologists" by Alan Lightman and Roberta Brawer (Harvard University Press, 1990).

It's a wonderful book of interviews with 27 leading cosmologists where they discuss many subjects: their youth and how they became cosmologists, their (possibly changing) views on the correct model for the universe, and their philosophical perspective on whether the universe has any "point." In addition, there is a wealth of references, which include papers and books written by the interviewees, along with seminal papers in the history of cosmology.

Jim Peebles is, of course, one of the 27. Unfortunately, people like Edwin Hubble and Milton Humason had died by 1990 and were not included. I thought I'd give a brief overview of each cosmologist and their insights.

The first on the list is Fred Hoyle (1915-2001), one of the older interviewees. He first discusses his sophistication at age 12 (!):

By the time I was around 12, I had understood the difference between being a layman who is interested and having a real understanding. Out of this grew my strong feeling that before one can be involved in science, one has to have a tremendous sense of craftsmanship. I still get mountains of letters from the lay public, proposing various ideas, and you can chuck it all out because you know that the brain isn't properly ordered to understand the problems they aim to solve. 

It is true that those without a scientific background tend to underestimate the knowledge and understanding needed to do science, especially physics. They have a neat idea, and they often feel that that's all it takes to overthrow decades of work by professionals. Unfortunately, they often don't have the background to know that what they're doing is wrong. It's quite amazing that Hoyle felt that he was able to distinguish crackpots from such a young age.

Hoyle is one of the more famous (perhaps the most famous) proponent of the steady state theory of the universe. This is the idea that even though it appears that the universe is expanding, it really is in some kind of "dynamic steady state," and that it would look the same as viewed at any epoch. And his recollection of how that model came about is interesting. First there was the article "Relativistic Cosmology," by H.P. Robertson in 1933 in Reviews of Modern Physics. He and Hermann Bondi were wondering if Robertson had really considered all the possibilities, all the possible models for the universe. Thomas Gold suggested that the universe might be steady state, which was something that Robertson had not considered in his article. Then Bondi and Hoyle said that model would require the creation of matter, and they didn't like that aspect. After a while, Hoyle found a physical model that could account for the matter creation - "a crude way of coupling a scalar field to gravity" - and all three gradually came around.

Quite apart from championing the idea of the steady state universe, Hoyle says that "I didn't go beyond saying that the steady state theory is a possibility. When I have defended it, I always defended it on the grounds that what were claimed as disproofs were things that a mathematician would not regard as disproofs. They were full of holes."

It appears that now, after much new observational data, there are few (or none) cosmologists who still defend the steady state theory. Along with Hoyle, Bondi and Gold are dead. Jayant Narlikar, who developed with Hoyle a theory of gravity specifically to mesh with the steady state model, is 81 years old, but I have not read any recent strong statements from him. The Hoyle-Narlikar theory of gravity is incompatible with the expanding universe and doesn't fit the recent observational data, so that is probably a dead end, too.

In the physics community, however, Hoyle is also famous for predicting the 7.6 MeV excited state of the carbon-12 nucleus that was necessary for models of nuclear fusion in stars to produce the necessary quantities of heavy elements (see here). But that is another story ...

The Scientific Method

While perusing an old issue of Geophysical Research Letters, a journal that publishes research in a wide area of physics: geophysics, atmospheric physics, space physics, planetary physics, etc., I ran across the following paper

What’s interesting about this article is that it is an excellent example of one piece of the scientific method in action. From the introduction,

“Measurements of carbon dioxide … have been made at Mauna Loa … since 1958 by Scripps … One objective … has been to document global-scale secular CO₂ trends. A duplicate, but quasi-independent, program has been underway since June 1974.”

Already the Scripps Institution of Oceanography had been measuring the CO₂ concentrations on Mauna Loa since 1958 and had seen an increase of 1.14 ppm (parts per million) per year. As is par for the course, scientists don't rely on one measurement of an important quantity, they seek "reproducible results." In this case, a different method was used by NOAA's Geophysical Monitoring for Climatic Change (GMCC) program to measure the same CO₂ concentration. Their result is shown here:

There is obviously an annual variation, but superposed on that is a "secular" increase, that is, one that is monotonic. It keeps on increasing. Even though it is only two years, this secular increase agrees with the earlier result.

What did the earlier result look like? This:

Again, there's a secular increase superposed on an annual variation. Peterson et al. have this to say about the earlier data:

"... the year-to-year increases were quite variable, from less than 0.5 to more than 2.0 ppm. At this time, the GMCC and Scripps records cannot be absolutely compared because of calibration problems..."

So, while the two methods were in general agreement, it was difficult to compare two measurements using completely different methods. In any case, more measurements were made, and an absolute comparison was achieved, at least to a level that was consistent with the uncertainties in the original observations.

The scientific method in action!

The Joy of Mathematical Proofs

I just received a new physics textbook that I ordered online - yes, I know, I don't need any more physics textbooks - and, as usual, no matter how familiar the material, I can always find something to learn that I didn't know.

This book is Matter in Motion: The Spirit and Evolution of Physics, by Ernest S. Abers and Charles F. Kennel, two UCLA professors. I was a students in Abers's quantum mechanics classes, and Kennel was in the plasma physics group, so I knew them both, although I hadn't known that they had written a book in 1977 for their "Physics for Non-Science Majors" class. I discovered the book while perusing the July 1977 issue of Physics Today while looking for another article (but that is another story, perhaps to be written about in a future post).

The review praised the book for not trying to do too much, and successfully dispelling "the widely held misapprehension that science consists of little more than a vast collection of uncontestable facts meticulously gathered and catalogued by individuals distinguished primarily by their ability to repress their emotions completely." They extend their discussion of the history of physics to the pre-Galileo period, where "Greek and medieval science finally get their day in court." That is, Abers and Kennel show how the Greeks obtained their results, rather than simply telling you.

My two favorites (that I have come across so far) are a simple proof of the Pythagorean theorem (one that they claim is essentially the same as the original) and a neat proof that there are only five regular solids. I've already posted about Euler's formula

F + V - E = 2

in August 2014 when I discussed Zometools. I mentioned then that there were at least 20 different proofs. Now, I don't have a classical math background. In fact, I'm one of the physicists that avoid as much math as possible, not because I don't love it, but because I like to use it rather than play around with it for its own sake. However, the latter is sometimes lots of fun. Back in 2014 I learned one of those proofs. And Abers & Kennel use Euler's formula to prove that there are only 5 regular solids (also known as Platonic solids: tetrahedron, cube, octahedron, dodecahedron, icosahedron).

So, now that I can prove some things, does that make me a mathematician?

Walter Elsasser "Memoirs of a Physicist in the Atomic Age"

Memoirs of a Physicist in the Atomic Age by Walter M. Elsasser
My rating: 4 of 5 stars

Elsasser was the founder of the dynamo theory of the Earth's magnetic field, and also had a successful career in other areas of physics, nuclear physics in Paris with the Joliot-Curies, for example, as well as meteorology. He was prolific, and published many journal articles in these areas. In his later life he turned to biology, and wrote three books on biophysics that never were quite accepted by the biological community.

In this book, he gives a more personal view of famous physicists of the early 20th century (Curie, Born, Oppenheimer, Wigner, Schroedinger, etc) than the well-known histories by Gamow and Segre - i.e., less physics - but interesting and enjoyable. His philosophical ideas I sometimes could not follow (or agree with), but the fact that he interacted professionally with so many famous physicists made for an interesting life - and an interesting read.

One scene that depicted 1922 Germany was especially eye-opening. While I knew that Philipp Lenard (Nobel Prize Physics 1905) was a strong supporter of the Nazi party, I didn't realize the extent to which this permeated his lectures, and the extent to which anti-Semitism had quickly escalated after World War I. Elsasser describes his first physics lecture at the University of Heidelberg like this:

“Every seat in the hall was taken. In walked Professor Lenard wearing an impeccably tailored suit; to his left breast there was fastened a silver swastika of gigantic proportions, perhaps ten centimeters square. This was most unusual, if one remembers that in spite of war and revolution, Germany had then still remained a place of law and order. A distinguished senior professor was most certainly not expected to brandish symbols of political extremism in class. But the students thought otherwise. They applauded intensely. They clapped, and then they shouted; they kept on clapping and shouting, on and on and on. How long this continued I cannot say precisely, but it was certainly the most dedicated and loudest ovation I ever witnessed in my life, before or after."

The recent (2017) biography on Einstein on the National Geographic channel, "Genius," depicts a similar scene in one of Lenard's lectures. There, he refuses to cancel class for the funeral of the assassinated Jewish politician, Walther Rathenau, and instead lectures to supportive students about the need to abolish the "Jewish physics of relativity" and return to "pure German physics."

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UPDATE: In Jeremy Bernstein's biography Einstein, he describes anti-Semitic (and anti-Einstein) activity even earlier, in 1920:

"In 1920 an anti-Einstein League was formed in Germany, and it offered substantial sums of money to anyone who would write refutations of Einstein's work. On August 24, 1920, the League sponsored a meeting in the Berlin Philharmonic Hall, which Einstein himself attended, where swastikas and anti-Semitic pamphlets were on sale, at which Einstein and his work were attacked. A few of his colleges respond in a letter to the 'Berliner Tageblatt' and a few days later Einstein himself wrote an angry letter, also published by the 'Berliner Tageblatt' --- which deeply shocked Ehrenfest, who seemed to feel that Einstein should have ignored the matter as unworthy of his attention. From this time on, until he finally left Germany in 1932, Einstein and his work were the targets of a steadily mounting campaign."

Lola Montez

This lady has one of the craziest stories around. Everywhere in Munich and Bavaria you hear stories about "crazy King Ludwig," and they are usually referring to Ludwig II, the young king who built not one but three fairy tale castles, the most famous of which is Neuschwanstein.

However, his grandfather, Ludwig I, had his own set of interesting problems. Who knows if he was crazy, but he was certainly crazy in love with Lola, who was not his wife. The wife of Ludwig I was Therese of Saxe-Hildburghausen. She is famous because the party after their wedding in 1810 turned out to be the first Oktoberfest. And they liked it so much, they've held it every year since then at a large field in the south of Munich called the Theresienwiese.

Now, Ludwig I ended up abdicating the Bavarian throne in 1848 (a time of much unrest in Germany, but that story is for another day) twenty years before his death, partly due to the scandal of his affair with Lola Montez. She purported to be a "Spanish dancer," but in fact she was Irish. Ludwig I made her a Countess, and she had some influence on his political decisions (this was part of the scandal). However, what I found interesting is what she did after she was forced to flee Bavaria in 1848.

She went to many parts of the world (France, London, Australia), but she spent a fair amount of time in, of all places, Grass Valley, California, just outside of Sacramento. Her home is California Historical Landmark No. 292. And among other things, the highest point in Nevada County is Mount Lola, named after her.

Ulm

While my students went off to Prague for the weekend, I went to Ulm on Saturday. It's a very old city - founded around 850 CE - and is situated on the Donau (Danube) River. For some reason I am drawn to the Donau, not only because of the song. There are several cities on the Danube that I'd like to visit, not least of which is BudaPest, and also Bratislava. But they are too far to go for this trip. For now, I'll content myself with visiting the Bavarian cities on the Donau: Ulm, Ingolstadt, Regensburg. Yes, I know that Ulm is in Baden-Württemburg. But it used to be in Bavaria, and, being that Neu-Ulm across the river is in Bavaria, and noting that you are allowed to travel by train to Ulm using your Bayern ticket, I contend that it should count as Bavaria.

Here is a nice view of Ulm from 1572, in which you can see its most outstanding feature, the Ulmer Münster! This is a church that has the highest steeple in the world, measuring 161 m. You can climb to the top, which I did; well, almost the top. The stairs reach 143 m in 768 steps. And it takes about 20 minutes, unless you're very fit, but still you have to contend with people coming down. The first two thirds are "one way" stairs, so you can effectively go as fast as you wish.

However, the top third is a single stairwell climbing up the center of the the spire. As you can see from the photo below, there is a nice superstructure for the spire, with a column in the center, and a spiral staircase in the center of the column. There's not much room to pass, and some young children were a little frightened. And everyone had to take it slow.

Most of the city center was bombed by the RAF in 1944, but amazingly the Münster was essentially untouched. This was fortunate, because it's construction began in 1377, so it is a "cathedral" with much history. It wasn't completed until 1890 (talk about patience), and it also isn't technically a cathedral, since Ulm went Protestant in 1530 (it's now a Lutheran church).

When I got up to the top, the view, of course, was great. The red roofs of the city buildings spread out along the Donau were quite the sight.

In the photo on the left, from lower down (far below the top) you can clearly see the flying buttresses, as in Notre Dame. In the photo on the right, from the top, you can see the entire church, with the two steeples toward the east. I need to learn my cathedral architecture: chapel, nave, altar, etc. Here's one place to learn it.

Finally, the inside was incredibly large, and no pictures would do it justice. They did have beautiful stained glass windows, and I tried to give a feeling for them below. There were several along the sides of the church.

The Pullach Deutsch - Französisches Freundschaftsfest

Yesterday, Freitag 24 Juni, was the start of the 23rd Freundschaftsfest on the Kirchplatz in Pullach im Iasartal, just south of Munich, on the Isar river. The square was closed off for food, drink (lots of bier und wein), and music. My favorite Weissbier (Franziskaner) was served, along with Rotbratwurst (chili hot) and much else. As you can see from the schedule, the fun will continue all weekend.

However, the weather may not cooperate. It's supposed to rain starting tonight, and also on Sunday. Hopefully that won't put too much of a damper on things.

There were plenty of cute kids playing festival games (ring toss, etc), and winning prizes, like stuffed animals and roses.

And there was even a marching band! (Note: below is a 6MB Quicktime Movie)

Prost from Pullach!