Fun in the snow

After Kathy, Megan, and Sarah left, Caitlin stayed for a couple more days. We went to the two main palaces in Munich, the Schloss Nymphenburg on the last day of the year, when the building was closed, but the grounds were open. In addition to a huge building, the grounds are extensive, with many walking paths and gardens. On summer days its a popular place to go for Münchner.

Panorama of the 'summer' palace for the Bavarian royalty, Schloss Nymphenburg. On this day, however, it was covered in snow.

And on the previous day we went to the "Munich Residenz," the main palace of the Bavarian royalty, which is now a museum. Also, a portion of the museum houses the treasury - all the crowns and precious jewels that they had collected over the years.

Crown of Queen Kunigunde (975-1040). It is assumed that she actually wore this crown, but it is not known for sure. The crown was on a "head reliquary" and therefore might have been placed there after her death. It's one of the oldest items in the treasury.

St George slaying the dragon. With lots of jewels.  St George is the patron saint of the House of Wittelsbach, which ruled Bavaria from the 1100s until 1918, when they were deposed. He is also the patron saint of the Munich Residenz, and this valuable item is not allowed to leave the Residenz.

Really cool pocket watch from 1620. Unfortunately there was no detailed description, even in the self-guided audio, so I don't know anything about its history. However, if you look closely, on a high resolution image below, the dials denote the following. Top: Lunar cycle and phases of the moon. Right: Standard 12 hour clock. Bottom: Calendar with the day of the month and month of the year. Left: Day of the week. Center: I-II-III-IIII, but I'm not sure what this represents. Anybody?

It's good to be home

After a month of this

I came back to this

The autumn in Munich was very mild, lots of warm days, and only a couple of brief snowfalls that immediately melted. Then, the day after Christmas, we got four days of solid snow, which was good for the family, who wanted to see snow. We also were able to visit Neuschwanstein in snow, and also Salzburg - and, of course, Munich. Most of January, and the beginning of February, it was snowing. Not an overwhelming amount, though, just a few inches every few days. In fact, I enjoyed the snow; there wasn't too much of it, and it looked very nice. A change of pace from Florida. The temperature was pretty steady, right around freezing, but not brutally cold, so my jackets that I had brought with me served their purpose admirably.

The best part was that I met a lot of great people and I'd like to thank them for making my time in Germany worthwhile:

Karl, Philip, Alec, Connor, Sophie, Billy, Will, Timo, Astrid, Luis, Tessa, Sebastian, Helmut, Lukas, Guido, Alexander, Wolfram, Gerald, Dirk, Ruslan, Sandro, Nicole, Aino, Christian, Thomas, Annette, Veronica, Michael, Jack, Klemens, Peter, Carolyn, Merit, Maria, Alexandra, Shyam, Eno, Kevin, Ralph, Steffie, all my students, and last, but not least, Coco.

I can't wait to return!

Chinese in Berlin?

My airbnb host in Berlin told me an interesting story that I have not had time to confirm. He said that there were four countries that were to divvy up Berlin after WWII: Russia, US, Britain,  and China! For some reason, France was not included since they had already "lost." Since China was so far away and didn't want to have to administer an area on another continent, they said Russia could have their region, just give them money. This was why Russia had half of Berlin, and the Allies had the other half. I said that I hadn't heard of that, and he said "if you dig deeply enough on the internet, you'll find it." I took that to mean that he was into conspiracies, you could probably find some whacko espousing this view, but it wasn't true. So far, I haven't been able to find out anything about this.

But the map of Berlin is interesting. It shows the city divided almost exactly in half along a north-south line, except for the city center, the Mitte, cut out and given to the Soviets. This was where my airbnb apartment was, just off of Alexanderplatz, along Alexandrestraße. The BrandenburgerTor is at the west end of this cutout, just inside the Soviet zone.

Map of Berlin from the Berlin Wall Memorial, showing the Berlin Wall in red.

Map of the German occupations zones. From Wikipedia.

As can be seen from the entire map of postwar Germany, the US occupation zone included Bavaria. And if you look closely at the photos of the town of Garmisch here, you can barely see barracks that are part of a US installation, one of the few remaining in Germany.

The cable-stayed bridge

"Today...this method is often a civil engineer's first choice for bridges...They go up faster than alternative approaches and cost less because they use less material." - Amy Nordrum, Scientific American, February 2015.

I think the first cable-stayed bridge that I saw was the Sunshine Skyway Bridge across Tampa Bay. I probably saw it in 1988 when I visited Florida for a physics conference (in Hollywood) and I made a trip to Clearwater to visit relatives. Since Tampa Bay is so large, you can see it from a great distance, and it looks very impressive.

Sunshine Skyway Bridge, Tampa Bay, Florida, U.S. At dawn.

The second one I saw was across the Savannah River, near Savannah, Georgia. That one caught me by surprise as we were moving from Washington to Florida in 2001. You don't really see the bridge until you are almost on it, and I wasn't expecting it.

Eugene Talmadge Memorial Bridge, Savannah, Georgia, U.S.

One bridge that I haven't seen, but would like to, is the Santiago Calatrava bridge in Redding, California, across the Sacramento River. Technically, this is a "cantilever spar cable-stayed" bridge, a design that was pioneered by Calatrava and used in some of his other bridges in Spain and Argentina, among others.

Sundial Bridge at Turtle Bay, Redding, California, U.S.

The quote at the top is from an article about the new Tappan Zee bridge in New York, which will be a cable-stayed bridge, with eight traffic lanes and will be the widest cable-stay in the world. The article claims that there's a cable-stay under construction in Los Angeles. I can't think of where it might be, except for the Port of Los Angeles, near Long Beach.

A final bridge that I'd like to see, but I didn't get a chance when I was in Germany, is the Millau Viaduct, in France. Of all the photos I've seen, it is the most impressive.

Millau Viaduct, France.

The usefulness of useless knowledge

The title is supposedly a quote of Abraham Flexner, one of the co-founders of the Institute for Advanced Study in Princeton, that ivory tower where employees are allowed to think about whatever they wish, with no pressure to produce any results whatsoever.

In the January 2015 issue of Physics Today, Oscar Greenberg has an article titled "The origin of quark color," in which he discusses this history of his idea that quarks have three types of color "charge," similar to the two types of electric charge (positive and negative) and the one type of gravitational "charge," i.e., mass. But he starts off philosophically about how "the pursuit of these useless satisfactions proves unexpectedly the source from which undreamed-of utility is derived" (another Flexner quote). He makes the point that quark color was "useless" in this sense. In fact, the same could be said of electric charge and electricity and magnetism in general. Greenberg also repeats that (probably apocryphal) story of Michael Faraday showing one of his electricity and magnetism experiments to a prime minister, who asked "What good is it?" And Faraday replied "I don't know Mr Prime Minister, but one day you will tax it." (see here for some of the history of the quote). Electricity and magnetism has certainly turned out to have "undreamed-of utility" and also to be taxed beyond belief.

When I was a kid, I remember reading about "pure" research and "applied" research, and I was not really sure what kinds of things would fit into the "pure" category. But I guess what I've been doing (see here) can be classified as "pure." Recently, one of my ex-students asked my what I was working on, and I told him about that work on solitons in space plasmas, and he replied "What do you think/hope it will accomplish? Would it create better spacecraft in the future?" I said "Well, at this point it's very close to "pure" research, i.e., we just want to understand the universe in which we live a little better." I guess I was getting a little "philosophical" myself. But I think that you never know how the issues you work on are going to be used (or used for) in the future. It reminds me of the mathematician G.H. Hardy, who said.

"I have never done anything 'useful.' No discovery of mine has made, or is likely to make, directly or indirectly, for good or ill, the least difference to the amenity of the world."

And interestingly, much of his work has found applications in science.

Update: Here is the latest on the pure research associated with quark color.

Solitons in space plasmas

Along with two of my colleagues, I just finished a paper that should be accepted in the "Journal of Geophysical Research" soon. What's neat about this paper, other than the fact that it's the first application of a technique that was first suggested over 20 years ago, is its sociological history. The ways of science are often serendipitous, and this is a good example.

A few years ago a masters student, Harry, came to me and wanted to write his thesis on solitons (for a more mathematical introduction to solitons, see here, and for a picture of a soliton, see here, and for a history of the observation of the first soliton, see here) in space plasmas, and wanted me to be his advisor. I told him that while I did know a lot about space plasmas, I didn't know much about solitons, and therefore I couldn't guide him in the proper direction, but that I'd be happy to be his advisor and we'd learn about the subject together. This is unusual in that in addition to technical guidance, and advisor usually knows the particular field, and can suggest certain fruitful directions to the student. However, in my experience I've found that my most successful masters students are those that come to me with their own definitive idea, and in addition to learning the subject with them (sometimes from them) I simply give them technical guidance in plasma physics in general. This way they already have motivation, because it's a topic of their choice. I've heard that Feynman was of a similar mind, and didn't want students who came to him and asked what topic they should work on.

In any case, we started, as usual, by reading the literature, and one of the papers that Harry sent me was written by someone who I had shared an office with while a grad student at UCLA. He was an expert on solitons! So I contacted Bob, and after some email exchanges, where he gave Harry and me some advice, I invited him out to Daytona for a visit. He was on a sabbatical at the time, and was able to visit us for a week, during which he gave a departmental colloquium, and also suggested some very good directions for Harry's thesis. Harry duly finished his thesis, graduated, and is now working for Lockheed out in California while we finished polishing up his thesis for publication.

So, in addition to writing a great thesis, I have renewed a friendship that was on a 20-year hiatus, and started a new collaboration. Several of the ideas in Harry's thesis have suggested other problems to work on, and Harry and Bob and I will be pursuing these ideas in the future.

So, what's this neat idea? It's the fact that you can use the inverse scattering transform (IST) to determine whether or not a soliton (or solitons) is embedded in a particular magnetic field profile that has been observed (in our case, by the Ulysses satellite that is in the solar wind). In the first figure below, there's a plot of the magnetic field observed by Ulysses, along with a plot of the soliton that we found using the IST analysis. You can see that they don't match exactly, because there are other waves in the observed magnetic field - not just the soliton - and those waves show up as a difference in the two curves, solid versus dashed.

Observed magnetic field components (solid lines) and predicted magnetic field components of a single soliton (dashed lines) deduced from the IST. At time t = 0.

To see the soliton and the other waves distinctly, we did a numerical simulation and propagated the magnetic field forward in time, and compared that to the soliton moved forward in time. This comparison is shown in the second figure below. Notice that the two curves match much better in the region of the single bump - that's the soliton - but you can also see the waves propagating away from this region. Those are the waves (not part of the soliton) that were initially part of the magnetic field profile.

Normally, given a particular magnetic field, it is in general difficult to tell if there is a soliton embedded in that profile simply by looking. It may resemble a soliton, but that resemblance may simply be masking the fact that there are lots of waves interfering in such a way as to look like a soliton. The IST method, however, gives a definitive answer, although you must run a numerical simulation to see what other waves are embedded in the profile. You can clearly see below that there are some other waves, but that they propagate away at a different speed, and leave the soliton behind.

Observed magnetic field components (solid lines) and predicted magnetic field components of a single soliton (dashed lines) deduced from the IST. At time t = 55.2.

If you are interested in reading the entire paper, it's posted on the arXiv, here. The arXiv is a repository of "preprints," papers in draft form before they get published in order to disseminate more quickly than waiting for publication. It's a good place to watch to keep abreast of the latest developments in a particular field.

Nobel Prize Winners I Have Known

Well, not really. More like "Nobel prize winners whose talks I have attended."

The first was Richard Feynman [Physics 1965], back in 1981 or '82. I was a student at Santa Monica College, and a friend took me to a lecture at UCLA by Feynman. At this point, I hadn't taken any physics, or perhaps I was in my first semester, so I didn't understand a thing. From what I know now, he was talking about the two-slit experiment, but to me it was very confusing. The hall was jam packed, though, and I recall sitting on the steps in the aisle. I couldn't figure out what all the fuss was about. Of course, I know now. I also remember where I was when I found out he had died - I was in my TA office in the basement of Knudsen Hall, and I was discussing him with my fellow TAs in 1988.

The second and third were up in Santa Cruz. Hans Bethe [Physics 1967] came to the physics department to give a talk on SN 1987a, so I'm guessing it was in the spring of 1987. He was old, but definitely still very sharp. Around the same time, Linus Pauling [Chemistry 1954, Peace 1962] came to Santa Cruz to give a talk. I don't remember the topic, but I was very impressed at how he was able to switch gears. Apparently, he was scheduled to give a fairly high-level department colloquium, but so many people showed up that the venue had to change at the last minute. He correctly realized that most of the audience would not understand his planned talk - they had just come to see Linus Pauling - so he gave a more popular level talk, on the fly. That, to me, is someone who really knows his subject - and his audience - well.

As a young grad student at UCLA in about 1988, Carlo Rubbia [Physics 1984] came to the department (we had several faculty who worked at CERN) and one of the "events" that was organized was an informal talk between Rubbia and the grad students. It was mostly a question-and-answer session, and I recall that he was rather pompous. But I guess that's just his style, and people have speculated that someone with a less forceful personality would not have been able to get the experiment built that detected the weak intermediate vector bosons.

The next was in 1993. Russell Hulse and Taylor [Physics 1993] had just won the prize in October for the discovery of the binary pulsar from Arecibo in 1974. Hulse at that time was Taylor's grad student, but he had since switched to plasma physics. He happened to be going to the annual plasma physics meeting in November, so they quickly organized a special lecture for him. I don't recall any of the details, but he talked about the history of how he made the discovery.

The next was John Mather and George Smoot [Physics 2006], who gave talks at the April 2007 meeting of the APS (American Physical Society) in Jacksonville. They had just won the Nobel prize in 2006, and I went to that meeting with several students from ERAU. It was mostly to give them experience at a technical conference, but a happy bonus was the joint talk by the Nobelists. They gave a great lecture to a packed, standing room only, audience.

Sometime in 2011 or '12, I think, the Prescott campus organized a lecture by Steven Weinberg [Physics 1979], and they streamed it live to the Daytona campus. Unfortunately, there were only 3 of there to watch it - a disappointing turnout. Apparently, Weinberg was just recovering from an illness, so he didn't actually travel to Prescott, but gave the talk via video from his office at UT. For us in Daytona, it didn't matter, we weren't there in person. But he have a excellent explanation of why the Higgs is a necessary component of the electroweak theory - i.e., the standard model of particle physics - and how it fits into the puzzle, even though its discovery by the LHC hadn't yet been confirmed.

Now, I never met him, nor heard him speak, but John Bardeen [Physics 1956, Physics 1972] has to go on this list, since he's a member of the family! My wife is his first cousin, twice removed. That is, my wife's grandmother is a Bardeen, and she's a first cousin with John. Unfortunately, I never got a chance to meet him. But I have met several of the other incredibly smart Bardeens, including Chris Bardeen.

The reason for this list is that John Mather is coming to speak at ERAU-Daytona on February 20, 2015 at 7:00pm. So, even though I've heard him speak before, I will increase my "Nobel number" by 1.