Tuesday, December 14, 2010

Power failure

Oh yes, and I was stupid enough to forget my UK plug adapter at the London hote

Monday, December 13, 2010

Very British

Travelling again... this time I took a small break between two meetings, and ended up in warm(!) and sunny(!) London. Main task, however, was getting a decent amount of sleep first, so I ended up being inappropriately lazy. Ah well... Saturday evening I went to see Stomp - a strange but fascinating hybrid of pantomime, percussion, and dance performance. Now I know what things you all can use to make a bang! A later highlight was an exhibition of advertisment poster art by Rene Gruaud for Dior. My personal favourite is the Flower Woman... See here for a nice review and the source for the image. unfortunately it's completely impossible to get poster prints for a reasonable price. Otherwise it was great again to wander through the City, well to be accurate mostly through the West End and surroundings. It's been such a long time, I had not even seen Millenium Bridge, Tate Modern, or the Eye yet. (Well maybe except for on Doctor Who.) It's still a vivid, beautiful, fashionable, young, and exclusive place, where something's happening all the time. When I left, at Leicester Square the red carpet was just rolled out for the gala premiere of Burlesque with Cher and Christina Aguilera. And I really started laughing when I went to see the crown jewels in the Tower, and one of the golden ceremonial maces was missing and marked not with "under restoration" as a republican foreigner might expect, but with "in use"... Monday finally was shopping day. (Not only for me but for a few million Londoners as well I guess...) Various museum shops, Waterstones, HMV, Harrods, ... I'm starting to wonder what the Lufthansa agents at the airport will tell me though. Anyway. Time to get to Britain more frequently again.

Monday, November 29, 2010

Server moved and nearly fully operational again

Just a quick update: the new picture gallery server, a Xen domU instance hosted at ispOne, is running fine, so after some tests I changed the DNS entries and www.ostpforte.de is now served from Frankfurt. A few files are still missing, but that will be fixed soon. Finally, since the server is now located outside the internal Maximilianeum network, the picture upload feature as implemented previously does not work anymore. I'll have to come up with a new mechanism... soon... in the meantime, please just mail me a DVD :)

Friday, November 26, 2010

Ostpforte going virtual

It was a fragile thing from the start, just leaving an old piece of hardware in the basement of the student home as a (low-priority) webserver, and moving out to a different city in a different country... From that point of view it was quite surprising that the picture gallery server that I was administering kept working nicely for years and years. That's over now... some combination of freak accidents left it unbootable. Most likely that is only a software problem (the kernel comes up but udev does not generate any devices), and by now, I've moved back to Bavaria and am only 90min by train away. Anyway, though, when I'm in München I usually have better things to do than sitting in a dusty basement (that I dont have any key for anymore) and fumbling around with rescue cd's.

The real world comes to the rescue. I am constantly amazed about new lows in pricing for about everything computer related, and this time it was virtual server hosting. I mean, I used to be up to date, but then some time passed when I was busy otherwise, and now suddenly one can get a small Xen instance with Gentoo preinstalled and unlimited server traffic for 5€ per month! OK, I may in the end go for a slightly bigger package since the data does not entirely fit into 20GByte, but anyway... rsync is running. :)

Wednesday, November 10, 2010

Pluggin' a cool plug-in for Firefox

An important part of my work is reading scientific publications, which nowadays all come as online pdf files. Unfortunately, with Gentoo amd64, the Acrobat Reader plugin situation has lately been far from satisfying, with the plugin crashing and pdfs disappearing from the screen regularly. I know that the recommended thing to do is to install a 32bit firefox-bin, which supposedly works more stable with the 32bit Reader. However, from a Gentoo poweruser point of view, that's definitly uncool.

So, what else can we do? Turns out, there is a really nice solution for this problem, as long as you already run KDE and use it to view documents: remove the Reader plugin completely, and just install kde-misc/kpartsplugin. Automatically, after a Firefox restart, your browser can display everything that a KPart is available for. This means, a pdf or ps will get you an embedded viewer just like Okular, and much more... Somebody has been thinking this through a lot, you get buttons "Open in separate application" and "Save as file", and if there are several KPart's available, you can choose one and optionally save that preference. Works great here, and the pdf display is way faster!

Tuesday, November 2, 2010

Another home gadget

It has ...
cassis ~ # uname -a
Linux cassis 2.6.36-gentoo #1 Sat Oct 30 01:34:28 CEST 2010 armv5tel Feroceon 88FR131 rev 1 (v5l) Marvell OpenRD Ultimate Board GNU/Linux
... taken me some time to realize that I need an "always on" home server. Not really for big amounts of data or lots of computing power, but for the small conveniences - as printing easily from my laptop to my usb printer, or staying always online on freenode with a quasselcore. The first is something most DSL routers can do today, the second they usually can't. And besides, where is the fun with a prepackaged solution? Requirements: runs Gentoo, is absolutely silent, low power consumption, some hard disk space, USB ports.
At first I tried a GuruPlug, but what I did not realize until it was on my desk: it's fan makes quite some noise, and there's unfortunately no soundproof server rack in my flat. So, now I have settled for a (fanless) OpenRD Ultimate board, and I can say it really lives up to my expectations so far. For those who know Raúl's SheevaPlug installation instructions, the process can here be done roughly the same way, with two small caveats:
  • Raúl's kernel does not work, we need at least 2.6.35 (I'll place a binary online... see below)
  • The console kernel parameter needs to be console=ttyS0,115200n8
Otherwise, the preinstalled bootloader provides many more additional options to get the required files into memory than the one of the SheevaPlug or the GuruPlug. You dont have to hassle with network and tftp, but can just load kernel and initramfs from an (ext2 or fat-formatted) USB storage device, MicroSD card, or even eSATA disc...
Finally (but that applies to both devices of course, they are binary compatible), what I find really astonishing is how many Gentoo packages "just work" on these arm gadgets, even if they dont have the ~arm keyword (yet). This is really the power of a source-based distribution. Cheers!

UPDATE: Try the kernel image from here (together with Raúl's initrd) and tell me if it works! Untested so far...

Southern Skies

Beginning of the week is paper sorting time, and once again something interesting has come up in the arXiv blog: a detailed report on how an "outburst" of a star called η Carinae around 1845, when it became the brightest star of the sky for a few years, has entered the oral tradition of the Australian Aborigenes! Interesting read...

Saturday, October 16, 2010

digikam-1.5.0 and koffice-2.2.2

Here's the kde news of today: we now have digikam-1.5.0 and koffice-2.2.2 available! Compile and enjoy... and remember, all digikam versions above 1.2 require kde-4.5. kipi-plugins-1.5.0 will hopefully follow sometime during the next days.

Friday, October 15, 2010

Ancient but vibrant athmosphere

I'm living at the moment in Regensburg, Germany. The longer I'm here, the more I'm convinced that this is a great place to be... let me tell you why. :) First of all, Regensburg is an old place. For the Americans out there, with old I mean REALLY old. There are still remains of a Roman fortification built around 200AD. It's golden age however started when in 1146AD the first stone bridge across the Danube was finished. Here. Regensburg became a massive trade center, free city, ... Much later it also was for some 150 years the permanent seat of the Reichstag, the parliament (or, more correctly, diet) of the Holy Roman Empire. I don't really want to summarize the Wikipedia article though. The point is, the city was a rich and important center for ages, and it had a lot of luck: its buildings survived one war after the other, and even the concrete-crazy 1960's. Today, it's a UNESCO world heritage site.
That's one side of the story. The other side is that in 1962 the University of Regensburg was newly founded. Today, it has about 17000 students, with a campus in walking distance from the city centre. With the influx of students, the city center is thriving. The old architecture is no good for cars, so most of the center is ~pedestrian area. Many student dorms and rental flats are there, even in historical buildings dating back hundreds of years. The density of cafes, bars, beer gardens, pubs is amazing. I live straight in the middle, and when I get back from the office or lab in the evening I am again and again astonished at the athmosphere around me... Just a few steps away there's a medieval basement turned into a popular restaurant/bar place with the nice name "The Mended Drum"... When there's a slowdown in work, I'll for sure some day again take my camera and tripod and try to capture the spirit of the city - as long as I'm not in some bar sipping drinks with friends. Anyway, enough for today. :o) Cheers!

University news update

Finally... the bachelor exam is graded, and most of the results are already entered into the university database. Now that means- time to focus on research again! Just in time, letters from the administration have arrived, confirming the booking of the project money on the internal accounts. Yeah! Besides, Daniel, the first nanomechanics diploma student, has handed in his thesis and is employed as PhD student now, and a new diploma student will start on monday. The new research group is growing... On the spintronics side, we've been discussing the measurement data of the last months again and again, and slowly get a picture of some things. Meanwhile, the office renovation actually advances nicely, with lamps and cable ducts being installed at the moment. And I've started preparing the call for tenders for our next biggish lab equipment, and caught up with skimming across the ~400 papers published in the meantime. :) New term, new luck!

Tuesday, October 5, 2010

It's out - congratulations!!!

At least once every year, some physics researches have an uneasy sleep. That night has just passed, and the Nobel Prize 2010 in Physics was awarded to Andre Geim and Konstantin Novoselov of Manchester University "for groundbreaking experiments regarding the two-dimensional material graphene". Congratulations!!! For the last few years I have been listening to a lot of talks on graphene physics, mostly in Alberto Morpurgo's group in Delft, but also at conferences by the leads of the field, including the two stars of the day. While I have not always shared the unlimited enthusiasm for this material, it's physical properties are fascinating indeed. And since Samsung has recently demonstrated the roll-to-roll production of 30-inch graphene films for transparent electrodes (free preprint version) and a touch screen panel with a graphene electrode worked on the very first attempt, the technical usability has been proven. For mesoscopic physics, now only the question of clean edges and boundary conditions remains to be solved. Maybe we should just roll these graphene sheets up and form tubes? :o)

Sunday, October 3, 2010

Collectd - The system statistics collection daemon

Collectd is a really nice piece of software that I found in the Sunrise overlay some time ago (when I was practising there to become a Gentoo dev :o). It's a lightweight, modular background process for collecting statistics on the running system. Data sources and sinks are wildly configurable, and you can even write your own plugins in Perl, Python, or Java. Now we also have it in Gentoo as app-admin/collectd, and if you need a quick way to visualize the resulting bit flood, there is kde-misc/kcollectd as real-time data plotter. Enjoy!

Feeling manganese

The workshop is over and I'm now definitively feeling manganese. After so many talks about spin effects in and material properties of GaMnAs magnetic semiconductor compounds, I was glad to be back to nanotubes and superconductors for a while. Anyway, the stay in Niederalteich was nice and fairly quiet, even though we had stunning 19 talks on wednesday!
Afterwards, well, normal work started again. I finally have been able to more or less finish the proofreading of one BSc and one Diploma thesis. Friday a first oral exam marked the beginning of a new series during the upcoming weeks (the student did OK), and then it was finally weekend. :)

Tuesday, September 28, 2010

Dutch detour

We made it to the internal SFB689 spintronics workshop in Niederalteich, though barely in time. The origin of the delay is so bizarre that it just has to be reported: on the motorway, some sort of heavy duty vehicles were transporting two tram cars across the Bavarian province. That's not so strange in itself, but one of them seemed strangely familiar to me, with a logo "HTM" and a destination displayed as "Station HS". Who had the crazy idea to give a Dutch tram car from Den Haag an excursion into the Danube hinterland?!!! Anyway, see for yourself...

Saturday, September 25, 2010

Assembly line physics

After more than three days of non-stop exam grading (~130 students, 10 questions, ~35% completed), it was time for a break. I mean, at some point I might actually be frustrated enough to really run off to the McDonalds in Maximliansstraße and get some blank job application forms, and I think this might not really go down well with the faculty administration. (Not only with the administration, of course. :) If I find the time, I'll have to place a reference solution online, since most of the questions were so easy to solve. But to be fair, some people did rather well, so not all is lost. (And since the exam was designed to be "too long for available time", it's probably normal that some questions are just not answered.) Next stop then was (among some other things) preparation of the internal spintronics workshop next week in Niederalteich monastery. Some of the guys in our group have to give a presentation, so we've been discussing the slides...

Friday, September 24, 2010

Nanotubes, nanoonions, nanooysters

Thanks to the arXive blog, another gem of recent preprints has surfaced. Multiwall carbon nanotubes, when irradiated, turn into onion-like balls - and the pressures at the center of these balls can be so large that the carbon structure even crystallizes into diamond at the center! See the original paper for more details... Update... Why is this cool? Well, just imagine what pressures one needs to grow artificial diamonds. In nature diamonds crystallize somewhere around 50bar, and the process takes literally ages. Nanotubes are grown in the lab pretty quickly, and the astonishing thing is that intramolecular forces alone can generate such extreme conditions.

Thursday, September 23, 2010

Photo galleries offline

For those who have not noticed yet, the photo gallery server at www.ostpforte.de is down. For the technically minded, it failed to reboot after a kernel update (because of CVE-2010-3301). Since the box is physically in a different city in the basement of a building where I have no key, this may take a while. Well, at least I then have some time to sort the Korea photos from summer...

Piled higher...

Have I already mentioned that I'm (as many people around the world at university labs) a big fan of Jorge Cham's PhD Comics?! Right now I'm sitting in the office for a late shift of grading the big exam, and all that comes to my mind is the cartoon series on Cecilia grading undergrad homework... :)

Saturday, September 18, 2010

Database mania

Somehow about every bigger software package nowadays wants to use a full-scale database backend. Just after I kicked amarok out of my box, now I realized that digikam-1.4.0 actually depends on an existing mysql installation. It's nowhere in the documentations (yet?), but in hindsight the CMakeLists.txt in the main directory is pretty explicit in its wishes. Now what is then the point of using an abstraction layer like qt-sql, you say? Well, surprise, there is another bug where the qsqlite plugin just not seems to suffice. Now at runtime. I shared the resulting fishy feeling with the penguins running my chroot compilers nice and quietly in the background. The hair-rising result is that digikam-1.4.0 only starts up if qt-sql supports both sqlite and mysql...

Things to do...

Somehow the last days of the week already became pretty busy. How did I spend Friday? Well, planning with an engineer the renovation of offices and discussing in detail the locations of ethernet sockets, cable ducts, ceiling lamps, ... Then, starting to read and commenting on two work-in-progress theses of >70 pages each. And finally, nearly finishing this stupid bachelor exam. One more question to go (that's something for this evening), and then follows tomorrow in the office printing and stapling the sheets. (And locking the resulting pile of paper away properly. :o). The personalized cover sheets with names and matriculation numbers are already finished. Some colleagues have promised to help as "invigilators", some more help will still be organized, and monday at noon this should be done and over with. I just hope that nothing was messed up with the participant lists, and that someone from the administration can be reached monday morning in case of unexpected problems with formalities...

Thursday, September 16, 2010

First bump- digikam-1.4.0, kipi-plugins-1.3.0

There's definitely something magic about becoming a Gentoo dev. Suddenly you can go fix these bugs yourself! Anyway, thanks to my mentor tampakrap and all the other guys who helped, I now have made my way to commit access. Yay!
Here's my first real piece of Gentoo news: kipi-plugins-1.3.0 and digikam-1.4.0 have been bumped from the kde overlay to the main tree. Be warned that both require kde-4.5... And to answer the question before it is asked, I only bumped kipi-plugins-1.3.0 since this is what we already had. I know 1.4.0 is out there too... soon... :) Via a few corners, Fortran may still be required (digikam uses sci-libs/clapack, which depends on virtual/blas) - that's something that can and will still be fixed sometime. Enjoy!

Back at the office

Touchdown of the plane in München- and immediately the world was grey and rainy. Well, any trip to Italy cannot last forever. And at least I have a remarkable sunburn as a souvenir... Of course, being away for some days implicates that work piles up. Most urgent right now is preparing the questions for the physics bachelor exam of the first year chemistry students (they will have to solve them on monday!). 6 questions finished, 4 more to go...

Monday, September 13, 2010

Picture gallery online

Grignano harbour and the
ICTP guesthouse
And just to prove how nice it is here, I've uploaded some pictures. Click on the thumbnail to see more! :)
By the way, the large building on the right edge of this photograph is the Adriatico Guesthouse of the ICTP (International Centre for Theoretical Physics).

Sea and sun

The weather forecast was far too nice on saturday, so I wrote some e-mails, made some phone calls, and spent some money. Two more days in Bella Italia!!! Which means spending the day in a very relaxing day at the beach in the sun, and every now and then dipping into the sea for some refreshment. To keep my few remaining geek points, I'm reading pms-3... well, not only...

Friday, September 10, 2010

Weekend, vacation, whatever...

The conference is over (and was indeed very interesting), the looming-deadline research proposal sent off, the sun has already been shining nearly the whole day and is just setting slowly dark red over the sea, and I'm off now for some beers with the Delft guys in the center of Trieste. Cheeeers!

Wednesday, September 8, 2010

Brainfood for physicists

It seems that people are pretty keen on keeping us happy here at the conference. After listening to top-of-the line talks, the brain definitely needs some specialized thinking-food though. So I'd say this sweet coffee break add-on is fully justified. :)

Tuesday, September 7, 2010

You think you've seen it all (in your telescope)?

Compared to actual experimental physics, I have a tendency to think of astronomy as boring. Come on, it's not as if you can quickly flip a switch on your warp drive, have a close look what's really out there and tinker with it a bit. But, every now and then something amazing is discovered, as this stunninly beautiful spiral with a size of 1/3 light year. A gigantic sprinkler, lit by background galactic starlight... There's more information on it directly on the Hubble space telescope website, including the original paper discussing the discovery. Great!

Sunday, September 5, 2010

Theoretical physics heaven

I managed to leave office and home yesterday, for a really promising conference. Deadlines are looming for a lot of paperwork, but thanks to modern computer technology work never really leaves you. So, train to München, plane to Italy... Right now I'm sitting on the terrace of the guesthouse of the local centre for theoretical physics (hosting the conference), overlooking the small yacht harbour, and watching the sun set over the Adriatic sea. I have not been to Italy for far too much time, and now it's really hard to keep typing. Though, even writing a research proposal is somehow much more pleasant here at the coast or on the terrace of a grand cafe at the piazza, sipping an espresso doppio and waching the crowd...

PS. You can buy ethernet cables here in the guesthouse 24h per day from a vending machine. Right now they are sold out though... :)

Sunday, August 29, 2010

New digikam-1.4.0 for the KDE krazy

After tidying up the Gentoo libpgf and libclapack patches for digikam-1.3.0, I realized with surprise that they now apply to digikam-1.4.0 without any problems! So, earlier than expected, we have now in the kde overlay a shiny new digikam ebuild for the krazy kde-4.5 users. Test and enjoy!

Friday, August 27, 2010

The Mathematical Secret of Viking Jewellery

One of the really valuable online resources for a physicist who wants to extend his horizon every now and then is the arXiv blog - picking out the gems from the hundreds of daily fresh preprints. Today, the blog editors have found a really nice one again. "The Mathematical Secret of Viking Jewellery" points us to an article connecting Viking gold and silver bracelets with the theory of maximally twisted wires. "Hidden Beauty in Twisted Viking Neck Rings", arxiv:1008:4306. Worth a look!

New blog

Yes, this is the obvious "New blog" post. It has taken me a long time to accept the usefulness of this web-2.0 feature. But maybe I've got someting interesting to tell after all...

A quick note on the name of this blog. "dilfridge" is lab slang for "dilution refrigerator" - a pretty complex (and expensive) apparatus, that has anyway become something of a standard tool in low-temperature physics labs worldwide, for reaching the temperature range 0.003K - 0.3K (degrees above absolute zero). My research experiments take place at these temperatures, and after some years I find the technology still fascinating...