Archive for the 'math' Category

Open knowledge

Wednesday, June 29th, 2011

Short notice: I am giving a talk on contents of the game scheme article and the scientific platform article on July 1st at the open knoledge conference in Berlin.


Thursday, May 26th, 2011

An upload of an updated version of the article draft “New economic schemes in games” is at the corresponding randform blogpost.

New economic schemes in games

Friday, March 25th, 2011

In the blogpost on the return of investments I proposed to use games for testing new economical scenarious. I currently try to make an article out of that.
In the draft I sofar have given an overview about games and roughly motivated why I think that it may be a good idea to introduce new economical schemes. In particular I talk about the limitations of this planet, design and in particular about something that I dubbed “recycling-run-away effect”.

Amongst others I also try to line out why I think that the nuclear waste problem may be a worse problem than the safety of reactors (see also the first post on Fukushima).

Comments are appreciated, here is the draft:
update (06072015) :
It currently looks as if an article format is rather not suited for the writings and findings made within the context of the game draft article. It is also still not clear wether this project will ever be finished and if in which form. You may though still find on and off some informations in this context, likethis blog post is an example.

update (06072011) : This blog post is now used as a referrer URL for the game scheme article, thus newer versions of the article and comments will be uploaded more or less regularily. Please note that this offer to our randform readers costs our private money. Since randform is currently purely financed by Tim Hoffmanns income as a math professor, we may eventually be forced to reduce or close this offer, depending on download rate, inflation, etc. Most of the content of the article is also spread on the Azimuth project like the section about the Game environment. The Azimuth updates are usually more current.

->version July 06, 2011

The most essential content article of the article was presented on July 1st at the open knowledge conference 2011 in Berlin:

Talk: “Testing new toy economies/political structures in MMOGs” at

older versions of the article:

->version May 25, 2011

->version april 26, 2011

-> New economical schemes in games, version march 25, 2011

Fukushima, calculations and comments

Monday, March 14th, 2011

On sunday the 7 th fleet reported:

The U.S. 7th Fleet has temporarily repositioned its ships and aircraft away from the Fukushima Dai-Ichi Nuclear Power Plant after detecting low level contamination in the air and on its aircraft operating in the area.

The source of this airborne radioactivity is a radioactive plume released from the Fukushima Dai-Ichi Nuclear Power Plant. For perspective, the maximum potential radiation dose received by any ship’s force personnel aboard the ship when it passed through the area was less than the radiation exposure received from about one month of exposure to natural background radiation from sources such as rocks, soil, and the sun.

The ship was operating at sea about 100 miles northeast of the power plant at the time.

24*30 = 720

So this means the boat received a 720 fold radiation at a distance of about 160 kms of the troubled Fukushima nuclear plant from what’s supposed to be normal.

Even if one assumes that the density of such a plume disperses quadratically one would have 720*(160^2/270^2) = approx. 250 times higher dose then normal, or in other words in one hour one would perceive about a third of a months radiation dose above normal being in such a plume at a distance of 270 kms (which is the approximate distance between Fukushima and Tokyo). Luckily the ship could get out fast of the hazardous zone.

Unfortunately the possibilities to alter weather are very small. In fact there were experiments in Abu Dhabi and it seems China is also doing a lot of research in that direction, seen critical by some others. The latest research item in cloud seeding seems to have been laser shots into the air over the sky of Berlin (see also this article ).

The information about what’s really going on at the plant is fuzzy. It is understandable that some people would like to avoid a panic and thus would not make all information available to a broad uninformed public, who might draw false conclusions. But some people would like to appease people by making unscientific claims about certain likelyhoods (while at the same time claiming that nothing can be measured!). But one should think about how such an approach may impair credibility…this holds especially true for some certain news agencies, who’s reports are less based on facts but on biased commentaries disguised as “facts”.

So here a bit of information taken together:
An interactive map from the New York times of the Fukushima plant with a BWR design which (if I understood correctly) is by General Electric. An illustration by Hitachi of the concrete Fukushima plant seems to be in this pdf. The design looks a bit differently than the General electrics one…
A rather matter of fact and informative blog post about what happened at Fukushima by what seems to be a pro-nuclear writer (at least he cites pro-nuclear sources). What one got to hear sofar is that the reactor vessels and the containment of the troubled plants are still intact.

Our thoughts are with the japanese people and their grief.

Moreover we hope that the brave workers at the Fukushima power plants will succeed with their plans to avoid the worst. We hope that it will be possible to supply more and better equipment (see e.g. Kyodo news about the 5 fire pumps) to the dangerous Fukushima area and that with international help the results of the earthquake, Tsunami and nuclear disaster can be mitigated and that the worst possible nuclear scenarios won’t happen at Fukushima.

update 16.3.2011: I forgot to include a link to the

->overview on nuclear energy on randform

In this overview I actually saw the probability of a terrible accident with currently exisiting reactors as rather small. So in this overview I focused on problems with future types of nuclear energy generation (which include even more dangerous nuclear technology) and with the waste problem. I am asking myself now if I should give nuclear energy even more critical scrutiny.

A proposal for a pre-preprint archive

Thursday, March 3rd, 2011

our little postbox in munich two years ago

The last days there had been a big public discussion in Germany about scientific publishing. The reason for that discussion was that the former german minister for defense Karl-Theodor zu Guttenberg had included texts into his Ph. D. thesis, which were not by himself, but which were on the other hand not appropriately marked as a citation. The number of these plagiarized texts in his dissertation was so big that this “secretely pasting in” of texts by other authors had to be called systematic. As of march first, 2011 the site GuttenPlag had found plagiarized texts on 324 of 393 pages of his dissertation. After a longer process which included strong protests especially from the academic community, which included the revocation of his degree and a declaration of his doctoral advisor Peter Häberle Mr. Guttenberg finally resigned from his post as a minister for defense. Among others the declaration of his doctoral advisor Peter Häberle contained the sentence:

Die in der Promotionsschrift von Herrn zu Guttenberg entdeckten, mir unvorstellbaren Mängel sind schwerwiegend und nicht akzeptabel.

(translation without guarantee: The – to me unexplicable – found shortcomings in Mr. zu Guttenbergs dissertation are severe and not acceptable.)

The investigations into this case haven’t been finished, in particular the University of Bayreuth (which was in charge for the thesis) seems still to be investigating and e.g. checking wether the plagiarism was intentional fraud. There seems also to be the possibility of juridicial consequences (see e.g. here and here.)

In short the damage that had been done with this affair is quite big and thus a sensible question is “how could that happen and how could one prevent further cases like this?”

I hope that the future will bring more clearness into the case and will give an answer to the first question. Whatever the result will be it is already clear by now, that something went utterly wrong in how the dissertation was made and in how it was supervised.

In the randform post Alexandre Grothendieck writes a letter I had promised to speak about the proposal of a “closed pre-preprint section for the arxive for timestamping works” i.e. a kind of “safe” for work in progress. I think that such a section in an open access preprint archive could in particular be useful in the supervision process of a doctoral thesis and thus eventually help preventing similar cases as the above. It would also have other benefits. Let’s explain this.


poincare oddyssee

Wednesday, July 7th, 2010


Last time when I was in Göttingen I found a poster at the math department documenting an art science collaboration between mathematics professors William Thurston, Kazushi Ahara and Sadayoshi Kojima on one side and a team around clothing designer Issey Miyake, notably including chief designer Dai Fujiwara of Issey Miyake (here a link to a partial version of the poster, see also absnews article by Jenny Barchfield). A result of this collaboration is that the Issey Miyake Fall-Winter 2010-2011 ready-to-wear collection is inspired by the geometrization conjecture.

From the poster:

In the mid-October of 2009, Prof. Thurston showed us the detail drawings of the “8 Geometry Link models as Metaphor of the Universe” They inspired us to make the collection based on them, accompanying design study with rope and toile. Considering the body itself as the Universe, we have added our own interpretation of beauty to them. The new perception of the body shared by all the members of the team resulted in the discoveries of new lines and forms, which were then applied to textile, color and detail studies. Thus the new collection has taken shape steadily, revealing its whole picture eventually. To sum up the exchange with Prof. Thurston led us to find a completely new kind of beauty and embody it in clothing. This mission was, as it were, an odyssee to explore the Universe with infinite imaginations.

The geometrization conjecture roughly says (I am not an expert on this) that a three dimensional volume form without boundary (a two dimensional analog of such a form would be for example the surface form (i.e. the “skin”) of a ball or the surface form of a doughnut) can be decomposed into “pieces” which have one of 8 characteristic “geometric structures”, which means roughly that in a small neighbourhood of any such “piece” there is – out of only 8 characteristic ways – one specific way to measure length. A theorem states that any three dimensional (oriented) volume form without boundary can be obtained by cutting a “thick” (that is instead of a rope take a ribbon) link out of a three dimensional sphere. Thus you can characterize special types of three dimensional volume forms (here: “the pieces”) by assigning a link to them. This is – by what I understood sofar- why there are 8 links (or link models) on the poster – they characterize the 8 types of possible “pieces”, which built up three dimensional volume forms without boundary.

Why do they call these 8 links “Metaphor of the Universe”? I can only make wild guesses, which sound rather like science fiction than science: Maybe if you imagine the space of the universe to be eventually such a three dimensional volume then by cutting it into pieces (may be along black hole horizons huh?!) and “measuring distances” (determine a metric) one could make deductions about the actual form of the universe? Or – reversely by making assumptions about the form of the universe (like e.g. that its space is a three sphere) one may get informations about what could be inside black holes…given that one finds all black holes…(this is just a funny joke).

But joking aside – I think they call it Metaphor of the Universe because these simple 8 links may be used to describe quite complicated things.

->wikipedia link math and fiber arts

Days of Harmonics

Monday, June 28th, 2010


The International society for the interdisciplinary study of symmetry ISIS (not to confuse with Isis Healing or other Isis disambiguations) is soon organizing a conference called “Days of Harmonics” (Regular registration fee: 400 Euro) (Aug. 23 – Aug.28 2010, AUSTRIA). The proceedings are probably going to be published in the journal visual mathematics by the mathematical institute Belgrade.

about inspection optimization in nuclear energy

Friday, December 4th, 2009

In an earlier randform post about scaling factors in nuclear power generation I tried to explain what is implied if nuclear power generation is going to be increased. Among others I was talking about the risk of a nuclear accident which is going to rise by scaling things up. An important quantity in risk assessment in nuclear power generation is the core damage frequency. The corresponding Wikipedia article links to a ressource by the Electric Power Research Institute by which the probability of a damage of the nuclear core was in 2005 (i.e. the more dangerous type of fast breeder reactors, which will dominate in the future is included in this average only to a small amount) at 2*10^(-5)=0.00002 per reactor and year (there seem to be ressources which indicate that this frequency may be higher though).

This means that is if one has approx. 500 reactors worldwide the likelihood of a core damage somewhere in the world was in 2005 one damage in 100 years, if we take again a factor ten as in the randform post about scaling factors in nuclear power generation then this would rise to one core damage every 10 years. If we include an higher risk for fast breeders (which is a technology, which hasnt been tested exhaustively) then this likelihood rises again. Core damages are quite crucial because they can lead to a nuclear meltdown.

Other risks are therefore often calculated in relation to the core damage frequency. While answering to a comment about Leukemia I stumbled upon the “Studies on Applying Risk Informed In-Service Inspection for Indian Nuclear Power Plant and Heavy Water Plant” by G. Vinod from the reactor safety division at the indian Babha Atomic Research Centre in which probabilistic safety assessment techniques for indian nuclear power plants which among others are using the core damage frequency are discussed in particular with regard to optimizing inspection. A citation from the article

An optimum plan should be devised subjected to constraints such as risk to plant, cost of inspection and radiation exposure to workers, if the component is in radioactive area.

Its not clear to me to what extent inspection optimization may lead to an increase of the core damage frequency.

about reputation

Tuesday, September 29th, 2009


In a comment about a recent study whose neutrality was not so clear I was asked by a reader:

If there is all this data as you say on the internet then why do you need this reputation thing at all, i mean can’t you just check wether this Greiser person is right?

The study which the reader meant to be checked used data about leukemia occurences in children who lived in the vicinity of a nuclear power plant. This data was -to a great extend- gathered together via the internet and was then statistically evaluated. So the reader assumed that -given that all the necessary information is available- that one could just check wether the study is right.

My answer:
In principle -given that all information is provided in the study- and – given that oneself can access all data (this is unfortunately not always that easy) one can check wether all the in the study given data was correctly evaluated, one can follow the statistic reasoning and the methods which were used a.s.o. The question wether the study is correct or not should thus not be expected to be answered plainly with a yes or no, but at least include explanations about the involved methodology. All that takes a lot of knowledge and experience which is -for an outsider- not so easy to acquire. That is even though I am a mathematician it would take me probably quite some time to understand and evaluate the involved reasoning (it is not exactly my field), it is quite likely that I would end up with open questions and thus would need to consult other people.

One can compare this a little bit with a medical diagnosis, that is in principle all the medical information is available in text books, articles etc. and without having studied medicine one can have a “feeling” about how correct a diagnosis is, however – depending on the symptoms and ones own knowledge- people usually prefer to see a doctor instead of feeling inclined to cure themselves. The craftmanship of a mathematician -although this may not be so obvious- is comparable to that of a physician.

Nevertheless it happens that people won’t go see a doctor. This may happen because people can’t afford to pay a doctor and/or because they are convinced that their methods (or those of a non-medical-doctor) are better. And there are indeed cases were non-doctors may have better results. Nevertheless the typical scenario is that a learned doctor knows more and can help you better than a non-doctor. This holds also true for “crowd knowledge” that is you may ask around in fora about what to do with what symptoms, but typically you wouldnt like to rely on them completely.

Here one should note an important feature: Among others a doctor is someone who was evaluated by a certain group of people who know the subject. That is professional organisations, universities etc. hand out certificates which should give you some trust that this person knows what he/she is saying and doing. This is mostly what reputation is about. It is a guideline. Or put differently: Given a specified task the chance that you will end up with a completely incapable person which had been certified for this task by a respectable institution should be smaller than the chance that an uncertified person is incapable. This doesnt exclude the case that there are uncertified persons with a better knowledge than certified ones. This is just -at the moment- on average less likely.

I wrote “at the moment”, because there are unfortunately tendencies which dilute this rather helpful feature, as can be seen e.g. in the certification problem in the already mentioned outsourced learning environments/online classes. Certification problems can also be found in “cheap education” e.g. by certifying large amounts of students, which makes cheating easier (for example by handing in essays, which were not authored by oneself), academic misconduct and/or corruption e.g. due to financial interests etc. Moreover the possibilities for free autonomous learning are much, much better than before (which is good), so the number of highly trained individuals without a certificate are most probably on the rise. Traditional systems of evaluation may thus be loosing their influence. Personal recomendations would thus become more important, which makes it on the other hand harder to enter a foreign field as an outsider.

The above (unemployed) patient in the foto had a bad bike accident, which resulted unfortunately not only in a torn muscle. Thanks to a “still” rather good medical care in Germany within one week and with the help of several specialists and MRI a not so common injury could be diagnostized fastly and within 2 months the patient should be able to walk properly again….

Why do I write “still”?

Because in Germany the costs for health care are on the rise. This is not only due to an aging population but also to a great extend due to rising costs for pharmaceutical products, where new, patented products play a major role. According to this article in Berliner Zeitung on total the costs for physicians in Germany are meanwhile smaller than the costs for pharmaceutical products. Nevertheless suggestions of politicians which are about to form Germanys new government suggest to cut down on health care on the whole and instead secure a socalled “basic care” for the masses which could be supplemented by additional care – if you have the money. As a result the stockmarket for certain pharmaceutical companies soared right after the elections.

historical reading: -> hippocratic oath

College for $99 a Month

Wednesday, September 16th, 2009


Just a quick link to an interesting article in the Washington monthly about possible future developments within the US and other high-tuition-dependent-educational systems ->College for $99 a Month

very, very short summary: the article explains that cheap online education (eventually outsourced to India etc.) may lure college students into taking standard classes in the internet instead of in a typical college. This development could be accelerated due to the economic crisis. Standard courses usually “nurture” the more specialized classes, hence it can be feared that the overall quality may suffer from this.