31 January 2016


A well-designed quote conveys interesting and often powerful ideas and makes one think for a time disproportionately longer than the length of the quote.

I have decided to add a quotes collection on my page. I try to restrict to quotes pertaining to Academia, but I can't promise I won't divert.

Anyway, here is a quote that impressed me today:
  • Most [people] discover that they have often be working in the affine plane without realizing that it could be so designated. (H.S.M. Coxeter)
Coxeter is the Grand Man of classical geometry who lived in the 20th century. Some of his books should be compulsory in middle/high school education. Alas, exactly the opposite is happening: to my total dismay I learned that Swedish schoolchildren never learn why the angle bisectors of a triangle pass through the same point. Instead, I was told, a Stockholm school made computer games a mandatory course. Not designing computer games, mind you, but playing them. No wonder that university students have no clue that there is a proof of the Pythagorean theorem. Yes, they can state it (and so can the greengrocer) but not only do they not know a proof, but--what's worse--they're not even aware that a proof is needed.

Back to the affine plane, however, even under ideal schooling circumstances, what makes the affine plane so elusive is the quick passage from Euclidean geometry to coordinate geometry (thanks Descartes!). Typically (I guess not any more), a schoolchild would learn a lot of Euclidean geometry in school but then pass on quickly to linear algebra in his/her first-year university course. The affine (and so goes for the projective) plane, responsible for a lot of elementary mathematics, would go by very quickly, if at all.

Pondering the Coxeter quote carefully is, perhaps, all is needed in order that the affine plane be re-surfaced from the stack of one's toolset.

30 January 2016

Violence in Sweden

There are a lot of things happening in Sweden that makes everyone who is not Swedish feel very uncomfortable.

The most recent of them is the attack to immigrants by about 100 masked people in central Stockholm. Although it appears that Sweden is welcoming immigrants it is rather clear to someone who lives here that a large fraction of people do not like them. The attacks that took place today are not the first. They happen, perhaps at a smaller scale, almost weekly. But it is a policy in Sweden that violence should not be reported. Central Stockholm and Uppsala, as well as many other Swedish towns, are accommodating immigrants from many countries, including Syria, Afghanistan, Romania, etc. One sees them on the streets. You can't go to a supermarket without seeing beggars often staying outside in the cold. Many people "help" them by giving them tips but even this is hard because the Swedish government adopted the policy of discouraging people from using cash, the intention being to force everyone use credit cards. Some beggars are now carrying credit card readers so they can accept credit card donations from people. But many people would rather not see anyone who looks darker than them. And since they cannot express their opinion openly, they put on a mask and beat street people up.

I know some people who work for the Uppsala city council who tell me that the phenomenon of attacking Syrian refuges camps is not uncommon. "I've never heard anything about it", I said. "You won't", they replied, "because the attacks are not reported." Apparently, only when something leaks out one finds out officially. Otherwise, it's hard to know what's going on. A few weeks ago there was this mass sexual attack in Cologne, Germany, from the other side: that is, by migrant people. Someone I know in Uppsala told me, around the beginning of the year, that similar things have been taking place in Sweden. "I can't believe it", I said. Again, the answer was "they are not reported". And, indeed, 2 weeks ago something leaked out. There were sexual attacks, by migrant youths but police did not make the information public. When the BBC found out they questioned the chief of the Swedish police who admitted that information is not released.

It happens both ways. Regardless of whether Swedes attack immigrants or the other way around, one cannot always find out: these attacks often don't make the news. Not by negligence; but by design.

In 2013, the now infamous Stockholm riots took place. A relatively high proportion of immigrants and second-generation immigrant residents, including a substantial number from Somalia, Eritrea, Afghanistan and Iraq instigated a mini-revolution by burning cars, throwing bricks, vandalizing, etc. Somehow, this was thought to be against the image that Sweden is portraying towards the outside world so it was not reported. When it leaked out, police declared it was terrorist groups. Although one may call such acts terrorism, it's not the kind that take place elsewhere. Apparently, the revolting migrants were expressing their frustration for their segregation and attacked innocent, of course, people. Just like in Paris suburbs a few years ago, at a smaller scale. As for segregation, it is rather obvious that many people who don't like typical Swedes are being kept apart. There is a neighborhood in Uppsala, Gottsunda, where they put immigrants. When we first moved to Sweden and were looking to buy a house we were explicitly warned not to go to Gottsunda. Such racist comments I thought existed only in Texas (and had experienced them). But Sweden, in some sense, is even more racist.

Back in 2011, when we had just moved to Sweden, there was this infamous mass killing in Norway by that human monster called Anders Breivik. The day after the killings, several people in Sweden started posting on Swedish newspaper sites, anonymously, their support for Breivik. I remember I got a call from Stockholm and was told to take a look at what they were saying. With the help of Google Translate, I read several of their comments and was appalled and scared. Good to know, however, I thought, that many people around me in Sweden support Breivik and would kill those whom they consider responsible for supporting immigrants. But my thought was quickly overturned: the Swedish newspapers decided to censor the readers' comments by deleting them and by closing their sites for a couple of days. They also created filters and other gadgets so that readers can't post anonymously (and, who knows, censor those who expressed their sympathy for Breivik).

Taking the train to and from Stockholm, one encounters some sad angry youth in neo-Nazi uniforms and tattoos: SS tattoos on their shaved heads. The reaction of passengers is to ignore them. I think they are scared, but I can't tell because they don't discuss it. I met Nazi demonstrations in Uppsala a few times. In 2010 or 11 there was this riot at the center of Uppsala by a bunch of angry young Nazis with pictures of blond men chasing black people. I approached one of them and asked him what's up. He said "we're against immigrants because they steal our jobs". I replied that "I'm an immigrant too and have the job of a professor in the University." I think I was aggressive and the young Nazi got scared. He replied  "it's only black immigrants we don't like. White Europeans are OK." "But I'm American", I said. He looks at me and says "It's OK, Americans are white Europeans." I didn't finish my sentence when a cop approached me and told me to get away.

And then, sometime later, we saw more riots of neo-Nazis, probably from the so-called "sverige demokraterna" party. The funny thing was that they had asked support of Greek Nazis from the equivalent "golden dawn" Nazi party. They brought them to Sweden for support!

The times are very fearsome. There is violence from all sides and it's rather clear that violence will escalate. I'd rather know than be in darkness. So I don't appreciate the censorship of information in Sweden. The Police view is that they should not "disturb" people by revealing that there was violence, rapes, murders, etc. But not all agree. It is silly and irrational not to know the truth. Take, for instance, the pre-war Jewry in Germany. Many of them were in denial that something bad would happen to them. Would it not have been better if they knew so they could get out while the could? When they finally found out what the true intentions of the Nazis were it was too late.

P.S. The latest response by Swedish government: Deport 80 thousand immigrants.  Previous response (4 weeks ago: fence borders.)

11 January 2016

Between sunrise and sunset in Uppsala

People ask me how much daylight do we get in Uppsala these days. The official answer is that the sun rises at 8:42 am today, 16 January 2016, and sets at 3:12 pm. But the real answer is in the video clip here. In it, you can see what the sun looks like between "sunrise" and "sunset.

What is rather peculiar here is that people don't like lights. Restaurants, for instance, turn their lights down during darkness, so much so that one needs a flashlight in order to read the menu. I find this practice extremely irrational and peculiar. (See also here for a related story.)

P.S. Walking on the streets, you see people whose sole purpose is to walk towards their death, or so it seems. They never speak, they don't respond to a "hello", they are miserable-looking. It looks like they are walking straight to their grave.

2 January 2016

How to force a cash-free numismatic policy to people

Say you are a government that wants to control every single transaction done in your country. How can you achieve this? Here are the steps.
  1. You make sure that subdivisions of your basic coin (cents, say) become rarer and rarer until they vanish completely.
  2. You instill the idea that money is counted only in terms of integers. There is no 38.51 units, but 39. In the US, for instance, there are still pennies, nickels, dimes and quarters and they still have a certain value. But, you should convince people that your country is more progressive than the US and that there is no value to decimals
  3. You make sure that banks in your country carry no coins.
  4. Ditto for cash of any denomination. Banks become cash-free organizations.
  5. You punish those who still want to use cash. For example, those who want have cash for their businesses must pay a fee of 20%.
  6. If someone insists in storing cash in a bank, then you make sure that he has to file a monthly report of how much cash he has.
All these steps have been taken by Sweden. And so, little by little, there will be no cash in the country. Everybody, regardless of whether they want it or not, must use a credit card (or some form of electronic transaction). Unlike the US or the UK, credit cards are not free. I am charged something like 50 US dollars per year for a credit card. (The cost is 0 for my US credit card.)

What about security, some ask. Surely, electronic transactions are not 100% trustworthy. But no problem: in Sweden, there is no such thing as consumers' rights. If, say, your credit card is stolen and used by someone else then it is your fault. The bank or credit organization carries no responsibility. So, it's a great system for those who issue the cards, bad news for those who use them.

But why would anybody want such a system? Who benefits? Again, the answer is simple. You, as a government, will have full control of even the tiniest transaction. You know who gives what to whom at any point of time. And that, at no cost and no responsibility: you have transferred all responsibility to individuals: they are responsible if something goes wrong, not you, the government.

But your governmental psychologists warn you that this system will not work if people realize your motives. So, how do you make sure that this will not happen? Again, very simple. (The solution has been found and implemented by Sweden.) You make people want this change by convincing them that they are a society of the future. And that it's the smart thing to do. You know, more than anything else in the world, individuals want to be smart. If they are convinced that they're smarter if they use electronic cash, then the job is done. And they have. Everyone goes around chanting the mantra "we are the most smart people, because we will soon have no cash (not like those idiots in Japan who still use small coins-ha ha)".

Some examples of what is going on. (References available upon request, but here is an account of the story as picked up by the Dec. 26 2015 issue of the New York Times. 
  1. Cafe owner in Uppsala gets penalized for having cash deposits. 
  2. Church-worshippers pay money to their gods via a machine called kollektomat.
  3. Some homeless people carry credit card readers.
  4. There is no way to get coins from a bank.
  5. There is a way to get coins from a private company, but they charge money for that.
The most scary thing of all of this is that individuals will apparently carry full responsibility for any fault in the system.

The brave new world?

Church worshippers send money to their god via mobile phones or similar electronic gadgets. This reminds me that Greek priests already communicate with god via mobile phones.
P.S. The system is not fully functional yet. In Sweden, public toilets cost. In order to urinate, for example, at the Stockholm Central Station you must use a10 SEK (about 1.20 USD) coin. But if you only have a 20 SEK note, how do you get change? The bank? No, the bank will not make change. You need coins in order to urinate (or defecate). I've seen people desperately going around trying to hold their bladder and I secretly smile: "You, foreigners, don't you know that you never go out without a couple of 10 SEK coins? You never need them for anything else, except for going to the toilet."


What measure theory is about

It's about counting, but when things get too large.
Put otherwise, it's about addition of positive numbers, but when these numbers are far too many.

The principle of dynamic programming

max_{x,y} [f(x) + g(x,y)] = max_x [f(x) + max_y g(x,y)]

The bottom line

Nuestras horas son minutos cuando esperamos saber y siglos cuando sabemos lo que se puede aprender.
(Our hours are minutes when we wait to learn and centuries when we know what is to be learnt.) --António Machado

Αγεωμέτρητος μηδείς εισίτω.
(Those who do not know geometry may not enter.) --Plato

Sapere Aude! Habe Muth, dich deines eigenen Verstandes zu bedienen!
(Dare to know! Have courage to use your own reason!) --Kant