First Gem: jekyll-onebox

I published my first Ruby gem. The Liquid tag jekyll-onebox allows to display HTML previews (embeds) for links to popular websites.

Initially, I wanted to blog about my travels. In the end, I refactored old code on my computer to publish eventually my first Ruby gem in the official repo at RubyGems. Welcome now jekyll-onebox on Github and RubyGems! :tada: :clap:

So if you use Jekyll for blogging, you can install this plugin and add HTML previews for links to popular websites very easily.

{% onebox %}

The previews are rendered using the gem onebox that powers link previews for Discourse forums.

Have fun with it and let me know if you encounter problems!

Security Issues due to bad Mail Practices: The LyonMUN case

So many associations use GMail for their general communication with members. Often, this comprises the sending of newsletters. Recently, the organisers of the UN politics simulation MUN LyonMUN leaked this way by accident a large number of participants mail addresses (mine as well). I decided to raise awareness of the security risks by a little experiment and also to test the reaction of the organisers.


On Friday 0:251, I received a mail from the organisers of this year’s [Model United Nations] (MUN) conference in Lyon called LyonMUN. The mail has been sent from to 222 people, that either participated in earlier editions in the conference or already signed up for this year’s edition. Purpose of the mailing: promote the upcoming edition and urge people to pay the conference fees.

The problems in here are:

  • The sender mail address is difficult to verify (I come back to this later).
  • All 222 people have now the mail addresses of all others. That means, many personal mail addresses have been assumably accidentally leaked by the organisers.

Due to the way mail works, you cannot undo a mail once it has been sent. The only possible measures are to inform the data subjects in a transparent manner on the incident and potential security implications and to take precautions to prevent future incidents.

I made a bad experience when I made during the last year’s edition LyonMUN 2016 in the role of a participant the remark that one aspect of their conference may intimidate the participants: They offered to allow sending anonymously roses to individual participants with a message read out loud by the organisers in front of the assembly without prior consent of the receiver. I thought this may open doors to potential bullying. The then president of LyonMUN Mélanie Villar and now secretary general just made a IMHO snide remark and that’s all what happened. I was certainly a bit disappointed and expected a debate taking into account that promoting debating is one of the purposes of MUN associations and events.

For that reason, I though of a more creative approach to initiate a discourse. It is not like security in the internet is not a topic for LyonMUN. On their website, the press team posted not even 2 weeks ago an article concerning cyber defence. Unfortunately, LyonMUN has apparently not adopted adequate measures on their own. Let’s see what happened!

  1. Maybe the sender was tired after working past midnight and less attentive of what s/he is doing. ↩︎

INSA Pedagogy Colloquium

Last week, I got the chance to present at the 5th Colloquium on Pedagogy my field report on the education of first years engineering students at INSA Lyon as I observed it during my soon 2 years teaching experience.

You may also want to read a communication entitled What does Active Learning Mean for Mathematicians? published in the Notices of the American Mathematical Society (AMS, Vol. 64, Nr. 2) earlier this year (2017).

Herbst-Gedicht (2016)

Place Louis Pradel (Opéra) in Lyon, France: Hatschi!
Place Louis Pradel (Opéra) in Lyon, France: Hatschi!

Nach meinem ersten Herbst-Gedicht aus dem Jahr 2010 nun 6 Jahre später ein versöhnliches Gedicht zur selben Jahreszeit.

Morgentliche Träumerei

Mühelos rolle ich den Berg hinunter
und biege ab, die Opéra zu meiner Rechten,
überquere die Rhône und werde munter.
Der Sonne Strahlen sich durch Morgennebel flechten.

Das gleißende Licht bringt mich zum Niesen,
und dass seit jeher an der selben Stelle.
Der Schein bricht sich im Tau der Uferwiesen,
auf dass ihr Glanz den jungen Tag erhelle.

Dann ungefähr eine halbe Stunde vor acht Uhr,
passiere ich die sonnengekrönte Präfektur.
Freilich kann man Sie vom Ufer aus nicht sehen,
dennoch kann ich dem Bann Ihrer nicht entgehen,
der es vermag meinen Gedanken ihren freien Lauf zu nehmen,
sie dort Kreise ziehen zu lassen und ganz für sich einzunehmen.

Derweil mein Rad mich weiter Richtung Süden trägt
und ich mich glücklich dieser Gegenwart besinne,
mein Herz mitunter völlig neue Rhythmen schlägt
und ich hellwach dem altgewohnten Trott entrinne.

Die Rhône ziert keine Welle, es verkehrt kein Frachter.
Sie erscheint ganz still und ruhig in ihrem Lauf,
doch verborgen dem oberflächlichen Betrachter,
birgt ihre Tiefe Bewegendes zuhauf.

Verfasst am 23. September 2016.

Mailing-List 2.0: Discourse

You got a few people working on something and you seek for an efficient way to communicate (ideas, news, messages, etc.) online. This guide gives you an overview about what you could expect in the past and what you should ask for nowadays.


According to Wikipedia, the first mail was sent in 1971. The access to a network we call Internet today was quite limited in these early days. Users have been mostly universities, and I guess, not everyone, but mostly the STEM disciplines Science, Technology, Engineering, and Mathematics. So it comes at no surprise that mails are perceived as inconvenient and antiquated.