More Hiking in Modern Math World


For one hour, I will take you through some of the most amazing recent subfields of mathematics. From computational theory to chaos theory, from infinity to ergodicity, from mathematical physics to category theory, we will be unveiling mind-blowing results of modern mathematics. Although primarily aimed at non-mathematicians, it should be of great interest to everyone.

Youtube’s Most Horrible Video on Math


When I saw the following video, I was deeply, deeply, deeply shocked. And still am…

What shocks me isn’t even the fact that this is fundamentally wrong (pi is NOT 22/7 NOR 3.14!!!). Nor that this channel has 600,000 subscribes! Nor that the company doing this video seems to involve a lot of people and money. Nor even that none of the comments reacts to the awfulness of the video…

What profoundly shocks me is how it completely destroys the very concept of mathematics!

First, mathematics is not about numbers nor calculations! What’s crucial about pi has nothing to do with the fact that it’s a number! What matter in mathematics are concepts and their definitions. In particular, pi is essential because it’s the ratio of the circumference of a circle divided by its diameter. It must be taught as such!

Second, pi is an awesome number because it precisely can’t be written as a fraction (it’s even transcendental, which makes it even more awesome!). This is one of the most beautiful result in mathematics! Saying that pi is 22/7 isn’t only wrong, it also butchers the actual beauty of the evasiveness of pi! For instance, one of the awesome fact about pi is that its decimals contain all numbers! In other words, pi itself has much more information than all fractions combined!

Finally, and most importantly, mathematics is not about memorizing facts for the tests. Mathematics is a world of exploration, where every discovery can be a mind-blowing unforgettable moment! Teaching maths as is done in the video above is the sad murdering of one of the finest art humankind has ever created…

I can only hope that such a teaching is an isolated case (but I do fear the worst)… And I think it is essential to highlight and explain why it is very, very, very wrong.

To conclude, here’s the kind of ridiculous aftermaths of such a teaching, presented in this awesome video by Numberphile…

Also, as I’m talking about pi, I should mention that many mathematicians, myself included, want to replace pi by tau. Learn why with my article on imaginary and complex numbers!

A Trek through 20th Century Mathematics


In this talk, I will take you through some of the greatest simple ideas of the 20th century. From operations research to topology, from set theory to graph theory, from fractals to infinity, we will explore different regions of the world of mathematics. While this presentation is primarily aimed at non-mathematicians, it should be of great interest to everyone.

Along the Mekong to Pak Beng, Laos


Laos Immigration

The entrance to Laos from Chiang Khong, Thailand, is quite popular! Weirdly enough, the Laotian authorities didn’t seem that much prepared nor organized to welcome the crowd of tourists at the border…

After endless hours of queueing, Bertrand and I eventually got through. It felt like winning the lottery!

We then got to enjoy a peaceful cruise down the mighty Mekong river towards Pak Beng. Well, sort of… Let’s look at the bright side and say that, each of the numerous times the engine of our boat overheated, we got a chance to sit on the sandy shores of the breathtaking Mekong river. Wonderful!

Stopped on the Mekong

These recurrent stops made us arrive late in the dark at Pak Beng.

But then came the awesome part of the story at a local restaurant. A German backpacker we met three days earlier and a Swiss traveler joined us. We had a nice dinner and, as we went to pay, the restaurant manager and his wife had us sitting, chatting and having rounds of local rice whisky. Laotian style!

The Incredible Night in Pak Beng

The manager was an old Laotian man who talked English, French and Vietnamese. I was talking to him in Vietnamese, he was replying to Bertrand and I in French, I tried to translate in German, and we all talked together in English. At some point, the manager started to sing old French songs (et j’ai crié, crié!), which both Bertrand and I knew, but whose lyrics none of us could remember even nearly as well as he did!

But, more importantly, he taught us some Laotian! In particular, we learned the difference between how are you? (sabaidiiiiii) and I’m good thanks (sabaidi).

This night was a crazily unique awesome night, which I will never forget! Without a doubt, it was the most memorable night of backpacking I have ever had!