Doing maths at a Parisian café, looking for various ways to derive Pi

Advertisements

Simon took part in a Coding Train livestream in Paris!

Simon and Daniel Shiffman after the livestream

The video below is part of Daniel Shiffman’s livestream hosted by GROW Le Tank in Paris on 6 January 2019 about KNN, machine learning, transfer learning and image recognition. Daniel kindly allowed Simon to take the stage for a few minutes to make a point about image compression (the algorithm that Daniel used was sort of a compression algorithm):

Here is a different recording (in two parts) of the same moment from a different angle:


What are exams good for?

“I can see that your son has native speaker skills, but we still cannot give him a passing grade”, the English examinator told me in an apologetic tone of voice. She and her colleague at the Brussels examination committee had just finished their assessment of Simon’s oral English and brought Simon, a whole storm of emotions on his face, back to me in the waiting room.

“We were just wondering, does he speak Dutch? We weren’t sure he understood the tasks and they were written in Dutch”, — the examinator was sympathetic of Simon’s young age as most of the other kids taking the same test were about 6 years his seniors. As it turned out, the first task was to describe several photos of “criminals” (one of them with many piercings), the second task involved choosing two things that Simon would like to do from a list of recreational activities (the list included an escape room and a Stonehenge trip). “I just didn’t know what to say!” Simon was catching his breath in between the sobs. “It’s an impossible question, because I had to choose two things I like from a list where there wasn’t anything I liked!” The examinator suggested Simon could have said why he disliked those things. “If you don’t find something interesting you just don’t find it interesting, it’s a given fact! You can’t explain it!” – he told her in English.

Another fact is that Simon wouldn’t be able to perform these tasks in any of the three languages he speaks. Not because his vocabulary or grammar don’t stretch that far. I often hear him construct amazingly intact sentences, which I immediately record, like this one recently: “This is incredible! We’ve found a connection between a discrete problem, of what’s the smallest number that divides all of the numbers in a given sequence, to a continuous problem, of what is the fundamental frequency of a combination of sine waves. In other words, we found a discrete solution to a continuous problem!” Simon loves deep philosophical or scientific questions, but often cannot answer open questions lacking substance. He doesn’t care if you ask him to describe someone’s looks on a picture, it’s not important to him. He doesn’t know how to pick two things he likes from a list of things he doesn’t like. It’s just the way his mathematical brain is wired.

“Can I send you one of the many videos on Simon’s YouTube channel as an alternative proof of his excellent oral English skills?” I asked, still shocked at the absurdity of the situation. “Because I dare to say Simon speaks English better than any other student you have examined today”. The examinator agreed that I was probably right in my judgement but couldn’t accept anything else but a completed exam task.

Although distressed about what Simon had to go through, I can’t help feeling content with today’s scoop. What can provide a more obvious proof that exams don’t do a good job measuring one’s skill than this example of a 9 year old who gives hour-long science lessons on YouTube, speaks at grown-up creative coding meet-ups and is often mistaken for a native speaker, but doesn’t pass his oral English exam because he’s being asked questions that don’t interest him?

It wasn’t Simon who failed today, it was the exam that failed to measure his English. And this raises a whole lot of questions. Why is this system of measurements, that clearly doesn’t work for everyone, has become decisive in how our society views someone’s ability? And what is the use of spending so much money and nervous cells on something that doesn’t work?

Wouldn’t it be more fair towards both the students and anyone who honestly wants to know their level to actually look at what they can do with their knowledge in real life (their actual projects, videos of their social engagement) instead of the fake setting at the exam? Wouldn’t it be wiser to observe a student’s gradual progress in a given area, instead of stressing the students out and giving them the impression that it’s all about the examinator checking off that box and they can forget what they have learned the next day, because all that matters in our society is the passing grade?

“I’m so neutral about this”, Simon told me (in English) when he was lying in bed the same evening. “Because on the one hand, I kind of feel bad. And on the other hand, it’s so beautiful how we sort of accidentally taught them how exams can show false negatives or false positives. Because the exam showed a false negative. Even the examinators know it’s a false negative”.

Simon on his way to Brussels today

About Maxwell

Simon: You can derive the speed of light from Maxwell’s equations. 

Me: Because they used to think it was infinite, right?

Simon: Maxwell’s equations aren’t invariant to the Galilean transformation, which means that the Galilean transformation is wrong, which means that Newton’s mechanics is wrong. The actual transformation is the Lorentz transformation, and this is the exciting one. Because that’s what you need for Einstein’s relativity!

More quantum physics: quarks hit by photons and what does a z boson do?

Simon told me about strong force and what happens to a quark inside a nucleon if a high energy photon hits it and pushes it outside the nucleon: a new quark and antiquark are created.

But what if the photon was so strong that it pushed the quark even further? It would create another quark and another antiquark.

Then Simon switched over to drawing Feynman diagrams to show how a w boson emitted by a quark or a changes that quark or lepton (charm to strange, bottom to top, electron to electron neutrino, etc.) “We don’t know what the z boson does” , Simon says. “Maybe it’s there for no reason!”

The Lorentz factor

Simon has just graphed this to show how the Lorentz factor or gamma ( on the y axis) is dependent on the speed of the object (the x axis). The 100 on the x axis is the speed of light. You can see how the speed makes virtually no difference to the Lorentz factor (of relativistic time and mass) until the speed of the object reaches about 85 percent of the speed of light. At around 90 percent of the speed of light the Lorentz factor reaches 2 (which means that time is twice as slow by then and the relativistic mass doubles), and at 99 percent the factor is already 7. For 100 percent or the speed of light itself, the Lorentz factor equals infinity, Simon explained.