This video has been inspired by the wonderful Matt Parker and his video on the Stand Up Math channel:
Yesterday was Pi day and we are still celebrating! Simon experiments with calculating Pi with a physical thing, a pendulum. For the experiment, he cut a cord one fourth of the local gravity value (9.8m/s^2), that is 245 cm. One full swing of the cord makes Pi (measured in seconds)! Simon measures the time the pendulum makes 10 swings and divides that number by 10, to get the average duration of a swing.
The values Simon got were pretty close! The closest he got (not in this video, but later that day) was 3,128 sec., which is exactly the same value that Matt Parker got! What is the chance of that?
The formula is t = 2Pi times square root of l over g (where l is the length of the cord and g the local gravity).
Starring the cute 3Blue1Brown Pi. Here is some extra footage, with the 3Blue1Brown Pi riding the pendulum:
Simon wrote a program in Processing that plays the music of Pi. The idea to assign every integer a sound frequency belongs to the Numberphile channel, but Simon came up with the code. He plays the music for the first 41 digits of pi.
Impressions of Simon’s monthly science workshop with John Maas, from Wednesday this week. The main topic was the pH value, acids and bases. We used red cabbage water as a pH indicator – it still smells bad in the apartment!
Simon loves the conductive paint. After we finished making the Bare Conductive Voltage Village kit (previous post), he made two circuits, parallel and series, on his own without and help on my behalf. He did use weak AAA batteries first, so it didn’t work. When I told him he should switch to the 9V batteries, his circuits started to shine!
This is Simon’s parallel circuit:
And this is a series circuit:
When Simon got a new RaspberryPi 3 from Sinterklaas on Sunday joy quickly turned into drama as he discovered the old (and only) keyboard we had at home was outdated and had no usb connection. His original plan was to use the television screen as the RaspberryPi screen and that would have let towards constant struggle with those other members of the family who actually wanted to watch tv. What made things worse was that it was Sunday and all Belgian computer stores (and all other Belgian stores) were closed. Simon was devastated as he’d really set his mind on this project. We jumped in the car and drove to The Netherlands where people never stop working and neither does MediaMarkt. Within an hour we got a wireless keyboard and a nice Samsung screen, both at a good price, and went for a drink on the Grote Markt square of the old Dutch town Bergen op Zoom. And now we’ve got one more “desktop”.
Simon wrote a poster with electricity formulas (from memory) this morning and applied one of them (Ohm’s law) to his advanced lemon experiment.
We had already tried this experiment before but one lemon did not light an LED. Simon’s become more of an expert this time around. He used not one but 4 lemons now and measured the voltage (in Volts) and the current (in Amperes).
And he employed his sister as assistant.
The four lemons gave us almost 4 Volts!
Simon used his voltage and current measurements to determine the resistance:
He then decided that 24 Ohms was too little and added a resistor to his lemon circuit:
But with a resistor the LED light did not light up – apparently the voltage became too low. After all, the voltage is the resistance times the current. I suggested Simon try it again without the resistor, with the almost 4 Volts the lemons made. And it worked!
Didn’t really feel like going to his first Fench class this morning. All he wanted to do before and after French class was program:
We were utterly shattered when at the end of day two the PiTop stopped working. First it froze and we had to force reboot it by pressing the on/off button. This may have caused corruption of the MicroSD. The PiTop’s power does go on but the screen remains grey. Simon was crying bitterly at first but started looking for rebooting solutions on YouTube later in the evening. He is planning to reimage the SD-card tomorrow. Even if that doesn’t help there is a lot of learning involved in the process I believe. I have also written a letter to the PiTop support team.
Yesterday, while we were celebrating Halloween, Simon had more important things to do: he assembled his first laptop and spent hours programming it.
Mom, I’m going to build a heat generator!
This is Simon on his way to the Digisnacks class yesterday expecting to get his hands on the Makey Makey. Was a little disappointed after class: didn’t get to do as much as he had hoped. Did use the tangerines though.