Exercise, Experiments, Notes on everyday life, Physics, Simon teaching, Together with sis, Trips

A lot of fluid dynamics at Technopolis

Today we celebrated my 40th birthday with a family trip to Technopolis, a mekka for science-minded kids in the Belgian town of Mechelen. (Technically, my real birthday is in two days from now, but I have messed with the arrow of time a little, to speed things up).
The entrance to the museum is adorned with a red lever that anyone can use to lift up a car!
Simon and Neva lifting up the car
The beautiful marble run and math and physics demo in one
Galton’s board and Gaussian distribution
Simon explaining the general relativity demo, which is part of the marble run
This was probably the winner among all the exhibits: a wall to climb with a mission (Simon figured it out rather quickly – one had to turn “mirrors” to change the direction of light (green projection) and have the light rays extinguish the targets.
Simon tried to explain this to other children, but they only seemed to want to climb. It was sad to see how no one cared to listen (well, except for Neva of course).
Simon was already familiar with this optical illusion. Later he saw another version of this on an Antwerp facade.
The logic gates were too easy.
the center of gravity
Huge catenaroids! Something Simon had already demonstrated to us at home, but now in XXL!
cof
And huge vortices! Another passion.
Hydrodynamic levitation! Hydrodynamic levitation!
Look! A standing wave!
And another standing wave!

Here Simon explains one more effect he has played with at home, the Magnus effect.

Astronomy, Geography, Geometry Joys, Good Reads, Milestones, Murderous Maths, Physics

High and low tide

We drew a line to mark how far the sea has pulled back between 17:30 and 21:00 o’clock. It’s amazing to observe the the Moon in action! We have read about this dance that the Earth and the Moon dance with each other, circling round and round in what is currently our favorite book, Eine kleine Nachtphysik by Wolfgang Rosler:

Codea, Coding, Geometry Joys, Java, Milestones, Murderous Maths

Simon’s Codea Tutorials and the Arc-Tangent

A set of awesome Codea tutorials that Simon recorded for those who are just starting to program in Codea. Simon ported examples from Processing (java) into Codea (Lua):

In the second tutorial (in two parts), Simon explains how to write a physics simulation program in Codea using forces like gravity, friction and spring force. Anyone watching will get to use some trigonometry and see what arc-tangent is for! The original code in Java comes from Keith Peters (Processing).

Here are some notes from when Simon was explaining the arc-tangent to me the other day:

DSC_0716

 

Coding, Geometry Joys, Java, Milestones, Murderous Maths, Physics

Pendulum Force

This is a beautiful “lecture” that Simon in his pajamas, chocolate paste adorning is face, game me Friday morning. He spoke about pendulum force, a force he was about to apply in a coding project.

The other videos form the very beginning of the lecture, with Simon plays with sine and cosine and explains why location, velocity and acceleration can be vectors and can be angles:

And this is the code where pendulum force is used. It’s an example from The Nature of Code book by Daniel Shiffman, from Chapter 3 on Oscillation:

Coding, Java, Milestones, Physics, Simon's Own Code

The Nature of Code Forces example translated into Lua

Another translation involving the Codea app, only this time Simon decided to translate an example from Daniel Shiffman’s book The Nature of Code (Java) into Lua. The example comes from Chapter 2 of the book, Forces, and focuses on creating forces in the Processing world. Forces are vectors that can be applied to objects, those can be either some forces made up specifically for a project or forces modelling those already present in the real world. The chapter discusses Newton’s second law in detail (Net Force equals mass times acceleration). I have noticed that, thanks to Daniel Shiffman, Simon knows the three Netwon laws very well by now.

Simon introduced gravity, restitution, mass (many objects of varying mass) and wind to his Lua sketch:

 

 

Here is a photo of Simon’s code after he added restitution (velocity times -0.8):

IMG_4718

In the second video, Simon also briefly talks about the force of friction (Frictio=µNv). He read about friction in the same chapter and became fascinated with it. Since he was telling me about it when we were outside today, I asked him to repeat it in the video.

 

 

Coding, Java, Physics, Simon makes gamez, Simon's Own Code, Space

MotorAttractor with Box2D in Processing (Java)

In this project Simon combined two exercises and one example from Daniel Shiffman’s Nature of Code book, Chapter 5 – Physic Libraries. The specific physics library used here is Box2D. Simon combined exercises 5.6 (Bridge) and 5.10 (Attraction Apply Force), and example 5.7 (Create a windmill) to create a motor that catapults particles towards an attractor. If the particles fly past the attractor, “bricks” can be added to the canvas by clicking the mouse – the weight of the bricks helps regulate the motor in the right direction. For this project, both gravitational attraction and global gravity force were applied: