Optical Illusions in Processing (Java)

Simon created three optical illusions in Processing (Java) playing with color. For better effect, you can download Simon’s code on GitHub: https://github.com/simon-tiger/colorIllusions

The Part 1 video is about the first two illusions. The third (and the coolest) illusion is in Part 2.


Simon writes:
Illusion 1: A checkerboard with blue and yellow squares, but if you move away from it, you see white.
Illusion 2
Mode 1: A disk with red and green, but when you spin it, it becomes yellow.
Mode 2: A disk with red and cyan, but when you spin it, it disappears.
Illusion 3: A rainbow of colors, but when you pause it from flickering, you only see red, green, and blue.

If Illusion 2 Mode 2 doesn’t work, change the background from 255 to between 128 and 135.
If any of the other illusions don’t work, try doing them on a different screen.

Inspired by Physics Girl videos.




The Slinky Experiment

Inspired by the Veritasium channel, Simon tests throwing a Slinky nd watching it collapse together and only then fall to the ground. He then ties a tennis ball to the Slinky and observes how it would behave if he throws it out of the window.

Color Opposites

Here Simon placed the primary colors in the next to the secondary ones (that he mixed using only the three primary colors) so that the colors that are absolute opposites of each other are also standing opposite to each other: blue is the opposite of yellow, magenta is the opposite of green and red is the opposite of cyan.

How much iron is there in your favorite cereal?

If you put a cereal flake in a bowl of water you can steer it with a strong magnet. The magnets above aren’t strong enough, but the really powerful ones below (that are dangerous to pull apart as they can actually injure you) are:

And if you grind the cereal into powder, the powder sticks to the magnet because of the iron atoms in the cereal:

Inspired by the Veritasium channel.

Experimenting with electromagnetism

Here Simon tried to induce a magnetic field by allowing electric current to go through a conductor that is normally not magnetic (copper wire). The green stick is a magnet that got attracted to it once the circuit closed.

The copper wire also began to slightly attract the steel paperclips.

The Best Shape for Train Wheels

Simon explains why train wheels are actually shaped like truncated cones. Inspired by a Numberphile video about stable rollers. The wooden slopes for the experiment Simon designed himself and his grandma (an ingenious craftswoman and woodworker, although a physician by profession) manufactured them for him.

Slowing down the time

The first thing Simon said this morning was: “Mom, do you know that if you keep moving, you get one quadrillionth of a second per second younger than if you just sit still?” Simon had heard this fact on VSauce the night before (and I think we watched another VSauce video earlier and also read in our Eine kleine Nachtphysik book about how in spacetime, we barely move through space and only move through time, and the faster one moves through space, the slower one moves through time – that’s why time stops for anyone moving through space at the speed of light.

This morning, Simon wanted to calculate how much less older one gets within a lifetime of 100 years if one keeps moving all the time. He first calculated how many seconds there are in a 100 years. He said he knew that there were 10! seconds in 6 weeks and went on from there:

And then, multiplied that value by one quadrillionth (see below). He ended up with approximately one three hundred thousandth of a second per 100 years – getting that much less older than if you sit still for a century. The value is very approximate, as Simon is not exactly sure whether the initial value of one quadrillionth per second is correct – it could be even less!




Our first MEL Chemistry set has arrived!

We have received our first MEL Chemistry box, something the kids were really impatient to start. And guess what, finally something to be proud of being a Russian from St.Petersburg – that’s where MEL Science kits are actually being made! It’s been a while since I have seen a “Made in Russia” on anything awesome.

The first two experiments we tried today were part of the Artificial Sea Set: Chemical Seaweed and Chemical Jellyfish. They both involved working with metal salts (sulphates) and watching them react with different solutions. The time lapse video above shows the seaweeds “growing”: “Metal salts gradually dissolve and react with the potassium hexacyanoferrate(II). Insoluble copper, iron and zinc compounds form. These don’t just precipitate out but form “bubbles” because of the osmotic pressure. The fancy chemical seaweed grows from these bubbles”.

It was fun to watch the metal salts change colours: iron turned bright blue and blue copper sulphate turned brownish red!

The funny little things in the petri dish are the “jellyfish” we made as a finishing touch to our artificial sea. We created theses by firing metal salt solutions into sodium silicate (liquid glass). “An ion exchange reaction occurs between the sodium silicate and the metal salts. As a result, insoluble metal silicates form. These resemble jellyfish!”

Metal salts starting to grow in potassium hexacyanoferrate:

Unboxing the first kit:

Busy with the experiment(s):

We also dived into the MEL Chemistry app that allows you to see all the molecules of the reagents involved in 3D.