Making Sense of Irrational Numbers

Like many heroes of Greek myths, the philosopher Hippasus was rumored to have been mortally punished by the gods. But what was his crime? Did he murder guests or disrupt a sacred ritual? No, Hippasus's transgression was mathematically proving the hitherto unprovable. Ganesh Pai describes the history and math behind irrational numbers. Lesson by Ganesh [...]

The Chemistry of Cookies

You might not believe it, but there's chemistry in baking cookies. You stick cookie dough into an oven, and magically, you get a plate of warm, gooey cookies. Except it’s not magic; it’s science. Stephanie Warren explains via basic chemistry principles how the dough spreads out, at what temperature we can kill salmonella, and [...]

Why Do Compressed Air Cans Get Cold?

This video is about compressed air cans (aka gas dusters) and why they get cold when you spray them. They cool off because the refrigerant inside (1,1-difluoroethane) is under pressure and boils off when the pressure lowers, and energy lost to the latent heat of vaporization cools the can a lot. Difluoroethane normally boils at [...]

How sugar affects the brain

When you eat something loaded with sugar, your taste buds, your gut and your brain all take notice. This activation of your reward system is not unlike how bodies process addictive substances such as alcohol or nicotine -- an overload of sugar spikes dopamine levels and leaves you craving more. Nicole Avena explains why [...]

Specialised HCI Economics Classes at Bukit Timah

Term 2 is a challenging time for J2 HCI students because the school is embarking on “flipped learning” (see point 5) which essentially means the students are left largely on their own with no lectures or tutorials for the topic “Firms and Market Structures”. This is a topic with quite a number of difficult concepts [...]

Grit: the power of passion and perseverance

What separates successful students from those who struggle: GRIT? In this Ted video, Angela Lee Duckworth explains her theory of "grit" as a predictor of success. But what is "grit"? Grit is passion and perseverance for very long term goals.

The Paradox of Value

Defining value is not as simple as it seems. Explore the paradox of value by watching this video from Ted-Ed's Constantly Curious. Imagine you’re on a game show and you can choose between two prizes: a diamond … or a bottle of water. It’s an easy choice – the diamonds are more valuable. But if [...]

What is Entropy?

There’s a concept that’s crucial to chemistry and physics. It helps explain why physical processes go one way and not the other: why ice melts, why cream spreads in coffee, why air leaks out of a punctured tire. It’s entropy, and it’s notoriously difficult to wrap our heads around. Jeff Phillips gives a crash course [...]

32 O-Level Math Exam Scripts Lost – SEAB

A total of 32 students who sat for their GCE O-Level Additional Mathematics examination last year have been given the option of retaking Paper 2 of the Additional Mathematics exam, after their answer scripts went missing in the United Kingdom. The affected students were from two secondary schools – 20 from Nan Hua High School [...]