EPISODE 1 · 12 min
Why can sand think?
Here's something I never understood. The chip in your phone is a sliver of silicon. And silicon, joined to oxygen, is silica, the same…
Watch & read ▶THE WATCH LIST
Every episode, explained simply.
30 episodes across 3 series. Each one has the video, the full narration and every source.
10 EPISODES
Silicon
How purified sand became the transistor, the chip and the data centre, one question at a time.
EPISODE 2 · 10 min
Doping: a few wrong atoms on purpose
Last time, we purified silicon until it was one of the purest things people have ever made. And on its own, it was almost useless: a…
Watch & read ▶
EPISODE 3 · 11 min
The one-way street: diodes and rectifiers
Last time we left Russell Ohl's cracked silicon rod, p-type on one side and n-type on the other. Where they met, a flashlight made about…
Watch & read ▶
EPISODE 4 · 11 min
1947: how Bell Labs stumbled into the transistor
Last time, we ended on a one-way street. A diode can steer a current, but nothing lets a small signal open or close it, so it can't make a…
Watch & read ▶
EPISODE 5 · 11 min
Switch and amplifier: BJT vs MOSFET
Last time, Bell Labs built a little crystal device that let a small signal control a big one. That sounds like getting something for…
Watch & read ▶
EPISODE 6 · 11 min
The integrated circuit: printing circuits with light
Last time, we met the MOSFET: a switch whose gate holds it on or off for almost no power, and which, for decades, got better as it shrank.…
Watch & read ▶
EPISODE 7 · 11 min
Logic from switches: gates, CMOS and the 555
Last time, we learned to print switches by the million. But a switch only knows two things: on, and off. It can't decide anything. So how…
Watch & read ▶
EPISODE 8 · 11 min
How silicon remembers: RAM, ROM and flash
Last time, two gates wired in a loop held a single bit. But that bit is lost when the power goes off. Your phone is different. Let the…
Watch & read ▶
EPISODE 9 · 12 min
CPU vs ASIC vs FPGA vs GPU
Last time, we put logic and memory together. Now, what do we build out of them? Apple's 2024 iPhone 16 Pro answers in an odd way. Its main…
Watch & read ▶
EPISODE 10 · 12 min
Data centres and what's next
Last time, we filled a building with chips. So where does all this go next, and what's stopping it? The short answer is heat. Let's walk…
Watch & read ▶10 EPISODES
Australian Science
Ten things Australians invented or discovered: what they solved, how they work, and who really deserves the credit.
EPISODE 1 · 12 min
Wi-Fi: how CSIRO beat the echo
This season is about things Australians invented or discovered, told honestly. What each one solved, how it works, who shared the credit…
Watch & read ▶
EPISODE 2 · 11 min
The black box: David Warren's flight recorder
Every airliner carries two boxes that nobody hopes to open. Everyone calls them black boxes, but they're painted bright orange. And the…
Watch & read ▶
EPISODE 3 · 11 min
The bionic ear: Graeme Clark's cochlear implant
If the part of your ear that actually hears is gone, how can you hear? For hundreds of thousands of people, the answer is a thin wire…
Watch & read ▶
EPISODE 4 · 12 min
Penicillin: from Fleming's mould to a medicine
Before the nineteen-forties, a scratch could kill you. The first antibacterial drugs, the sulfa drugs, had only arrived in the…
Watch & read ▶
EPISODE 5 · 12 min
Seeing with sound: Australia's ultrasound pioneers
How do you make a picture of the inside of a body using nothing but sound? No knife, no X-rays, just a crystal pressed against the skin…
Watch & read ▶
EPISODE 6 · 12 min
The doctor who drank bacteria: Marshall, Warren and ulcers
How do you prove that a germ causes a disease, when almost every expert is sure it can't? In 1984, a young doctor in Perth tried the most…
Watch & read ▶
EPISODE 7 · 12 min
A vaccine against cancer: Frazer, Zhou and HPV
You can't catch cancer. Or so most of us assume. But almost every case of cervical cancer starts with a virus you catch, and can vaccinate…
Watch & read ▶
EPISODE 8 · 11 min
Spray-on skin: Fiona Wood and Marie Stoner
If a burn takes most of your skin, where does the new skin come from? In Perth in the 1990s, a surgeon, Fiona Wood, and a scientist, Marie…
Watch & read ▶
EPISODE 9 · 11 min
Plastic money: how Australia made polymer banknotes
Scrunch an Australian banknote into a ball, and it springs back. Try to tear it, and it's hard even to start. That's because it isn't…
Watch & read ▶
EPISODE 10 · 11 min
The Dish: how Parkes helped show the Moon landing
In July 1969, an estimated six hundred million people watched a man step onto the Moon. Most of that moonwalk reached them through a radio…
Watch & read ▶10 EPISODES
Mathematics Puzzles
Ideas so simple a child can ask them, that took humanity centuries to crack.
EPISODE 1 · 12 min
What is zero, and why did it take so long to invent?
Here's a puzzle. Write a 2 and a 5 side by side, and you've got 25. Now slip a little circle in between them, and you've got 205. You…
Watch & read ▶
EPISODE 2 · 12 min
What is infinity, and can one infinity be bigger than another?
Here's a puzzle. Which are there more of: the counting numbers, one, two, three, forever, or the square numbers, one, four, nine, sixteen?…
Watch & read ▶
EPISODE 3 · 11 min
Does 0.999… really equal 1?
Here's a puzzle. Write zero, a decimal point, and then nines, forever. Zero point nine recurring. Is that equal to one, or just a little…
Watch & read ▶
EPISODE 4 · 11 min
Should you switch doors?
You're on a game show, facing three closed doors. Behind one is a car, and behind the other two, goats. You pick door one. The host, who…
Watch & read ▶
EPISODE 5 · 11 min
Why do 23 people probably share a birthday?
Here's a bet. Walk into a room of 23 people, chosen at random, and offer even money that two of them share a birthday. Not your birthday…
Watch & read ▶
EPISODE 6 · 12 min
Why do prime numbers keep your bank account safe?
Last time we ended on a lock anyone can check but only you can close. To see how it works, start with a puzzle in two halves. First…
Watch & read ▶
EPISODE 7 · 12 min
Why does pi never end?
Here's a puzzle you can do in the kitchen. Wrap a string once around a jar lid, then lay it straight across. It goes across three times…
Watch & read ▶
EPISODE 8 · 11 min
How did Achilles ever catch the tortoise?
Here's a puzzle. Achilles, the fastest runner in Greek legend, races a tortoise and gives it a head start. Before he can pass it, he has…
Watch & read ▶
EPISODE 9 · 11 min
How did seven bridges start the maths behind Google Maps?
Here's a puzzle. A river splits around an island, and seven bridges join the island, the two banks and a piece of land to the east. Can…
Watch & read ▶
EPISODE 10 · 12 min
Can maths prove everything?
Here's a puzzle. Read this sentence: this sentence is false. Is it true? If it's true, then what it says holds, so it's false. But if it's…
Watch & read ▶