Home » Latest » Network Technology » A beginner’s guide to quantum computing | Shohini Ghose

A beginner’s guide to quantum computing | Shohini Ghose

3

InfoSearched 156 Network Technology

6.8

SaveSavedRemoved 0

A quantum computer isn’t a faster version of your laptop — it’s a completely different kind of machine, and the coin flip proves it.

Dr. Shohini Ghose wants you to stop thinking of quantum computers as souped-up PCs. In her TEDWomen talk, recorded in November 2018 and published on TED’s digital channels in February 2019, the Wilfrid Laurier University physicist and TED Fellow breaks down what actually makes a quantum machine different from every computer that came before it — and why a simple coin-flipping game is the easiest way to see it.

• Ghose argues quantum computers aren’t upgraded classical machines, comparing the leap to the difference between a candle and a light bulb: “You cannot build a light bulb by building better and better candles.”
• In her coin-flip demonstration, a classical player is stuck choosing heads or tails, while a quantum processor uses a qubit held in superposition — “kind of like stirring a mixture of two fluids” — guaranteeing the quantum machine wins once the coin is measured.
• She points to three real-world payoffs of mastering superposition and entanglement: simulating molecules to speed up drug discovery, building mathematically unbreakable encryption, and teleporting quantum information across secure networks.

Candle Analogy Supersedes Speed Comparison

Most explainers pitch quantum computers as faster calculators. Ghose pushes back on that framing immediately. Her point is that classical computers, no matter how many transistors get packed onto a chip, are still running on the same binary logic — bits locked into either 0 or 1. A quantum computer doesn’t just do that logic quicker; it runs on an entirely different physical process, which is why she insists you can’t get there by incrementally improving what already exists, any more than stacking candles gets you electric light.

The Coin-Flip Game That’s Impossible to Win

To make the abstraction tangible, Ghose walks through a coin game pitting a human against a quantum machine. The human is bound by classical bits — a coin is either heads or tails, a definite 0 or a definite 1, the moment it lands. The quantum side plays with a qubit sitting in superposition, occupying both states at once rather than committing to one.

That fluid, undecided state holds no matter what the opponent does to the coin along the way — flip it, don’t flip it, doesn’t matter. The superposition survives until the instant of measurement, at which point the quantum player comes out ahead every time. It’s a small parlor trick, but it’s Ghose’s way of making superposition feel less like math and more like something you can watch happen.

“A quantum computer is not just a more powerful version of our current computers, just like a light bulb is not a more powerful candle. You cannot build a light bulb by building better and better candles.”

Superposition, Entanglement and the Qubit

The qubit is the entire foundation here. Where a classical bit is forced into a binary choice, a qubit can hold both values simultaneously through superposition — and when multiple qubits become entangled, their fates link together regardless of distance, a property that underpins how quantum processors can explore many outcomes at once instead of one at a time. It’s the same subatomic behavior that shows up in coverage of physical quantum hardware, including the kind of machine unpacked in the Holy $H!T episode that literally unboxes a quantum computer.

Location of Tangible Performance Gains

Ghose doesn’t stop at theory. She lays out three concrete lanes where mastering qubits changes what’s computationally possible: simulating molecular structures to speed up drug discovery, building encryption that’s mathematically unbreakable rather than just hard to crack, and teleporting quantum information across secure networks. Each of those depends on the same underlying trick — superposition and entanglement doing work that classical bits simply can’t replicate, a challenge tied closely to the broader hardware race chronicled in pieces on the extreme physics now pushing Moore’s Law to its next level.

Ghose’s talk never pretends quantum computers are close to sitting on a desk — the whole point of the candle-and-light-bulb line is that this is a different animal, still being built from scratch. But the three applications she names aren’t hypothetical wish-list items; they’re the actual reasons labs are racing to stabilize qubits in the first place, and each one — faster drug discovery, unbreakable encryption, teleported information — is a separate finish line with its own timeline still being worked out in physics departments like hers.