The Weirdest Science
Quantum mechanics describes how the universe works at the smallest scales. And it's strange.
Things that seem impossible happen routinely in the quantum world. Let's explore five key concepts.
1. Wave-Particle Duality
Light and matter are both waves AND particles.
Shine light through two slits, and it creates an interference pattern — proof it's a wave. But light also comes in discrete packets (photons) — proof it's a particle.
The same applies to electrons, atoms, even molecules. They behave like waves when not observed, like particles when measured.
What it means: The nature of reality depends on how you look at it.
2. The Uncertainty Principle
You cannot simultaneously know a particle's exact position AND momentum.
This isn't about measurement limitations — it's fundamental. The more precisely you know where something is, the less you can know about how fast it's moving.
Heisenberg showed this with mathematics, not philosophy.
What it means: At the quantum level, perfect knowledge is impossible. Nature has built-in fuzziness.
3. Superposition
Particles exist in multiple states simultaneously until measured.
An electron doesn't have a definite position until you look. Before measurement, it's in a "superposition" of all possible positions.
This isn't uncertainty about our knowledge — the electron actually exists in multiple states.
Schrödinger's Cat: A thought experiment where a cat is simultaneously alive AND dead until observed. It illustrates how absurd quantum mechanics seems at large scales.
4. Quantum Entanglement
Two particles can be connected so that measuring one instantly affects the other, regardless of distance.
Einstein called this "spooky action at a distance." If two entangled particles are separated by light-years, measuring one immediately determines the other.
This has been proven experimentally. It's real.
What it means: Quantum mechanics is non-local. Connections exist that transcend space.
5. Quantum Tunneling
Particles can pass through barriers they shouldn't be able to cross.
A ball can't roll through a wall. But an electron can "tunnel" through barriers that should stop it.
- Computer chips work
- Stars fuse hydrogen
- Scanning tunneling microscopes image atoms
What it means: At quantum scales, the impossible happens regularly.
Why It Matters
- Computers and smartphones
- Lasers and LEDs
- MRI machines
- GPS satellites
Without quantum mechanics, modern technology wouldn't exist.
Learn More
This article is based on our audio course Physics Fundamentals. Listen to Episode 8: "Quantum Mechanics: The World of the Very Small" for the complete exploration of this fascinating field.