Four strange ideas
Wave-particle duality
Light and electrons act as both waves and particles
Uncertainty
You can't know position and speed exactly at once
Superposition
A particle can be in a mix of states until measured
Entanglement
Linked particles share one state, even far apart
Quantum in everyday life
| Technology | Quantum effect |
|---|---|
| Transistors and computer chips | Electrons in semiconductors |
| Lasers | Atoms releasing matched light |
| LED lights | Electrons dropping energy levels |
| MRI scanners | The quantum spin of atoms |
| GPS atomic clocks | Exact atomic energy levels |
Much of today's economy runs on devices designed with quantum physics.
A short history
- 1900Max Planck: energy comes in small packets, or quanta
- 1905Einstein explains light as particles (photons)
- 1920sBohr, Heisenberg and Schrödinger build the theory
- TodayQuantum computers are an active area of research
Sources: American Physical Society; Nobel Prize archives
Remember
Quantum rules seem strange, but they are among the best-tested ideas in science and they power modern electronics.
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Answer key
- What does wave-particle duality mean?Things like light act as waves and particlesLight and electrons show both behaviors.
- Which everyday device depends on quantum physics?A computer chipTransistors rely on quantum behavior of electrons.
- What does the uncertainty principle say?You can't know position and speed exactly at the same timeThere's a built-in limit to how precisely both can be known.
- Who proposed that energy comes in small packets in 1900?Max PlanckPlanck started quantum theory.
- What is entanglement?Linked particles that share one state even when apartMeasuring one instantly tells you about the other.