📏 Measurement & Collapse
Discover how measurement transforms quantum superposition into classical reality
Your Progress
0 / 5 completedFrom Quantum to Classical
🔍 What is Quantum Measurement?
In quantum mechanics, measurement is fundamentally different from classical observation. When you measure a quantum system in superposition, it doesn't simply reveal a pre-existing value—it forces the system to choose one outcome, destroying the superposition in the process.
Measurement irreversibly changes the quantum state. Once measured, a qubit in superposition collapses to a definite classical state (0 or 1).
🌊 Before & After Measurement
Before Measurement
After Measurement
🎲 Probability & Randomness
While measurement outcomes are probabilistic, the probabilities are precisely determined by the quantum state before measurement.
Born Rule
The probability of measuring a particular outcome is the square of the amplitude:
where α|0⟩ + β|1⟩ is the quantum state
⚙️ Properties of Measurement
Irreversible
Once collapsed, you cannot recover the original superposition
Fundamentally Random
Individual outcomes are unpredictable, even with complete information
Instantaneous
Collapse happens immediately upon measurement, not gradually
💡 Key Insight
Measurement is the boundary between quantum and classical worlds. It's the process that transforms quantum possibilities into classical reality, making it central to understanding how quantum computers produce usable results.