University Quantum Mechanics I · The Infinite Square Well · 6.07
Measurement probabilities and what a superposition is not
An energy measurement returns Eₙ with probability |cₙ|², and the projection postulate says an immediately repeated measurement returns the same Eₙ, so we carry the state forward as ψₙ.
Course-map guide · not a complete lesson or simulationScope & orientation
What this subsection covers
An energy measurement returns Eₙ with probability |cₙ|², and the projection postulate says an immediately repeated measurement returns the same Eₙ, so we carry the state forward as ψₙ.A strong response uses bar chart of |cₙ|² over n and states where the model stops being reliable.
Reasoning checklist
Evidence, assumptions and limits
Assumptions to state
State the system, observable, approximation, and conditions held fixed before using a model.
Evidence to collect
Do the resonances of a string clamped at both ends fall at fₙ = n f₁ with n - 1 interior nodes, and where does the analogy with Eₙ break?
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Do the resonances of a string clamped at both ends fall at fₙ = n f₁ with n - 1 interior nodes, and where does the analogy with Eₙ break? Useful evidence includes resonances for n = 1 to 6 with node positions measured, fₙ fitted against n, the fitted f₁ against v/2L, and fₙ proportional to n set beside Eₙ proportional to n² with the differing dispersion named.
Limits to state
This GioPhysics course map is an adaptable learning sequence, not academic credit, accreditation, or a universal university syllabus.
Read the complete note
This GioPhysics course map is an adaptable learning sequence, not academic credit, accreditation, or a universal university syllabus. It is a first dedicated quantum-mechanics course, distinct from University Physics V, which covers quantum mechanics alongside atomic, nuclear and particle physics in twenty units: this course is narrower, slower, and teaches the linear algebra it needs rather than assuming it. Hydrogen appears here as an introduction, with the full radial derivation belonging to a second course. A midterm examination is assumed around week 8. Follow your institution's published scope, notation, laboratory programme, and assessment rules. A result should be checked against units, signs, limiting cases, and the conditions under which its model was derived.
Diagram & examples
Work the claim before choosing an equation
Interactive concept map
Follow the model from claim to evidence.
Model, evidence, and boundary
What must be stated before selecting an equation for Measurement probabilities and what a superposition is not?
modelModel, evidence, and boundary turns the stated idea into a representation that can make a prediction.
Example questions
Try the reasoning before revealing the structure.
What must be stated before selecting an equation for Measurement probabilities and what a superposition is not?
Quick check
Test the reasoning, not recall
What must be stated before selecting an equation for Measurement probabilities and what a superposition is not?
Choose an answer to test the model.