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University Quantum Mechanics I

University Quantum Mechanics I · Measurement and the Uncertainty Principle · 4.02

Eigenvalue equations and determinate states

Q ψ = q ψ is the statement that every measurement of Q returns q: substitute it into σ-Q squared = ⟨(Q - q)²⟩ and the spread is zero.

Course-map guide · not a complete lesson or simulation

Scope & orientation

What this subsection covers

Q ψ = q ψ is the statement that every measurement of Q returns q: substitute it into σ-Q squared = ⟨(Q - q)²⟩ and the spread is zero.

A strong response uses bar charts of |cₙ|² over a spectrum and states where the model stops being reliable.

Reasoning checklist

Evidence, assumptions and limits

01

Assumptions to state

State the system, observable, approximation, and conditions held fixed before using a model.

02

Evidence to collect

Does the momentum spread inferred from single-slit diffraction scale as 1/a, and does repeating one slit N times narrow the fitted width or only the error on its mean?

Read the complete note

Does the momentum spread inferred from single-slit diffraction scale as 1/a, and does repeating one slit N times narrow the fitted width or only the error on its mean? Useful evidence includes profiles at five slit widths, fitted angular half-widths, inferred Δ-p against ℏ / 2 Δ-x with the slit named as a state preparation rather than a disturbance, and N repeats on one slit showing the error on the mean fall as 1/root-N while the fitted width holds..

03

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.

01 · Physical claimEigenvalue equations and determinate states

Q ψ = q ψ is the statement that every measurement of Q returns q: substitute it into σ-Q squared = ⟨(Q - q)²⟩ and the spread is zero. Only normalisable eigenfunctions count as states, so no determinate state of x or p exists on the whole line.

02 · RepresentationThe subsection's claim

Model, evidence, and boundary

03 · TestPrediction before measurement

What is the strongest test of a claim about Eigenvalue equations and determinate states?

04 · Evidence & boundaryDecide, then qualify

Does the momentum spread inferred from single-slit diffraction scale as 1/a, and does repeating one slit N times narrow the fitted width or only the error on its mean?

Read the complete note

Does the momentum spread inferred from single-slit diffraction scale as 1/a, and does repeating one slit N times narrow the fitted width or only the error on its mean? Useful evidence includes profiles at five slit widths, fitted angular half-widths, inferred Δ-p against ℏ / 2 Δ-x with the slit named as a state preparation rather than a disturbance, and N repeats on one slit showing the error on the mean fall as 1/root-N while the fitted width holds..

Interactive diagram for Eigenvalue equations and determinate states: follow the physical claim through its representation, proposed test, evidence, and model boundary.

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.

Diagram check

What is the strongest test of a claim about Eigenvalue equations and determinate states?

Quick check

Test the reasoning, not recall

What is the strongest test of a claim about Eigenvalue equations and determinate states?

Choose an answer to test the model.