The Spacetime Metric

Level 3 · Undergraduate core teaching kit · First- and second-year university

Quantum mechanics I–II

Use the learner record during the live investigation, then use the instructor guide to facilitate comparison, address misconceptions, and assess evidence-bounded reasoning.

Learner lab record

Discrete spectrum and basis-state audit

How do Hamiltonian parameters and boundary conditions determine allowed energies and measurement probabilities?

Setup

Use the quantum-spectrum laboratory. Keep the model family fixed while changing one Hamiltonian parameter, then compare normalized state weights and adjacent energy gaps.

Predict first

  1. 1. Predict whether every energy shifts by the same factor under the chosen scale change.
  2. 2. Predict what normalized probabilities must sum to.
Variables
VariableRoleUnit
Hamiltonian scale or confinement parameterindependentdeclared model unit
Quantum numberstate indexinteger
Allowed energies and gapsdependenteV or model energy
State probabilitiesdependent%

Observation columns

model parameterstate nenergyadjacent gapamplitudeprobability

Analyze

  1. 1. Which boundary condition produces discreteness?
  2. 2. How do amplitude and probability differ?
  3. 3. Which trend belongs to this Hamiltonian rather than all quantum systems?
  4. 4. What result would reveal failed normalization?

Conclusion frame

Changing ___ from ___ to ___ changed the n=___ energy from ___ to ___ while total probability remained ___; this follows from ___.

Instructor guide · 55–70 minutes

Teach the investigation, not the interface

Learning target: Learners connect a specified Hamiltonian and boundary conditions to a normalized discrete spectrum without universalizing one model.

Prepare

  • Review eigenvalue equations and normalization.
  • State the model Hamiltonian and boundary conditions.
  • Prepare one classical-continuum comparison.

Facilitation moves

  • Ask what operator defines energy.
  • Separate amplitudes from squared magnitudes.
  • Require model-specific language for every spectrum trend.

Accessibility and participation

  • Provide energy tables alongside level diagrams.
  • Read ket and operator notation aloud in plain language.
  • Use patterns and state labels in addition to color.

Evidence of learning

  • A normalized probability audit
  • A parameter-controlled spectral comparison
  • A stated Hamiltonian and boundary condition

Misconception checks

Every quantum system has equally spaced levels.

Equal spacing is specific to the harmonic oscillator; other Hamiltonians produce different spectra.

A probability distribution means the system secretly occupies every measured outcome classically.

The state supplies amplitudes and outcome statistics; ontological interpretations go beyond that shared operational rule.

Extension

Add a weak perturbation, predict first-order shifts, and compare them with the laboratory's numerical spectrum.