GLOBAL KNOWLEDGE ARK

Reference library

Foundations

Explore concepts, laws, equations and methods, with clear explanations of their use and sources. Choose an area of study or find a specific entry.

More filters

Reference entries

Showing 1591–1620 of 1709 reference entries

PhysicsSpecular and diffuse reflection

Reflection angles are measured from the local normal.

ModelPhysicsTotal internal reflection and evanescent fields

Total reflected flux does not mean zero field beyond the interface.

ModelPhysicsSpherical-mirror images and signs

A virtual image is formed by ray extensions, not actual ray convergence.

ModelPhysicsPhotoelectric threshold and stopping potential

Photon frequency sets maximum photoelectron energy in the single-photon model.

ModelPhysicsDe Broglie wavelength and particle momentum

A momentum state has a spatial wave phase.

ModelMeasurementQuantity kind and physical dimension

Equal dimensions do not make quantities interchangeable.

DefinitionMeasurementQuantity value, numerical value and unit

A numerical value depends on the chosen unit.

DefinitionMeasurementCoherent derived units

Coherence means no extra numerical factor in the base-unit product.

DefinitionMeasurementOrdinal quantities and nominal properties

Ordering and category labels do not justify ordinary arithmetic.

DefinitionMeasurementMeasurement principle, method and procedure

A physical phenomenon, an approach and a detailed procedure have different roles.

DefinitionMeasurementMeasuring instrument and measuring system

A complete measurement system can include more than one device.

DefinitionMeasurementSensor, transducer and detector

Component names describe different measurement roles.

DefinitionMeasurementInstrument indication and measurement result

A displayed reading is only one part of a measurement result.

DefinitionMeasurementAdjustment, calibration and zero adjustment

Changing an instrument response differs from determining its calibration.

DefinitionMeasurementReference and conventional quantity values

An accepted comparison value need not be an exact true value.

DefinitionMeasurementIndication interval, measuring interval and span

Possible readings differ from a validated interval of measurement.

DefinitionMeasurementRated operating conditions

Instrument properties are specified within a domain of use.

DefinitionMeasurement · ChemistrySelectivity of a measuring system

Responding to a target differs from excluding interference.

DefinitionMeasurementDiscrimination threshold and dead band

An undetected input change differs from an interval with no output change.

DefinitionMeasurementStability of a measuring instrument

Time stability differs from short-term repeatability.

DefinitionMeasurementMaximum permissible error and accuracy class

A specification limit is not an uncertainty estimate.

DefinitionMeasurementDefinitional uncertainty

More repetitions do not resolve an underspecified measurand.

DefinitionMeasurementRelative standard uncertainty

Relative uncertainty uses a nonzero measured magnitude.

DefinitionMeasurementBlank indications and null measurement uncertainty

A zero or blank reading can still have uncertainty.

DefinitionMeasurementTarget measurement uncertainty

An intended-use target differs from achieved uncertainty.

DefinitionMeasurementIntermediate precision conditions

Within-location changed conditions differ from strict repeatability.

DefinitionMeasurementCommutability of a reference material

Certification alone does not establish equivalence across procedures.

DefinitionChemistrySubstances, elements, compounds and mixtures

Chemical composition and spatial uniformity describe different features of matter.

DefinitionChemistryPhysical change and chemical change

A change of phase need not change chemical identity.

DefinitionChemistryEmpirical, molecular and structural formulas

A formula's subscripts represent different information in different chemical models.

Definition
ModelSource checked

Total internal reflection and evanescent fields

Physics

Total reflected flux does not mean zero field beyond the interface.

Key knowledge

For lossless isotropic media with n₁>n₂>0, light incident from medium1 at θ_i>arcsin(n₂/n₁) has no propagating refracted ray and unit reflected normal power at a single planar semi-infinite interface. The field in medium2 decays evanescently rather than vanishing. A nearby second high-index medium can couple that field and frustrate total reflection.

Values and equations

θ_c=arcsin(n₂/n₁); θ_i>θ_c for n₁>n₂

θ_c,θ_i
Critical and incident angles from the interface normal rad
n₁,n₂
Incident/transmitted medium refractive indices 1

Conditions and scope

  • Stationary planar interface, classical monochromatic fields, isotropic transparent nonmagnetic media and incidence angle from the normal.
  • Absorption, anisotropy, a finite second layer or other boundaries change the simple unit-reflection problem. The penetration depth can grow near the critical angle; “a few wavelengths” is not a uniform bound.
Sources · 2

References

Sources retain their recorded scope. A source link alone does not establish verification of every statement.

  1. University Physics Volume 3, §1.4: total internal reflectionSamuel J. Ling, Jeff Sanny and William Moebs — OpenStax, Rice University, University Physics (2016)Textbook chapteropenstax.orgRead source
  2. Oscillations and Waves, Total Internal Reflection, equations7.102–7.121 and frustrated reflection discussionRichard Fitzpatrick — University of Texas at AustinCourse notesfarside.ph.utexas.eduRead source

Evidence and review

Read OpenStax§1.4 critical angle1.5 and Fitzpatrick actual Total Internal Reflection body equations7.102–7.121/7.125 plus frustrated-reflection paragraphs. Use only critical angle, exponential field and zero normal flux conclusions; exclude suspicious amplitude-label equations7.118/7.134 and the prose implication that a phase retarder polarizes unpolarized light.

2026-10-10 · /root/audit_life_earth_chemistry — independent Chemistry/Life/Earth editor. Independent AI editorial review of this entry's statements, equations, applicability conditions and source coverage. Source checks apply to these claims within their stated limits.

Related reference entries

Explore relationships within this area of study and its connections to other areas.

Showing 1–3 of 3 relationships

Scientific relationships · 3 / 3

The relationship type describes the connection. Its linked statements, sources and conditions define the scope.

  1. Uses definition
    Relationship sources · 2

    Linked statements

    • For lossless isotropic media with n₁>n₂>0, light incident from medium1 at θ_i>arcsin(n₂/n₁) has no propagating refracted ray and unit reflected normal power at a single planar semi-infinite interface. The field in medium2 decays evanescently rather than vanishing. A nearby second high-index medium can couple that field and frustrate total reflection.

    This relation concerns the stated total internal reflection and evanescent fields claim and its conditions; it does not assert an unqualified prerequisite or an additional theorem.

  2. Related to
    Relationship sources · 2

    Linked statements

    • For lossless isotropic media with n₁>n₂>0, light incident from medium1 at θ_i>arcsin(n₂/n₁) has no propagating refracted ray and unit reflected normal power at a single planar semi-infinite interface. The field in medium2 decays evanescently rather than vanishing. A nearby second high-index medium can couple that field and frustrate total reflection.

    The two records describe related physical or metrological models or distinctions; the present claim does not require every hypothesis or result in the linked record.

  3. Related to
    Relationship sources · 2

    Linked statements

    • For lossless isotropic media with n₁>n₂>0, light incident from medium1 at θ_i>arcsin(n₂/n₁) has no propagating refracted ray and unit reflected normal power at a single planar semi-infinite interface. The field in medium2 decays evanescently rather than vanishing. A nearby second high-index medium can couple that field and frustrate total reflection.

    This relation concerns the stated total internal reflection and evanescent fields claim and its conditions; it does not assert an unqualified prerequisite or an additional theorem.

Entry detailsPermanent link to this entry ↗
Record identity
foundation-physics-total-internal-reflection
Revision
foundations-refresh.1
Structured reference record
Foundational reference additions