Youngs Double Slit⚠ unverified
Physics / Optics · Compute the bright-fringe position factor in the double-slit experiment
Parameters
| Input | Symbol | Unit | Default | Description |
|---|---|---|---|---|
| lambda_ | λ_ | m | 1.0 | Wavelength of the light |
| d | d | m | 1.0 | Separation between the two slits |
| m | m | — | 1.0 | Fringe order (dimensionless integer) |
| Output | Symbol | Unit | Description |
|---|---|---|---|
| result | sinθ | — | Sine of the fringe angle (dimensionless) |
The science & history
Understanding the Parameters
- $m\lambda/d$ — must be ≤ 1 for a real angle; $\theta = \arcsin(m\lambda/d)$.
- Small-angle form $y = m\lambda L/d$ on a screen uses $\theta \approx y/L \approx \sin\theta$.
Derivation (Approaching a Proof)
Path difference between slits is $d\sin\theta$. Constructive interference when $d\sin\theta = m\lambda$.
History
Thomas Young’s double-slit experiment (1801) established the wave nature of light.
Related Concepts: Diffraction Grating, Diffraction Single Slit, Coherence Length
Notes: Registry calculator youngs-double-slit (unverified). Output is $\sin\theta$, not $\theta$.