## What is the (Angular) Wavenumber?

Here you will learn how wavenumber is defined, how it can be calculated and illustrated, and how it is related to angular wavenumber.

About the light as a wave and a ray.

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Lesson ## What is the (Angular) Wavenumber?

Here you will learn how wavenumber is defined, how it can be calculated and illustrated, and how it is related to angular wavenumber.

## Related formulas

Formula ## Definition of the Wave Number

`$$ \nu ~=~ \frac{1}{\lambda} $$`Formula ## Definition of the Angular Wavenumber

`$$ k ~=~ \frac{2\pi}{\lambda} $$`Formula ## Relationship Between Wave Number and Angular Wave Number

`$$ k ~=~ 2\pi \, \nu $$`## Related Illustrations

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Lesson ## Interference and How The Path Difference Causes It

Learn how constructive and destructive interference results from the path difference and how to mathematically add two sine waves.

## Related formulas

Formula ## Destructive Interference Condition (Path Difference)

`$$ \Delta s ~=~ \left( m - \frac{1}{2} \right) \, \lambda $$`Formula ## Condition for Constructive Interference (Path Difference, Wavelength)

`$$ \Delta s ~=~ m \, \lambda $$`## Related Illustrations

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Lesson ## Double-Slit Experiment with Light

Young's double-slit experiment with light. You learn how the interference pattern of the double-slit is formed and which role light diffraction plays.

## Derivations & Experiments

Derivation ## Double-Slit Formula

Here we derive the double-slit formula, which you can use, for example, to find the wavelength of light using a double-slit experiment.

## Related formulas

Formula ## Double slit experiment (wavelength, path difference, slit distance)

`$$ \class{red}{\Delta s} ~=~ \frac{\class{violet}{x} \, \class{blue}{g}}{\class{green}{a}} $$`## Related Illustrations