# Single-slit diffraction

> A narrow beam through a thin slit fans into stripes on the screen — diffraction, not a hard shadow.

![Single-slit diffraction](https://www.loomrume.com/optics/stills/single-slit.png)

**Thomas Young** · 1665 Grimaldi — Young’s wave paper 1801

Francesco Grimaldi had already watched sunlight fan after a narrow slit and called it diffraction. Young’s 1801 Bakerian lecture made the wave picture respectable in Britain — mostly with two slits, but a single opening is enough to see the lobes.

Wider slit, narrower fan; more lobes if you ask the tracer for them. The pattern is not a geometric shadow. Drag the jaws and the screen stops looking like a lamp with a card in front.

## Sources

- [Diffraction](https://en.wikipedia.org/wiki/Diffraction)
- [Thomas Young](https://en.wikipedia.org/wiki/Thomas_Young_(scientist))
- [Francesco Grimaldi](https://en.wikipedia.org/wiki/Francesco_Maria_Grimaldi)

## Links

- [HTML](https://www.loomrume.com/examples/single-slit)
- [Open in Studio](https://www.loomrume.com/experiments/new?template=single-slit)
- [llms.txt](https://www.loomrume.com/llms.txt)