Yes, LED black lights can make certain things glow. This happens because of a phenomenon called fluorescence.
How Fluorescence Works
LED black lights emit ultraviolet (UV) light, which is invisible to the human eye. Many materials contain phosphors. These phosphors absorb the invisible UV light and then re-emit it as visible light, creating the glowing effect. As explained in the provided video, "[...]They glow when you shine a black light on a phosphor." The light absorbed is at a lower visible frequency, causing the glow.
What Glows Under a Black Light?
Several substances exhibit fluorescence under black light:
- Certain paints and dyes: Many white paints and brightly colored fabrics contain fluorescent dyes that react strongly to UV light.
- Minerals and rocks: Some minerals fluoresce brightly when exposed to UV light, revealing their unique colors.
- Biological materials: Certain organisms, like scorpions, exhibit fluorescence naturally. (Note: This is not always visible with standard LED blacklights).
- Security markings: Many security tags and inks are designed to glow under UV light.
Types of Black Lights and Their Effectiveness
While the core principle remains the same, the intensity and effectiveness of a black light can vary depending on factors like the type of LED used and the power output. Stronger black lights will generally produce a brighter glow in fluorescent materials.
Conclusion
LED black lights cause fluorescence in specific materials containing phosphors, making them appear to glow. The intensity of the glow depends on several factors including the black light's intensity and the type of material.
