# How do things "glow in the dark"?

**URL:** <https://boards.straightdope.com/t/how-do-things-glow-in-the-dark/219266>\
**Category:** Factual Questions\
**Created:** [December 16, 2003, 5:48am UTC](https://boards.straightdope.com/t/how-do-things-glow-in-the-dark/219266 "2003-12-16T05:48:15Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![ramper](https://avatars.discourse-cdn.com/v4/letter/r/a9a28c/32.png) [@ramper](https://boards.straightdope.com/u/ramper)\
**Post date:** [December 16, 2003, 5:48am UTC](https://boards.straightdope.com/t/how-do-things-glow-in-the-dark/219266/1 "2003-12-16T05:48:15Z")

</div>

When I went to bed the other night, I looked at the ground and saw my glow-in-the-dark frisbee lying/glowing there. So tell me… how?

---

<div class="post-metadata">

**Author:** ![antechinus](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@antechinus](https://boards.straightdope.com/u/antechinus)\
**Post date:** [December 16, 2003, 6:18am UTC](https://boards.straightdope.com/t/how-do-things-glow-in-the-dark/219266/2 "2003-12-16T06:18:05Z")

</div>

Briefly: first a phosphorescent substance in the plastic absorbs light thus exciting electrons to higher energy levels.

Then over an extended time the electrons relax to levels which correspond to the release of photons of light the colour of which is emmitted by the phosphor.

Analogy: like they jump up to the top of a building when a UV photon hits, then slowly walk down several flights of stairs and jump out at a lower level to release a green photon.

---

<div class="post-metadata">

**Author:** ![antechinus](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@antechinus](https://boards.straightdope.com/u/antechinus)\
**Post date:** [December 16, 2003, 6:19am UTC](https://boards.straightdope.com/t/how-do-things-glow-in-the-dark/219266/3 "2003-12-16T06:19:47Z")

</div>

I shoulda just looked [here](http://www.howstuffworks.com/question388.htm).

---

<div class="post-metadata">

**Author:** ![antechinus](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@antechinus](https://boards.straightdope.com/u/antechinus)\
**Post date:** [December 16, 2003, 6:27am UTC](https://boards.straightdope.com/t/how-do-things-glow-in-the-dark/219266/4 "2003-12-16T06:27:43Z")

</div>

> [@](#):
>
> \*Originally posted by antechinus \*  
> \*\*I shoulda just looked [here](http://www.howstuffworks.com/question388.htm). \*\*

I take that back. That site is crap.

[This is better.](http://math.ucr.edu/home/baez/spin/node17.html)