Friday, June 22, 2012

What makes things glow-in-the-dark

From: Sue E.
Sent: June 22, 2012
To: undisclosed recipients
Subject: Fw: What makes things glow-in-the-dark

I always wondered about this. Neat article from mentalfloss. Sue
-----
If you’re a member of my generation or the one that raised it, your house was probably full of all sorts of glow-in-the-dark stuff in the 80s and 90s. Yo-yo’s, stickers, action figures, clothing, you name it. As a kid, I thought it was just short of magic. The effect is less impressive to adult me, but the chemistry behind it is pretty cool.

Your average glow-in-the-dark doodad gets its glow from a phosphor, a member of a group of substances that radiate visible light after being energized. Some phosphors are natural, like ones found in your teeth and fingernails, and chemists have also created hundreds of others. The ones most useful for glow-in-the-dark items are those that can be energized by normal light and have a pretty long persistence (glow time).

Take a phosphor that fits the bill, mix it in with the plastic to be molded into the product, and you have yourself a glow-in-the-dark whatever. Light from the sun or the living room lamp energizes the phosphors in the plastic and excites them, and with the lights off, you can watch as their atoms slowly lose this extra energy in the form of a dim glow.

Beyond the usual glow-in-the-dark artifact, there are some special cases where glowing products work a little differently. Glow sticks work by chemiluminescence — that is, the light is emitted as a product of a chemical reaction. Items that need to glow continuously with little or no “charge,” like clock or watch hands that glow for hours after a light has been turned off, work by radioluminescence. Timepieces like this still use phosphors to create the glow, but also have a little bit of a radioactive element like radium added to the glowing parts, which gives off small amounts of energy — not enough to be dangerous to the user, but, historically, a problem for the people who make the products — that constantly charge the phosphors in the same way a light would and keep the item glowing through the night.

* Phosphors played another large role in my childhood besides powering my glowing toys, and helped create the images on the displays of my grade school’s ancient computers. In other words, you can thank them for your first Oregon Trail experience.

Read the full text here: http://www.mentalfloss.com/blogs/archives/130651

No comments:

Post a Comment

Don't be shy. Leave a comment below and tell the world what you think.

Related Posts Plugin for WordPress, Blogger...

Our Sponsor: Rosa For Life

Treat yourself as though you were at a spa with this soft cotton bath hair wrap. It dries hair quickly, is water absorbent and washable. The soft cotton fabric dries quickly and will be ready for your next hair washing.

- Made of Soft Premium Cotton.
- Just twist, flip and button. Easy to use.
- It makes a perfect gift for the girls in your life.
Made by Rosa For Life in the USA.

The Rosa For Life brand takes pride in providing you with the highest quality in material and craftsmanship. You will not be disappointed with the high quality and comfort of your Rosa wrap.

These also make great gifts for the girls in your life. Each Rosa wrap is packaged in a nice white gift box, including gift tissue paper. All you have to do is gift wrap or place in a nice gift bag.



Customer Reviews 

Stumble It!

Follow Us By Email