Caitlin -
Webster's Dictionary says that Phosphorescence is:
"(1)
luminescence that is caused by the absorption of radiation at one
wavelength followed by delayed reradiation at a different wavelength
and that continues for a noticeable time after the incident radiation
stops; (2) an enduring luminescence without sensible heat"
Basically,
this is the kind of thing that you get with glow-in-the-dark stars.
Special molecules in the plastic in the stars absorb light. The energy
from the light is stored by the electrons in each molecule. After a
while, the electrons release the energy again as light, rather than
heat.
You might be wondering what makes certain molecules so
special that they can hang on to energy for minutes or longer before
releasing it as light, even though most molecules hang onto energy for
much, much less than a second. Unfortunately, the answer requires
learning something about the very strange properties of electrons, part
of a field called quantum mechanics.
-Tamara
(published on 10/22/2007)
