Why is it called "glow in the dark"?

Doesn't it glow ALL the time?

Pilsner Man2011-02-24T14:03:07Z

Favorite Answer

The same reason some people say hot water heater, or big Samoan.

BuddMyster2011-02-24T21:28:21Z

The cell's in it absorb light and then store it and give it off as long as the energy last. Glow bugs do it chemically.

bob g2011-02-24T21:08:18Z

No, it is not observed to glow when it isn't dark so therefore only glows in the dark.

?2011-02-24T21:04:33Z

Yes but it only shows up in the dark