Direct Chemical
- Chemoluminescence (Lightsticks)
- Fluorescence
- Phosphorescence
Read more about this topic: Light Sources
Famous quotes containing the words direct and/or chemical:
“As for your friend, my prospective reader, I hope he ignores Fort Sumter, and “Old Abe,” and all that; for that is just the most fatal, and, indeed, the only fatal weapon you can direct against evil ever; for, as long as you know of it, you are particeps criminis. What business have you, if you are an “angel of light,” to be pondering over the deeds of darkness, reading the New York Herald, and the like.”
—Henry David Thoreau (1817–1862)
“We do not want actions, but men; not a chemical drop of water, but rain; the spirit that sheds and showers actions, countless, endless actions.”
—Ralph Waldo Emerson (1803–1882)