Small dots produce blue light. Larger dots produce red
light.

And if you examined just one dot, you'd see something
strange, Siy-Ronquillo's advisor, chemist and physicist
Michael Bartl said. "The nanoparticle itself would decide
when it emits light."

"They are completely unpredictable," he said. They are
"one of the few examples of quantum mechanics in the real
world." Quantum mechanics explains the behavior of very
small particles.