i know that white clothing or light colored things glow in blacklight. how come there's no white on a black t-shirt in daylight but there's little white specs that show up when there's blacklight?

 

hmmmm i know this but i dont remember

 

Those white specs are detergent particles, dandruff, daily dustballs, sunbleached spots, etc

 

yeah that's what i've been told, but how and why do they show up?

 

Phosphors are substances that give off light -- or fluoresce -- when they are exposed to light. When a photon hits a phosphor atom, one of the phosphor's electrons jumps to a higher energy level, causing the atom to vibrate and create heat. When the electron falls back to its normal level, it releases energy in the form of another photon. This photon has less energy than the original photon, because some energy was lost as heat. In a fluorescent lamp, the emitted light is in the visible spectrum -- the phosphor gives off white light we can see.

Hint: go to
how stuff works.com