Does one 200 watt bulb put out as much or more light than ten 20 watt bulbs? [more inside]
posted by leemajors on Aug 14, 2009 - 23 answers

Why does an incandescent light bulb have an broad, continuous spectra when viewed with a spectrometer? Why doesn't it have some lines like a sodium lamp? I guess I'm asking why photons come off of a black body and why are their wavelengths spread out. Bonus points for clarity and accessibility of the answers.
posted by bdc34 on Oct 7, 2008 - 5 answers

What, if any, is the relationship between bandwidth and power? [more inside]
posted by odinsdream on Nov 19, 2007 - 14 answers

Do the green light triggers for motorcycles actually work? [more inside]
posted by electroboy on Nov 16, 2007 - 11 answers

What would happen if you could create a perfect two-way mirror into a sphere? [more inside]
posted by Lownotes on Oct 30, 2007 - 12 answers

Why do porous objects (wood, textile, hair, etc) appear darker when wet then when dry? A googling gave me this ("surface reflection and refraction"), but that doesn't sound entirely reasonable, as it merely talks of light being scattered, but the light in question is already diffuse. This also gives some suggestions, but nothing conclusive. Any chem/physics MeFiers know this?
posted by fvw on Dec 12, 2003 - 7 answers