query: Why some materials pass light and others do not?
positive_passages.docid: 8507
positive_passages.text: Why is glass transparent?
negative_passages.docid: 119516
negative_passages.text: What is the actual mechanism behind the reflection of various colored light by material of different color?
negative_passages.docid: 103322
negative_passages.text: How can a red light photon be different from a blue light photon?
negative_passages.docid: 30839
negative_passages.text: Why don't loop currents produce light?
negative_passages.docid: 40148
negative_passages.text: Does light have mass?
negative_passages.docid: 140411
negative_passages.text: Is there a substance that doesn't reflect OR absorb light from the visible light spectrum?
negative_passages.docid: 133259
negative_passages.text: Loss in energy by light after reflections
negative_passages.docid: 158780
negative_passages.text: What common materials absorb most infrared light?
negative_passages.docid: 90476
negative_passages.text: Why can light (photons) bends in a curve through space without mass?
negative_passages.docid: 51708
negative_passages.text: Why do LEDs not obey Ohm's law?
negative_passages.docid: 44171
negative_passages.text: Does visible light heat things up?
negative_passages.docid: 116871
negative_passages.text: Do photons take all paths or not?
negative_passages.docid: 104989
negative_passages.text: What causes refraction of visible light?
negative_passages.docid: 128327
negative_passages.text: Why does light bend towards the normal when passing from a rarer to a denser medium?
negative_passages.docid: 5832
negative_passages.text: Why don't metals bond when touched together?
negative_passages.docid: 50604
negative_passages.text: Why doesn't a lighter flame cast a shadow?
negative_passages.docid: 79910
negative_passages.text: Why does a light object appear lighter in your peripheral vision when it's dark?