Ch 7: 4.22.19 Daily Quiz material (no math) Flashcards
why are sunrises/sunsets red?
as sunlight travels through the thicket part of the atmosphere, colors are being absorbed. red is the least absorbed and reaches us the best.
what word describes diamonds showing flashes of color?
“fire”
why can we hear a vacuum down the hall but can only see it if within light of sight to the door?
light waves don’t diffract well around a doorway, but sounds waves do
why is the sky sometimes a hazy white?
particles in the air scatter other colors than blue, but then the colors mix back together to give a hazy white effect.
why are diamonds bright and shiny?
good total internal reflection causes the light to come out at the top
what causes a mirage of a water puddle on a hot road?
the air just above the road is hot, so a boundary is made between the hot air and the air above it. light crosses the boundary and severely refracts (basically reflects), and we perceive the light as coming from a puddle (self note: why water? b/c it’s a reflection of the blue sky). as we get closer, the angle changes and the mirage disappears.
why does a grain silo seem to shimmer ona sunny day from across a field?
as the reflected light travels above the field, the air current causes the light to slightly refract one way or the other
the reason stars twinkle is similar (self note: air temperature difference is the reason for air currents to begin with)
2 examples of total internal reflection?
- fiberoptic cables
- water fountains lit from the bottom
why is the mid-day sun yellow-white?
as sunlight travels through the thinnest part of the atmosphere, less colors are absorbed, so what reaches us is a better mix.
what word describes a bright and shiny diamond?
“brilliance”
why do diamonds show flashes of color?
dispersion causes the colors to separate out
what is an example of diffraction grating?
the color spokes from a CD (compact disc)
when different wavelengths spread out
dispersion
why is the sky blue?-
air molecules absorb sunlight and release the energy as scattered light. violet is the color that is scattered the most, but our eyes see blue better.
how a wave bends around a corner
diffraction
