optical effects Flashcards
What are double rainbows?
Natural example of refraction + dispersion of light.
How can we see rainbows?
Sun must be behind you, light must reflect off something for it to return to your eyes.
What is a rainbow?
Arc of colours of the visible spectrum (ROYGBIV) that appears opposite of the sun.
What causes rainbows?
Reflection, refraction, + dispersion of the sun’s rays as they pass through raindrops.
How do sundogs (parhelia) occur?
Ice crystals in the atmosphere reflect sunlight (clear, cold mornings/evenings when crystals are in the air).
What is apparent depth?
Optical effect where the image of an object appears closer than the object is.
How does apparent depth occur?
Rays of light from the object being observed have been refracted when they move from the water to the air on their way to the eyes.
What is shimmering?
Apparent movement of objects in hot air that is over objects and surfaces.
What is a mirage?
Optical effect caused by the refraction of light rays passing through layers of air that have very different temperatures.
