- Slides: 15
Phenomena Related to Refraction
Phenomena Related to Refraction Apparent depth: the depth that an object appears to be at due to the refraction of light in a transparent medium Air Water
Phenomena Related to Refraction Air Water
Phenomena Related to Refraction Apparent depth is why it’s not as easy to catch fish using your hands Air Water
Phenomena Related to Refraction The “Flattened” Sun: When the Sun is near the horizon during sunset, it appears to be oval in shape (flattened)
Phenomena Related to Refraction Air is more dense near the Earth’s surface than higher up in the atmosphere, so when the Sun is close to the horizon, light from the bottom of the Sun is refracted more than light from the top of the Sun. Figure 5 pg 536 (Nelson)
Phenomena Related to Refraction RAINBOWS: White light that passes through a water droplet undergoes “dispersion” (separation into its constituent colours)
Phenomena Related to Refraction Light passing through a Prism also undergoes dispersion.
Phenomena Related to Refraction Each colour of light refracts differently because they all move at slightly different speeds. SLOWEST INCREASING SPEED FASTEST So each color has a different angle of refraction (R). Blue and violet light move the fastest
Phenomena Related to Refraction This is why you can only see a rainbow when the sun is behind you
Phenomena Related to Refraction Shimmering on a lake: Light rays travel from cool air (slowly, because more dense) into warmer air near the water (faster, because less dense) causing the light to refract farther away from the normal. Eventually, total internal reflection occurs in the lowest warm air layer (not in the water), resulting in multiple virtual images of the moon.
Examples of total internal reflection Mirage In a desert.
Mirage • On a hot day, you may see a pool of water at a distance in a desert. Hurray! Sorry! What you see is just a MIRAGE.
• It happens due to total internal reflections. Image of the sky layers of air near the ground – hot – less dense than upper air – lower refractive indices
• When light meets a layer of air near the ground at an angle greater than C, Image of the sky Total internal reflection occurs.