Light & Optics Final Unit Test Flashcards
What are the 5 types of light?
-Incandescent
-Bioluminescent
-Chemiluminescent
-Fluorescent
-Phosphorescent
What is Incandescent light?
-The emission of visible light through hot objects, such as a lightbulb. These objects heat up and glow as electricity passes through them.
What is Bioluminescent light?
-The emission of light from a living organism, like a firefly.
What is Chemiluminescent?
- Light produced from a chemical reaction where there is no heat.
What is Phosphorescent?
-Materials that absorb light and release it over time, for example, a glow-in-the-dark stick, that emits light when all other light is gone.
What is a Fluorescent light?
-The emission of light by particles that have absorbed UV energy. Objects that emit light after absorbing UV energy, which includes solar-powered objects.
Explain how at least 4 animals view the world
Turtle: Can see one color that humans cannot; otherwise has the same vision as humans
Cats: Eyesight is enhanced in darkness, and their eyes reflect more light in the dark.
Flies: See fewer colors than humans, but have a wider FOV, and for them, the world appears to be slower
Snakes: Colorblind, but have good depth perception and infrared vision, meaning they can visualize heat.
Why do fireflies, for example, flash light? What light source is this?
-They use it to attract mates with their unique flashing patterns for recognition and to distinguish each other. They can also use it to scare predators. This light source is biluminescence.
Why do animals use bioluminescence?
Bioilluminescence can be used for attracting mates, deterring predators, and detecting prey. Example: Jellyfish
Why are blue animals so rare?
-Animals cannot naturally be blue, no matter their diet, no animals can contain any blue pigment. The blue color appearance only due to the shape and structure of the animal’s body parts, such as a bluejay’s wings.
What is the impact of light pollution on migratory birds?
Light pollution at night is called ALAN. This light can attract birds, making them lose their sense of direction during migration. The immense amount of light produced by ALAN also encourages animals to hunt at night, making them easy targets for predators.
What is myopia, and how is it fixed?
Myopia is nearsightedness, a condition that makes seeing far away difficult. This means that your lens is too curved or your eye is too long. To correct this, you have to stretch the light rays out so the focal point is at the back of the eye. I concave lens would do the trick.
What is hyperopia, and how is it fixed?
Hyperopia is farsightedness, a condition that makes it difficult to see objects close to you. This means that either your cornea is undercurved or your eyeball is too short. To solve this, you have to bend the light rays so the focal point moves towards the front of the eye. This is a convex lens.
What is the Law of Reflection?
The incident angle is equal to the reflected angle
Types of Reflections (2)
Regular Reflection: When parallel rays hit a smooth surface and reflect in a orderly fashion
Diffuse Reflection: When parallel rays hit a rough surface and scatter
What is the law of refraction
The change in the direction of light as it passes from one medium to another. If light travels from a less dense medium to a more dense medium, the light ray will slow down and go towards the normal. Vice Versa
What are the Parts of the eye, and what does each part do?
Cornea: A window at the front of the eye that covers the iris and pupil. The cornea refracts light
Pupil: Allows light to enter your eye
Lens: Located behind pupil, and it focuses light onto your retina
Iris: It surrounds the pupil and is the colored part of your eye. Controls how much light enters your eyes
Ciliary Muscles: Allow your eye to adjust and focus on objects at different distances.
Vitreous Humour: Clear fluid that fills the space between your lens and retina, basically filling the inside of your eye.
Retina: The light-sensitive inner lining at the back of the eye. This contains rods and cones, which detect light and send pulses
Optic Nerve: Located at the back of the eye and it sends messages to your brain.
What are Rods and Cones?
-Located in the retina and are used to detect light
Rods: Provides a black and white image with limited detail along the edge of your vision. Rods are sensitive to light and work better in low light levels
Cones: Provides a colored image with sufficient detail and it is the center of your vision. Sensetive to movement but work better in higher light levels and are less sensitive to light.
How does light travel through your eye?
First light refracts off your cornea, then it passes through the pupil, where it meets the iris. The iris then controls how much light passes through, after that, it hits the convex lens that converges the light inward onto your retina. The retina turns the light into electrical signals that get sent to your brain by the optic nerves.
