Optics Flashcards
What is light?
A form of electromagnetic radiation and travels in waves
What is the electromagnetic spectrum?
A way to measure light in different frequencies. The wavelengths range from 0.00001nm to 500nm. The longest is radio waves and the shortest is gamma rays.
How many categories is light split into?
Two main categories and four subcategories.
Incandescence is?
Light energy released by heat. Solids heated til they release light. (Hot metal, sun, fire and old lightbulbs.)
What’s luminescence?
Light energy released by electrons moving levels.
Fluorescence is?
Absorbs energy, re-emits as light. (Neon lights)
Bioluminescence is?
Light from living things (jellyfish, algae, firefly and anglerfish.)
Phosphorescence is?
Absorbs light lengths (shorter) releases longer wavelengths as light. (Glow in the dark)
What does the cornea do?
It’s clear like a window and helps focus incoming light.
What does the pupil do?
It’s an opening in your eye. (The black part.)
What does the iris do?
It’s the coloured part of your eye and controls the size of your pupil, it makes the pupil bigger when it’s dark to allow more light through. Makes the pupil smaller when it’s bright to let less light in.
What does the lens do?
It focuses oncoming light into your eye, thins and thickens to help you see things far and near.
What are your colour receptors called?
Rods and cones. Which are located in the retina
What do rods do?
Help us see in low light
What do cones do?
They detect red, green and blue
What does the retina do?
The image is projected onto the retina and flipped upright then transmitted to the optic nerve.
What does the optic nerve do?
It transfers the image to your brain
What are the light detecting cells called?
Photoreceptors.
What is the thin layer in the back of the eye?
Retina
What is the oval part of the eye?
The lens
What is the connection to the brain?
The optic nerve
What is the thin layer in the front of the eye?
The cornea
What is the hole in middle of the eye?
The pupil
What are the things surrounding the hole in the eye?
The iris
What are the primary additive colours?
Red, green and blue
What are the secondary colours?
Yellow, cyan and magenta
What do you get when you mix red and green?
Yellow
What do you get when you mix red and blue?
Magenta
What do you get when you mix blue and green?
Cyan
What does cyan, magenta and yellow make?
Black
What does yellow, red and blue make?
White
What colours are used in the TV screen?
Red, green and blue
What are the colours of the visible colour spectrum in order? (Longest to shortest)
Red, orange, yellow, green, blue and violet
How does the angle of incidence and reflection work with mirrors?
When light hits the mirror at angle it bounces off at the opposite angle. The angle of incidence to the angle of reflection.
How would you appear in a concave mirror?
Upside down
How would you appear in a convex mirror?
Puffed out and weird.
What happens when light passes through a double concave lens?
It spreads out
What happens when light passes through a double convex lens
It focuses the light to the focal point.
How does a concave lens help nearsightedness?
When it hits the eye it focuses it in then immediately spreads it to the flipped image at the back of the eye after it hits the focal point.
How does a convex lens help farsightedness?
It focuses the light onto the image at the back of the eye.
