UNIT C: EYEBALLS Flashcards
idk
What was Pythagoras’s theory of light?
Light consisted of beams of light
What contributions did Euclid make to the early ideas about light?
light reflects off a mirror at the same
angle that was shone on it.
What did property of light did Ptolemy describe?
light beams bend when the
go from air to glass.
Why is al-Haytham an important figure in the discoveries about light?
light bounces off objects and travels to the eye.
What did Sir Isaac Newton learn about light?
light is made up of a mixture of different colours.
Who discovered the speed of light and how did he do it?
Albert A. Michelson measured the speed of
light by timing how long it would take to
travel from one mountain peak, bounce off
a mirror on another and come back.
What are the 4 properties of light?
1) Travels in straight lines.
2) Can be reflected.
3) Can bend.
4) A form of energy.
What is an optical device?
Any technology that uses light
Who helped the development of the microscope?
Anton van Leeuwenhoek discovered little animalcules in a pond and led the discovery of a microscope.
What is a microscope?
Microscopes allow you to see great detail by combining the power of two lenses.
What is a telescope?
An optical device that can make you see far away
What did Galileo do to the telescope?
Improve the design that allowed him to discover new things.
What are the two types of telescopes?
Reflecting Telescopes and Refracting telescopes
What is a reflecting telescope?
Large mirror curved inwards and focused to a second mirror then the eyepiece.
What is a refracting telescope?
2 lenses at each end of a telescope. The larger lens (or the objective lens) is the one that gathers light and the smaller lens (or eyepiece) Allows you to see the object.
What are binoculars?
2 refracting telescopes fixed together
What are ray diagrams?
Ray diagrams help to show how light travels.
How does light travel from a source?
A Straight Line called a ray
What are TRANSPARENT material?
Materials that can let light pass through
What are TRANSLUCENT material?
Materials that allow some light but not all light to pass through
Define Opaque.
Material that does not allow any light to pass through.
Opaque materials can cast ____
shadows
What’s this difference between Non-Luminous and Luminous objects?
Non-Luminous objects don’t produce light while Luminous objects produce light.
What’s another name for a flat mirror?
Plain mirror
What’s the difference between concave and convex mirrors?
Concave mirrors have a surface that curves inwards while Convex mirrors has a surface that curves outwards
What is the law of reflection?
When a ray of light hits a plane mirror at an angle and it bounces off the mirror at exactly the same angle
What’s the angle of incidence?
the angle between the incident ray and the normal.
What’s the angle of reflection?
the angle between the reflected ray and the normal
If the object is far away from the focal point, the reflection is ___ ___
Upside down
As the object gets closer to the focal point, the reflection gets ____
Bigger
As the object gets between the focal point and the mirror, it becomes _____ and _____
upright and larger
How is light refracted?
When light travels at an angle from one substance to another, it bends.
How does the eye gain light?
Light enter through the pupil
What does the iris do?
a circular band of muscle
What happens to the pupil when light decreases?
Pupil gets larger (aka it dilates)
What is the difference between rods and cones?
Rods are sensitive to light and Cones detect color
What are the 2 cells that are sensitive to light?
Rods and Cones
How is light focused in the eye?
Muscles change the shape of the lens to move the focal point.
What are the 2 main eye problems?
Farsightedness and nearsightedness
What’s the difference between Farsightedness and nearsightedness?
Farsighted people cannot see close objects and near-sighted people can’t see objects close
What type of lens a person would wear if they were NEARSIGHTED and why?
Concave because the focal point fall in front of the eye
What type of lens a person would wear if they were FARSIGHTED? and why?
Convex because the focal point falls behind the retina
What is the individual unit of a compound eye called? and describe it
Ommatidium is a long tube with a lens on top and a focusing cone it. Bellow that are light sensitive cells.
What is a pixel?
Pixel (or picture element) is a a square that has a specific number assigned to it which represent coordinates and a colour.
Define resolution of a digital image.
It’s the amount of pixel to create a really accurate of a real picture.
What is a charge-coupled device (or CCD)?
In a digital camera, light falls onto a Charge-Coupled Device and it’s like a piece of grid paper that records the image using an electrical
charge.
