UNIT C: EYEBALLS

Question 1

What was Pythagoras’s theory of light?

Answer 1

Light consisted of beams of light

Question 2

What contributions did Euclid make to the early ideas about light?

Answer 2

light reflects off a mirror at the same

angle that was shone on it.

Question 3

What did property of light did Ptolemy describe?

Answer 3

light beams bend when the

go from air to glass.

Question 4

Why is al-Haytham an important figure in the discoveries about light?

Answer 4

light bounces off objects and travels to the eye.

Question 5

What did Sir Isaac Newton learn about light?

Answer 5

light is made up of a mixture of different colours.

Question 6

Who discovered the speed of light and how did he do it?

Answer 6

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.

Question 7

What are the 4 properties of light?

Answer 7

1) Travels in straight lines.
2) Can be reflected.
3) Can bend.
4) A form of energy.

Question 8

What is an optical device?

Answer 8

Any technology that uses light

Question 9

Who helped the development of the microscope?

Answer 9

Anton van Leeuwenhoek discovered little animalcules in a pond and led the discovery of a microscope.

Question 10

What is a microscope?

Answer 10

Microscopes allow you to see great detail by combining the power of two lenses.

Question 11

What is a telescope?

Answer 11

An optical device that can make you see far away

Question 12

What did Galileo do to the telescope?

Answer 12

Improve the design that allowed him to discover new things.

Question 13

What are the two types of telescopes?

Answer 13

Reflecting Telescopes and Refracting telescopes

Question 14

What is a reflecting telescope?

Answer 14

Large mirror curved inwards and focused to a second mirror then the eyepiece.

Question 15

What is a refracting telescope?

Answer 15

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.

Question 16

What are binoculars?

Answer 16

2 refracting telescopes fixed together

Question 17

What are ray diagrams?

Answer 17

Ray diagrams help to show how light travels.

Question 18

How does light travel from a source?

Answer 18

A Straight Line called a ray

Question 19

What are TRANSPARENT material?

Answer 19

Materials that can let light pass through

Question 20

What are TRANSLUCENT material?

Answer 20

Materials that allow some light but not all light to pass through

Question 21

Define Opaque.

Answer 21

Material that does not allow any light to pass through.

Question 22

Opaque materials can cast ____

Answer 22

shadows

Question 23

What’s this difference between Non-Luminous and Luminous objects?

Answer 23

Non-Luminous objects don’t produce light while Luminous objects produce light.

Question 24

What’s another name for a flat mirror?

Answer 24

Plain mirror

Question 25

What’s the difference between concave and convex mirrors?

Answer 25

Concave mirrors have a surface that curves inwards while Convex mirrors has a surface that curves outwards

Question 26

What is the law of reflection?

Answer 26

When a ray of light hits a plane mirror at an angle and it bounces off the mirror at exactly the same angle

Question 27

What’s the angle of incidence?

Answer 27

the angle between the incident ray and the normal.

Question 28

What’s the angle of reflection?

Answer 28

the angle between the reflected ray and the normal

Question 29

If the object is far away from the focal point, the reflection is ___ ___

Answer 29

Upside down

Question 30

As the object gets closer to the focal point, the reflection gets ____

Answer 30

Bigger

Question 31

As the object gets between the focal point and the mirror, it becomes _____ and _____

Answer 31

upright and larger

Question 32

How is light refracted?

Answer 32

When light travels at an angle from one substance to another, it bends.

Question 33

How does the eye gain light?

Answer 33

Light enter through the pupil

Question 34

What does the iris do?

Answer 34

a circular band of muscle

Question 35

What happens to the pupil when light decreases?

Answer 35

Pupil gets larger (aka it dilates)

Question 36

What is the difference between rods and cones?

Answer 36

Rods are sensitive to light and Cones detect color

Question 37

What are the 2 cells that are sensitive to light?

Answer 37

Rods and Cones

Question 38

How is light focused in the eye?

Answer 38

Muscles change the shape of the lens to move the focal point.

Question 39

What are the 2 main eye problems?

Answer 39

Farsightedness and nearsightedness

Question 40

What’s the difference between Farsightedness and nearsightedness?

Answer 40

Farsighted people cannot see close objects and near-sighted people can’t see objects close

Question 41

What type of lens a person would wear if they were NEARSIGHTED and why?

Answer 41

Concave because the focal point fall in front of the eye

Question 42

What type of lens a person would wear if they were FARSIGHTED? and why?

Answer 42

Convex because the focal point falls behind the retina

Question 43

What is the individual unit of a compound eye called? and describe it

Answer 43

Ommatidium is a long tube with a lens on top and a focusing cone it. Bellow that are light sensitive cells.

Question 44

What is a pixel?

Answer 44

Pixel (or picture element) is a a square that has a specific number assigned to it which represent coordinates and a colour.

Question 45

Define resolution of a digital image.

Answer 45

It’s the amount of pixel to create a really accurate of a real picture.

Question 46

What is a charge-coupled device (or CCD)?

Answer 46

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.