History
What did Pythagoras believe?
That beams of light came from the person's eye and when those beams made contact with an object, the sensation of sight occurred.
Define luminous and non-luminous. (100 bonus points if the team can provide an example for both)
Luminous objects produce light (example: candle or jelly fish)
Non-luminous objects absorb, reflect, or transmit light. (example: clock, dice, moon).
(Look at the diagram on the right to the board) What is letter "B" most likely called?
reflected ray
The aperture of the camera transmits light. Which part of the eye most likely has the same role?
In the eye, the pupil transmits light.
What does it mean if a TV has a higher resolution than an older TV?
It means that the higher resolution TV will have more pixels in a certain area.
Al Haytham was the first to accurately describe what?
Describe how we see! He suggested that light bounces off objects and then travels to the eye where the sensation of sight occurs.
What is refraction?
the bending of light as it travels from one substance to another. It occurs when light strikes a different medium of a different density at an angle.
A refracting telescope uses the principle of refraction to gather and magnify light. Does a refracting telescope have a convex or concave glass lens?
Convex glass lens
What part of the camera is similar to the cornea?
The protective glass on the camera is like the cornea. They both protect and are responsible for refracting light towards the pupil.
Why is a convex mirror used as a rear view mirror on a car?
Convex mirrors are curved outwards and they spread out (diverge) light rays. Images in a convex mirror appear smaller and show a wider range of view. Therefore, they will show more cars in the mirror.
What did Sir Isaac Newton propose?
He proposed that sunlight (white light) was somehow changed or modified to form coloured light
Define nearsightedness and farsightedness
nearsightedness: see objects that are closer clearer. Farther objects are blurry.
farsightedness: see objects that are farther clearer. Closer objects are blurry.
What is the difference between transparent, translucent, and opaque?
Transparent - light will travel (transmit) through an object that is transparent
Translucent - some light will travel (transmit) through an object that is translucent, but not all. Some light may be reflected or absorbed.
Opaque - no light will travel through an object that is opaque. Light is either reflected or absorbed.
What are photoreceptors?
Are cells that make up the retina of the eye. These cells detect light (rods) and colour (cones) (2 types of photoreceptors)
Why is your reflection upside down on a spoon?
Due to the inward curve of the spoon as it acts a concave mirror. Because it is inwards, it reflects the light rays differently. The light rays from your face go straight towards the top of the spoon and are reflected downwards. Meanwhile, the light from your feet go to the bottom of the spoon and get reflected upwards. The point where all of these light rays meet is called the focal point. When you are beyond this point, then your reflection is upside down. If you are in front of the focal point, your reflection will be upright.
Using two mirrors and a beam of light, what did Albert A. Michelson find?
He placed two mirrors about 35.4km apart, sent a beam of light from one mirror to the other, and using an extremely accurate timing device, he measured how long light took to travel the distance.
What is the law of reflection?
the angle of incidence is equal to the angle of reflection
What are the four main properties of light? (Each property is 100 points - other teams can steal if the team doesn't get them all)
1. Light travels in straight lines
2. Light can be reflected
3. Light can bend
4. Light is a form of energy
What is the tapetum lucidum and what does it do?
The reflective lining behind the retina and this surface amplifies light.
Explain how a light ray would be refracted in a substance that is more dense? (A is less dense and B is more dense)
An increase of density in an object increases the bending of light (refraction) because the light speed is slower.
What did Antonie van Leeuwenhoek experiment with and what technology did he invent? (500 extra points if what new branch of science this led to is mentioned)
He experimented with a simple microscope of his own design. He looked at things like pond water, blood, and the plaque scraped from his own teeth. This all led to a new branch of science called microbiology.
What is a pixel?
A single unit of colour
Which type of mirror and lens allows light rays to diverge? Which type of mirror and lens allows light rays to converge? (each question worth 250 points - other teams can steal)
Diverge: convex mirror and concave lens
Converge: concave mirror and convex lens
Letter "G" represents which part of the eye from the drawing on the board?
Aqueous humour
What type of eye is most often found in insects and crustaceans? What is an advantage and a disadvantage?
Compound eyes
Advantage: very large range of view
Disadvantage: low clarity and resolution