Light And Optics 1+2 Flashcards
What did Pythagoras believe about light?
Light beams came from people’s eyes and allowed them to see objects.
Who discovered that the angle of incidence equals the angle of reflection?
Euclid.
What phenomenon did Ptolemy describe regarding light?
Light beams bend when they go from air to glass.
What did al-Haytham contribute to the understanding of light?
He accurately described how vision works and that light bounces off objects to reach the eye.
What did Rene Descartes propose about sunlight?
Sunlight is somehow changed or modified to form colored light.
What did Sir Isaac Newton demonstrate with a prism?
White light is a mixture of different colors of light.
Who made the first accurate measurement of the speed of light?
Ole Romer in 1676.
What was the speed of light calculated by Albert A. Michelson?
299,798 km/s.
List the six properties of light.
- Light travels in straight lines
- Light is a form of energy
- Light can bend
- Light can be reflected
- Light can be absorbed
- Light can be transmitted
What is an optical device?
Any technology that uses light.
Who built the first microscope?
Hans and Zacharias Janssen in 1595.
What are the two lenses in a microscope called?
Eyepiece and objective lens.
What did Galileo Galilei contribute to astronomy?
He refined the telescope and discovered celestial features.
What are the two types of telescopes?
- Refracting telescopes
- Reflecting telescopes
What is a ray diagram used for?
To show how light travels and behaves in different situations.
What creates a shadow?
The absence of light.
Define transparent materials.
Materials that can transmit light.
Define translucent materials.
Materials that allow some light to pass through.
Define opaque materials.
Materials that do not allow any light to pass through.
What does absorption of light mean?
Light that strikes a material may be partially or fully absorbed.
What is the Law of Reflection?
The angle of incidence is equal to the angle of reflection.
What is a normal line in reflection?
A line perpendicular to the mirror at the point of reflection.
What happens in regular reflection?
Incoming rays travel parallel and bounce off in the same direction.
What characterizes diffuse reflection?
Light rays are reflected in different directions from a rough surface.
