Unit 3 - Optics Flashcards
What is bioluminescence?
the production of light in living organisms as the result of a chemical reaction with little or no heat produced
bacteria, fungi, marine invertebrates, fish, glow-worms and fireflies
What is hyperopia?
the inability of the eye to focus light from near objects; far-sightedness
–> in need of positive meniscus: a modified form of the converging lens shape
What is myopia?
the inability of the eye to focus light from distant objects; near-sightedness
–> in need of negative meniscus: a modified form of the diverging lens shape
What is presbyopia?
a form of far-sightedness caused by a loss of accommodation as a person ages
–> to help, use converging lenses
What is specular reflection?
If there is a series of parallel incident rays that strike a flat reflective surface, the angles of incidence for these rays are all identical. Angles of reflection will also be identical, and the reflected rays will all be parallel to each other.
EX: Disco ball
What is diffuse reflection?
Rays directed at an irregular surface. Incident rays would all have different angles of incidence. Their angles of reflection would also be different. Rays would be reflected or scattered in many different directions.
- EX: reflection of crumpled aluminum
What is total internal reflection?
When the angle is greater than 90 °, you get a total internal reflection. The critical angle is theangle of incidence that produces a refracted angle of 90৹. REFLECTS BACK INTO MEDIUM
What is refraction?
Light travels in straight lines through air, but
when travelling from one material into another (i.e. water) you have a bending or change in direction of light.
What does an image in a plane mirror look like?
S (same size)
A (upright) (horizontally inverted)
L (behind mirror)
T (virtual)
What are the laws of reflection?
- The angle of incidence equals the angle of reflection.
- The incident ray, the reflected ray, and the normal all lie in the same plane.
What are the uses for concave mirrors?
- flashlight
- telescope
- car headlights
- cosmetic mirror
What are the uses for convex mirrors?
- security mirror
- rear-view mirror on cars
- sunglasses
What are uses for plane mirrors?
- household mirrors
- kaleidoscopes
- periscopes (submarines)
What happens when the incident ray goes to an area more dense/slower speed of light? (refraction)
Light bends towards the normal.
