LIGHT: MIRRORS AND LENSES

True

Objects become visible because they reflected most of the light they receive from different lights sources such as the sun.

Reflection

When light hits the surface of an object and bounces, the interaction is called

Refraction

When light enters the boundary of two transparent object and bends, the interaction is called

Christian Huygens

Dutch physicist who proposed the wave theory of light

Christian Huygens

The first scientific study on light was done by

Christian Huygens

was a Dutch mathematician and physicist

Christian Huygens

He stated that light, like sound, has wavelike properties.

Wavelike-properties

Reflection, refraction, diffraction, interference, and scattering

Sir Isaac Newton

He opposed the wave theory of light

Corpuscular theory

Issac Newton formulated the _______________ which states that light is made up of very fast and tiny particles that travel in straight lines

Particle theory of light

Another name for the Corpuscular theory

Corpuscular theory/Participle theory of light

Properties of light such as reflection and refraction can be explained in this theory

James Maxwell

discovered electromagnetic waves; realized light was a type of electromagnetic wave

James Maxwell

inferred that an alternating current in a circuit would radiate energy in the form of electromagnetic waves through a vacuum at the speed of light (3x10^8 m/s)

James Maxwell

He proposed that if the velocity of propagation of the electromagnetic disturbance is the same as the speed of light, then light is a form of electromagnetic radiation

Heinrich Hertz

German physicist who demonstrated an experiment to show the electromagnetic nature of light, thereby confirming Maxwell's proposal

Heinrich Hertz

Demonstrated existence of radio waves 1887

Spectra of radiation

is the range of all types of EM radiation.

Spectra of radiation

Another phenomenon that needed an explanation and is related to light is the ______________ emitted by hot or incandescent objects.

Classical Wave Theory

radiant intensity would increase as the wave-length goes to zero

Classical wave theory

Predicts that radiation intensity increases as wavelength decreases

Max Planck

German physicist who developed quantum theory and was awarded the Nobel Prize for physics in 1918.

Max Planck

German physicist who suggested that the exact shape of the graph could be predicted if radiant energy is assumed not t be continuous but occurring in packets of energy called quanta

Quanta

packets of energy

quantum hypothesis/plank's equation

E=hf

Plank's constant

h

Photon

A quantum, or packet of light is now referred to as __________

Plank's Quantum Hypothesis

This idea suggest that light is transmitted as photons of light rather than wave

Albert Einstein

He applied the photon model of light to explain the Photoelectric effect

photoelectric effect

The emission of electrons from a material when light of certain frequencies shines on the surface of the material

Albert Einstein

stated that a photon supplies the necessary energy to eject the electrons from the surface of a material.

Nobel Prize in 1921

Einstein won this award for his theory of photoelectric effect

Imaging devices, photomultiplier tubes, photocells, and light meters

The photoelectric effect has various practical applications such as

Compton effect

scatter of x-ray photons from the atoms of the body

Compton effect

is the scattering of an x-ray photon by its interaction with an electron

Compton effect

is the scattering of an x-ray photon by its interaction with an electron

Compton effect

reveals the material's structure, which causes the scattering

Compton-scattered photons

the intensity of this photons can measure the density of material such as bones

Radiant energy

Quanta

Quantum

Photon

Photoelectric and Compton effect

these theories proved that light and electromagnetic radiation, in general, are composed of photons.

Dual nature of light

the statement that light exhibits both wave and particulate properties

Dual nature of light

wave theory and particle theory

Louis de Broglie

He proposed the dual nature of light theory

Momentum

a particle property of light

Wavelength

a wave property of light

Dual nature of light

proves that light behaves sometimes as a wave and at other times as photons or particles

Luminous objects

Objects that produce their own light

Luminous objects

Examples of this are Light bulbs, burning objects, the sun, and the stars

Illuminated objects

Objects that reflect light

Reflection of light

is an important optical phenomenon

Concept of a ray

To understand reflection you must first learn ________________

Light ray

is a single line of light coming from a point source; it's arrowhead points to the light direction of propagation.

The nature of the material and the texture of the surface of the medium

The amount of reflected light depends on two factors:

Normal

an axis perpendicular to the object's surface

Smooth

When the reflecting surface is _____________, the reflected rays of a beam of light are parallel to one another.

Regular reflection/specular reflection

The reflected rays of a beam of light are parallel to one another.

Polished surfaces

Examples of this are mirrors and bright metals, which produces regular reflection

Rough

If the reflecting surface is __________ the reflected rays are not parallel, they reflect in all directions.

Irregular reflection/Diffuse reflection

When the reflecting surface is rough, the reflected rays are not parallel; they reflect in all directions.

Mirror

is any object that has smooth, shiny surface where almost all light striking the surface is reflected.

Image

The reflected light forms an __________

Image

is a copy of an object formed by the light

Plane mirror

is a mirror with a flat surface.

Plane mirror

Examples of this are mirrors used in dressing rooms, bathrooms and rearview mirrors in cars.

Virtual Image

Everything behind the mirror does not physically exist; the image formed is a _____________

Virtual image

does not exist in the place where it appears to be

Laterally reversed

Your image is not exactly like you. It is reversed from left to right or ____________

Laterally reversed

Reversed from left to right

Spherical mirror

Has a curved reflecting surface

Concave mirror

If it is the inner surface that reflects light, the mirror is a

Convex

If it is the outer surface that reflects light, the mirror is a

Center of curvature C

The center of the sphere in which the mirror forms a section

Vertex V

the center of the mirror

Radius of curvature R

The distance between the vertex and the center of curvature

Focal point/Focus F

the point at which reflected rays meet

Focal length f

the distance from the vertex to the focal point of a spherical mirror; half the distance of the radius of curvature of the mirror.

Principal axis

a line passing through the center of the curvature of the surface of a lens or mirror and through the center of curvature

Ray diagram

is a tool that presents the paths light take from the source to the observer.

Positive

Focal length f for concave

Negative

Focal length f for convex

Always Positive

Object distance

Positive

Image distance is real image

Negative

Image distance is virtual image

Image distance

The distance from the mirror to the image

Object distance

The distance from the mirror to the object

Linear magnification

The ratio of the size of an image to the size of the original object.

Positive

Linear Magnification M for upright image

Negative

Linear Magnification M for inverted image