Oscillation and waves Flashcards
is a disturbance that
carries energy through a medium
of a space
wave
classification of waves
motion, medium
classification of waves based on motion
transverse
longitudinal
classification of wave sbased on medium
mechanical
electromagnetic
have Crest and Trough. In
vibration are perpendicular to
the direction of the motion
Transverse waves
have compression and
rarefaction.
the vibrations are parallel to the direction of the
wave motion
longitudinal waves
are combination of transverse
and longitudinalwaves. This produce the
circular motion of the wave
surface waves
of a wave is the maximum
displacement of the particles of the medium
from their equilibrium position
amplitude
is the distance between two
successive crest or trough, or between two
successive or rarefaction
wavelength
equals wavelength times
frequency.
wave velocity
wave properties and interactions
reflection
refraction
diffraction
interference
the bouncing back of wave
reflection
bending of waves as they
pass from one medium to another
refraction
the bending of waves as
they pass an edge or corner
diffraction
results when two waves
meet to combine constructively or
destructively
interference
has a dual nature. itsometimes acts as a set of waves / stream of partices
light
two ways to produce light
incandescence
luminescence
light produced when something is heated
incandescence
light caused by ,movement of electrons of the material from higher energy levels to lower energy levels
luminescence
Some gases can be made to produce light by passing an electric current through them called
electric discharge through ionized gases
Light travels in a straight line except when diffracted at the rate of around
3 x 10^8 m/s
is the separation of white light into its component colors
dispersion
is polarized if its vibrations are confined to a single
plane
light wave
pigment is produced when primary pigments are combined
black
Light produced by the eye and that it interacts
with the light that object gives off
He knew that the moon shines by light reflected from the sun and was also aware of the cause of solar eclipses.
Empedocles
Proposed that sight is caused by the visual rays
emanating from eye and striking the object
vision resulted from light rays emerging from a person’s eye and striking an object
Pythagoras
Believed that every object contains numerous
amounts of replicas and continuously emits its
replica
Democritus
peeling away of images from an object that then enters the eye, in Democritus’ theory of optics. - democritus
‘Eidola’
is a work on the geometry of vision written by the Greek mathematician Euclid around 300 BC.
science of the study of light
optics
product of electromagnetic waves
light
study of mechanical waves
acoustics
Light is emitted by sources other than eye and
that vision is produced when light reflects an
object
epicurus
Presented the law of reflection and discussed the
propagation of light rays in straight path
🞆 Questions the origin of the light within the eye
euclid
Light is made up of the particles of the sun
🞆 Dharmakirti theorize that light is a stream of
energetic particles.
believed that matter consisted of indivisible “atoms,” thought that light must be a particle given off by the sun.
lucretius
1st discovers Snell’s Law
dealt with the optical properties of curved mirrors and lenses and has been described as the discoverer of the law of refraction (Snell’s law).
uses this law to derive lens shapes that focus light with no geometric aberrations, known as anaclastic lenses.
designed convex lenses that focus light rays that are parallel, which can cause an object to burn at a specific distance
ibn sahl
Discovers but did not publish his version of Snell’s Law
thomas harriot
Derives but did not publish the Snell’s law but its
posthumously gets the credit
willbrord snellius
Independently derives Snell’s Law. (accused of plagiarizing Snellius,
gets the credit but
in France only)
🞆 Described light as pressure
descartes
First quantitative studies of the refraction as it
passes transparent medium
ptolemy
Corpuscular theory
🞆 light is made up of small discrete particles called
“corpuscles” (little particles) which travel in a
straight line with a finite velocity and possess
impetus
newton
Calculate the speed of light using the timing of
the eclipses of Jupiter’s Moon
ole romer
Propagation of light through simple lenses
roger bacon
Introduces ether, a medium that light is thought
to travel in a vacuum
🞆 Wave Theory of light
christian huygens
Diffraction effects and thin film interference
robert hooke
Provides mathematically that light can only be
polarized if it is a transverse wave
augistine-jean fresnel
Discovers that the plane of polarization of light
can be rotated by magnetic field
🞆 Leads to realization that light is a high frequency
electromagnetic wave
michael faraday
If a parallel beam of light falls on a small spherical
obstacle, there will be a bright spot at the center
of the shadow
simeon denis poisson
Light as Electromagnetic Wave
james maxwell
Attempts to detect the ether that light travels
through and fails
michaelson and morley
Blackbody radiation
🞆 Resolves the ultraviolet catastrophe by
mathematically by treating light emitted by a
blackbody as a discrete particle called “quanta”
planck
Photoelectric Effect
einstein
Duality of Light
loius de broglie
Uncertainty Principle
werner hiesenberg
Quantum Mechanics
Erwin Schrodinger
Showed
experimental
evidence of EM
Waves and their link
to light
Heinrich Hertz
(1879)
Demonstrated the
magnetic effect
based in the
direction of the
current
Andre-Marie
Ampere
istheunit tomeasurethefrequencyofwaves
hertz
Electromagnetic spectrum consists of
Radio Waves,
Microwaves,
Infrared,
Visible Light,
Ultraviolet Waves,
Xray
GammaRays
Thesearetransverse wavethat donot require
mediumtopropagate
◼Theyalltravel at thespeed oflight
electromagnetic waves
◼Longest wavelength
◼Lowest frequency
◼AM and FM Radio
◼VHF and UHF television Broadcast
◼Communication with submarines, mines and
mobile phones, RFID,
Radio/hertzian waves
◼Between Radio waves and Infrared
◼Most popular application is Microwave
oven(2.45Ghz; 12.2cm)
◼Radio detection and Ranging(Radar) system
(to monitor distance of distant object)
◼Application
◼Bluetooth
◼Monitoring heartbeat
microwaves
◼Means “Below red”
◼Anything that has temperature above zero kelvin emits _
◼Thermal Motion, Night vision, thermograms
◼Other animals such as snake also have _
detectors near their nostrils(used to hunt at
night)
infrared radiation
◼Narrow band of electromagnetic spectrum
that can be detected by human eye
◼3.84 X 1014 Hz -7.96 X 1014Hz
◼Colors were first realized by Sir Isaac Newton
◼Colors are subjective to human physiological
and psychological response
Visible light
Means above Violet
◼Johann Wilhelm Ritter
◼Three regions
▪ UVA –premature aging and wrinkling of skin
▪ UVB –Skin cancer, Sun burning cataracts
▪ UVC –Extremely dangerous but does not enter
Earth’s surface because of ozone
◼Formation of Vit D(UVB)
◼Fluorescent lamp, sterilization, pest control
devices and authentication of documents
ultraviolet
r Unknown Radiation
◼Most of their wavelength are smaller than
atom
◼Wilhelm Konrad Roentgen
◼Has high energy that is enough to penetrate
skin and muscle
◼Developing materials(super conductors)
x-ray
◼Most Energetic of all waves
◼Produced in Earth by means of:
▪ Electron-positron annihilation, neutron pion decay,
nuclear fusion and fission and radioactive decay
◼Other sources
▪ Pulsars, neutron star, black holes and supernova
◼Most dangerous
◼Used in medicine
▪ Radiation therapy, gamma knife surgery and
diagnostic procedures
◼Sterilization of Foods
gamma rays
