HISTORY T.O Flashcards
● Also known as:
○ Emission theory
○ Particle theory
- States that light emitted by
luminous objects consist of tiny
particles of matter called
corpuscles.
● Corpuscles always travel in a
straight line.
ISAAC NEWTON
-Also known as:
○ Undulatory theory
-States that light emitted in a
series of waves that Spread out
from a light source in all
directions. These waves are not
affected by gravity.
- He disagreed with Newton and
said that light traveling from air
to water will decrease speed and
vice versa
CHRISTIAN HUYGENS
-Performed a decisive experiment
that seemed to demand a wave
interpretation, turning the side of
support to the wave theory of
light.
THOMAS YOUNG
Stated that light waves travel as
separate packets of energy
called quanta or photons.
● Merged the subjects of the
Corpuscular, Wave, and
Electromagnetic Theories
together.
● Later, it was proved that the
correct and most accurate theory
was the Quantum Theory.
MAX PLANCK
-performed
experimental support for the
wave theory
HEINRICH HERTZ
-published
results of his experiments and
analysis, which required that light
be a transverse wave. He
assumed that light waves in an
ether were necessarily
longitudinal, light rays can not
pass around obstacles
AUGUSTIN FRESNEL
predicted that there should be
light with even longer
wavelengths than infrared light
● Early discovery of radio wave
wavelengths than infrared light
JAMES CLERK MAXWELL
- demonstrated the existence of
the waves predicted by Maxwell
by producing radio waves in his
laboratory.
HEINRICH HERTZ
-number of wave cycles that pass
a point in one second, measured
in hertz (Hz)
FREQUENCY
-distance between two
consecutive peaks of the wave
WAVELENGTH
-It consists of a continuous signal
which is analogous to some other
quantity. For instance, the signal
voltage varies with the pressure
of the sound waves.
ANALOG SIGNAL
● It consists of a signal which only
consists of discrete values.
DIGITAL SIGNAL
-radio waves move easily, making it
the most common medium for
communication
RADIO
- where there’s no air, radio
waves can travel long distances without
much interference
SPACE
-absorbs radio waves
more than air does, so special
low-frequency radio waves are used for
underwater communication
WATER
● These are long-range waves and
are reflected by the ionosphere
HIGH FREQUENCY RADIO WAVE
30kHz to 3MHz
LOW MEDIUM FREQUENCY
1.7 to 30 MHz
Short WAVE FREQUENCY
88 to 108 MHz
HIGHEST FREQUENCY RADIOWAVE
30 to 300GHz
EXTREMELY HIGH FREQUENCY
Is a range of frequencies, wavelengths
and photon energies covering
ELECTROMAGNETIC SPECTRUM
s a key phenomenon in radio
wave transmission where radio
waves bounce off objects or
surfaces, depending on their
shape and materia
REFRACTION
radio waves change direction
when they pass through media
with different refractive indices,
altering their speed and bending
towards or away from the
boundary between the media.
This affects the propagation path
and signal strength.
REFLECTION
When radio waves encounter
obstacles or openings
comparable in size to their
wavelength, they bend around
the obstacles and spread out. The
extent of diffraction depends on
the wavelength and the size of
the obstacle or opening, leading
to complex wave patterns.
DIFFRACTION
g between
radio waves and infrared light on the
electromagnetic spectrum.
MICROWAVES
refers to waves of electric
and magnetic fields.
ELECTROMAGNETIC RADIOTION
Theorized
electromagnetic radiation,
JAMES CLERK MAXWELL
An American physicist and
electrical engineer who invented
the magnetron, a vacuum tube
that generates high-frequency
electromagnetic waves, including
microwaves
ALBERT WALLACE HULL
an engineer at
Raytheon, accidentally discovered
that microwaves could heat food when
a chocolate bar melted in his pocket
during radar experiments
PERCY SPENCER
Infrared waves are ____
than visible light
LONGER
★ Infrared waves are ____
than radio waves
SHORTER
★ _____ is invisible to the
human eye.
INFRARED LIGHT
● who discovered infrared
FREDERICK HERSCHEL
Shortest infrared wavelength
(nearest the visible spectrum), with
wavelengths 0.78 to about 2.5
micrometers (
NEAR INFRARED
with wavelengths 2.5 to
about 50 micrometers
MIDDLE INFRARED
- refers to a
specific range within the infrared
spectrum of electromagnetic radiation
FAR INFRARED
-Is the portion of the
electromagnetic spectrum that is
detectable by the human eye.
VISIBLE LIGHT
-involves phenomena like
reflection, refraction, dispersion,
diffraction, and interference, which
describe how light interacts with
different materials and surfaces.
VISIBLE LIGHT
Speed of visible light
299,792 km/per second
between 400 to 750 terahertz
FREQUENCY OF VISIBLE LIGHT
between 400 and 700 nanometers
WAVELENGTH oF VISIBLE LIGHT
- began a
series of experiments with sunlight and
prisms. He demonstrated that clear
white light was composed of seven
visible colors.in a room with closed
shutters, he works with a small opening
to isolate a single ray of sunlight. In the
stream of light, he places a glass prism
ISAAC NEWTON
A FRENCH CHEMIST AND PHYSICIST DISCOVERED GAMMA RADIATION IN 1900 WHILE STUDYING RADIATION EMITTED FROM RADIUM
PAUL VILLARD
DISCOVERED ALPHA AND BETA RAYS
ERNEST RUTHERFORD
Have a shortest wavelength and highest frequencies of all radiation
GAMMA RADIATION
Are generated by nuclear explosion lightning and the less dramatic activity of radioactive decay
GAMMA WAVES
Pass through the body and are captured on film or digital detectors to create an image
IMAGING PROCESS
ELECTRONS ARE ACCELERATED AND THEN DECELERATED
X-RAY GENERATION
FISRT X-RAY IMAGE
Hand of Wilhelm RONTGEN wife in December 22 1895
HAVE MUCH SHORTER WAVELENGTHS
X-RAY
REFERS TO THE REGION OF THE ELECTROMAGNETIC SPECTRUM BETWEEN VISIBLE LIGHT AND X-RAY WITH A WAVELENGTH FALLING BETWEEN 400 AND 10 NM.
ULTRAVIOLET
ULTRAVIOLET FIRST DISCOVERED BY
JOHANN RITTER
- Extremely harmful and is almost completely absorbed by Earth’s atmosphere
-The most harmful and almost completely absorbed by atmosphere
UV-C LIGHT
