HISTORY T.O Flashcards
(53 cards)
● 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
