Download Fully explain/describe/define the following terms. Give a viable

Fully explain/describe/define the following terms. Give a viable application of each term.
Provide graphs, photographs, tables, etc. where appropriate to facilitate your
understanding.
a) Stefan-Boltzmann Law
It states that, the thermal energy radiated by a blackbody radiator per
second per unit area is proportional to the fourth power of the absolute
temperature. This is given by the following formula:
𝑃
= 𝜎𝑇 4 𝑗⁄𝑚2 𝑠
𝐴
𝜎 = 5.6703 × 10−8 𝑤𝑎𝑡𝑡/𝑚2 𝐾 4
b) Wien's Law
It is a law of physics that is used to describe the scale of thermal radiation. Wien's
displacement law states that the black body radiation curve for different
temperatures peaks at a wavelength inversely proportional to the temperature.
c) Hubble's Constant/Law
Hubble’s law describes the relationship between velocity of recession and the
distance of a Universe. His findings showed that there is direct or linear relationship
between a galaxy’s velocity of recession and its distance. The law simply means that
galaxies farther away from us are moving away faster from us. A galaxy twice as far
away is moving away twice as fast.
d) Relativity
In physics, the theory of relativity or simply relativity usually comprises two theories
by Albert Einstein: special relativity and general relativity. Concepts introduced by
the theories of relativity include: Measurements of various quantities are relative to
the velocities of observers.
e) Tully-Fisher Law
It describes the luminosity of spiral galaxies and their speed of rotation. The law
states that the fourth power of the circular velocity of stars around the core of the
galaxy is proportional to the luminosity. Tully-Fisher relation is a correlation of
spiral galaxies between their luminosity and their speed of rotation. The bigger the
galaxy, the faster it rotates and vice versa.
f) Roche's Limit
The smallest distance to which a large satellite can approach its primary body
without being damaged by tidal forces is called the Roche’s Limit. The limit is
theoretically two and half times the radius of a larger body if the satellite and
primary are of similar composition.
g) Drake's Equation
It is a probabilistic argument derived from Bayes, and which is used to arrive at an
estimate of the number of active, communicative interplanetary civilizations in the
Milky Way galaxy.
𝑁 = 𝑅∗ . f𝑝 . n𝑒 . f𝑙 . f𝑖 . f𝑐 . L Where
N = Number of civilizations in the Milky Way, R∗ = rate of star formation, fp
= fraction of stars with planetary systems,
ne = number of planets per solar system that can support life,
fl = fraction of plantes where life appears,
fi = fraction of life bearing planets on which intelligent life emerges,
fc
= fraction of civilizations that develop a technology that releases detectable of
their existance in space, and L =
the duration with which such civilization releases detectable technologies into space.
h) Kepler's Laws
These laws were developed by Johannes Kepler. The three Kepler laws are:
Law of Orbits- It states that all planets move in elliptical orbits, with the sun at one
center.
Law of Areas – the law states that a line that connects a planet to the sun sweeps out
equal areas in equal times.
The Law of Periods – according to this law, the square of the period of any planet is
proportional to the cube of the semi-major axis of its orbit.
i) Newton's Laws
Isaac Newton came up with three laws of motion:
First Law (Law of Inertia) – the law states that unless an external force is applied to
an object, every object in a state of uniform motion has the tendency of remaining in
that state of motion.
Second Law of Motion – according to Newton, the relationship between mass of an
object, m, its acceleration, a, and the applied force, F is F=ma. The direction of
force vector is the same as the acceleration vector.
Third Law of Motion – Newton’s Third Law of Motion states that for every action,
there is an equal and opposite reaction
j) Rayleigh's Law
This law was derived by Lord Rayleigh in 1871, applies to particles that are smaller
than the wavelength of the light being scattered. The law states that the percentage of
light that will be scattered is inversely proportional to the fourth power of the
wavelength. Small particles scatters a much higher proportion of short wavelength
light than long wavelength light.
k) Fraunhofer lines
Named after the German physicist Joseph von Fraunhofer (1787–1826), Fraunhofer
lines are a set of spectral lines. The lines were originally observed as dark features
(absorption lines) in the optical spectrum of the Sun.
l) Hertzprung-Russell diagram
The diagram was developed independently in the early 1900s by Ejnar Hertzsprung
and Henry Norris Russell. HR diagrams are of two forms: the theoretical HR
diagram which plots the temperature of stars against their luminosity, and the
observational HR diagram (color-magnitude diagram) that plots the color of stars
(or spectral type) against their absolute magnitude.
m) Inverse Square Law
According to physics, an inverse-square law is any physical law stating that a
specified physical quantity or intensity is inversely proportional to the square of the
distance from the source of that physical quantity. Since it is strictly geometric in its
origin, the inverse square law applies to diverse phenomena. Inverse law is obeyed
by point sources of gravitational force, electric field, light, sound or radiation.
n) Mass-luminosity relation
This is an equation giving the relationship between the mass of a star and its luminosity.
The relationship is represented by the equation: where L⊙ and M⊙ are the luminosity
and mass of the Sun and 1 < a < 6. The value a = 3.5 is commonly used for mainsequence stars
o) Mass-radius relation
According to this law, if both the radius R and mass M of a main-sequence star are
in solar units, then R = M 0.8.
p) Nebular theory
It is an explanation of how the solar system was formed. First developed in 18th
century by Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace, the
Nebula Theory was first developed by Kant, then Laplace and later by astronomer
Victor Safronov who built his nebular theory on Laplace’s findings. Despite
numerous challenges from numerous theorists, the attempt to replace it did not
succeed. It was not until the 1970’s with Soviet that the modern (and widely
accepted) Solar Nebular Disk Model (SNDM) came into being.
Our solar system was formed 4.568 billion years ago when a small part of a giant
molecular cloud experienced a gravitational collapse, according to the modern
nebula theory. The Sun was formed by the collapsing mass collected in the center,
while the rest of the material flattened into a protoplanetary disk, out of which the
planets, moons, asteroids, and other small Solar System bodies formed. The Solar
System has evolved considerably since its formation as a result of collisions between
objects, planetary migration and the capturing of extra-solar objects by our own
system.
q) Olber's paradox
Named after a German astronomer Heinrich Wilhelm Olbers, Olbers' paradox, also
called the "dark night sky paradox", is the argument that the darkness of the night
sky conflicts with the assumption of an infinite and eternal static universe.
r) Standard Solar Model
The standard solar model (SSM) is the treatment of the Sun mathematically as a
spherical ball of gas (in varying states of ionization, with the hydrogen in the deep
interior being completely ionized plasma).
s) 21-cm radiation
21-cm Line Radiation is the wavelength of the hyperfine transition of hydrogen.
Most of the hydrogen gas in the interstellar medium is in cold atomic form or
molecular form. In 1944 Hendrik van de Hulst predicted that the cold atomic
hydrogen (H I) gas should emit a particular wavelength of radio energy from a slight
energy change in the hydrogen atoms. It is useful in that when the 21cm radiation
undergoes red-shifting, astronomers and scientist can judge distances very nicely,
thanks to the hydrogen flip-flop.