Black holes, Neutron star, White dwarf, Brown dwarf: General Knowledge USA Quiz.
By knowledgeterminal - December 15, 2018
Section one: USA map pointing (states and capital)
Section two: World map pointing (countries and capital)
Europe
Section three: USA historical events
1801–1805
The First Barbary War ( Tripolitanian War/ the Barbary Coast War) was the first of two Barbary Wars, in which the United States and Sweden fought against the four North African states Tripoli, Algiers, and Tunis and Sultanate of Morocco ("Barbary States"). Pirates from the Barbary States were seizing American merchant ships and holding the crews for ransom, demanding the U.S. pay tribute to the Barbary rulers. This led to the war which ended with peace treaty.
Section four: world historical events
1271
Kublai established the Yuan dynasty which ruled over present-day Mongolia, China, Korea as d the role of Emperor of China. Kublai was the fourth son of Tolui and a grandson of Genghis Khan., By 1279, the Mongol conquest of the Song dynasty was completed and Kublai became the first non-Han emperor to conquer all of China.
Section five: Black holes, Neutron star, White dwarf, Brown dwarf
1)
A Star shines due to
fusion of hydrogen into helium in its core, releasing energy in the form of
gamma rays which loose some energy and become photon when they reach the
surface (after 100000 years)
2)
Stars are maintaining a
balance between gravity trying to collapse them and their internal heat trying
to swell them. Averaged sized star like the Sun lasts for 10 billion years and
ends by expanding briefly and then blowing away its outer layers leaving behind
the gravitationally compressed core. Under pressure and temperature Hydrogen
fusion makes helium, helium fusion makes carbon. Lower-mass stars stop at
carbon. (hydrogen less in 2 billion years)
3)
But more massive stars
die (within 100 million years ) with a huge bang. If the star has more than
about 8 times the Sun’s mass, it can create temperatures in its core in excess
of 500 million degrees Celsius, and then carbon will fuse into neon, magnesium,
and some sodium to oxygen to silicon (2-3 billion degrees) can fuse to iron.
When iron fuses it actually sucks up energy instead of creating it which
shrinking, compressing the core, heating it up even more. The gravity of the
core is so strong that the outer parts crash down on the inner part very fast,
the core collapses gravity becomes extremely intense
a. Neutron star
i.
Death of (before
collapse had a total of between 10 and 29 solar masses.) 1.4 and 2.8 times
the Sun’s mass star. Explosion occurs and a ball is left behind composed almost
entirely of neutrons.
ii.
Milliseconds ago it was
fusing silicon into iron, but now it’s collapsed under its own immensely
powerful gravity.
iii.
The collapse takes a
fraction of a second, but a lot happens in that fraction of a second
iv.
If the core has a mass
more than about 1.4 times the mass of the Sun electron degeneracy (No two
electrons can occupy identical states, even under the pressure of a collapsing
star) fails to stop the collapse
v.
Under these huge
pressures Protons, electrons, and other subatomic particles merge to form
neutrons
vi.
Neutrons resist being
squeezed too tightly together (neutron degeneracy)
vii.
If the core is less than
about 2.8 times the Sun’s mass, the collapse stops generating a huge shock
wave, which, along with a flood of energetic subatomic particles called
neutrinos, blasts outwards, blowing up the star
viii.
Its mass would be more
than Sun, with volume of sphere 20 km across
ix.
The first neutron star
was detected in 1965
x.
Pulsars are neutron
stars flashing (twin beams of energy away from the star) in brightness as they
spin coupled with their incredibly strong magnetic fields
b. White dwarf
i.
Death
of star 1.4 times the mass of the Sun, it becomes a white dwarf which a very
hot ball of super-compressed matter about the size of the Earth (composed of
carbon and oxygen)
ii.
nearest
known white dwarf is Sirius B, at 8.6 light years
iii.
White
dwarfs are the final evolutionary state of stars whose mass is about
10 solar masses. ( 97% of stars in the Milky Way.)
iv.
A
black dwarf is a hypothetical stellar residue of a white dwarf after it has
cooled sufficiently that it does not emit heat or light. The time required for
a white dwarf to become black dwarf is longer than the current age of the
universe (13.8 billion years) so no black dwarfs exist in the universe now
c. Black hole
i.
When
mass is MORE than 2.8 times the Sun’s, the gravity of the core can actually
overcome the tremendous resistance of the neutrons and continue its collapse.
ii.
There
is literally nothing in the Universe that can stop the collapse.
iii.
A
neutron star, have an escape velocity of 150,000 km/sec – that’s half the speed
of light (compared to The Sun with an escape velocity of over 600 km/sec. )
iv.
It’s
like an infinitely deep HOLE, and no light can come out, so it’s BLACK.
v.
That
region of space, that surface around the black hole where the escape velocity
is the speed of light, is called the EVENT HORIZON as any event that happens
inside can’t be known
vi.
Black
holes also come in different sizes. The kind I’ve been talking about has a
minimum mass of about 3 times the Sun’s, and might get as high as a dozen or
more times the Sun’s mass, if the parent star was big enough. We call these
stellar-mass black holes. If it happens to gobble down more matter, it gets
more massive, and the event horizon grows as well.
vii.
The
black hole gets bigger. In the 1970s it was first proposed that black holes could form in the
centers of galaxies, and the first one was discovered, in the center of Milky Way whose mass is 4.3 million times the mass of the Sun
d. Brown dwarf
i.
A
planetary body having mass less than about 0.075 times the Sun’s mass, roughly
75 times the mass of Jupiter, it would fail to fuse hydrogen to helium but it
would radiate its heat away.
ii.
Very
low mass stars are red (the most common type of star in the Milky Way),
which emit light in the infrared e.g. Proxima Centauri
Section six: quiz
QUESTIONS
1.
According to the UN,who is the most widely translated author in
the world?
|
2.
Which philosopher is best known for his statement cogito
ergo sum ( I think therefore I am?
|
3.
Philosophy comes from the Greek philosophia, meaning
what?
|
4.
Metaphysics is the study of what?
|
5.
What is the pen name of Eric Arthur Blair?
|
ANSWERS
1. Agatha Christie
2. René Descartes
3. Love Of Wisdom
4. Existence
5. George Orwell
2. René Descartes
3. Love Of Wisdom
4. Existence
5. George Orwell
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