Download The Basics of the Universe

The Basics of
the Universe
Table of Contents
Introduction………………………...……1
The Beginning……..……...……..………2
A starter’s guide to the
cosmos
Our Place in the Universe……….………3
By: Aashish Bharadwaj
The Sun…………………………….……7
Our Solar System………………….…….4
Comets…………………………….…….9
Meteoroids…………………………...…10
Asteroids………………………….…….11
Lifetime of a Star…………………….…12
Neutron Stars……………………….…..14
Extraterrestrial Life………………….…17
The Oddities and the Normalities...........18
Our Future………………………….…..19
Space Records……………………….....20
Fun Facts………………………….……22
Glossary……………………...…….…..23
Introduction
The Beginning
Have you ever looked up at the sky and wondered,
“Where are we? How did we get here? When did it begin? Why
did it happen this way?” If you have, then this is the book to read.
If you would like something more advanced, then I would suggest
reading a book by Brian Greene or watching “The Universe,” a
series created by History Channel.
The start of everything was about 15 billion years ago.
Most scientists agree on a theory called the ‘Big Bang’. They
came up with this theory using their knowledge of the universe.
The universe is expanding, so it would be contracting if you were
to view time in reverse. Eventually, everything would be the size
of a tiny neutron that has planc length1 and contains planc
energy2. The start of time would be when this neutron suddenly
expands. It would be very silent since there is no air in space to
carry sound waves. Within the first second, molecules would have
formed, hydrogen being the most abundant. In a year, you would
start to see solids starting to form. In a million, stars would begin
their violent lives. In 2-3 billion, stars would clump together to
form galaxies. In 10 billion, the Sun would have formed. In
another 0.5 billion, the Earth would said hello. Wait another 4.5
billion years, and you would see yourself. This is the timeline of
the universe. It is everything in existence, from stars to this book.
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1
1
2
10-32
Energy required to have 11 dimensions according to string theory
Our Place in the Universe
Our Solar System
How big are the cosmos? How old are we? First, let us
discuss size. Earth has a diameter of 8,000 miles and a 2dimensional circumference of roughly 25,000 miles. If you were
to travel the diameter of the Earth in a car with unlimited fuel,
then you would take about 8,000 minutes, or 5 to 6 days! Thu Sun
is about 93 million miles away from us, and the next closest star is
system is Proxima Centauri, Beta Centauri, and Alpha Centauri,
which is 4.3 light years away. A light-year is not a measurement
of time, but instead distance. Light travel 186,000 miles per
second. Multiply by the amount of seconds in a year to obtain the
distance of a light-year. At this speed, you could travel around the
Earth 7.5 times a second! Our galaxy is about 100,000 light years
across. The galaxy that is nearest to us is Andromeda, which is
2,500,000 light-years away! The viewable universe is trillions of
years across, yet is bigger than just what we see through our
telescopes! There are quadrillions of stars in the universe. Thu
Sun is in the Orion Arm of our galaxy – The Milky Way, which is
in the Local Group. (galaxy cluster.). This is part of a
supercluster, which is a part of the universe. There are trillions of
superclusters in the universe. If this makes you feel insignificant,
then knowing that the rate of expansion - known as inflation – is
accelerating will make you sick. Do you want to feel even
smaller? If you do, then read on! If the entire life of the universe
could be put in a 24-hour day, then you humans would arrive
during the last few seconds! Even though all of this is true, I still
feel quite large. Our atoms have come from exploding stars, so I
feel as if I am a part of the universe, instead of in it.
Our solar system consists of many bodies that orbit the
Sun, which is our life-giving star. Here is a list of the bodies in it.
Inner Solar System
Mercury: The temperature ranges from -200 to 500o F. This is
because it has a very thin atmosphere since it is small, therefore
not trapping any heat in. It has zero moons, and many craters. It
has a year of 88 Earth-days because it is so close to the Sun, only
an average of 56 million miles away. This may seem to be huge,
but it is not compared to the other planets. Its day is 58 Earthdays, but it actually seems to take 176 Earth days instead of 58
because of its orbit!
Venus: This planet was named for the Roman Goddess of Love
and Beauty, but it is anything but lovely. Temperatures soar to
900o F. This is because it has a very thick atmosphere. It has a
double hurricane system, which is the system of the two
hurricanes at its poles. This is a result of the planet constantly
trying to cool itself off. Venus is 67 million miles away from the
Sun. It has a year of 224 Earth-days, but a day of 243 Earth-days!
The size of Venus is barely smaller than that of the Earth, so it is
known as ‘Earth’s sister’. It is visible in the sky with the naked
eye. It has no moons.
Earth: This is our home planet. It is known as the ‘Blue Planet’
because of its many oceans. It is the first planet to have a moon,
known as The Moon. Its actual name is ‘Luna’.
Mars: Named after the Roman God of War, this planet is red due
to its dusty terrain that has gone through oxidation. Mars is about
half of the size of the Earth, and has a thin atmosphere. There is
ice scattered around the planet. Two rovers, named Opportunity
and Spirit, have roamed the landscape, searching for signs of life.
So far, none has been found, even though they have searched for
many sols.3 Mars is 146 million miles away from the Sun, and has
a year of about 687 Earth-days. Its day is barely longer than
Earth’s. The average temperature is -81o.
Asteroid Belt: This not a planet, but instead a belt of asteroids
that are orbiting the Sun. There are millions of asteroids in it,
some of which have their own moons.
Uranus: A light blue gas giant that has a 98o axial tilt. This means
that its glowing rings are almost orbiting vertically. Its magnetic
field has a tilt of 60o. It has its own big storm called The Great
Blue Spot. Uranus is nearly 32,000 miles in diameter. Each day is
18 Earth-hours, and each year is 84 Earth-years. It is 1.8 billion
miles away from the Sun, and has nearly 40 moons.
Neptune: A dark blue, extremely windy gas giant. It has a very
mobile storm that is called The Great Dark Spot. It is titled ‘The
Windy Planet’. It has a few rings, and about 35 moons. It is about
30,000 miles in diameter. A year is 165 Earth-years, and a day is
20 Earth-hours.
Past the Outer Planets
Outer Solar System
Jupiter: A huge gas giant that rotates in just nine Earth-days, and
orbits the Sun in 12 Earth years. It has a storm 2.5 times the size
of the Earth, known as the Great Red Spot. It has rings that are
barely visible and nearly 80 moons. It has a diameter of 88,700
miles, and is 480 million miles away from the Sun.
Saturn: A very light gas giant that is known well for its rings,
which Galileo Galilei4 mistook for ears. Saturn has a storm known
as The Great White Spot. A day on Saturn is 10 Earth-days, and a
year is equivalent to 30 Earth-years. It has nearly 70 moons, and
is 883.5 million miles away from the Sun. It is the last planet that
can be seen in the sky with the naked eye.
Pluto: A dwarf planet that has no atmosphere and three moons,
one of which is so big relative to the size of Pluto that they are a
like a binary system5. It has a very eccentric orbit that crosses
Neptune’s orbit. It has a surface temperature of -400o.
Kuiper Belt: A belt of comets and dwarf planets.
Oort Cloud: Dusty sphere surrounding the Sun at a very great
distance.
Nemesis: A theoretical brown dwarf, or failed star, that
mysteriously orbits the Sun beyond the Oort Cloud.
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3
4
Martian days
ancient Italian astronomer
5
A system where two bodies orbit each other
The Sun
more violent. The Sun has lived for 5 billion years, and has
another 5 billion years to go. In about 4 billion years, the Sun will
Our star is the main reason for our existence. At the center
of the Solar System, we would not have light, heat, seasons, or
even life. It is a yellow-dwarf, has a surface temperature of
10,000o F, and fuses 6 billion tons of hydrogen to helium per
second! One second of this power could supply California for an
entire week. Even though this is true, it is in-fact a relatively cool
star when compared to others. At a distance of 93 million miles
from the Earth, or one AU, (Astronomical Unit), it takes 8
minutes for its light to reach us. The Sun can fit a million Earthsized inside of itself. It has dark spots called Sunspots. These are
regions where less heat is emitted. Also in these areas are highly
magnetic disturbances that can cause Solar Prominences, loops
protruding from the Sun that can last for days. These are multiple
times the size of the Earth.
run out of hydrogen, and will be left with helium. It will begin to
fuse it, growing in size and swallowing up Mercury, Venus, and
turning Earth into a soup. It will become a red giant, and have a
hotter core, but a cooler surface. This stage will not last very long
because the great energy that it will produce will also cause it to
release its outer layers, creating a nebula. A white dwarf will
remain, which will then later turn into a black dwarf.
Prominence
Sun
The Sun slowly rotates at different speeds in different
area. This is possible because it is a ball of plasma. The Earth
faces a group of Sunspots every few years. Solar wind is blown,
which hits the Earth and causes an Aurora. These can interfere
with electronics and electromagnetic devices and appliances.
When the Earth is closest in its orbit to the Sun, and the Sunspots
are facing its way, the electromagnetic storms produced can be
violent. As the Sun grows older, these storms will grow even
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Comets
Meteoroids
A comet is also known as a ‘dirty snowball.’ It is made of
ice and dust, but not ice from just water. It is a mixture of many
different cold solids. In our solar system, comets reside in the
Kuiper Belt and the Oort Cloud. Some leave these places and
make a very eccentric and elliptical orbit around the Sun, which
blows wind at them, thereby causing them to have tails that can be
millions of miles long.
Have you ever seen a meteor shower? These are caused by
meteors falling towards the Earth. Meteors are rocks that have
entered the Earth’s atmosphere. At least one million hit the Earth.
These are called meteorites. When these rocks are in space, they
are called meteoroids. As meteors fall towards the Earth, they burn
up in the atmosphere. They are usually 1-100 ft in size, and wander
around randomly in space. If you think that you will forget the
difference between the three types, then this is for you.
Tail
Nucleus
Comets appear as bright streaks in the sky, and remain
there for many months. They glow due to the ions6 that are
charged there. When the comets have passed the Sun and gone to
the other half of its orbit, they will appear to move backwards.
Some comets that elect to either commit suicide, or be roasted by
the Sun are called Sungrazers. These either hit the Sun or come
very close to it.
Mete’roid’ – ‘void’ of space
Me’teor’ – ‘tear’ of Earth
Meteo’rite’ – ‘site’ of an impact
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6
Ionized particles
Asteroids
Lifetime of a Star
Big space rocks are called asteroids, ranging from 1-100
miles in diameter! They mainly call the asteroid belt their home,
but some have irregular orbits. Some are even so big that they
have mini asteroid-satellites (another name for a moon) orbiting
them! Asteroids have been known to impact the Earth. One
asteroid that was about 15 ft in diameter created the Arizona
crater, and another caused the extinction of the dinosaurs when it
struck the Yucatán (Yucatan) Peninsula 65 million years ago. Infact, many asteroids bombarded the Earth when it was in its
infancy, causing it to grow larger.
Reading the
next part may ALARM you.
The life of a star is very violent. A star is a ball of plasma
that fuses matter and releases a lot of energy in the process. Let us
take three different stars as an example.
A particular asteroid by the name of Apophis will come
closer to the Earth than our geostationary satellites are to it on
April 13, 2029. It can in even be seen in the sky with naked eye. If
it passes over a 5-mile wide weakness in the Earth’s gravitational
field, then it will come back to hit us in 2042. The chances of this
are very small, but substantial enough to cause uncertainty.
Star A: Low mass, red dwarf star. A red dwarf is a relatively
smaller star, glowing red in color. It continues to do so for
trillions of years, since it does not burn fuel rapidly.
Star B: Medium mass star that is a bright yellow, about 1.5 times
the mass of the Sun. Formed from a protostar made of gases from
a previous massive star, it burns for 10 billion years before
swelling into a blue giant. It fuses many elements before creating
its own nebula. It turns into a white dwarf, emanating its
remaining energy. Then, it becomes a black dwarf.
Star C: High mass star, blue and big, with 100 solar masses. This
star fuses many elements in the periodic table, but for a VERY
short period of time. It eventually bloats into a blue supergiant,
fusing molecules to make iron. This element is poison, since
fusing it does not produce any energy. Within a matter of seconds,
the star, which is billions of miles across, collapses on itself. Its
outer layer bounces off its core and blasts into outer space in the
biggest explosion known to man. This is a supernova, and it
releases more energy than the Sun will produce in its entire
lifetime. After this, it releases two bursts of gamma rays 7 at its
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7
Strongest wave in the electromagnetic spectrum
poles, destroying anything in its path. What remains is a neutron
star. You will learn more about these in the next chapter.
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Neutron Stars
After a supernova, a neutron star is leftover. It is the core
of the previous star, and does not sustain nuclear fusion. They are
very dense because the atoms are compressed to such an extent
that only the nuclei are left, since the lack of fusion allows gravity
to crush it. In fact, the size of the star is so small now that it can
be compared with that of the Earth, and one bucketful of its
material - assuming that we can obtain any - has as much mass as
Mount Everest. Some of these are called magnetars, while others
are called pulsars. Neutron stars spin very rapidly, and this causes
them to have very strong magnetic fields, and the ones with the
strongest are called magnetars. Pulsars have two light beams (not
harmful at a distance) that emit out of their polar regions, and if
these are facing Earth, then the star appears to blink very quickly,
hundreds to thousands of times per second! Finally, there is one
more type: A black hole. These monsters can only be created by
an extremely massive supernova. (Some call it a hypernova)
These are so densely packed at a single point that the resulting
gravity produced at that point stops even light from escaping past
the event horizon – the point of no return. Black holes are literally
holes in space, and cannot be seen. We know that they exist
because of its effects on surrounding matter. In fact, it is thought
that there is a supermassive black hole at the center of our galaxy,
and most other galaxies as well, orbiting it. The material spiraling
around a black hole is called the accretion disk, and if you were to
look at the inner edges, then you would just see warped colors. In
the center is the singularity, which is the point of infinite density.
These will gobble up matter and add to the size of the black hole.
At this point, time is nearly at a standstill, (a very confusing
concept to explain) and all of Einstein’s equations fail because
they end in “cannot divide by zero” error.
Event Horizon
affect life as we know it, and you are about to learn about life
away from Earth. Everything that there is to know about black
holes cannot be told because all of that was barely skimming the
surface! A whole series could be written about the monsters of the
universe.
Singularity
Accretion Disk
Since the gravity is much greater at the singularity than it is at the
event horizon, (because of the concentrated gravity) anything that
was to fall into it would be spaghettified, a term used to describe
the process of entering a black hole. It would be stretched apart,
including the atoms! Even though you cannot see these atoms,
you may see them with other matter if they are ejected out at the
poles. Black holes that do this are called quasars, ejecting matter
because they took in too much at once. These beams are VERY
hot, and slightly cool down as they fly through space. They could
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Extraterrestrial Life
The Oddities and the Normalities
E.T. is short for extra-terrestrial, which means ‘away from
territory.’ When you add ‘life’ to it, it becomes ‘aliens,’ which
almost certainly exist. It is not a matter of belief, but instead of
scientific probability. In the vastness of space, it is almost
inevitable that another planet like ours exists. Astronomers have
already discovered many planets orbiting stars like our own, and a
particular few have caught their attention. In addition, they have
received a short radio signal called the WOW signal. It was
rhythmic, but was never heard again. Our closest hope to
discovering aliens is on Jupiter’s moon, Europa. It has an
atmosphere and water. Since life as we know it must have water,
this would be a good place to look at. The only obstacle is the
temperature, which is well below zero. Another place to look is
on Titon, the 2nd largest moon in our solar system, and Saturn’s
greatest. It has liquid nitrogen, but life could possibly live off it.
In fact, life may even inhale gas to quench its thirst! Even though
we may be able to find some, it may be a bad idea, according to
Stephen Hawking8. He says, “If we were to find life forms, then
one of us would be like Christopher Columbus, who did not treat
the Native-Americans very well at all.
What is normal and what is odd? For one thing, we
ourselves are not normal. Neither is our Sun, because most stars
orbit other stars in binary systems, suggesting that most dots in
the sky are actually two dots that may or may not eclipse each
other, like our Moon’s eclipses, which are also odd. Additionally,
the size of the Sun is relatively small compared to those of most
other stars, since it is only a yellow-dwarf. Looking farther out,
Saturn has a perfectly formed hexagonal storm at its northern
polar regional area. It is dark brown, whereas the rest of the planet
is white. A normality is nebulas filled ethyl alcohol, which we
drink! Even further are three black holes orbiting each other. If
they were to collide, then gravitational waves would be sent out.
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8
A world famous astrophysicist who is well known for his theory of radiation from black holes that is
emitted due to feedback. It is called ‘Hawking Radiation.’ He is physically disabled and needs a computer to
talk for him.
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Our Future
Space Records
The biggest question is about our future. What awaits us?
The first scientific theory that came out was called “The Big
Crunch.” In this, gravity makes everything smash together. It was
recently discredited due to the discovery of the acceleration of the
rate of the expansion of the universe, which puzzled scientists,
since it would be like tossing an atom up and seeing it accelerate
upwards! A new one is “The Big Freeze,” which states that the
universe will expand forever and die in cold. An unlikely theory is
called “The Big Rip,” which states that everything will tear to
pieces. The Big Freeze is the most widely accepted theory, which
is based on the second law of thermodynamics, which states that
everything must rot. Do not worry though, because it will be in
trillions of years.
Biggest Moon in Solar System = Ganymede, which belongs to
Jupiter and has a 3,269 mile diameter.
Biggest Planet in Solar System = Jupiter, which is 318 times the
mass of the Earth.
Fastest Orbit in Solar System = Mercury, at 88 Earth-days.
Fastest Orbit in Solar System = Neptune, at 165 Earth days.
Brightest Star in Night Sky = Sirius A, which is 8.6 light-years
away. It is a giant white star with a white dwarf companion called
Sirius B.
Fastest Winds in Solar System = Neptune’s, with speeds of up to
1,250 mph.
Most Powerful Explosion = Supernova, which releases more
energy than the Sun will release in its entire lifetime.
Slowest Rotation in Solar System = Venus’s, with 243 Earth days
and retrograde9 rotation.
Shortest Rotational Period in Solar System = Jupiter’s, which is
9.84 Earth hours.
Biggest Volcano in Solar System = Olympus Mons, an extinct
volcano on Mars, which is 3 times the size of Mount Everest.
Biggest Canyon in Solar System = Valles Marineris on Mars,
which is 5 times the size of The Grand Canyon.
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9
Clockwise
Least Dense Planet in our Solar System = Saturn, with 0.93% the
density of water.
Most Visible Planet in Sky = Venus
Hottest Planet in Solar System = Venus, with a surface
temperature of about 896o Fahrenheit.
Fun Facts
 Venus goes through phases like the Moon.
 Mercury was named after he messenger of Roman
Gods.
 Mercury’s craters are named after famous people
like Mozart.
 Edmond Halley was the first person to predict the
appearance of a comet.
 Neptune was not found, it was calculated.
 Mars was named after the Roman God of War due
to its red appearance.
 Jupiter was named after the King of Romans Gods.
 Brown dwarves have iron precipitation, which falls
at an extremely high speed.
 The moons of Uranus are named after characters in
Shakespeare’s plays, such as Juliet.
 Neptune is named after the Roman God of the Sea.
 Venus was named after the Roman God of Love and
Beauty.
 Saturn was named after the Roman God of
Agriculture.
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 Planet means wanderer in Greek.
 The biggest star ever discovered is one million times
the mass of the Sun.
Glossary
Accretion Disk: Disk of material that orbits a black
hole.
Asteroid: Big space rock.
Binary System: System of two stars that orbit each
other.
Black Dwarf: Dead core of a star that lets off no
energy.
Black Hole: Remnants of a dead star that exploded in a
hypernova, creating a point of space that is so dense
that light cannot escape its gravity.
Blue Giant: Giant blue star.
Blue Supergiant: Very giant blue star that is near the
end of its life.
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Brown Dwarf: Failed star.
Comet: Icy rock that leaves off a tail when it
approaches a star.
Gas Giant: Relatively big planet that is composed of
only gas and has no solid surface.
Inflation: Rate of expansion of the universe.
Dwarf Planet: A massive body that is too small to be
considered as a planet.
Light Year: Distance that light travels in a year, about
6,000,000,000,000 miles.
E.T.: Short for “extraterrestrial.”
Magnetar: Neutron star with very strong magnetic field.
Event Horizon: Boundary past which light cannot
escape.
Meteor: Falling space Rock.
Extra-terrestrial: Away from territory.
Meteorite: Space rock that has impacted a planet.
Event Horizon: Boundary past which light cannot
escape.
Meteoroid: Small space rock.
Moon: Satellite, or small object, that orbits a planet.
Galaxy: Big group of stars that usually has a black hole
at its center.
Nebula: Giant cloud of gas in space.
Galaxy Cluster: Group of galaxies.
Neutron Star: Star that is so dense that the atoms are
squeezed into nuclei.
Orbit: Path around an object.
Solar Mass: Mass of one Sun. Used for comparison.
Planet: Big object in space that usually orbits a star.
Solar System: System of a star and planets
Protostar: Star that is in its early stages.
Solar Wind: Particles thrown by the Sun.
Pulsar: Neutron star that appears to pulse because two
beams are emitted from the poles.
Star: Giant ball of plasma that sustains nuclear fusion.
Supercluster: Group of galaxy clusters.
Quasar: Black hole that spews out matter from its
poles.
Red Dwarf: Small red stars that shine for trillions of
years.
Red Giant: Giant, dying, red star.
Rings: Tons of space rocks that orbit a planet.
Satellite: Body that orbits a mass.
Singularity: Point of infinite density.
Supernova: Giant explosion that is caused by a dying
supermassive star.
Universe: Everything in existence.