Transcript BIG BANG - UW Atmospheric Sciences

The Big Bang
By Alex K Chen (note, this is
a middle school presentation I
did, but it impressed people
enough for me to repost this)
In the following slides, I will…
• Explain to you quite a bit about the Big Bang, and how the universe came into
formation after the Big Bang…
• Give you a basic Timeline of the Big Bang
• Explain to you why the Big Bang is now such a popular theory among scientists,
and why you should believe it.
•Lastly, I will give you an opportunity to ask questions about the Big Bang to me.
Just a warning, I am not the most experienced person in this subject, so I will not
know everything about the Big Bang.
WARNING: Listening to this presentation can make you extremely bored, especially when you
don’t understand what I’m saying, and when I get into the quantum physics. Young adolescents are
at an especially high risk.
Please also note that I am not a person whom really likes pictures, so don’t expect a good amount
of pictures in this presentation. You may find the good amount of text annoying as well.
So from here on out, the presentation will begin!
Test Questions:
I will not give the answers out now, so that I will make sure
that you are actually paying attention to this presentation. If
you still were foolish enough to doze off, then I will give out
my test questions at the end of my presentation. ;)
1: What is the process known as, in which early in the
universe's lifespan, the size of the universe is increased by
1050 times within a tiny fraction of a second?
2:What are the three lightest elements?
Once upon a time, around 15 billions
years ago…
There was absolutely nothing in the universe
There was not even an universe
Except for an infinitely small, extremely hot point
So small it occupied no space and was nearly
infinitely dense
So hot - hotter than anything you can name
Singularity – so we call it
Then it exploded in what we call
The Big Bang
After the Big Bang, the universe formed, and it
exploded violently…
•Within a tiny fraction of a second, the universe expanded
rapidly, and the first particles were created. These particles were
known as quarks, anti-quarks, and leptons. Radiation also
formed, as you can see with the yellow squiggly lines. Ever since
this period, there was a constant “warfare” between matter and
anti-matter, which released radiation in the process. By 10 -43
seconds, gravity also separated from the other forces, and
became its own separate force.
Inflation
•The universe continued to expand, and grow cooler. By 10 –33
seconds, the temperature dropped to 1027 degrees Kelvin and
underwent a phase transition, kind of like the process in which
water turns into ice.
•As a result from the decreased heat, the strong nuclear force
split off from all of the other forces in a process known as
symmetry breaking that released a whole lot of energy.
•Then, suddenly, the universe expanded exponentially, in which
the universe expanded by a factor of 1050 times that it originally
was.
•After inflation, the universe continued to expand, but more
slowly. However, it never stopped expanding, and still expands
to this date.
Quark Soup
•By 10 –12 seconds, the weak and electromagnetic forces separated and now there were four
uniquely known forces.
•During the Grand Unification Epoch, quarks and leptons and their corresponding anti-matter
particles were constantly colliding with each other, creating photons of radiation. Two
colliding photons could also create matter and anti-matter. Quarks could decay into leptons,
and vice-versa.
•Matter, Anti-Matter, and Radiation existed in nearly equal amounts, during this epoch.
•By the end of the Grand Unification Epoch, quarks and anti-quarks eventually decayed into
hadrons.
•Hadrons included the more stable baryons as well as the less stable mesons. Both baryons
and mesons had their corresponding anti-matter particles. Baryons are also known as protons
or neutrons, the building blocks of today’s elements.
•By 10 –4 seconds, there was no longer any energy to create baryons, and a large amount of
baryons collided with anti-baryons, leaving few survivors and creating a huge wave of
photons.
•When the universe was 1 second old, the universe even cooled to the point in which electron
and anti-electron pairs could no longer be created, and another mass annihilation occurred,
leaving behind even more photons and fewer electrons.
•Eventually, Neutrinos stopped interacting with other particles, not even anti-neutrinos. As a
result, they escaped annihilation, and still drift through the universe in large numbers, and
can be a significant factor to the dark matter of the universe.
Big Freeze Out
•During the Era of Nucleosynthesis, beginning 1 second after the Big Bang and ending 100 seconds
afterwards, almost all of the present day helium and deuterium was created. Some of today’s
lithium was also created, in smaller numbers (Regular hydrogen atom nuclei did not have to be
created, as they consisted of only one proton!).
•Around 100 seconds after the Big Bang, the temperature dropped far enough in which protons
could join together with neutrons without being torn apart by highly energetic photons. By this
time, positrons, the anti-matter of electrons, have been completely annihilated, although a few
electrons did survive annihilation.
•Conditions were finally now ripe enough so that protons and neutrons would form helium nuclei,
consisting for around 24% of all of the light elements. The nuclei for heavier hydrogen, and lithium
would also be created by now.
•The protons that were not joined together with neutrons were destined to become hydrogen nuclei.
There was a large amount of protons left, and hydrogen nuclei afterwards consisted of 75% of all
atomic nuclei.
•The hydrogen and helium nuclei will eventually join up with electrons to form atoms 300,000
years later, and are also the seeds of future stars, which create even heavier elements. However, for
now, there are only hydrogen, helium, and lithium elements, also known as the three lightest
elements in our universe.
Parting Company
For the next 300,000 years….
•The universe continued to expand and cool
•Photons of electromagnetic radiation could not move freely, as they kept colliding
with electrons or other matter. Radiation and matter were interconnected.
•When the universe cooled down to around 3000oK, electrons could now orbit nuclei
without being knocked off by photons.
• and electromagnetic radiation can travel throughout the universe without being
disturbed. Now the universe has become transparent.
•By the time the universe is 300,000 years old, the three lightest elements H, He, Li
were formed when electrons started to orbit around the nuclei of these atoms. The
universe back then was composed of mostly H, with a bit of He, and a trace of Li
•The vast sea of photons free to travel across space still persists to this day, in the form
of the Cosmic Microwave Background.
•This radiation has now cooled to around 2.73 degrees above absolute zero, but is still
among the strongest pieces of evidence for the Big Bang. It was also extremely smooth
•Tiny ripples have also been discovered among the radiation, which are minute
fluctuations of matter and energy. These fluctuations were amplified by gravity to
form many of the objects that now make up our universe: stars, galaxies, etc.
Timeline of the Universe
Separation of Forces:
•gravity separated from other forces (10 -43 seconds)
•strong nuclear force separates from other forces (10-33 seconds)
•weak and electromagnetic forces separate (10-12 seconds)
•quarks combine to form particles( 10 micro seconds)
•nuclei of light atoms form (3 minutes)
Basically, there are four main forces in the universe, as theorized by the “Standard Model” of matter. One is
the familiar gravitational force, which is a long-range force, dominating the interactions of matter across vast
distances.
There is also the electromagnetic force, which is also long range, and keeps electrons inside their nuclear
orbits. Electromagnetic force is also behind electromagnetic radiation, which can travel over infinite
distances. There are many types of electromagnetic radiation at different wavelengths, including visible light,
gamma rays, radio waves, infrared, etc.
The strong nuclear force binds the particles that make up the nuclei of atoms. This force only operates under
very short, sub-atomic distances.
The weak nuclear force is the force that underlies some types of radioactive decay. This force only operates
under very short, sub-atomic distances.
Physicists also theorize that all four forces are carried by particles called bosons, which do interact at certain
energies. At a high enough temperature, these forces to become indistinguishable as they were just after the
Big Bang when the temperatures were extremely high.
In the Grand Unification Theory, the forces start to merge when you look back far enough into time when
the temperature is much higher.
What Particles Really Are…
You may have been confused by all of the scientific words
that I have used earlier in this presentation. Well, you should
be confused no more after reading this slide. : )
•Basically, quarks are the building blocks of protons and
neutrons, which are the building blocks of atoms.
•Leptons are the building blocks of electrons, and
neutrinos.
•Anti-quarks have only been in the universe for a very
short period of time. When it meets a quark, both of them
annihilate each other.
Why Scientists Believe in the Big Bang:
Why We Believe in the Big Bang
The following list does list 5 major reasons why most
scientists believe in the Big Bang. There are many other
reaosns, but these reasons are the main reason why
scientists believe in the Big Bang.
I.
The Night Sky
II.
The Expanding Universe
III. Background Radiation
IV. The Abundance of Helium
V.
The Evolution of Stars and Galaxies
Bibliography:
I know you’re all yearning for me to go to the next page, but in order for me to
actually get a decent grade in this assignment, I actually need to post my
bibliography here! Yes, I know it’s boring, and I really loathed creating this
part as well, but the bibliography is still essential for a decent grade in this
presentation!
Tanabe, Michael J. "Cosmology." World Book. 2001 edition.
No Article Author. "Cosmology." Astronomy and Space No Editor. Volume 1. Detroit: U.X.L., 1997.
Sweitzer, Jim. "Do you Believe in the Big Bang?" Astronomy December 2002: 34-39
Trefil, James. 1001 Things Everyone Should Know About Science. New York: DoubleDay, 1992.
Red Shift 3. CD-ROM. Tempe, AZ. Piranha Interactive Publishing, 1998.
A Brief History of Time. CD-ROM. Milpitas, CA. Creative Labs, Inc.1994.
Haramundanis, Katherine. "Astronomy." The New Book of Knowledge" 1995 edition.
"Cosmic Mystery Tour." University of Illinois. 30 September 1995. 21 November 2002.
<http://archive.ncsa.uiuc.edu/Cyberia/Cosmos/CosmicMysteryTour.html>
Questions?
Now is the time to ask any of your pitiful and annoying questions
that you may have in mind for me. ;) Please do not be cowardly,
and ASK a question, as long as it is a reasonable question, and
quiz me on some Big Bang information if you want to prove
yourself more superior than me, in terms of knowledge about the
Big Bang.
You may also direct any compliments or flames towards me. Go
ahead, flame me all you want, it won’t change my feelings
whatsoever. ;)
The End – No, it’s not the end of the world! This is
actually the time before quasars even started to form, it’s only
just after 300,000 years after the Big Bang when the first
atoms formed. This presentation only covered The Big Bang
up the to the time Atoms formed, and if it covered more time,
then I would be overextending this presentation (Some of you
would also be bored to death right now. ;)). After all, if you
really want to know about the future after 300,000 years, you
can search for more of this stuff on the Internet. But I’m all
done now, and I’ certainly hope you enjoyed this presentation.
Or else… *evil grin*
For the written summary of the information, as well
as for additional information, come to [DELETED].
Mr. Galloway, please come here for the written
summary of the information, as I posted it here so
that I wouldn’t have to kill more innocent trees by
printing out paper.
I cannot tolerate your presence any longer! Now get lost, or
else! :P