Transcript Here

Our place in the Universe
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This is what we think our galaxy, the
Milky Way, looks like.
The Sun is about ½
way from the center
on a galactic arm
The Sun
takes 225 million
years to orbit the
center
The sun is NOT this big NOR is
it a star shape (shhh it’s round).
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The Sun is NOT the biggest star!
• 109 Earths fit across the diameter of the SUN.
• You can fit 1.3 million Earths INSIDE the Sun
• The Sun, the planets and anything that orbits the Sun is
called the Solar System.
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These stars are bigger
These stars are
NOT the biggest
either
The SUN
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These are!!!
The sun is
so small in
this picture
that it takes
as much
space as
ONE pixel of
this image!!!!
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Average?
• We estimate that there are between 100
and 400 billion stars in the Milky Way
Galaxy.
• The Sun is an average star in size and
temperature.
• Every star you see at night are stars that
are MUCH bigger and MUCH brighter than
the Sun.
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Is the Milky Way the only galaxy
out there???
NO WAY!!!
We are one of
billions!
* We estimate there are over 100 billion
GALAXIES beyond our own!
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Hubble Ultra Deep Field (HUDF)
Hubble took 11 days to look at a spot in the sky that appeared to be empty. This is
what it found.
• Every point of light you see is another
galaxy filled with 100s of billions of stars.
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Where did they all come from?
•BANG!!! (the
big one)
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What is the BB?
• Approximately 13.82 billion years ago
(bya) or, 13,820,000,000 yrs. there was an
explosion OF space and time (not IN
space and time like normal sized bangs).
• So, in short, the Big B was the formation of
our Universe (all energy, matter, and
space-time)
BANG!!!
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E= mc2
• Energy =
matter x speed
of light squared
• It means
energy can be
converted to
matter and
vice-versa.
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Does it matter?
• Initially after the Big Bang there was only
Energy.
• As the universe expanded, it cooled. This
allowed the first subatomic particles to
form (protons, neutron, electrons).
• The simplest elements were the first to
form. Hydrogen and helium. The fuel for
STARS!
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Is there any evidence of the BB?
• YUP!!! There are TWO main pieces of
evidence:
1. The universe is expanding…
2. In every single direction we look in space
we see…
Cosmic Background
Radiation
– That’s left over energy from the Big Bang
bouncing around the universe.
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Here is a map of it
You have to imagine that this is our entire 3-dimensional view of
the sky flattened into a map.
EVERY 3-dimensional direction we look we see CBR (cosmic
background radiation).
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