Transcript Observation: Red Shift

Did you ever wonder …
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How the earth or even the universe came to
exist?
Before…
After…
Lets start our investigation
Observation: Red Shift
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When we looked (observation) at galaxies beyond
our very own Milky Way and measured the
wavelength of light, we realized that it was redshifted. This happens to waves that move away
from us (the observer).
This is just like what
happens to the sound
of a siren when it
moves away from you.
Red Shift
What does that mean?
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If you look all around you and you see
everything in the universe moving away
from you, what do you think that
means?
Hmmm.
I wonder…
Developing Hypothesis
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Everything around us is moving away! So it seems
the universe is expanding. The universe could have
started out small then got bigger and we inside it
look at all the things around as moving away. The
theory that we accept to explain how the universe
originated is called The Big Bang.
According to Big
Bang Theory, the
universe as we
know it today and
everything in it
started out as an
unimaginably
dense dot.
Big
Expansion
In a fraction of a second the
universe expanded from a tiny
point to billions of light years
wide and it released a lot of
energy in the form of light.
Whoaaa!
Prediction
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Using the Big Bang theory, Ralph Alpher, Robert
Herman, and George Gamow predicted that we
should see this light as some sort of Cosmic
Microwave Background uniformly (evenly)
throughout the universe.
How would you write this prediction in an If then
statement?
IF the Big Bang Theory were true and the universe
suddenly expanded and released energy, THEN we
should see an even distribution energy throughout
the universe.
Problem
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We didn’t know how to find it.
Man this is tough.
Annoying or Amazing?
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In 1964 two radio astronomers Arno Penzias
and Robert Wilson working in Bell Labs in
Murrey Hill, NJ detected this annoying “noise”
in their data.
They went through many tests to try to find the
source of the noise.
Interpret Observation
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They looked all around the sky and collected
light in the radio and microwave range. They
mapped what they collected and this is the
“noise” they found. Describe what you observe.
Supporting Evidence!
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Later scientists from Princeton realized that this
“noise” found by Penzias and Wilson was
predicted 16 years before using the Big Bang
Theory! We found strong supporting evidence!
Recap
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We observed red-shift of light form galaxies
beyond ours.
We hypothesized that the universe is expanding.
We developed our hypothesis into the Big Bang
Theory. It explains how the universe started and
how it is expanding. We think that in during the
initial expansion, a lot of energy in the form of
light was released.
Recap Continued
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We used the Big Bang Theory to predict that we
should see an even distribution of light
throughout the universe. We called this the
Cosmic Microwave Background.
We observed what we expected to observe thus
supporting the theory.
HOORAY!
Big Bang Theory
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Lets learn more about the Big Bang Theory.
The universe was a dot then it expanded then
subatomic particles such as protons, neutrons,
and electrons formed.
Then The Universe Started to
Cool
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After the initial expansion, the Universe started
to cool. What do you think happened to the
subatomic particles? (Hint: Think about water vapor
when it cools.)
QuickTime™ and a
decompressor
are needed to see this picture.
Recombination
The subatomic particles move slower so they
don’t bounce off each other as violently giving
them enough time to pull on each other and
formed hydrogen atoms.
Then these atoms cool more and formed clouds.
A Star is Born
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These clouds of
atoms are called
Nebulas. They
form through
gravitational
interactions.
Nebulas are
where stars are
born.
Like this one
Inside Stars
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The more and more
atoms get pulled towards
the center due to
gravitational interactions.
At the same time
bouncing off of each
other creating lots of
pressure.
What do you imagine it
would feel like to be at
the center of a star?
Fusion
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When there’s enough pressure in the center, two
hydrogen atoms fuse forming 1 heavier atom,
helium. 1 proton
2 protons
1 proton
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During the fusion process, light is emitted.
When there is fusion in the big ball of gas, it
becomes a star.
Kaboom!
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If the star were very
massive, At some
point, it can no longer
go through fusion.
When it does, the star
can no longer support
itself and so it
collapses inward
causing a huge
explosion called a
Supernova.
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decompressor
are needed to see this picture.
Forming Heavier Elements
QuickTime™ and a
decompressor
are needed to see this picture.
We are just star dust
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The remains of the
supernovas create
new nebulas as they
cool off and then
create more stars and
“solar” nebulas. 5
Billion years ago, our
sun was born, and
soon after, our home,
the Earth.
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decompressor
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