Transcript The Big Bang

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Which colors combine to make up white light?
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Understand where our universe came from
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Be able to explain why gravity exists
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Be able to explain where every heavy atom in
the universe came from
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Remember your volcano quiz project is due
tomorrow!
We should probably have a final exam at
some point…
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Prevailing cosmological model for the birth of
the universe
All of space was contained in a single point
◦ “Singularity”
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Universe has been expanding ever since
Happened 13.8 billion years ago
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From 0 to 10
seconds.
Rapid expansion of the universe
The universe was extremely hot
−32
◦ Over 1029 Kelvin
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The four fundamental forces were united as
one
◦ Gravity, Electromagnetic, Strong, and Weak
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From 10
seconds to 1 second
The universe was still extremely hot, but
started to cool
−32
◦ Just less than 1029 Kelvin
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Universe was made of “quark soup”
◦ Quarks, electrons, and photons
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As the universe continued to expand it also
continued to cool, and the particles lost
energy.
A few minutes into expansion protons began
to pair with neutrons
◦ Most protons remained alone
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After 379,000 years electrons combined with
the protons and other nuclei
1.
2.
3.
What was the “singularity”?
How long did the “inflation” stage of the
universe last?
How many years did it take electrons to pair
up with protons and neutrons?
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The universe continued to cool and expand
Gravity began to take over and pulled the
newly formed atoms together
These hydrogen nuclei collected to first form
“gas clouds” then collapsed and became stars
◦ About 400 million years into it
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As start developed they attracted each other
and formed galaxies
◦ 1 billion years into the universe
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Eventually planets developed after stars
created heavier elements
Universe continued to expand and cool
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Universe has started to expand at an
increasing rate.
Expansion driven by dark energy and dark
matter
1.
2.
3.
How long did it take stars to begin to form
in our universe?
How long did it take the first galaxies to
form?
What do we believe is driving the increasing
expansion of the universe?
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Newton figured out the law of gravity
◦ Same equations we used to land men on the moon
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Einstein figured out why there is gravity
◦ The universe is made of a four dimensional space
time fabric.
◦ Everything with mass bends the fabric.
◦ The more an object bends the fabric the stronger its
gravitational pull is
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Explain Einstein’s reasoning for why there is
gravity.
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Explain Einstein’s reasoning for why there is
gravity.
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Fusion takes place in the core
◦ Proton-Proton Chain (accounts for 85% of the Sun’s
energy)
◦ Takes 800,000 to 1,000,000 years for energy to
leave the Sun
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Fusion reactions can only take place when the
nuclei have large amounts of thermal energy or
pressure.
The energy released by the fusion that produces
one helium-4 nucleus is 25 MeV
One dynamite molecule reacts to produce 20eV
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Atomic bombs only use fission.
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Hydrogen bombs use fusion and fission.
◦ The heat required for the fusion reaction is
produced by exploding an atomic bomb.
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There is no theoretical limit to the amount of
destruction a hydrogen bomb can cause.
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Can we fuse other atoms together to continue
to produce heavier elements?
Yes!
About 0.2% of the Sun’s energy is from fusing
atoms into Lithium and Beryllium.
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Once the Sun stops fusion it will no longer be
stable.
It will expand to the size of Mars’ orbit(Red Giant)
It will begin to heat up and helium will begin to
fuse into carbon (triple alpha process).
The core will become carbon.
There will be a layer of helium around it fusing
more carbon.
There will be a layer of hydrogen around the
helium layer fusing more helium.
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Energy will be released and blow off the outer
layers into space.
The core is solid carbon now.
Core cools down and becomes a white dwarf.
Continues to cool until it is nothing but ash.
Black Dwarf.
Our star is lame and will only create elements
up to carbon!
1.
2.
3.
4.
What process happens in stars to allow
them to radiate so much energy?
Why haven’t humans been able to convert
over to fusion power yet?
Will the Earth orbit the sun forever?
What will remain of the Sun after it “dies”?
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The bigger the star the more pressure and
heat it has.
Giant stars can fuse more elements than ours!
They form “fusion shells”
Heavier elements will fuse in the smaller
shells while lighter elements will fuse in the
larger shells.
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Sadly even the
largest stars will
only fuse up to
iron.
Where do all the
other elements
come from?
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When a star continues to collapse until the
core reaches nuclear density.
Sudden stop and rebound of falling material.
◦ Like big time explosion…
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10 𝐽𝑜𝑢𝑙𝑒𝑠 of energy released.
They can be seen during the day.
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Rebound energy (10 𝐽) interacts with
elements that are still falling towards the core
and gives them enough energy to fuse into
new heavier atoms.
These new heavy atoms as well as everything
but the core is ejected in every direction into
space.
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Neutron star is left in the middle.
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If it has enough mass it can further collapse
into a black hole.
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Long story short every atom here on Earth
and anywhere else in the universe was create
by a star.
1.
2.
3.
Will every star become a supernova when it
dies?
Is a black hole left behind after every
supernova?
Where does every heavier element in the
universe come from?
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What will happen to Earth once the sun begins
to die?
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Volcano Quiz Projects
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Final exam this Friday. Open notebook.
◦ 50 multiple choice questions
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Review Wednesday and Thursday
◦ Jeopardy and Kahoot
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http://www.universetoday.com/33454/howdo-black-holes-form/
Can light escape the gravity of a black hole?
No
What holds every galaxy together?
A supermassive black hole.
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Cosmological singularity
Mass, Spin, and Charge
◦ All have mass. Only certain ones have spin or
charge.
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Space-time warp
◦ Infinitesimal Volume, infinite density
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No one knows what it is like inside one
Our knowledge of physics ends at the “Event
Horizon”
◦ EH: A boundary in spacetime beyond which events
cannot affect an outside observer (point of no return)
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The cosmological singularity is in the middle
Once the singularity has formed, the mass has
disappeared from the universe.
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Collapse of the largest stars
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The collision of supermassive objects in space
◦ Two neutron stars collide.
If the mass of
the Earth could
collapse to a
singularity is
would have a
diameter of
9mm.
1.
What is the density of a black hole?
2.
Is every black hole spinning?
3.
What is the event horizon?
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If a black hole is completely alone in the
universe and has no spin, and no charge…we
can’t find it.
Observe black holes by them destroying their
neighbors.
Observe the effects of their large gravitational
fields.
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A black hole will pull matter off of a star.
◦ This process is called accretion
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An accretion disk forms around the black hole
◦ It spins faster and faster as the matter gets close to
the event horizon
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Produces large amounts of x-rays
◦ High intensity
◦ Seemingly random
1.
2.
3.
If a black hole is completely isolated, not
rotating, or producing a charge, can we find
it?
What are two things we look for when trying
to find black holes?
What is “accretion”?
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https://www.youtube.com/watch?v=mn3Egf5
9F8c
What happens to you as you fall in?
You go through “Spaghettification”
◦ http://en.wikipedia.org/wiki/Spaghettification
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What does it look like to the person watching?
You slow down and then eventually fade away
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https://www.youtube.com/watch?v=CGS3mZj
L8zA
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What happens when you jump into a black
hole?
Can we use black holes to cut through spacetime?