Transcript File - lmhs science

Origin and
Formation of the
Universe
Thursday October 24
LT: I can list the evidence for the origin of
the universe
 BR: What fascinates you most about
space?

2
Monday 10/28
LT: I can cite evidence that the universe is
expanding
 BR: describe why this statement is true or
not?


“To look out into space is to look back in
time?”
3
Wednesday 10/30
LT: I can describe the life cycle of a star
 BR: What is a galaxy? What holds
galaxies together?

4
Tuesday 10/29

LT: I can cite evidence that the universe is
expanding

BR: What had to happen in the early
universe before matter could form?
5
Friday October 25
LT: I can tell how big, how far, and how
old a star is based on objects surrounding
it.
 BR: What support is there for the Big
Bang? How big is space?

6
How big, how far, how old

Put these in order of How big they are smallest
to largest. We will discuss your choices
afterwards. Try to come to an agreement.
How big
 Sun
 Saturn
 Milky way

Earth
Moon
Pleaides
Hubble deep field
7
How Far

Put these in order of nearest to Earth to farthest.
We will discuss your choices afterwards. Try to
come to an agreement

Whirlpool Galaxy
Pluto
Moon
Hubble Deep Field
Sun
Saturn
Pleiades



8
How Old?
Put these in order of How old they are
youngest to oldest. We will discuss your
choices afterwards. Try to come to an
agreement
 Hubble deep Field
Sun
 Stegosauras
Moon
 Earth
Pleiades
 Great Pyramid of Giza

9
How do scientists know
about Earth’s formation?
 Scientists
use direct observation
and theoretical models to try to
understand how the universe formed.
10

Origin of the Universe NOtes
11
Theories [models]
of Universe Formation
 Big
Bang Theory
 Steady
State Theory
12
The Big Bang Theory

The most widely accepted theory for the
formation of the Universe
13
The Big Bang Theory

All matter was once compacted
in a tiny, dense particle, smaller
than a piece of dust.

The particle was compacted by
extreme pressure and
temperature
14
Building a Universe
• an expansive event called
the big bang instantaneously
filled space with all matter
and energy
The Big Bang Theory
The Big Bang Theory
DOES NOT
state that the universe
was created from a
“giant explosion”!!!
16
The Big Bang Theory

10-43sec

Initial, hyper-(super fast) expansion,
NOT an explosion!


Matter and energy are propelled outward in all directions
10-32sec

Hot soup of electrons, quarks and other particles
17
The Big Bang Theory

10-6sec


3minutes


Rapid cooling allows quarks to clump into protons and
neutrons
protons and neutrons combine into atomic nuclei
300,000years

electrons join nuclei to make atoms
(mostly Hydrogen and Helium); light (photons) is emitted
18
The Big Bang Theory

1 billion years

Gravity brings together atoms of H and He forming
giant clouds that will become galaxies.
19
Galaxies, families of billions of stars
20
OUR galaxy, the Milky Way, a spiral galaxy
21
Big Bang Timeline
22
The Big Bang Theory

Over the next 13.7 billion years, inflation
continued and the universe cooled [-270C]

Inflation continues today, and according to the
BBT, inflation should never end…
23
Consequences of
the Big Bang
 If the universe did come into existence
through an expansive event, there should be
some evidences:

The mix of the elements should be known

The universe should have a measurable Temp.

The universe should be expanding
Abundance of Light Elements

Elemental composition of the present
universe closely matches the predictions
made by the BBT:
Nucleosynthesis
ABB
Present day
76% Hydrogen 73% Hydrogen
24% Helium
26% Helium
25
Big Bang “After Glow”

In the early moments following the BB, the
universe was giving off large amounts of IR
radiation (thermal energy) and visible light.

As the universe expanded, it cooled.

Weak radiation should be dispersed in all
direction of space.
26
Arno Penzias and Robert Wilson
Early 1960s - Penzias and Wilson
are hired by Bell Labs to evaluate
the performance of the new radio
telescope to be used in trans-Atlantic
telephone communications.
They found a small, unexplained
signal regardless of the direction
the telescope is pointed. It is not
enough to be a problem, but they
are curious.
1964 - They become aware that the
noise in their telescope is the cosmic
background radiation predicted by
the Big Bang theory.
Bell Labs’ radio telescope.
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COsmic Background Explorer

In 1992, COBE announced a measurement that showed
that the background radiation was ALMOST uniform
This measurement
confirmed the
temperature to be app.
2.73K
Remnant echo of the BB
image of the (extremely tiny) anisotropies
in the cosmic background radiation
29
Expanding Universe
THE BALLOON ANALOGY
SPACE between galaxies is increasing
30
Cluster of galaxies do not increase in size,
but the galaxies move further apart
31
The expansion is similar to the baking of bread.
The size of the bread increases and the distances
between the raisins also increase, but not the raisins.
If you sit on one of the raisins, you will see that all
the raisins are receding from you. Besides, the
farther away a raisin locates, the faster it recedes
32

In the 1920s, Edwin
Hubble determines that the
galaxies are:



Edwin Hubble with his cat Nikolus Copernicus.
(Colliers Magazine, 1949)
Moving away from the Earth
in all directions and
The father away they are,
the faster they move
outward
Hubble’s Law states that:
as the distance increases,
so does the velocity. This
implies that the universe is
UNIFORMELY expanding.
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34
How was this known???
Hubble used a phenomenon first discovered by the
Austrian mathematician and physicist,
Christian Doppler (1803-53).
 The
pitch of a note is how high or
low it sounds.
It depends on the frequency of the wave.
 Higher
the frequency of a sound wave,
shorter its wavelength, higher its pitch.
35
As the police car approaches, the SW from its
siren are compressed towards the observer.
The intervals between waves diminish, which
translates into an increase in frequency or pitch.
36
Conversely as the police car recedes, the
SW are stretched relative to the observer,
causing the siren's pitch to decrease.
37
By the change in pitch of the siren,
you can determine if the car is
coming nearer or speeding away.
38

A change in pitch results from a change/shift
in the frequency of the sound waves is
referred to as the DOPPLER EFFECT.
39
Doppler Effect [Light]

As the light from a galaxy travels away from us,
the distance between us and that galaxy increases,
thus light is “stretched” appearing redder.

Red has a longer wavelength than Blue
40
41
Red Shift and Blue Shift
The waves emitted by an object moving toward an observer are
squeezed; its frequency appears to increase and is therefore said
to be blueshifted. (shorter wavelength)]
In contrast, the waves emitted by an object moving away are
stretched or redshifted. (shorter frequency, longer wavelength)
Blueshifts and redshifts exhibited by stars,
galaxies and gas clouds also indicate their
motions with respect to the observer.
42
The Universe is
EXPANDING
and
SPEEDING UP
43
Galaxy’s velocity is proportional
to its distance
galaxies that are twice as far
from us move twice as fast
Every galaxy took the same
amount of time to move from a
common starting position to its
current position
44
The Future of the Universe
The rate of expansion of the universe
is increasing.
The universe will continue to expand forever,
as suggested by the BBT, and

stars making up the galaxies will age and die.
 as more stars die over billions of years, the
universe will eventually grow cold and dark OR

45
The Future of the Universe
The expansion will slow down as new matter
is “formed” [E=mC^2], and will eventually stop


It will begin to contract and collapse
until the universe contracts back to a single point
in a big crunch!

PULSATING (OSCILLATING) THEORY
46