Transcript Evidence of the Big Bang: EM Spectrum

• TODAY’S AGENDA:
• Notes: Introduction to the Big
Bang Theory
Homework:
1.
Introduction to the Big Bang Theory
The Origin of the Universe
Edwin Hubble
(1889-1953)
Astronomer who made several discoveries that provided clues for how
our universe began:
1.
Galaxies are “building blocks” of the universe.
– What’s the universe?
• Universe: All existing matter, energy & space
2.
The Milky Way (Earth’s galaxy) was 1 galaxy among billions of others.
– What’s a galaxy?
• Galaxy: Is made up of a cluster of stars (solar systems).
There are billions of galaxies within the universe.
3.
The galaxies are spreading apart from each other.
– How did he figure that out?
• Think about the Rubberband Lab…
The Big Bang Theory
– A scientific theory that states that the
universe was created from a high density of
matter (called a “singularity”) that
expanded at very hot temperatures,
shooting matter & energy everywhere.
Eventually, the matter began to cool off &
formed various galaxies.
Formation of the Universe
One Scientific Theory –
“The Big Bang”
All matter & energy in the universe was
concentrated in an EXTREMELY small volume
13-17 billion years ago, the BIG BANG occurred,
propelling matter & energy in all directions
universe expanded
Gravity condensed (clumped) matter
galaxies
Still many questions remain about the beginning of
the universe
But how did Hubble conclude
these things (right or wrong) about
our universe?
• What did Hubble (& many other
astronomers & scientists) study?
–STARS & the energy they give off!
The Heartbeat of a Star
• What are stars made of?
• What process is the “heartbeat” of
a star?
– When this process begins, a
star is born, & when this
process stops, a star dies…
Nuclear Fusion
A star is born when fusion begins in the star’s core (center)
H + H à He
Fusion is a reaction that combines 2 small nuclei (H) to form larger nuclei
(He)
The result is the release of a large amount of energy
What
are the 2
products
(outcomes) of
nuclear fusion?
Larger
nuclei
(atom)
LOTS
of energy!
More Out-of-this-World Terms!
• So what’s the difference between…
– Comets:
• Chunks of frozen ice, gases & rocky debris
traveling outside the Earth’s atmosphere
– Asteroids:
• Bodies of rock.
– The large collection of asteroids in our solar
system located between Mars & Jupiter is
called the Asteroid Belt
– Meteorites:
• Bodies of rock smaller than an asteroid, usually
only meters in size
• TODAY’S AGENDA:
• Notes: Evidence of the Big Bang:
EM Spectrum
Homework:
1. Wavestown Activity due
Wed/Thursday 12/4-12/5/2013 for 25
Points
CERN Article & Video Clip
Read through the short article about CERN (European Organization for
Nuclear Research).
DO NOT WRITE ON THE ARTICLE!!!
When you are finished reading, in your next Warm-up box, write 3 words that
summarize (sum up) what the article is about.
CERN VIDEO: So how do astronomers know what’s going on inside the core
of a star?
http://www.ted.com/talks/brian_cox_on_cern_s_supercollider.html
Evidence for the Big Bang?
1920’s – Edwin Hubble
At time of Big Bang, matter was SO dense & hot (billion
degrees) that the universe acted like a GIANT nuclear
reactor
Hydrogen (H) atoms fused (nuclear fusion) to make light
elements (helium (He), lithium (Li)
creating billions
of stars (in millions of galaxies)
Discovered Andromeda Galaxy: galaxies exist outside our
Milky Way
Galaxies are moving apart & away from other galaxies
The Expansion of the Universe
• Hubble likened the moving away (expansion) of the galaxies from one
another to cooking raisin bread…
– Each raisin represents a galaxy. When the bread is uncooked, the
raisins float in the batter relatively close to one another. When heat is
added, the bread itself expands, as well as the raisins within the bread
move further apart from each other.
Evidence for the
Big
Bang Theory
• Light &
Electromagnetic
Radiation
• Doppler Effect
(Doppler Shift)
Evidence for the Big Bang?
The Electromagnetic Spectrum
1665: Isaac Newton observed sunlight (white light) passing
through a glass prism produced a rainbow of colors =
visible light spectrum
Electromagnetic Spectrum Article
• Take out 1 piece of blank paper & label it
“Electromagnetic Spectrum Article
Summary”
– NAME, DATE & PER in the top right!
• Read the following article making sure you
keep in mind the key points
• You will be writing a one page summary
over the reading! Make sure you put effort
into this assignment, these are your notes!
Electromagnetic Spectrum
Article Summary
Main Idea
Sentence
Name
Per
Date
Pictures
Evidence for the Big Bang?
The Electromagnetic Spectrum
Visible Iight travels in the form of electromagnetic (EM) waves
ROYGBIV (red, orange, yellow, green, blue, indigo, violet) & white
Visible light is SMALL portion of electromagnetic (EM) spectrum
Radio waves
Microwaves
Infrared
Ultraviolet rays
X-rays
Gamma rays
Brain Pop: EM Spectrum
http://www.brainpop.com/science/
energy/electromagneticspectrum/
The Electromagnetic Spectrum
• WAVELENGTH: Distance from the top of one wave to the top of the next
wave
Each form of radiation has a different wavelength
What does a radiation’s wavelength tell us?
How powerful (how much energy) the radiation is
What kind of radiation it is
The Electromagnetic Spectrum
Visible light:
Red light = looooooooooooooongest,
Violet light = shortest
On the entire EM Spectrum,
Radio waves: longest wavelength
~500 m (5  102 m)
Visible light: middle
~.0000005 m
(5  10-7 m)
Gamma rays: shortest
wavelength
~.000000000005 m
(5  10-12 m)
Wavestown Activity
• For this assignment, you will be coloring and
answering the questions on the back side.
• For the front side, once it is colored, you are to
identify 5 examples of each energy in the
picture. Place the number next to the item to
identify which type of energy it radiates
• This is due Wednesday/Thursday 12/412/5/2013 for 25 Points!!
• TODAY’S AGENDA:
• Notes: Evidence of the Big Bang:
EM Spectrum
•
http://app.discoveryeducation.com/search?Ntt=big+bang+theory
Homework:
1. Wavestown Activity due
Wed/Thursday 12/4-12/5/2013 for 25
Points
• TODAY’S AGENDA:
• Notes: Evidence of the Big Bang:
EM Spectrum
Homework:
1. Wavestown Activity due
Wed/Thursday 12/4-12/5/2013 for 25
Points
Evidence for the Big Bang?
Spectroscopy: study of stellar (star) spectra (colors) to find
out chemical make-up of stars
Every star has a unique spectra = fingerprint
Heated chemical elements produce a
“bright-line”
spectrum
Series of thin colored lines spaced at uneven
intervals
Each element makes a different spectrum
Evidence for the Big Bang?
• Spectroscope: instrument used to separate light into its component
colors
– How it works:
1.Light reflects off of surface, like a mirror
2.Light diffracts (separates) different colors of light (like a prism)
• Scientists can tell the specific kinds
(i.e., nationalities) & percentages
German, 30% African,
Native American) of each element a star
is made from
(50%
20%
Atoms make
up each
chemical
element.
When
heated,
atoms
release a
specific
pattern of
light energy
(like in the
birth of a
star)!
No 2
elements are
the same!!!
A star’s
spectra = a
fingerprint!
EM
Spectrum
REVIEW
1.
2.
3.
How does the wavelength of electromagnetic radiation change from
gamma radiation to radio waves?
Which portion of the electromagnetic spectrum do human eyes
detect (see)?
The shorter the wavelength the greater the energy of a wave. Which
has more energy, x-rays or microwaves?
EM Spectrum Quiz
Write your NAME, PER, DATE on your EM Spectrum Quiz!
Answer the following questions in 1 complete sentence!
When finished, please turn your EM Spectrum Quiz in to the
EM Spectrum Quiz
• 1. What does EM stand for?
• 2. List the spectrum of radiatiuon from weakest to strongest
• 3. List the colors of the visible light spectrum from strongest to weakest
• 4. What radiation is the only form we can see with the naked eye?
• 5. Give an example of UV radiation
• 6. What does a long wavelength mean? Short wavelength?
• 7. A wavelength is defined as ________ to _________ on waves
• 8. Give an example of radiowaves
• OK, so we understand that there are many different forms of EM
energy (radiation) that stars (& other weird objects in the universe)
give off…
– But can that energy move?
– How can we tell the energy is moving? Closer to us? Further from us?
– How do astronomers tell whether a galaxy (& the stars/energy) is moving
toward or away from them
(observer) on Earth?
– Look at how the wavelengths of energy change!
The Doppler Effect…sound waves
In order to understand the Doppler Effect better, think about standing next to a
train track.
 What does the train’s horn sound like when it is approaching toward you
quickly?
 What does the train’s horn sound like when it is moving away from you
quickly?
http://paws.kettering.edu/~drussell/Demos/doppler/carhorn.wav
Evidence for the Big Bang?
The Doppler Effect
Occurs with starlight
light & other forms of EM radiation)
in galaxies too!!!
Scientists have observed galaxies
moving away & apart
each other at high speeds (Rubberband Lab?)
(visible
from
Light moving toward observer wavelengths of light
appear shorter = “Blue Shift”
Light moving away from observerwavelengths of light
appear longer = “Red Shift”
Evidence for the Big Bang?
The Doppler Effect
Shift in wavelengths of energy (radiation or sound) moving
toward or away from an observer =
“Doppler Effect
(Doppler Shift)”
The spectra of most galaxies is moving toward the Red
end = moving away from
us (our galaxy)
Degree of Red Shift = speed at
which galaxies are traveling
Now make your Conclusions!
http://paws.ketter
ing.edu/~drussell
/Demos/doppler/
carhorn.wav
• Taking what you just experienced with the train noise & what we just
talked about (Doppler Effect)…let’s reflect back to the…UNIVERSE!
– In your conclusion box, explain HOW astronomers study stars to understand
the movement of galaxies (& what is going on in our universe).
• You MUST use the terms Doppler Effect & blue- or red-shift in your
answer.
• Must be 15-20 sentences long
• When finished bring it up for a stamp!
Friday 12/6/2013
ANNOUNCEMENT: Please take out your notes and
take a couple minutes to review!!
Today’s Agenda
•Quiz: Energy and the Big Bang