Transcript The Big Bang Theory

The Big Bang Theory
Welcome the Barenaked Ladies:
http://www.youtube.com/watch?v=uS3qDDzgPio
Big Bang theory: An explanation for the origin of the universe
Hubble was one of the first astronomers
• Hubble’s Ideas:
to study galaxies
• 1) Many other galaxies exist (not just the milky way).
• 2) All galaxies are getting farther apart from each other (2
evidences support this theory). This means that the universe is
expanding and this was most likely caused by the big bang.
Hubble’s ideas were the foundation to the Big Bang Theory (BBT):
• BBT: states that the universe formed when an infinitely dense
point suddenly and rapidly expanded in a single point. All the
matter and energy that exists today were created during the early
minutes of that hot, rapid, expansion.
• The universe formed 13.7 billion years ago.
Evidence for BBT
• 1) Red spectral shifting
• 2) Cosmic background radiation
https://www.youtube.com/watch?v=hcds5Ob59Dg
Recall- The Wave Nature of Light
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Light is electromagnetic radiation (ER).
ER that we can see is called visible light.
Other forms of light that we cannot see also exist (ex: UV).
Longer wavelength carries less energy
Shorter wavelength carries more energy
White light is made of: ROYGBIV
Red light has
a long
wavelength
Blue light has
a short
wavelength
1) Red spectral shifting
• A spectroscope is an
optical
device
that
separates white light into
its colour spectrum.
• Spectral lines: Each
element produces its
own bar code when it
emits visible light (dark
lines in the spectrum).
• Hubble studied the light
of stars and determined
which elements they
contain by analyzing
their spectral lines.
Spectral Shifting: The change in position of
spectral lines to the left or the right of where they
normally are in the spectrum of a light source that
is not moving.
Blue wavelengths are shorter than red
wavelengths
1) Red spectral shifting
• If the lines shift
toward the red
portion, then
wavelengths are
getting longer.
• This means that
they are moving
away from us and
each other.
Hubble used a spectroscope to analyze the spectra of other galaxies. For each of
these galaxies he noticed that the spectra were red shifted. This means that the
galaxies are moving away from us. This is evidence that the Earth is expanding.
-What would Hubble have concluded if he saw blue-shifting occurring?
2) Cosmic Background Radiation
• The Big Bang is
though to have
released large
amounts of energy.
• Thought to be the
left over low energy
waves (microwaves)
from the original
expansion
The snow you see on your TV or the
“static” you hear on your radio are
some of this background radiation.
Expansion of the Universe: galaxies are
moving away from us at an ever faster
rate.
Galaxy A
Galaxy B
• It is not the galaxies or celestial objects that are
moving. It is literally the space in between them
that continues to expand (think back to the
balloon).
The Andromeda galaxy
• The Andromeda
galaxy is said to
collide with ours
(not in your lifetime).
• What kind of shift
will we observe from
this galaxy upon
inspection with a
spectroscope?
Explain.
The Big Bang Theory Recap
• https://www.youtube.com/watch?v=wNDGgL73ihY
Intergalactic travel- an
exploration activity
1. Find out what are the current providers of
this source of travel?
2. the cost of each trip?
3. is there any brochure/info booklet on this
type of travel available anywhere?
4. Ethical issues (if any) associated with
intergalactic travel?
Report your findings with: a report/poster/
website/ photoessay/ flipbook etc.