Transcript understanding-the

Universe
What do we know about the
universe?
Doppler Effect
The observed change in the frequency of
sound or electromagnetic waves due to
the relative motion of the source and
observer.
Red Shift
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Red shift
A change in the observed spectral lines
towards the red end of the spectrum. Any star
showing a red shift is moving away from
Earth.
Normal

Red shift
Blue Shift

A change in the observed spectral lines
towards the blue end of the spectrum. Any
star showing a blue shift is moving
towards Earth.
Normal
Blue Shift
Big Bang Theory
All galaxies are showing red shift. Telling
scientist that all galaxies are moving away
from each other. If we put this motion of
the galaxies in reverse all galaxies would
have been in one central location. From
this location 13 billion years ago a large
explosive happened sending all matter
outward.
Big Bang Theory
Another piece of evidence that supports the
big bang theory, was the detection of back
ground radiation. A low level radiation that
is consistent throughout the universe, that
is considered to be remnants of the big
bang explosion.
Evidence that supports the
Big Bang

In 1965, researchers using radio telescopes detected cosmic
background radiation, or low levels of energy evenly distributed
throughout the universe; considered a remnant of the big bang.
Other stuff created by the big bang.

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Analyzing the background radiation, scientist have discovered that
23% of the universe is made of a type of matter that does not give
off light but that has gravity that we can detect, we call this matter
dark matter.
A material called dark energy, is relatively unknown, scientist think
that is acts as a force that opposes gravity.
Universe Quiz
Scientists examine the light spectra from distant stars to
determine if the size of the universe is changing. Why do
astronomers believe the size of the universe is changing?
a. The red shift indicates that distant galaxies are
moving away from each other.
b. The red shift indicates that distant galaxies are
moving towards each other.
c. The blue shift indicates that distant galaxies are
moving away from each other.
d. The blue shift indicates that distant galaxies are
moving towards each other.
Measurements of light from 7 nearby stars were made. Doppler
analysis was performed and red shift was observed in all the
measurements. What does this evidence suggest about the stars?
a.
b.
c.
d.
All the stars measured are moving away from the Earth.
All the stars measured are moving toward the Earth.
Four of the stars measured are moving away from the Earth.
All of the stars are not moving relative to the Earth
What is the following: "The universe began in a
gigantic explosion called the ‘Big Bang.’"
a. Theory
b. Law
c. Observation
d. Fact
e. Superstition
Which of the following statements is the best
reason the big bang is an accepted scientific
theory?
a. A group of people met together and decided to make
it a theory.
b. There is no other way to explain the formation of the
universe.
c. Distant galaxies were observed to be moving away
from Earth.
d. Edwin Hubble was an honest man.
Why is the Big Bang Theory the most accepted theory of
how the universe was formed?
a. It is the simplest explanation of the current scientific
data.
b. It is based on a combination of scientific and religious
facts.
c. It has not been revised or changed by scientists for
many years.
d. It has been proven correct by using mathematical
models.