Exam Review-Galaxies and the Universe

Cosmic Microwave Background Radiation (CMBR, or CBR) supports the Big Bang Theory because

• all galaxies are moving closer together.
• the observed microwave temperature matches with predictions of the theory.
• all galaxies are not moving apart at all.
• the microwaves are getting higher in temperature as the Universe ages.

Starlight from far away galaxies is increasing in wavelength (red shifted), which shows that

• galaxies are moving together as the Universe collapses.
• galaxies move with no predictable pattern at all.
• those stars may be ready to go supernova!
• galaxies are moving away from each other as the Universe expands.

No scientists really know what the components (make up) of dark matter are in our Universe.

• True
• False

The fact that most galaxies are observed to be moving away from each other is supporting evidence for The Big Bang Theory.

• True
• False

Stars are known as blackbody (even though they're not black) radiators because observing their visible color allows their actual temperature to be calculated.

• True
• False

How is matter organized throughout our Universe?

• Matter is repelled from centers of gravity in the Universe.
• Matter is attracted to centers of gravity (dark matter) within the Universe.
• Matter is randomly scattered in the Universe.
• Matter is clumped around the center of the Universe.

Which force affects the motion of planets, moons, stars and galaxies in the Universe?

• Strong nuclear force
• Weak nuclear force
• Gravity
• Electromagnetism

What star type is located in the central diagonal area of an H-R diagram?

• Dwarf stars.
• Red Giants.
• Main-sequence stars.
• Blue Giants.

What star type is located in the lower left area of an H-R diagram?

• Blue Giants.
• Main-sequence stars.
• Red Giants.
• Dwarf stars.

Which choice orders celestial (space) objects from smallest to largest?

• Stars--> Galaxies-->Planets--> Moons
• Moons--> Planets--> Stars--> Galaxies
• Universe--> Moons--> Stars--> Planets
• Star--> Moons-->