Ch. 26.5 - The Expanding Universe

True

False

As a star moves toward Earth, the lines in its spectrum are shifted toward shorter wavelengths.

As a star or galaxy circles the Earth, the lines in its spectrum shift toward the middle of the spectrum.

As a star or galaxy moves away from Earth, the lines in its spectrum are shifted toward longer wavelengths.

The greater the observed shift in spectrum, the greater the speed the star or galaxy is moving.

the matter and energy in the universe was once concentrated in a very hot region smaller than a sentence period.

the universe began billions of years ago with an enormous explosion.

the universe came into existence in an instant.

the matter and energy in the universe has taken billions of years to form.

the existence of cosmic microwave background radiation.

the red shift in the spectra of distant galaxies.

the fact that the sun is about 20 billion years old.

the pulling of atoms together into gas clouds by gravity.

astronomers currently don’t know what it is or how it is distributed.

it cannot be seen directly.

it can be measured using the Doppler effect.

it can be detected by observing how its gravity affects visible matter.