Hubble's Law and Redshift Review

Front

What is Hubble's Law?

Back

Hubble's Law states that the farther away a galaxy is, the faster it is moving away from us. This relationship is used to determine the rate of expansion of the universe.

Front

What does redshift indicate about a star's movement?

Back

Redshift indicates that a star is moving away from the observer (Earth). The light from the star is stretched to longer wavelengths.

Front

What is the Doppler effect in relation to light?

Back

The Doppler effect refers to the change in frequency or wavelength of light from a source moving relative to an observer. If the source is moving away, the light is redshifted (longer wavelengths).

Front

What happens to the spectral lines of a star moving away from Earth?

Back

The spectral lines of a star moving away from Earth are shifted toward the red end of the spectrum.

Front

What does a blue shift in a star's spectrum indicate?

Back

A blue shift indicates that a star is moving toward the observer (Earth), resulting in shorter wavelengths of light.

Front

How can we determine if a galaxy is moving toward or away from Earth?

Back

By analyzing the spectral lines of the galaxy's light and comparing them to the known spectral lines of elements, we can determine if they are redshifted (moving away) or blueshifted (moving toward).

Front

What is the significance of the spectral fingerprint of an element?

Back

The spectral fingerprint of an element is unique and can be used to identify the element in distant stars and galaxies based on the specific wavelengths of light they emit or absorb.

Front

What does a greater redshift imply about a galaxy's speed?

Back

A greater redshift implies that the galaxy is moving away from us at a higher speed.

Front

What is the relationship between distance and velocity in Hubble's Law?

Back

Hubble's Law establishes a direct relationship: as the distance to a galaxy increases, its velocity (speed of recession) also increases.

Front

What is the role of the electromagnetic spectrum in understanding redshift?

Back

The electromagnetic spectrum includes all types of light waves. Redshift occurs when light waves are stretched, moving them toward the red end of the spectrum, indicating motion away from the observer.