Galaxies and the Expanding Universe

The video explores the history of astronomical discoveries, starting with mysterious blobs in the sky. Vesto Slipher identified a bluish blob moving toward Earth, while Edwin Hubble used Cepheids to measure distances, revealing the Andromeda Galaxy. The concepts of redshift and blueshift are explained, showing how galaxies move. Hubble's findings led to the understanding of an expanding universe, culminating in the Big Bang theory.

What was the initial belief about our galaxy 100 years ago?

• It was one of many galaxies.

• It was 100,000 light years across.

• It was the only galaxy in the universe.

• It was the largest galaxy.

What did Vesto Slipher discover about the bluish blob?

• It was part of the Milky Way.

• It was moving towards Earth at high speed.

• It was a new type of star.

• It was moving away from Earth.

How did Edwin Hubble determine the distance to the Andromeda Galaxy?

• By comparing it to the Milky Way.

• By calculating its speed.

• By observing Cepheid stars.

• By measuring its size.

What did the discovery of the Andromeda Galaxy reveal about the universe?

• It is much larger than previously thought.

• It is smaller than expected.

• It is the only galaxy.

• It is static.

What is the significance of a galaxy being blueshifted?

• It is part of the Milky Way.

• It is moving away from Earth.

• It is stationary.

• It is moving towards Earth.

What was the surprising observation about other galaxies besides Andromeda?

• They were all blueshifted.

• They were all redshifted.

• They were stationary.

• They were part of the Milky Way.

What does the redshift of a galaxy indicate?

• It is part of the Milky Way.

• It is moving away from Earth.

• It is stationary.

• It is moving towards Earth.

What did Hubble's discovery about the universe's expansion imply?

• The universe is rotating.

• The universe is expanding.

• The universe is static.

• The universe is shrinking.

What is the Big Bang theory?

• The universe is shrinking.

• The universe started from a single point.

• The universe is static.

• The universe is rotating.

What can the redshift and blueshift of galaxies help us understand?

• The age of the universe.

• The size of the universe.

• The rotation of the universe.

• The expansion of the universe.