Galaxies Don't Spin The Way You Think

The video explores how galaxies rotate, debunking the idea that they spin like solid objects. It explains that spiral galaxies are shaped by density waves, not angular momentum, and highlights the role of dark matter in influencing star speeds. Unique galaxies like NGC 4622 and the Black Eye Galaxy are discussed, along with elliptical and lenticular galaxies, which have different star formation characteristics.

What is the primary reason spiral galaxies do not rotate like solid objects?

• They have a fixed axis of rotation.

• They are made of solid matter.

• They are influenced by density waves.

• They are not affected by angular momentum.

How do density waves affect the structure of spiral galaxies?

• They make the arms disappear.

• They keep the arms in a fixed position.

• They cause the arms to rotate rapidly.

• They cause the arms to wind tighter.

What role does dark matter play in the rotation of galaxies?

• It makes stars orbit in reverse.

• It has no effect on galaxy rotation.

• It slows down the stars at the galaxy's edge.

• It speeds up the stars at the galaxy's edge.

How do astronomers study the changes in star orbits over time?

• By observing nearby stars only.

• By using telescopes to look at distant galaxies.

• By measuring the temperature of stars.

• By analyzing the color of galaxies.

What is unique about the galaxy NGC 4622?

• It has no dark matter.

• It rotates in the opposite direction of its arms.

• It has no spiral arms.

• It is a lenticular galaxy.

What distinguishes elliptical galaxies from spiral galaxies?

• They have more star formation.

• They have more dust lanes.

• They contain mostly older stars.

• They rotate faster than spiral galaxies.

What characteristic is shared by lenticular galaxies?

• They exhibit features of both spiral and elliptical galaxies.

• They are completely devoid of stars.

• They have the highest rate of star formation.

• They have no dust rings.