Exploring the Cosmos

What are galaxies and how do they form?

• Galaxies are formed by the explosion of supernovae only.

• Galaxies are static structures that do not change over time.

• Galaxies are small clusters of dust that float in space.

• Galaxies are large systems of stars and matter that form through gravitational attraction and coalescence of matter.

Describe the different types of galaxies.

• Spiral, elliptical, and irregular galaxies.

• Red, blue, and green galaxies.

• Compact, diffuse, and active galaxies.

• Cylindrical, spherical, and linear galaxies.

What role do supermassive black holes play in galaxy formation?

• Supermassive black holes only exist in the center of small galaxies.

• Supermassive black holes have no impact on star formation.

• Supermassive black holes are formed from the collision of stars.

• Supermassive black holes play a crucial role in regulating star formation and influencing the dynamics of galaxies during their formation.

Explain the structure of the universe on a large scale.

• The universe is a flat, two-dimensional plane.

• The universe consists solely of a single galaxy.

• The universe is structured in a cosmic web of galaxies, clusters, and voids.

• The universe is structured like a giant sphere with no voids.

What is the observable universe?

• The observable universe is the region of space that we can observe from Earth, limited by the distance light has traveled since the Big Bang.

• The observable universe is the part of space that is visible only through telescopes.

• The observable universe is a theoretical concept with no physical boundaries.

• The observable universe is the entire universe beyond our galaxy.

How do astronomers measure the distance to galaxies?

• Observing the color of stars in the galaxy

• Calculating the mass of the galaxy

• Astronomers measure the distance to galaxies using methods like standard candles, redshift, and the distance ladder.

• Using telescopes to measure brightness

What evidence supports the Big Bang theory?

• The theory of evolution

• Evidence supporting the Big Bang theory includes the redshift of galaxies, cosmic microwave background radiation, and the abundance of light elements.

• The existence of dark matter

• The discovery of black holes

Describe the timeline of the universe from the Big Bang to now.

• Formation of the Earth (2 billion years ago)

• The timeline of the universe from the Big Bang to now includes: Big Bang (13.8 billion years ago), formation of atoms (380,000 years post-Bang), formation of stars and galaxies (hundreds of millions of years later), formation of the solar system (4.6 billion years ago), emergence of life (3.5 billion years ago), appearance of humans (300,000 years ago), and ongoing expansion.

• Discovery of fire (1 million years ago)

• First dinosaurs appeared (230 million years ago)

What is cosmic microwave background radiation?

• A type of radiation used in medical imaging

• Radiation emitted by stars in the Milky Way

• The light from distant galaxies that has been redshifted

• Cosmic microwave background radiation is the remnant radiation from the Big Bang, filling the universe.

How does redshift provide evidence for the expanding universe?

• Redshift indicates that distant galaxies are moving away, providing evidence for the expanding universe.

• Redshift indicates that the universe is static and unchanging.

• Redshift is caused by the gravitational pull of black holes.

• Redshift shows that galaxies are getting closer together.