Creation of the Solar system
Life cycle of Stars
Big Bang Theory
Scientists Who Contributed
Evidence of the Big Bang Theory
100

Approximately how long ago did our solar system form?

4.6 Billion Years ago

100

What is the name of the stage in which a star spends most of its life?

Main sequence.

100

Approximately how long ago did the Big Bang occur?

13.8 billion years ago.

100

Which scientist is famous for observations showing that distant galaxies are moving away from us?

Edwin Hubble.

100

What does CMB stand for?

Cosmic microwave background.

200

What is the name of the cloud of gas and dust from which our Solar System formed?

The solar nebula

200

What two elements are involved in the main nuclear fusion process in a main-sequence star?

Hydrogen nuclei fuse to form helium.

200

What happened to the universe immediately after the Big Bang began?

The universe began expanding from an extremely hot, dense early state.

200

Which scientist proposed the primeval atom hypothesis?

Georges Lemaître.

200

What does redshift in the light from distant galaxies indicate?

That the universe is expanding, with light wavelengths stretched as space expands.

300

What force caused the solar nebula to collapse and eventually form the Sun?

Gravity

300

What does a Sun-like star eventually become after its red giant stage?

A white dwarf, after shedding its outer layers.

300

What formed as the universe cooled enough for electrons to combine with nuclei?

Neutral atoms, mainly hydrogen and helium.

300

Which two scientists discovered the cosmic microwave background radiation in 1965?

Arno Penzias and Robert Wilson.

300

Why is the cosmic microwave background considered evidence for the Big Bang?

It is leftover radiation from the early hot universe, now observed as microwaves in all directions.

400

Explain how planets formed from the disc of gas and dust surrounding the young Sun.

Dust and other materials collided and stuck together through accretion, forming planetesimals that grew into planets.

400

What are the two possible remnants of a very massive star after a core-collapse supernova?

A neutron star or a black hole.

400

Put these in order: first stars form, light nuclei form, first neutral atoms form, rapid early expansion.

Rapid early expansion → light nuclei form → neutral atoms form → first stars form.

400

What important contribution did Albert Einstein make to the scientific understanding of the universe?

His theory of general relativity provided the mathematical framework used to describe gravity, spacetime and the expansion of the universe

400

Identify three major pieces of evidence supporting the Big Bang theory.

Galaxy redshift and expansion, cosmic microwave background radiation, and the abundance of light elements such as hydrogen and helium.