Nebular Hypothesis and Big Bang

What made the spinning nebula contract?

Shockwaves from a nearby supernova

What’s the 3rd step of the Nebular Hypothesis

Spinning makes the nebula flatten into a disk shape with protosun in the center

What is accretion? (4th step of Nebular Hypothesis)

The process by which gravity causes a series of collisions, forming planetesimals

What’s the 5th step of the Nebular Hypothesis?

Planetesimals collide and become larger, turning into protoplanets and eventually planets and moons

What happens to debris in the solar system as planets get larger?

The solar system is cleared of debris

What’s the 7th step of the Nebular Hypothesis?

Protosun core increases to 10 million K and nuclear fusion of H to He begins

Why do we have differences between the inner and outer planets?

The heat and solar winds of the sun cause the gases in the planets closest to the sun to be able to escape the gravitational pull of those planets, but the outer planets got less heat from the sun, so they were able to keep their gases within their atmosphere

How did the universe start out?

All matter and energy was confined in one hot and dense body

What happened to the matter 14 billion years ago?

It spread out

What happened after the matter spread out?

Basic elements began to form (H and He)

After basic elements form, clouds of ___, ____ and ____ form.

hydrogen, helium, dust

Heavier elements are a result of _____ _____ in stars

Nuclear reactions

What’s happening to the universe now?

It continues to expand