 Scientists do not 100% know how the universe began.

 “The Big Bang theory” is the most widely accepted theory.

 ______years ago all the matter in the universe was

contained in a small package.

 It had infinite ______. (Something with ______

______is called a “singularity”)

 Lots of ______and ______built up until the package

exploded.

 All ______in the universe is a result of this explosion.

Timeline Since the Big Bang Evidence

 The universe is ______(remember space is cold!)

 The universe is ______.

Formation of Our Solar System

 The Sun is about ______years old.

 The planets are about ______years old.

Expanding Universe

 Doppler Effect

As the ambulance approaches, the sound waves from its siren are ______towards the observer. As the ambulance recedes, the sound waves are ______relative to the observer.

By the change in pitch of the siren, you can determine if the ambulance is coming ______or speeding away.

Red Shift/Blue Shift

Light behaves the same way as sound waves. If a star is moving ______to us, the light it gives off gets squeezed together, which makes it appear ______than it actually is.

If it is moving away from us, the light gets stretched out, which makes it appear more ______than it really is.

Formation of Our Solar System

 ______(the most widely accepted theory)

A large nebula condensed into a star, but in the process also formed an outer ring of material which became the planets.

 ______

A star collided with the Sun and the debris formed the planets.