What is the Big Bang Theory?

Balloon Demonstration… 1. Partially inflate a balloon. Twist

the opening and hold it shut. 2. Draw and label four squares A,B,C,

& D on the balloon. Measure the distance between the squares. Record the data.

3. Inflate the balloon to its fullest capacity. Repeat your measurements.

Balloon Demonstration… What happened to the distances between

the dots as you inflated the balloon? Did some of the dots move farther apart

than others? Why? Suppose the balloon represents the

universe. How does this activity show what is happening to the universe and to the galaxies in it?

What’s in an universe?

A universe contains

the Earth and everything on it. It also contains everything in

the solar system. All stars, of which the Sun is

one, are part of the universe.

Speed of LightLight travels at 300,000 km/s. If you traveled at the speed of light

it would take 10,000,000,000 (billion) years just to travel the distance astronomers see with their telescopes.

Astronomers Think…

They believe the universe was created 10-15 billion years ago.

Billions of years ago, the Universe was very small. A huge explosion, referred to by astronomers as the Big Bang, sent the entire universe flying out at incredible speeds.

Astronomers Think… Eventually matter cooled and condensed

into galaxies and stars. How did the big bang form galaxies?

Hydrogen and Helium are left in space after the Big Bang.

Planets formed. That the universe is still expanding.

How did the big bang form galaxies?

About 200 Million years later, Hydrogen and Helium joined to form stars.

Stars were drawn together by gravity to form a family of stars called- GALAXIES

What is the name of our galaxy?

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In 1927, the Belgian priest Georges Lemaître was the first to propose that the universe began with the explosion

Edwin Hubble found experimental evidence to help justify Lemaître's theory. He found that distant galaxies in every direction are going away from us with speeds proportional to their distance.

Astronomers Think…

Astronomers have discovered the outward motion of the galaxies have only slowed down a little since Big Bang.

The universe may continue to get Bigger and Bigger forever!

Package

Let’s review…

Who created the Big Bang Theory? In 1927, the Belgian priest Georges

Lemaître was the first to propose that the universe began with the explosion.

Explain the Big Bang Theory. A huge explosion, referred to by astronomers

as the Big Bang, sent the entire universe flying out at incredible speeds. The universe is still expanding.