card
075

Big Bang

OLogy Series
astronomy
card
075

Big Bang

OLogy Series
astronomy

Scientists believe that everything in the Universe began about 13 billion years ago in a giant explosion called the Big Bang. Over billions of years since the explosion, the Universe has expanded, and cooled, while matter formed into galaxies, stars, and planets. The observable Universe now measures 75 quintillion miles in all directions and continues to expand.

What kind of powerful instruments have scientists used to find evidence that the Big Bang really happened?

microscopes

giant magnifying glasses

satellite telescopes

Are you right?

Correct!

Powerful telescopes orbiting Earth have seen evidence of the Big Bang. These waves of radiation from the explosion are called the cosmic microwave background.

What force caused matter to form into galaxies, planets, and stars?

gravity

super glue

solar winds

Are you right?

Correct!

Over billions of years, gravity pulled gas, dust, and other stuff together to form all the objects in the Universe today.

Charles Liu, astrophysicist

Of all of the creation stories ever told, the only one with strong scientific proof is the Big Bang.

Scientists believe that the Universe is still expanding.

Fact
or
Fiction
?

Fact

In the 1920s, Edwin Hubble used powerful telescopes to discover that the Universe has been expanding in all directions ever since the Big Bang.

When: about 13 billion years ago
What: explosion that began the Universe
Temperature: trillions of degrees
Source: a tiny point of energy, smaller than the period here.
Result: observable Universe formed
Significance: only explanation of the beginning of time supported by scientific evidence

Image credits: courtesy of AMNH; Charles Liu: courtesy of AMNH.