Three American physicists were awarded the 2011 Nobel Prize in physics for their realization that the universe is expanding at a faster and faster rate thus transforming our understanding of how the cosmos works.

Saul Perlmutter of the Lawrence Berkeley National Laboratory at the University of California, Berkeley, Brian Schmidt of the Australian National University and Adam Riess from Johns Hopkins University and the Space Telescope Science Institute share the coveted prize.

Working in two separate research teams, they astounded the world's science community in 1998 with the news that the universe is not just expanding, but speeding up.

They achieved this by using exploding stars - supernovas - as a kind of measuring tape to measure distances for billions of light years across space. Their ability to use these "standard candles" as an extremely accurate measuring system proved conclusively that the expansion of spacetime was speeding up.

"I was one of those kids who always thought that we should know how the world works around us...And somebody should have given us an owner's manual about how the whole thing fits together and how you use it." -Saul Perlmutter, Lawrence Berkeley National Laboratory.

1. What is "physics" the study of?

2. What is a supernova?

3. What is a universe?

1. What is the Nobel Peace Prize?

2. Why are these prizes handed out each year?

3. Why is important to explore the universe and the events that occur in space?