After years of research and billions of dollars, California scientists believe that they are close to producing fusion, the same power that makes the sun burn, as an alternative source of energy.

Scientists at the Lawrence Livermore National Lab in California have completed work on a $4 billion laser that might be able to merge pieces of atomic mass together by burning them at high temperatures.

That burning process would create an enormous amount of clean and inexpensive energy that could be used as an infinite power supply in a time when America is trying to decrease its dependence on oil.

"Basically, all life comes eventually from fusion, from the fusion of the sun. And so if we could replicate this on Earth, we've got the clean, elemental power that powers everything on Earth, essentially," says science writer Charles Seife.

In this video, correspondent Spencer Michels reports on the latest development in fusion energy research.

"Fusion energy is the long-term solution. It is infinite -- essentially infinite fuel and it has no carbon waste." - Ed Moses, Lawrence Livermore National Laboratories

"I know it will work. The issues are economic and the time that's involved in gathering money to do something this large." - Ken Fowler, professor emeritus, University of California, Berkeley

"We're not there yet. Right now, we have to find a cheap way to do this, a reliable way. And so far we're just trying to make it work. I think of it as building the first gasoline engine." - Richard Muller, University of California, Berkeley

1. What is energy?

2. What are some current sources of energy?

3. What is "clean" energy?

1. Congress spent a lot of money to build this laser. Why are taxpayers funding research to find alternative sources of energy?

2. What might be possible downsides to this research?

3. According to the video, what issues stand in the way of producing fusion energy?

4. What previous scientific breakthroughs changed the way the world operated? How?

5. Do you think fusion will be a source of energy in 10 years, 50 years, 100? How would this change the landscape or the way Americans use energy?