To get more matter to form requires a much greater amount of energy, all in the same place.

However, the amount of matter and energy remains the same.

In the real world, people have a limited amount of time and energy.

Or put in other words, the total amount of energy is constant.

This needs a large amount of energy to get started, and is not easy to do yet.

This light was the first amount of physical energy ever in the universe.

In other words the amount of useful energy is always less after a change.

The amount of energy in a closed system is always the same.

That is, the amount of energy a thing has can be given a number.

"I wanted him to use the least amount of energy."