Beginning of Essay
Thousands of years ago human beings learned to make fire. By collecting and burning wood they were able to warm themselves, cook food, and manufacture primitive tools. Later, the Egyptians discovered the principal of the sail. Even more recent was the invention ....

Middle of Essay
.... separated from ore. However, a huge untapped source is our oceans. Sea water contains 3.3x10^(-9) (3.3 parts per billion) of uranium, so the 1.4x10^18 tons of sea water contains 4.6x10^9 tons of uranium. All the world's electricity usage, 650GWe could therefore be supplied by the uranium in sea water for 7 million years(Energy 25). This is a only a theoretical number because it is not possible to get all of the uranium out of our vast oceans. Also, it does not include the fact that in that many years, half of the uranium will no longer exist due to radioactive decay. So, at worst, we would get about 2 million years of power from it. Thorium is ....