A tool is usually more simple than a machine it is generally used with the hand, whilst a machine is frequently moved by animal or steam power.

Bloomberg's $50 million is not going to revolutionize the electric power industry. But his willingness to fight is already inspiring others to see Big Coal differently.

Another mode of accumulating power arises from lifting a weight and then allowing it to fall.

One thing you can say about nuclear power: the people who believe it is the silver bullet for America's energy problems never give up.