Personally, I think that the light bulb affects me the most. I use light all the time, from using it for homework, to getting ready for the day. I can't think of much around me that I use that is made of steel or stock markets. Oil is useful but I don't think I use it as much as light. Every room I enter, I turn on the light first. It's quick and fast and you don't have to own a lighter or matches. A light bulb is fast and efficient.