Humans see problems and immediately start thinking of ways to fix them in the community, at work, at school, and at home by creating a new tool or technology. For example, microwaves were invented to heat food quickly, calendars were made to keep track of time, and computers were developed to process and store data. Many inventions have completely changed our lifestyles, like the invention of electricity. Other inventions merely make life more convenient, like dishwashers and lint rollers. Some of the most impactful inventions of the nineteenth century that changed the way we live were the telephone, the bicycle, and plastic.