Prior to publishing his groundbreaking papers on special relativity and the photoelectric effect in 1905, Albert Einstein worked intermittently as a tutor and as a clerk in the Swiss government's patent office. As an assistant examiner at Switzerland's Federal Office for Intellectual Property, Einstein worked to evaluate patent applications relating to the registration of electromagnetic device inventions.
Working at the patent office, Einstein evaluated applications for devices such as an electromechanical typewriter and a gravel sorter. Einstein did well at this job, which he worked starting in 1903. The subject matter of these patent applications helped Einstein develop his intellectual approach to thinking about electricity.
He became so efficient at reviewing these patent applications that he was able to engage in thought experiments that helped him flesh out his theories about light, space and time. In 1905, just two years after beginning his work at the patent office, Einstein experienced what is known as his "miracle year," publishing the important papers that kicked off his scientific career.