(1858-1913) understood engines, but his early understanding was at the most basic of levels -- heat. After battling Typhoid and a spotty education, Diesel ended up working in development at a company called Linde, and his specialty was refrigeration. What does this have to do with a diesel engine? Lots. Unlike most internal combustion engines, Diesel's development didn't rely on spark plugs and a fancy mechanical ignition system to make the fuel explode. Instead, his invention relied on principals of thermodynamics, or the way heat behaves and the way it affects its surroundings. He did have a few stumbling blocks along the way. Diesel was determined to invent a better engine than the internal combustion gasoline engine that Benz was using in his newly invented motor cars after 1887. Unfortunately, sometimes his ideas blew up in his face, literally. An accident involving Diesel trying to reinvent the steam engine using ammonia almost killed him. He recovered after a hospital stay, and reportedly suffered some vision and other health problems.
Fast forward to 1898, and Rudolf Diesel is finalizing development on an internal combustion engine that relies only on its own compression to ignite the fuel. At almost 500psi in the combusion chamber, the Diesel engine has as much as 5 times the compression you'd find in a gasoline engine, and Diesel obtained the patent for this technology.
Unfortunately Diesel didn't live long enough to continue to develop the engine to the potential it eventually realized -- the rest of the world had to do that part. In 1913 he disappeared while sailing to London. His body was discovered days later floating at sea. Most experts and biographers have said the death was likely a suicide.