Howard Hathaway Aiken (March 8, 1900 - March 14, 1973) was a pioneer in computing, being the original conceptual designer behind IBM's Harvard Mark I computer.
Aiken studied at the University of Wisconsin-Madison and later obtained his PhD in physics at Harvard University in 1939. During this time, he encountered differential equations that he could only solve numerically. He envisioned an electro-mechanical computing device that could do much of the tedious work for him. This computer was originally called the Automatic Sequence Controlled Calculator (ASCC) and later renamed Harvard Mark I. With engineering, construction, and funding from IBM, the machine was completed and installed at Harvard in February, 1944. Grace Hopper joined the project in July of that year. In 1947, Aiken completed his work on the Harvard Mark II computer. He continued his work on the Mark III and the Harvard Mark IV. The Mark III used some electronic components and the Mark IV was all-electronic. The Mark III and Mark IV used magnetic drum memory and the Mark IV also had magnetic core memory.
Aiken was inspired by Charles Babbage's Difference Engine.