I like computers. But this has not always been the case. When I graduated from college, I spent the summer doing research at the University of Minnesota before grad school classes started in September. It was right at the time when computing skills were absolutely necessary for physics grad school but not absolutely necessary to get your undergraduate degree. In any case, I learned how to code that summer – baptism by fire. In about 12 weeks, I learned the Linux operating system to a passable degree (not expert) and used analysis programs in two different languages: Fortran and C++. I analyzed particle physics data with these two different programs and reported on the results. But first I had to learn the basics of computer programming and what a compiler does and what an executable is. I started at step 1. It was terrifying, and my learning curve had to be super steep. But I loved it. I hadn’t learned so much in so little time perhaps ever in my life. It was breathtaking, exhilarating. Look at everything I can do this week that I had no idea existed last week! Isn’t this amazing? That was my whole summer. That was the summer I began to fall in love with computers.

But I’m just in the last few years learning about the history of computing. Part of what I like learning is how the pioneers in computing fell in love with machines that could do so little compared to what we can do now.

The Mark I team at Harvard. Grace Hopper is in the second row. The team was a mix of Navy personnel and civilians.

Grace Hopper is one of my favorites. This woman was born in 1906, well before computers existed, and she graduated from Vassar in New York with majors in math and physics in 1928 and got her PhD from Yale in 1934. Those accomplishments were remarkable in and of themselves, but at that time, it was not quite as revolutionary that a woman would achieve them as you might think. The fraction of women in math at that time was at a level on par with the 1980s — it dropped in the 1940s and took a long time to recover. Vassar College, then a women’s college (it’s coed now), hired her as a professor and she started teaching. Pearl Harbor, as it did for so many Americans at that time, brought about a big change in her career.

Before WWII, roles for women in the military were limited to nurses. But this war started when Eleanor Roosevelt was First Lady, and there were several changes. Most famously, the WASPS were army air corps pilots who flew planes for the military (i.e. between bases, supplies, etc) so that more men could go into combat. There was also a WACS branch, women in the army. But Hopper wanted to join WAVES, the U.S. Naval Women’s Reserve (Women Accepted for Volunteer Emergency Service). She was too old and too small (105 pounds), so she had to get waivers, but in 1943, the Navy decided it needed all the talented mathematicians it could get and let her in. When she enlisted, she thought that she would be a code-breaker, something like Alan Turing was hired for in England. She went through basic training, and while she was there, her orders changed. She was sent to Harvard to join the Bureau of Ships Computation Project.

The Mark I computer in all its glory. Not exactly a desktop.

This was not some trivial calculation center. The world’s first working modern computer, named Mark I, was delivered to Harvard by IBM in 1944 and abruptly commandeered by the Navy. The first uses for the computer were for the Manhattan Project, as well as calculations for ships and submarines movement and firing, and those working on it were seen to be key for the war effort. There was no keyboard, no monitor to help with communication. It was a large panel of levers and knobs, and the output was a panel of little lights – the pattern they lit up in was the output. The input was a paper strip, called a tape, with holes punched into it to indicate a pattern of 1s and 0s.

Grace Hopper, with a paper tape in her hands, talks with Howard Aiken (left) and fellow programmer Robert Campbell, with Mark I in the background.

When Hopper arrived, the director of the project, Howard Aiken, asked her, “Where have you been?” He didn’t know why they would need to send a mathematician to Midshipmen’s School, and he had wanted her there months before. He was in charge, and she was second in command on the project. He gave her a problem, a deadline of one week, and left her alone with the noisy machine to figure out how on earth to communicate with it.

She figured it out and made her deadline. She excelled as an early programmer of the first programmable machine and stayed on after the war. She was a problem solver and learned how to work well with the team on the machine as well as with the machine itself. When she recorded the tasks carried out by the team on a long-term project calculating Bessel functions (“Problem L”), she very seriously listed the jobs of everyone on the team and then ended with this note: “computed, designed, coded, babied, nursed, pleaded with and mothered by Lt. (j.g.) Grace Murray Hopper, USNR.”

This machine that Hopper pleaded with and mothered was comically simple from our point of view.   It could do 3 addition/subtraction operations each second. Our computers can do over 1 billion operations each second.   But she knew every quirk of this machine, helped move it forward to its successors Mark II and Mark III, defined what it could and could not do. She and the machine were undefined without each other.

The innovation she’s most famous for is what changed the computer from a fast calculator into a machine that carried out complex tasks. It is the compiler. The first compiler, designed by Hopper, was a translator, taking code that was easier to understand from the human programmer and putting it into machine language to produce the input into the computer. This was the step that took her team so long during the war. Given a problem, how do you re-write it so that the computer can understand it and do what you want it to do? Compilers allow the humans to write in human language, and then translate the code into computer language. Hopper also, then, co-wrote one of the first programming languages (no longer in use). She also wrote the first programming manual. She insisted that there be industry standards to facilitate the growing software market. She helped bring about the software revolution that defines many aspects of our lives today.

Grace Hopper passed away in 1992, having devoted many years to both the Navy and computation. She lived an amazing life, but I do know that we have something in common.

She liked computers, too.

The LEGO people like Grace Hopper, too.

Further reading:

Harvard’s Mark I site

The Innovators: How a Group of Hackers, Geniuses and Geeks Created the Digital Revolution by Walter Isaacson