Grace Hopper

Amazing Grace · Mother of COBOL · Computer Scientist · 1906–1992

The mathematician and naval officer who built the first compiler and drove the creation of machine-independent programming languages, insisting that people should not have to think like machines.

Who was Grace?

Grace Hopper earned a mathematics PhD at Yale and taught at Vassar before joining the US Navy Reserve in 1943, when she was assigned to Harvard's Mark I, one of the first great calculating machines. She wrote its manual and its programs. Convinced that people should be able to write instructions in something closer to English, she built the first compiler — a program that translates human-readable code into machine instructions — and championed the machine-independent languages that led to COBOL, long the backbone of business computing. She popularised the term 'bug' after taping a real moth into a logbook, and taught with vivid props like a foot-long wire cut to the length light travels in a nanosecond. She retired from the Navy as a rear admiral at seventy-nine.

Major achievements

• Built the first compiler (the A-0 system), translating human-readable code to machine instructions
• Championed machine-independent languages, leading to FLOW-MATIC and COBOL
• Programmed the Harvard Mark I and wrote its operating manual
• Popularised the computing term 'bug' via the moth in the Mark II logbook
• Rose to rear admiral, one of the Navy's most influential technologists

Life in brief

• 1906 — Born in New York: A curious child who dismantled alarm clocks.
• 1934 — Yale PhD: In mathematics.
• 1944 — Harvard Mark I: Programs one of the first great computers for the Navy.
• 1952 — The first compiler: Her A-0 system translates code to machine instructions.
• 1959 — COBOL: Her work shapes the business programming language.
• 1986 — Retires a rear admiral: At 79, the Navy's oldest active officer.
• 1992 — Dies: Honoured as a pioneer of computing.

Explore the life of Grace — five chapters

1. Seven Alarm Clocks — A curious child and a Yale doctorate
2. The Mark I — Fifty-one feet of relays, and a moth
3. The Compiler — Being told for three years that it could not be done
4. COBOL — A language for people who were not mathematicians
5. Amazing Grace — Retired three times, and promoted to rear admiral at seventy-nine

Read the five-chapter life of Grace Hopper →

Where Grace appears in your course

Grace Hopper has a genuine claim on 1 lesson of the Pearson Edexcel International GCSE science course built into Incandio:

• Total Internal Reflection — Physics: Hopper used to hand out lengths of wire almost a foot long and call them nanoseconds — the distance a signal travels in a thousand-millionth of a second — so that engineers would stop treating transmission delay as negligible. That is exactly the quantity optical fibres exist to manage: how much information can be pushed down a channel, how far it goes before it fades, and how long it takes. She is the person on this page who understood that a communication technology is judged by what it does to time.

Teach what Grace discovered

From Human Language to Machine — ideas Grace is tied to on the Living Knowledge Map. On Incandio you prove you understand one by teaching it to Ember, the AI pupil, in Teach the Room.

Begin

• Start a conversation with Grace — a dramatised, historically grounded AI portrayal
• Read the Historical Brief
• Explore the life of Grace — five chapters
• Find your exam topics · Meet all 208 figures