When you hear the words "tech innovator" it's likely you imagine the young, breezily confident Silicone Valley start-up bro, or figures like Alan Turing or Steve Jobs. It's unlikely you're thinking of a womanthough women are central to the history of computing.

In 1843, Ada Lovelace published an algorithm for Charles Babbage's Analytical Engine – her work is now considered the first software written for a computer, subsequently making Lovelace the first computer programmer in history.

The term "computer" didn't even refer to machines originally. Dating back to the late nineteenth century, computers (or "human computers") described people who performed long, complex calculations on paper – and this job often fell to women who were less expensive to employ.

The "Harvard Computers" for instance, were a group of eighty women who processed large amounts of astronomical data at the Harvard Observatory under director Edward Charles Pickering in the late 19th century. Their efforts would transform astronomical study and inform the works of astronomers like Edwin Hubble.

The involvement of women in computation became a standard – to the degree that computing power was measured in units of kilo-girl hours. WWII only increased computational demands. In the US, the urgency to quickly calculate missile trajectories led to the development of ENIAC, the Electronic Numerical Integrator And Computer: the first programmable computer.

Its programmers were a group of six women called the "ENIAC girls". Despite originally having limited access to the highly classified military machine, the women successfully programmed the machine into operation relying solely on blueprints and diagrams. These women were Fran Bilas, Jean Jennings, Ruth Lichterman, Kay McNulty, Betty Snyder, and Marlyn Wescoff. They went largely unacknowledged for their efforts at the time.

Though women continued entering computer science after WWII, the trend peaked in the 1980s. Since then, the number of women studying the subject and entering the field started seeing a steady and steep decline (just see this chart at NPR). 

The gender disparity in computer science is a growing one. In 2015, only 18% of computer science degrees were received by women in the US. Meanwhile in the UK, despite an overall increase, female students still make only 17% of the total number of students who enroll into computer science programs, according to the Higher Education Statistics Agency.

Though the gap may be alarming there are organizations working towards making computer science more welcoming to women. To celebrate the contributions women have made to world of tech over the years, we look at five technologies intrinsic to our digital lives that wouldn't have existed without the incredible women behind them.

Wendy Hall: Hyperlinks

You’ve undoubtedly clicked on a link to reach this article – and it’s difficult to imagine the internet without links.

The web as we know it is an example of hypertext, or more specifically, hypermedia: a non-linear system of organizing and connecting text, videos, pictures and other kinds of files through references, or hyperlinks. While Tim Berners-Lee’s web browser may now be ubiquitous to the online experience, it certainly wasn’t the first application to consider the user experience of navigating information.

Pre-dating the Web was Microcosm, one of the earliest forms of hypermedia. The project, led by Dr. Wendy Hall at the University of Southampton in the late eighties, focused on how text and multimedia content could link together to allow users to learn about the ideas they engaged with. 

But unlike simple text hyperlinks of the Web at the time, Microcosm was dynamic. Drawing from a database, not only did Microcosm link to and from images and video, but also showed relevant links in real-time: links could adapt to suit how the individual user browsed content. Hall, interested more in the quality of how content linked together, effectively imagined a personalized browsing experience – not unlike how Google curates the web experience today. You can see Microcosm in action in this YouTube video.

Hall was born in West London in 1952. She studied mathematics at the University of Southampton – after a teacher discouraged her from studying medicine, calling it a masculine profession.

She went on to earn her PhD in 1977 from the University of Southampton and joined the University's Computer Science Group in 1984. By 1994 she became the University's first female professor of engineering. Hall also founded the Web Science Research Initiative (WSRI) with Tim Berners-Lee, an organization that investigates how the web is developing globally. She received a DBE in 2009, making her Dame Wendy Hall.

(Image: Cropped, Web Science Trust)

Gladys West: GPS

If you no longer rely on physical maps and a compass to get around, it's highly likely Gladys West will have shaped your life. She was instrumental in the development of what we know now as GPS, a satellite-based navigation system which offers incredibly accurate location data.

A few years after graduating from Virginia State University in Mathematics, West joined the Naval Surface Warfare Center in 1956. She was just the second black woman ever hired, becoming one of only four black employees at the time.

One of her key roles was to collect and process data sent by satellites, which could be used to help determine their precise location. She would then work with programmers to improve the effectiveness of the huge computers needed to power it. Both these tasks were vital in the development and eventual launch of a global positioning system, or GPS.

This was initially only available to the military, until a Soviet aircraft shot down a Korean passenger jet in 1983 after it strayed into prohibited airspace. Then-president Ronald Reagan believed that widespread access to GPS would have avoided such a tragedy and could do the same for future events.

Nowadays, GPS is built-in to devices that billions of people use every day, including car sat navs, smartphone, tablet and even laptops on the market. Many people are reliant on it for navigation, while it’s an increasingly popular tool on social media. A Quartz article even suggested the entire global financial system is dependent on it.

Despite all her success, West’s appetite for education has never waned. In 2018, at the age of 88, she completed a PhD from Virginia Tech University, which coincided with her induction into the United States Air Force Hall of Fame.

- Anyron Copeman

Hedy Lamarr: Bluetooth & Wi-Fi

In her lifetime, Hedy Lamarr achieved fame as an actor and Hollywood icon. It was only posthumously that she became known as an inventor. She began inventing as a child and continued into adulthood, maintaining a home laboratory and working on ideas in her trailer on film sets.

Howard Hughes gave her access to his team of engineers after she designed a more aerodynamic wing for his planes. But her great invention was the technology that helps to make wireless communication such as Bluetooth and Wi-Fi possible.

Living in Los Angeles during WWII, Lamarr was angered by reports of German submarines torpedoing refugee ships. Her first husband had been an arms manufacturer in her native Austria, and through him she had met German generals and other military officials. She offered to testify on German naval capabilities before the US National Inventors Council but she was rebuffed. So she decided to work on a way to give Allied forces an advantage.

She came up with a method to block enemy ships from jamming torpedo signals. By hopping between frequencies, wireless radio signals could avoid interception.

She recruited her friend and fellow inventor, the avant-garde composer George Antheil, to make a working model from her design. As a pianist, he came up with a concept using a format similar to player-piano rolls (the continuous rolls of paper with holes punched into them familiar from self-playing pianos in films).

Lamarr patented their invention and offered it to the US Navy but it was rejected. Some years later, the Navy shared the patent with contractors who used it as the springboard to develop frequency hopping technology. By 1962, the US ships blockading Cuba during the Cuban Missile Crisis were all using a frequency hopping system.

Frequency hopping spread spectrum (FHSS) technology is now used by Bluetooth to avoid interference problems. Frequency hopping has been conceptualised in some form or another since Tesla’s 1903 patent but it’s Lamarr and Antheil’s work that is referenced again and again as a key milestone.

Neither Lamarr nor her estate ever profited from the billion-dollar technology she helped to create. However, in 2014, nearly a decade and a half after her death, she and Antheil were inducted into the American National Inventors Hall of Fame. Among her other inventions was an instant fizzy soda cube. It’s not known whether the US military ever found a use for that.

Emma Rowley

Katherine Johnson: Moon landing

You may know Katherine Johnson if you’ve watched the 2016 film Hidden Figures, about three pioneering African American mathematicians at NASA during the Space Race -- who were all female.

Born Creola Katherine Coleman on August 26, 1918 in White Sulphur Springs, West Virginia, Johnson showed a strong inclination for mathematics from a very early age. After graduating high school at age 14, she began studying Mathematics and French at West Virgina State, where she was mentored by W.W. Schieffelin Claytor -- the third African American man to receive a PhD in Mathematics.

Johnson joined NASA as a “computer” in 1953, when it was called the National Advisory Committee for Aeronautics or NACA.

But with the dawn of the Space Race, her work became more crucial than ever. In 1961, Johnson joined the Space Task Group: the team tasked with making space travel a reality. There, she calculated the trajectory of the Freedom 7 mission that would make Alan Shepard the first American in space.

The following year, Johnson became pivotal to another ground-breaking mission: the Friendship 7 flight that made John Glenn the first US astronaut to orbit the Earth. It wasn’t an easy task. It would require linking Glenn’s flight to tracking stations across the world to computers in the US and Bermuda, which would then calculate Glenn’s orbital trajectory.

But Glenn did not trust the machines. Instead, he specifically requested Johnson to verify these machine-generated calculations first, by hand. Without her confirmation the mission would not go ahead. Johnson’s contributions to space travel didn’t end there of course. In 1969, she also helped calculate the Apollo 11 trajectory to the moon -- and back.

While Johnson remained an unsung hero through most of history, in 2015 President Barack Obama recognized her with the Presidential Medal of Freedom, stating “Katherine G. Johnson refused to be limited by society’s expectations of her gender and race while expanding the boundaries of humanity’s reach.”

(Image credit: NASA)

Karen Spärck Jones: Search Engine

If you landed upon this article after searching in Google, or some other search engine for "Women in Tech", or one of the women featured here, you will have arrived here thanks to the invention of Karen Spärck Jones.

Spärck Jones came up with a way that computers can understand human language, even though words have multiple meanings. Spärck Jones’ introduced this concept – known as inverse document frequency – back in 1972. This is what allows a search engine to return relevant results based on the frequency of the words and the context – it understands which word you mean. Not only is inverse document frequency the foundation of modern search engines, it is fundamental to the developments in AI that we are seeing today.

Born in 1935 in Huddersfield, Yorkshire, Spärck Jones studied history and philosophy at the University of Cambridge and, after a brief stint as a teacher, moved into Computer Science as a self taught computer programmer. During her computing career she campaigned to encourage women to enter the field. She came up with the slogan: “Computing is too important to be left to men.”

- Karen Khan

(Image: University of Cambridge)

Dr Adele Goldberg: Graphic User Interface (GUI)

Some technologies are so ubiquitous that it's difficult to imagine a world without them. The graphical user interface (or GUI) is one of these, quietly but fundamentally defining the relationship we have with computers and mobile devices. It's all around us, but invisible: like the fish in that old joke asking "What's water?"

GUI is the now-obvious-but-not-obvious-at-all-when-it-was-invented notion of a computer having a desktop that you can interact with directly. Applications, documents and folders are represented by icons that you move around using a mouse (or, in some early iterations, a lightpen). Anyone can do it. Command lines are intimidating; GUI is democratic.

Like most revolutions, GUI has many parents, but few can claim so significant a role as Dr Adele Goldberg. Working at Xerox PARC in the 1970s she wrote most of the documentation for the hugely influential Smalltalk-80 programming language; coming from an educational background her remit was, as she recalls, "to find a way to teach this to anybody".

One of the people she taught along the way was one Steven Jobs, who visited PARC in 1979 in search of inspiration. But not without a certain reluctance: aware of Smalltalk's value Goldberg initially refused point-blank to "give away the kitchen sink". Needless to say she was proved right when Apple implemented similar ideas in the Lisa and Macintosh, the latter subsequently taking over the world and making us all forget about the time before GUI.

- David Price

(Image: Terry Hancock, PyCon 2007)

Timnit Gebru: Ethical AI Advocacy

While we often trust AI to make complex decisions with greater accuracy than any human mind – it doesn’t mean AI is free of biases. The data training the algorithms can often be biased in itself.

Computer scientist Timnit Gebru, who led Google’s Ethical AI team, explore these biases. She is also a co-founder of Black in AI, an community that  supports and advocates for Black researchers and greater representation in AI.

A ground-breaking study she completed with fellow AI researcher Joy Buolamwini from the MIT Media Lab, found that prominent facial recognition software identify women of darker skin tones 35% less accurately than white men.

Gebru’s work in ethical AI isn’t free from backlash. In December 2020, she was dismissed from Google for wanting to publish a paper that would cast a harsh light on Google’s own AI practices.

The paper, titled “On the Dangers of Stochastic Parrots: Can Language Models Be Too Big?” investigated a variety of risks in large scale natural language processing models -- models like the ones that form the basis of Google Search.

The paper looked at the huge environmental and financial costs of data processing, the inherent biases in data collection, and the dangers of AI-generated language mimicry that lacks accuracy.

Google’s firing of Gebru caused a major controversy. Over 1,500 researchers and 1,2000 Google employees signed a letter of protest.

In February 2021, Google announced it would change how it oversees its researchers’ work in response to the uproar. The company also said it would work towards greater racial equity, particularly in managing racial biases in AI.

There’s no doubt Timnit Gebru's advocacy for more ethical AI will inform AI development for years to come.

(Image: Kimberly White/Getty Images for TechCrunch under licensed under Creative Commons)