HyperPhysics, the popular online physics resource, turns 25

In 1998 Georgia State University physicist Rod Nave launched a simple website called HyperPhysics to help science education graduates teach physics. He did not expect his creation to become one of the most popular physics sites in the world.

It was the early days of the internet, and Nave hand-coded the site, with its distinctive pink background, in HTML. Simple bubble diagrams link various concepts in physics, allowing the user to trace how ideas including electromagnetism, acoustics, and quantum mechanics are connected. The site begins with a map of 10 broad physics topics. Users can click through to the sections that interest them (such as “sound and hearing”), then delve deeper into the subject via options such as “sound propagation,” “periodic motion,” and so on. For each subject, easy-to-understand images and text explain different facets of physics.

Twenty-five years after its inception, HyperPhysics has been used by tens of millions of people. At 83, Nave, a professor emeritus at the university, continues to update the site and correspond with its visitors around the world. Now he and Georgia State are planning for the time when he hands the site over to others to manage.

The HyperPhysics content stems from a course that Nave taught for 30 years called Conceptual Physics, a broad survey of physics and astronomy from classical to quantum. With HyperPhysics, “I wanted an accessible coverage of the subjects [that students] would likely encounter in teaching physical science in the schools,” Nave says. Against a beige background, his individual entries include photos, diagrams, equations, internal links, and references to source material.

Nave ascribes the site’s unexpected success to fortuitous developments in technology. When he began working on the concept that would later become the website, he used HyperCard, a software and development tool for Apple computers. The software, released in 1987, was based on the idea of a stack of virtual cards, like in a Rolodex.

The software tool provided Nave with an important early lesson: Do not build educational programs on proprietary media. “They often disappear,” he explains—as HyperCard did in 1998. But by then the World Wide Web was gaining traction around the globe. Luckily for Nave, HyperCard and HTML were “very, very compatible.”

That is the first of multiple technology boons to which Nave attributes HyperPhysics’s success. The second was the adoption of smartphones, particularly the iPhone Operating System. Rather than having to repeatedly click a mouse to navigate between topics, users could simply tap the bubbles on the screen. “It’s one of the major influences that have made it so universal,” he says.

Nave continues to add to the platform, sometimes once every few weeks, sometimes daily. Most recently he wrote about the James Webb Space Telescope and its first images. If the site’s content were published in a single physical volume, that book would run about 6000 pages, Nave estimates. There is a full Spanish translation ; Nave says he has given permission to others looking to translate the behemoth into German, Chinese, Portuguese, and other languages.

Nave says that Georgia State doesn’t track the number of users on the site, but he estimates that there are about 2 million page views a day. One metric of the site’s success is his daily correspondence with users around the world. He says he receives about half a dozen emails a day. “One of the very rewarding things about HyperPhysics is that I’ve gotten help and discussion and suggestions [from people] worldwide,” Nave says. “My wife was amused when one morning at breakfast I got an email from Australia pointing out a misspelled word.”

He welcomes those interactions—whether over a typo or a conceptual disagreement—and says they have added a great deal to the site. For example, he once described the phenomenon of sun dogs , bright spots that appear in the sky on either side of the Sun. Nave had written that the optical event occurs in cold climes. However, after readers submitted images of sun dogs from locales including Atlanta, New Zealand, and the equator, Nave conceded his error and altered the entry.

Nave regularly grants requests from people wanting to use the site’s text or images for textbooks or other teaching materials. His custom illustrations are particularly in demand. He says that 50 years of sketching concepts on the blackboard in his classes have taught him how to make his diagrams easy to understand.

Nave has not received external funding for producing the site. Over the years he has covered some costs through the small fees he collects to send HyperPhysics content in physical form to those who do not have easy access to the internet. So far he has mailed DVDs or USB drives to people in about 90 countries. From the Faroe Islands (a tiny archipelago between Europe and Iceland) and Mauritius to Rwanda and India, high school teachers and university lecturers are using HyperPhysics in their classrooms.

“I just want to make it as accessible as possible,” Nave says. “I want it to be a free resource, and free of all those pop-ups that sometimes drive you crazy when you’re trying to find out information.”

And that is the plan, according to Deepak Raghavan, a Georgia State astronomy professor who heads the university committee that will steer the site’s future. After nearly two decades hosting the site on his computer, Nave transferred the site to a server in Georgia State’s computing services division in 2016. Three years later, the committee was formed to decide how to support and develop HyperPhysics once Nave steps back from the site.

Raghavan says that there have been discussions about modernizing the site, perhaps through using WordPress or another content management system, but that’s not a primary goal. “I don’t want to change the basic nature of HyperPhysics,” he says. “It is a great tool. It works well, so from the [user interface] standpoint, we don’t want to mess with a lot.”

The big question is who will operate the site once Nave hands it over: a single person or a small group. “I don’t know if there is anyone who has that level of passion, or interest, or depth of knowledge in such a wide area of physics,” says Raghavan, who first encountered HyperPhysics as a PhD astronomy student in 2013.

For now, Nave is happy to continue updating HyperPhysics and engaging with his web of unofficial collaborators. His next project is to incorporate large swaths of the seemingly nonphysical sciences. “I’m spreading out to biology, chemistry, and biochemistry, mainly with the idea of setting up a framework of those disciplines with a link to the basic physics that underlie them.”