Then she downloaded "The Elements: A Visual Exploration" to her iPad. Instead of making her drowsy, it blossomed in her hands. The 118 chemical elements, from hydrogen to ununoctium, came alive in vivid images that could be rotated with a swipe of the finger.
"It was like a breath of fresh air compared to my textbook," said Teitgen, who lives in Pittsford, N.Y. "I was really amazed by all the things it could do. I just kept clicking so I could read more."
More than 550 years after Johannes Gutenberg printed 180 copies of the Bible on paper and vellum, new technologies as revolutionary as the printing press are changing the concept of a book and what it means to be literate. Sound, animation and the ability to connect to the Internet have created the notion of a living book that can establish an entirely new kind of relationship with readers.
As electronic reading devices evolve and proliferate, books are increasingly able to talk to readers, quiz them on their grasp of the material, play videos to illustrate a point or connect them with a community of fellow readers. The same technology allows readers to reach out to authors, provide instant reaction and even become creative collaborators, influencing plot developments and the writer's use of dramatic devices.
Digital tools are also making it possible for independent authors to publish and promote their books, causing an outpouring of written work on every topic imaginable.
If the upheaval in the music industry over the last decade is any guide, the closing of more bookstores and a decreasing demand for physical books will force authors and their publishers to find new ways to profit from their work.
"There is not a single aspect of book publishing that digital won't touch," said Carolyn Kroll Reidy, chief executive of Simon & Schuster. "It is transformational."
"The Master of Rampling Gate," a novella by Anne Rice published in 1991 as a paperback, illustrates some of the possibilities. The work tells the story of a brother and sister who inherit a remote mansion occupied by the undead.
The out-of-print title was given new life in March, when it was reissued in digital form by Vook, an Alameda, Calif., start-up that sells titles for the iPad and iPhone. As a $4.99 application sold through Apple's iTunes store, "The Master of Rampling Gate" comes with video interviews with Rice and others. Rice speaks about her inspiration for her works and about the Gothic genre in which she writes.
Within the text are links to Web pages that elaborate on events and places in the story -- a description of the Mayfair neighborhood in London where the protagonists live or a history of the Black Death plague, which plays a key role in the fourth chapter.
"For me, this is a way to communicate with my readers, establish a connection with them and build a community around them," Rice said in an interview.
Vook (the name is a mash-up of "video" and "book") has published more than two dozen titles, including "Reckless Road," which describes the early days of heavy metal band Guns N' Roses. "Reckless Road" weaves in dozens of videos of the L.A. band's early performances and interviews with band members and groupies.
The videos and other digital features are designed to "project the emotion of the book without getting in the way of the story," said Brad Inman, Vook's chief executive and a former real estate columnist for the San Francisco Examiner. "We want to revive the passion for traditional narrative. Multimedia could be a catalyst for spawning more reading."
Vook does not disclose information about its finances or its payments to authors. Its biggest cost, Inman said, is the production of the videos.
Tim O'Reilly, whose O'Reilly Media in Sebastopol, Calif., is at the forefront of designing and distributing digital books over the Internet and on mobile devices, said technology has the power to "broaden our thinking about what a book does."
Owners of "iBird Explorer," a digital book produced for the iPhone by field guide publisher Mitch Waite Group, can play the songs of more than 900 bird species. Using microphones, it can also capture the chirps and warbles of wild birds and match them against a database of bird sounds to help the "reader" identify the species.
In addition to displaying pages from a book, digital e-readers can read them aloud, opening up a literary trove for the blind and the visually impaired who have long had only a thin selection of audio and Braille books to choose from. Devices made by Amazon.com Inc. and Intel Corp. are able to convert text into speech.
"You now have the ability to make a book talk," said George Kerscher, head of the Digital Accessible Information System Consortium in Zurich, Switzerland. Kerscher, who studied computer science at the University of Montana and is blind, has spent two decades lobbying publishers to make books more accessible to visually impaired readers.
Digital technology is also transforming reading from a famously solitary experience into a social one.
The newest generation of readers -- the texting, chatting, YouTubing kids for whom the term "offline" sounds quaint -- has run circles around the fusty publishing process, keeping its favorite stories alive online long after they're done reading the books.
At online fan communities for popular fantasy series like "Harry Potter" and "Twilight," young enthusiasts collaborate on new story lines involving monsters, ghosts and secret crushes.
Fans in other forums, blogs and chat rooms weave alternative endings or side plots for their favorite works. One site, FanFiction.net, features hundreds of short stories based on a series of young adult novels by Scott Westerfeld called "Uglies."
"They're extending the world by creating new characters," Westerfeld said. "That's what good readers do. They take apart the narrative engine and, examining the different parts, they ask how things could have been different." Authors are pulled into the scene by fans who barrage them with e-mail to share their reactions, ask how plots came about and glean hints of what will happen in the next novel.
"There's an ongoing feedback loop with my readers," said Westerfeld, 47, who splits his time between New York and Australia. He figures he's logged more than 30,000 e-mails from readers over the years. "They educate me a lot about the way they are reading. I'm a lot smarter about it now than when I was locked up in a room writing on my own."
He learned, for example, that writing about conflict can unsettle his younger readers.
"When two characters in my book have an argument, I get a lot of e-mail," Westerfeld said. "Adults see it as churn. But kids are far more affected by it, so I use it only when there is a real need in the story for conflict." Now that anyone with an Internet connection -- or even a cellphone -- effectively owns a digital printing press, the distinction between professional and amateur writers is rapidly blurring. Digital publishing has uncapped a geyser of creative output from authors who may never have made it into print or wouldn't have thought to try.
On Textnovel.com, thousands of cellphone-toting authors write novels via text message, one or two sentences at a time. Aspiring writers can sign up on the free site and begin writing, either from phones or computers. Readers can follow the stories online or receive a text every time their favorite author adds a plot twist.
Shannon Rheinbold-Gee tapped out her 85,000-word thriller about teenage werewolves in just under five weeks using the Textnovel site. The former middle-school teacher figured she had no chance of getting a traditional publishing deal.
"I had absolutely no concept of where it was going to go," said Reinbold-Gee, 37, of Otego, N.Y. As she wrote, "I would just throw things out and hope something hit the target."
It did. The book, "13 to Life," won Textnovel's first annual contest and earned its author a three-book contract with the prestigious St. Martin's Press, including a $10,000 advance. The first installment came out in paperback in June and will appear in Wal-Mart stores in August.
Reinbold-Gee, who now writes under the name Shannon Delany, frequently asked readers to help her make decisions about plot and character twists in "13 to Life." At the end of Chapter 6, she asked which beau her main character, Jessica, ought to go to the prom with. Fans voted for Jessica to go stag -- and that's how Reinbold-Gee wrote it.
Textnovel, which is funded by contributions from its own members, is just one example of how the Internet has become fertile ground for creative amateurs.
On Scribd.com, writers and digital packrats are building a huge swap meet for written works of every length, many of which once existed on paper.
Visitors can browse digital versions of novels and nonfiction books -- some by established authors, others by complete unknowns -- along with recipes for spinach calzones and 1950s-era manuals for building transistor radios, nearly all of which is free.
As in many places online, free content is the rule. Writers who are intent on making money will have to find creative ways to attract readers and build an audience. As the YouTube of books, Scribd provides a virtual printing press for budding writers and a community of potential readers. The company gets most of its revenue by selling advertising on the site.
A small portion of the titles on Scribd, roughly 15% of more than 20 million documents, is for sale. The prices, which are set by publishers, range from $1.99 for "The Dark Dreamweaver," a fantasy novel about an 11-year-old who ventures into a land of dreams, to a $27.99 book published by O'Reilly Media for designing Web pages. Scribd takes a 20% cut of those sales.
Trip Adler, a 26-year-old entrepreneur who started developing the site as a Harvard undergraduate, says it's on the verge of being profitable.
"It's like having a huge library at your fingertips, but with stuff you'd never think to look at," said Helen Black, a mother of five in Portland, Ore.
On Scribd, Black found a 1957 tourist map of Bemidji, Minn., where she'd gone to summer camp as a girl. She read a chunk of the Senate's healthcare reform bill, a document called "What's in a Can of Red Bull?" (partial answer: "meat sugar") and the 1894 diary of a woman traveling east from Oregon by wagon.
The proliferation of amateur content poses a conundrum for publishers, who must find a way to make a profit in a sprawling marketplace increasingly filled with free content.
"We've pretty much reached the point where the supply has now shifted to infinite," said Richard Nash, former head of Soft Skull Press, a small New York publisher. "So the next question is: How do you make people want it?" Part of the answer may be found on Goodreads.com, a digital library and social networking site where millions of members can log in and chat about any book they want, including many that will never see print.
Lori Hettler of Tobyhanna, Pa., runs one of the largest book clubs on Goodreads, with nearly 7,000 members chiming in from all over the globe. Discussions can go on for hundreds of messages, with readers passionately championing -- or eviscerating -- the club's latest selection.
A recommendation by Hettler can help little-known authors find an audience. Her recent picks include M. Clifford's "The Book" and D.H. Haney's "Banned for Life," both self-published efforts.
"Word of mouth goes a long way," Hettler said. "Once I review a book for one guy, he usually has someone he would like me to read, and then that guy has someone he would like me to read. ... It's this wonderful, endless cycle." Hettler may be broadening reading horizons, but some people worry that new technologies will diminish the classic reading experience.
Whereas printed texts often are linear paths paved by the author chapter by chapter, digital books encourage readers to click here or tap there, launching them on side journeys before they even reach the bottom of a page. Some scholars fear that this is breeding a generation of readers who won't have the attention span to get through "The Catcher in the Rye," let alone "Moby-Dick."
"Reading well is like playing the piano or the violin," said the poet and critic Dana Gioia, former chairman of the National Endowment for the Arts. "It is a high-level cognitive ability that requires long-term practice. I worry that those mechanisms in our culture that used to take a child and have him or her learn more words and more complex syntax are breaking down."
But Larry Rosen, a psychology professor at Cal State Dominguez Hills, said it was a mistake to conclude that young people learned less simply because "they are flitting around all over the place" as they read.
"Kids are reading and writing more than ever," he said. "Their lives are all centered around words."
Dr. Gary Small, director of the Center on Aging at UCLA and author of "iBrain," said Internet use activated more parts of the brain than reading a book did.
On the other hand, online readers often demonstrate what Small calls "continuous partial attention" as they click from one link to the next. The risk is that we become mindless ants following endless crumbs of digital data. "People tend to ask whether this is good or bad," he said. "My response is that the tech train is out of the station, and it's impossible to stop."