The astrophysicist Neil deGrasse Tyson has not one, but two books on the New York Times bestseller list. Most people don’t rush to the bookstore to buy the newest book with the word “astrophysics” in the title, but they’ll read Tyson’s books. Then again, there aren’t a lot of science books with the sentence, “Yes, Einstein was a badass.”

Tyson connects with millions of people because he’s an extraordinary communicator. But remarkably, one of the tools he’s used to discuss today’s most complex ideas is one of the world’s most ancient writing instruments: quill and ink.

You probably haven’t used a feather quill dipped in ink, but Tyson has. He’s a collector of writing instruments and can talk for an hour about his favorite quill pens or fountain pens, as does here. He’s so passionate about the subject, he can even name the ink he used in a calligraphy pen more than thirty years ago to take lab notes. How do these pens make Tyson a better communicator? Listen carefully to what he told Wall Street Journal about his passion for ancient writing instruments:

If you look at memorable speeches of the past, the rhythms happen to be in five-to-seven-word pulses. Then you learn that a single dip of a quill got you five or seven words. It may be that the rhythm was shaped by how much ink could sit in the shaft of a quill pen. As I write, I’m conscious of this. When you give a speech you don’t want your sentences to be too long.

Short sentences are best for communication.

Tyson’s right. Throughout history, great communicators understood the power of brevity. More than 2,000 years ago Aristotle, the father of persuasion, argued that sentences should be kept short so they are easy to read and easy to say out loud.

Thomas Jefferson wrote the Declaration of Independence for the ear. He read his own sentences out loud to get a sense of rhythm. The first fountain pen wouldn’t be introduced for another fifty years, so Jefferson was using quill and ink in his rented room in what is now known as the Declaration (Graff) House in Philadelphia. Visit the museum and you’ll see a small vase holding feather quill pens. Now listen for the “pulses” Tyson was talking about. You can almost see Jefferson re-dipping his pen.

We hold these truths to be self-evident [dip] That all men are created equal [dip] That they are endowed by their creator [dip] With certain unalienable rights [dip] That among these are [dip] Life, liberty and the pursuit of happiness.

Abraham Lincoln used a dip pen to write the Gettysburg Address. At only 272 words, it was short on words but had a big impact. The most famous section was written and delivered in five to seven word “pulses.”

Fourscore and seven years ago (five)

Our fathers brought forth on this continent (seven)

A new nation (three)

Conceived in liberty (three)

And dedicated to the proposition (five)

That all men are created equal (six)

Tyson’s observation is brilliant. It makes sense that great ideas were written and delivered in short bursts because the ink would run out! Regardless, it’s the way we’ve become accustomed to listening to information.

If you want people to listen to your ideas, keep your words simple and sentences short.

Tyson also learned to speak in short sentences very early in his career when he was the interim director of Hayden Planetarium in 1995. Scientists had discovered the first planet orbiting a star that was not the sun. NBC News sent a reporter to interview Tyson. He gave a long, highly technical explanation. His comments didn’t make the newscast. He realized that most people want shorter explanations–soundbites. For future interviews he rehearsed “three sentences abut a topic that are so tasty, you might want to tell someone else.”

Give your listener tasty morsels about a topic–simple words and short sentences. If you do, your audience will be more likely to remember your ideas and to share them.