Cool Worlds, an Astronomy Professor’s YouTube Channel, Takes Viewers on a Cosmic Quest for Knowledge

David Kipping’s videos about outer space have millions of views.

Christopher D. Shea
September 05, 2023

About a year after joining Columbia in 2015, David Kipping, a professor of astronomy, decided to finally follow through on a long-term plan to launch a YouTube channel to explore cosmic questions. In his first video, he announced his own lab’s discovery of Kepler-167e, an exoplanet about the size of Jupiter. His initial aim was to get 400 subscribers.

It took about two days to reach that goal.

The channel, Cool Worlds, now has more than 700,000 subscribers. Its most watched video, about the possibility of a constantly accelerating spaceship that could take human travelers to galaxies beyond our own, has more than 9 million views. Kipping’s signature style is to use hard physics to explore big ideas, including fantastical concepts that emerge from science fiction, and to set that to soaring music and clips from Hollywood movies about outer space. Columbia News caught up with Kipping to talk about how he runs his channel, why he does it, and what subjects he hopes to tackle next.

What motivated you to make a YouTube channel about astronomy?

When I was applying to my current job at Columbia, I said in my application that if I came here I wanted to create a YouTube channel. I’ve always been interested in science communications. But I found that when I did outreach, I was often giving lectures to other astronomers or astronomers-in-training. Those events are great, but you’re kind of preaching to the choir with them. The idea of our YouTube channel is to actually try to bring new people into the fold.

How did you come up with the name Cool Worlds, which is the name of both your YouTube Channel and your Columbia lab?

Lots of people name their lab after themselves: The Kipping Lab, but I didn’t want to do that. There was a group at the University of San Diego that had something called the Cool Star Lab. And I thought it would be fun to riff on that. I study exomoons and exoplanets—moons and planets outside our solar system—which tend to be far away from their star, so their temperature is cool. So that’s the source of the name, a double meaning.

When did you first feel that you had a hit on your hands?

After our initial burst of growth, we kind of flatlined for a while at 4,000 subscribers, and I was honestly considering stopping since it didn’t feel like it was going anywhere.

But, in early 2019, I published this video about artificial gravity, which is this concept you see in science fiction a lot, where you create gravity in outer space so that people can, for example, walk around on spaceships without floating. It’s something that would be necessary for space tourism. The video explores how we could actually create artificial gravity, which we haven’t yet done. It didn’t include my face, and was half an hour long. That was a tipping point because the video did really well, and it became the basis for our current style, which is what I’d call mini documentaries.

What do you think makes a video popular?

I make some videos because I know they’ll really interest people and get a lot of views, and some are more for me. Videos like our “How Big Is the Universe?” and “Why Going Faster-Than-Light Leads to Time Paradoxes” are among our most viewed, which I sort of expected. They took a lot of research, since they aren’t covering my personal area of expertise, and I had to fact check extensively to make sure everything was completely accurate. More recently, though, I did a video on why exomoons matter, which is something I can talk about pretty off the cuff, because it’s what I work on. I know fewer people are going to watch that, but I feel like it’s important to explain because exomoons deserve more attention.

Have you noticed any patterns in what people like to watch?

I think sometimes the news can buoy a topic, but sometimes it can exhaust people. UFOs have been in the news a lot lately because of recent Congressional hearings about them, but I think there’s a bit of exhaustion from that now. The goal is to make a video that people could watch in five years, and it would still feel up to date and current and relevant.

Who edits your videos?

Recently I hired a Columbia student, Jorge Casas, who was in one of my classes. He’s a big fan of the channel and wanted to get involved. It’s great to hire Columbia students.

Until Jorge came on board, I had mostly done it myself. I’ve been interested in movies since I was a kid and made martial arts movies in the backyard, so it wasn’t too difficult for me to learn the basics.

Your videos include a lot of clips from movies about outer space. Do you have a favorite space movie?

Possibly “Interstellar.” I think what I like about that movie is that there’s a hard science concept there—at least until the end, when it gets a little magical—but at the same time, it’s also trying to emotionally connect to the audience.

That’s also the mix that I try to have in my own videos (minus the magic). There’s a sober, humbling experience that I want viewers to feel. Because that's kind of how the universe makes me feel.

I like that with YouTube we can blend that line between science and art, science and emotion, while being highly accurate.

Do you have a favorite video?

The next one is always the one I’m most interested in.

Can you give us a sneak preview of your next topic?

I’m thinking of doing one about a physicist’s take on the possibility of carbon negative technologies that would actually remove carbon dioxide from the atmosphere. There's absolutely no way we'll ever be able to pull all the carbon dioxide emissions in the atmosphere back out, unless we invent some completely new form of energy production, like a super fusion plant or something. Stay tuned. Oh and also, subscribe to the new Cool Worlds podcast.