The Vera C. Rubin Observatory in Chile is now operational, and humanity's view of the universe will never be the same.

In this episode, we return to Carnegie Mellon University’s Rachel Mandelbaum, professor and head of the physics department – and a key architect of the observatory's data infrastructure — to hear what's happened since the revolutionary telescope first opened its eye to the sky.

Mandelbaum walks us through the observatory's first scientific data release, the launch of its public alert system, and the successful measurement of gravitational lensing using early commissioning data. She explains how CMU and the LINCC Frameworks team are building the software tools that will allow scientists worldwide to make sense of up to 10 million nightly cosmic alerts. And we discuss the Legacy Survey of Space and Time (LSST), the observatory’s decade-long mission to track 40 billion celestial objects that will essentially create a 10-year movie of our universe.

In this episode, you’ll learn: How the Rubin Observatory acts as a time machine for light from billions of years ago; the role of "alert brokers" in processing the 10 million nightly cosmic events the Observatory will track; and why understanding dark energy could be as transformative as the discovery of quantum mechanics.

Resources
Learn more about the Vera C. Rubin Observatory

In 2007, an unused key on the phone keypad became the internet's most powerful organizing tool. In this episode, we sit down with Chris Messina, the Carnegie Mellon University alumnus who invented the hashtag – now used more than three billion times a day – and famously gave it away for free.

Messina shares the fascinating journey of the hashtag, from its roots in early "nerd centers" like his BarCamp meetup to its rejection by Twitter’s founders as "too nerdy." You’ll hear how a 2007 wildfire in San Diego turned the symbol into a life-saving tool for citizen journalism, ultimately forcing tech giants to embrace it. The conversation explores the hashtag's evolution from a simple metadata tag to a catalyst for global social movements like #MeToo and #BlackLivesMatter.

Messina reflects on his principled decision to forego intellectual property rights, ensuring the hashtag remained free for the world to use.

Subscribe now on Apple Podcasts, Spotify, or wherever you get your podcasts. For more, info visit: cmu.edu/whatsnextpodcast.

The smiley face in your last text, the Kevlar protecting first responders, and the Wi-Fi signal connecting us all—where did they actually come from?

Welcome to Season 3 of Where What If Becomes What's Next, where we take you on a journey through 125 years of innovation at Carnegie Mellon University. To celebrate this milestone anniversary, we’re digging into the university archives to reveal the definitive stories behind 15 breakthroughs that didn't just advance technology—they redefined our world. From the spam saving benefits of CAPTCHAs, to the birth of artificial intelligence, to the pinch to zoom gesture on your smartphone—these are just some of the inventions you’ll learn about in Season 3.

This isn't a dry history lesson. It’s also a roadmap for the next century of innovation. With host Randy Scott, every other Thursday we’re going behind the scenes with the CMU makers and visionaries to bring you the stories you may know and the ones you won't believe.

The future is waiting. Let’s find out what’s next.

Subscribe now on Apple Podcasts, Spotify, or wherever you get your podcasts. For more, info visit: cmu.edu/whatsnextpodcast.