Organic artichokes, endangered species, the complexity of the universe, self-driving cars, and the illustrious words of Shakespeare usually don’t find themselves in one discussion series. 

But for UC Santa Cruz alumni Michael Riepe and David Hansen, topics like these make up Slug & Steins — a series of lectures composed of informal discussions hosted by UCSC Alumni Association.

During the series’ 40th installment on May 10, professor emeritus of astronomy and astrophysics and former UCSC Chancellor George Blumenthal gave a presentation on the last century of imperative scientific breakthroughs in our understanding of the universe. This lecture contributed to Slugs and Steins’ monthly series theme “A Century of Paradigm Shifts in our Thinking About the Universe.”

About 200 audience members were at the event including current students, alumni, and staff, with some calling in from outside the U.S.  

Blumenthal was invited as a speaker to discuss the important paradigm shifts, or major discoveries and developments that change how we view things, that have shaped human understanding of the universe over the last few centuries. In his talk, Blumenthal names seven of these shifts, including Einstein’s development in his theory of relativity, Hubble’s law, and dark matter.   

“I want to convey a couple of the key messages over the last 100 years. Just a dramatic number of changes, and our whole universe around us,” Blumenthal said. “Those changes have been accelerating in time and they’re happening more often today than they have been years ago.”

In his talk, Blumenthal said that about 100 years ago there was no holistic and consistent mathematical account of how the universe worked. Einstein’s General Relativity theory changed that, marking the first real shift in mankind’s approach to understanding the universe. 

“We are interested in his development of the general theory of relativity, which is a theory of gravity, since gravity is the dominant force, the largest scale in the universe,” Blumenthal said. “It’s a natural thing to use to try to understand the largest scale universe.”

Blumenthal then introduced the second paradigm shift: Hubble’s law, a theory that indicates the universe is constantly expanding. He discussed dark matter, an invisible matter that shows important clues about the formation of the universe, and dark energy, a force that’s causing the acceleration of the expansion of the universe.  

Other than the physical and biological sciences, the Slugs & Steins lecture series also covers topics from other divisions, including engineering, humanities, social sciences, and the arts. This past December, John O. Jordan from the literature department was invited to give a speech on Charles Dickens’s “A Christmas Carol.”  

This monthly series was founded three years ago by alum Michael Riepe, a software developer at Achronix Semiconductor, a tech company, and David Hansen, Vice President of administration and cofounder of educational startup Miaplaza. 

They volunteer for the Alumni Council and made the series to help the students network with alumni and professionals. 

“Our goal was to mix students with employers and alumni in Silicon Valley to try to make connections,” Riepe said. “Part of it is that if you put people together and you stir, good things will happen.”

Prior to the pandemic, the lecture series was held at Forager, a venue in San Jose. Since its inception, Slugs & Steins has produced 40 discussion events, with Monday’s event featuring Blumenthal marking its 40th.   

To Blumenthal, this point in history will not simply be remembered for masks and turbulent politics.

“We live in an era where we’re greatly expanding our understanding of the large-scale universe around us, and that’s exciting. We’re very lucky we’re living at this time in history because we’re learning so much more,” Blumenthal said. “At this time, it is inspiring to realize how much we’ve learned in 100 years. Before Albert Einstein, there was not even a self-consistent model for the widescale universe. And now, we have so much deeper understanding of what’s going on.”

Click here to see the recording of the virtual event with Blumenthal. Past events can be seen here

Slugs & Steins are always looking for interesting speakers. If any faculty members would like to give a lecture, or if any students and alumni have favorite faculty members, please contact email address: and!

These lectures are sponsored by the Alumni Association, the Alumni Council, the Alumni Engagement Office, and the Special Events Office. Slugs & Steins. To learn more about and donate to the Alumni Association Scholarship Fund, click here.