All Episodes

May 24, 2025 45 mins

Who are the “Redshift Wranglers” and what can they tell us about the evolution of our universe? To find out, Dr. Charles Liu and co-host Allen Liu welcome back astrophysics PhD candidate Sadie Coffin from the Rochester Institute of Technology whose focus is galactic evolution, and in particular, the spectroscopy of galaxies and their lights.

As always, though, we start off with the day’s joyfully cool cosmic thing: the Lucy spacecraft fly-by of asteroid 52246 Donaldjohanson, which was named after the American paleoanthropologist who discovered the Australopithecus afarensis “Lucy” fossil the spacecraft was named after.

Then it’s time to learn a little about Sadie, who explains how questioning the unknown is what drove her to study astronomy. Chuck, Allen and Sadie talk about the awe embodied in the study of the universe and the universe itself. Like Chuck, Sadie studies galaxy evolution, but Sadie focuses on a galaxy’s light, spread into spectra, and dissecting different features in that light.

You’ll hear about the citizen science project called “Red Shift Wranglers” that helps Sadie sift through all the spectroscopic data, and get an awesome explanation of the doppler effect and the way red shift, which measures speed, can be used to help build better maps of galactic evolution.

Find out how you can get involved with the project and join the ranks of the 3,500 Redshift Wranglers who’ve participated so far in “Wrangling galaxies and the universe together.” (See below for links.) You’ll also hear about other citizen science projects on Zooniverse like Galaxy Zoo. Sadie talks about the value of non-experts engaging with experts in a community, and the surprising number of people who want to get involved.

For our first audience question, Nina asks, “If nothing can go faster than the speed of light, why can galaxies have Z greater than 1?” Sadie’s explanation gets pretty technical, so we’ll let her do it in the episode.

Our next question comes from Jerry, who asks, “Will we someday no longer need scientists and have AI do all our research?” Sadie, who gets similar questions all the time relative to citizen science, believes these two things can be complimentary, and that in the name of improving science we can’t forgo either for the other.

We finish with a discussion about what defines an act of science and a work of art, the process of questioning, and the roles of humans and machines in these processes. Plus, Sadie tells us about the science-themed travel posters by Dr. Tyler Nordgren on her walls. Chuck also gets Sadie to talk about rowing and the lessons she’s taken from the sport into other aspects of her life and journey as a scientist.

If you’d like to know more about the Redshift Wrangler project on The Zooniverse and get involved, or to reach Sadie, visit https://www.zooniverse.org/projects/jeyhansk/redshift-wrangler or find Redshift Wrangler on Facebook and X (Twitter).

 

Listen to the COSMOS project episode referenced in this show with Dr. Jeyhan Kartaltepe, an astronomer and professor at the Rochester Institute of Technology.

Watch Sadie’s previous appearance in this short video shot at the COSMOS Team Meeting 2023.

We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon.

Credits for Images Used in this Episode:

  • The inner Solar System, with the Jupiter Trojan asteroids shown in green. – Credit: Mdf at Wikipedia/Public Domain.
  • Lucy skeleton (AL 288-1) Australopithecus afarensis, cast from Museum national d'histoire naturelle, Paris. – Credit: Creative Commons.
  • Absorption lines in the optical
Mark as Played

Advertise With Us

Popular Podcasts

Cold Case Files: Miami

Cold Case Files: Miami

Joyce Sapp, 76; Bryan Herrera, 16; and Laurance Webb, 32—three Miami residents whose lives were stolen in brutal, unsolved homicides.  Cold Case Files: Miami follows award‑winning radio host and City of Miami Police reserve officer  Enrique Santos as he partners with the department’s Cold Case Homicide Unit, determined family members, and the advocates who spend their lives fighting for justice for the victims who can no longer fight for themselves.

24/7 News: The Latest

24/7 News: The Latest

The latest news in 4 minutes updated every hour, every day.

Crime Junkie

Crime Junkie

Does hearing about a true crime case always leave you scouring the internet for the truth behind the story? Dive into your next mystery with Crime Junkie. Every Monday, join your host Ashley Flowers as she unravels all the details of infamous and underreported true crime cases with her best friend Brit Prawat. From cold cases to missing persons and heroes in our community who seek justice, Crime Junkie is your destination for theories and stories you won’t hear anywhere else. Whether you're a seasoned true crime enthusiast or new to the genre, you'll find yourself on the edge of your seat awaiting a new episode every Monday. If you can never get enough true crime... Congratulations, you’ve found your people. Follow to join a community of Crime Junkies! Crime Junkie is presented by audiochuck Media Company.

Music, radio and podcasts, all free. Listen online or download the iHeart App.

Connect

© 2025 iHeartMedia, Inc.