Revealing the Primordial Universe Through Its Oldest Light - W.L. Kimmy Wu - 02/27/2026

Описание: How was the early universe different than today? What can the oldest light in the universe tell us about the early universe? Join us for a 30-minute lecture about the early universe followed by a panel Q&A consisting of several astrophysicists to answer your questions about astronomy and space science. Timestamps and description below:

00:00 Announcements
4:58 Introduction of Presenter
7:20 Oldest Light Presentation
36:12 Oldest Light Q&A
36:22 "Why do CMB photons lose energy after they're emitted in the early universe?"
36:41 "Why is the CMB a sphere around us?"
37:23 "What came before the Big Bang?"
38:18 "Do we only see the small fraction of CMB photons coming towards us here on Earth?"
40:10 "Can we not see before the Big Bang because it was too hot?"
41:48 Intermission
48:37 Q&A Panel Introductions
53:18 "How do you differentiate between the CMB and light from intervening matter?"
55:38 "What assumptions go into deriving the age of the universe from the CMB?"
58:33 "Does the loss of energy due to cosmological redshift violate the conservation of energy?"
1:00:29 "Are there upcoming telescopes that will help with CMB discoveries?"
1:03:55 "Why is the CMB not totally uniform / homogenous?"
1:07:00 "Is the universe more likely to end or keep expanding?"
1:11:50 "Tell us more about microwave radiation."
1:12:57 "What are your thoughts about the current proposed budget cuts to science?"
1:20:24 "Are dark matter and dark energy also expanding with the universe?"
1:22:20 "Is it accurate to think of the expanding universe as an inflating balloon?"
1:24:22 "Are all momentum, angular momentum, and energy conserved from the initial Big Bang?"
1:25:39 "What is causing the Hubble Tension?"
1:31:10 "Why do we have matter and not anti-matter or just energy in the universe?"
1:33:35 "If the CMB is emitted at 400,000 years, how do we know about the first 3 minutes after the Big Bang?"
1:36:10 "Is it accurate to calculate distance with redshift?"
1:39:43 "In the past, did matter behave different because the universe was more compressed?"
1:43:08 "Would we be able to tell the difference between a galaxy made of anti-matter vs matter?"
1:46:50 "Do the current cosmological measurements support an open or closed model for the universe?
1:48:18 "If there is a relationship between SN Ia and the age of its stellar population, how would it affect measurements of the Hubble constant?"
1:52:35 "How do we measure the energies of quantum fluctuations?"
1:55:03 Concluding Remarks

Video Link for Narrated CMB Animation from Planck Collaboration:    • A Photon Travels Through Space and Time | ...  

Video Link for evolution in the power spectrum of the CMB:    • Searching for the Predicted Peaks in the C...  

Title: Revealing the Primordial Universe Through Its Oldest Light
Lecturer: W.L. Kimmy Wu
Abstract:
The cosmic microwave background (CMB) is light emitted by the universe over 13 billion years ago, which provides a snapshot of the universe in its infancy. Observations of the cosmic microwave background have led scientists to create a standard cosmological model that defines how the universe evolves over time. I will describe this model, known as LCDM, what it predicts for our universe, and highlight some of the ways that observations from other cosmological probes suggest how it may break down. I will summarize current efforts throughout astrophysics to further our understanding of the universe, its formation, evolution, and fate.