# @worldsciencefestival on YouTube

- **Type:** Video
- **Original URL:** https://youtube.com/watch?v=bRd7OdBhAj0
- **Gondola URL:** https://gondola.cc/posts/27524607-worldsciencefestival-youtube
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/b9d95e0625.jpg
- **Posted:** 2025-02-21T21:00:07.000+00:00
- **Account Owner:** WorldScienceFestival (@WorldSciFest) — https://gondola.cc/WorldSciFest

## Caption

Renowned astrophysicist and educator Alex Filippenko joins Brian Greene to discuss an increasingly disturbing cosmological mismatch known as the Hubble Tension, a gap that may require a radical rewriting of the history of the universe. 

This program is part of the Big Ideas series, supported by the John Templeton Foundation. 

Participant: Alex Filippenko
Moderator: Brian Greene

0:00:00 - Introduction
0:00:50 - Welcome to Alex Filippenko
0:03:58 - The Most Important Lesson of Science
0:06:47 - The Hubble Tension
0:12:04 - Measuring the Expansion Rate of the Universe
0:23:31 - How far out can we measure?
0:27:10 - Galaxies with Type 1A Supernovae and Cepheids
0:32:57 - Cosmic Distance Ladder Summary
0:37:30 - The Universe's Expansion Rate Today
0:47:20 - How can we be certain the measurements are correct?
0:51:00 - CMB and using Theoretical Models to Extrapolate the Expansion Rate
1:00:57 - Positive outcomes to this tension
1:02:14 - Filippenko's thoughts on the position of Wendy Freedman's recent paper
1:14:09 - Will the Cepheid data set remain at 42?
1:16:55 - Filippenko's thoughts on the Hubble tension
1:22:40 - How Cosmology became a precision science
1:25:11 - Is Inflation a Falsifiable Theory?
1:29:30 - Filippenko's view of Inflation and the Multiverse
1:31:08 - Filippenko's view of Cyclic Inflation and Steinhardt and Penrose's theories
1:35:15 - Falsifiable Aspects of Inflation
1:41:54 - Discovering the Accelerated Expansion of the Universe
1:47:54 - Filippenko's thoughts on Saul Perlmutter's team's analysis methods
1:50:47 - Filippenko's reaction to the initial discovery
1:59:04 - Thoughts on Dark Energy and the Great Rip
2:01:58 - Conclusion
2:03:16 - Credits

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#worldsciencefestival #briangreene #cosmology #astrophysics #alexfilippenko #bigbang #hubbletension #cosmicinflation #cosmicmicrowavebackground #multiverse #bigrip #darkenergy

## Stats

- **Views:** 168,159
- **Likes:** 2,137
- **Shares:** 0
- **Comments:** 271

## Tags

worldsciencefestival, bigbang, briangreene, cosmicmicrowavebackground, bigrip, multiverse, cosmicinflation, hubbletension, cosmology, darkenergy, astrophysics, alexfilippenko

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