Secrets of the Cosmic Microwave Background
Why Physics Stack Exchange recommends it
Physics Stack Exchange users link it when answering questions about the CMB, its anisotropies and power spectrum, and what can be learned from it.
Recommended by 2 people across 2 different months, 2024 to 2025.
What it is
A PBS Space Time episode hosted by Matt O'Dowd on the cosmic microwave background, the leftover glow from when the early universe first became transparent. It explains how the temperature fluctuations and power spectrum of that radiation encode information about the universe's origins and contents.
What people said
Recommends mmesser314 · 2024-12 · Physics Stack Exchange · on “In CMBR anisotropy experiments like Boomerang, how do we know the true spacing of hot spots in the CMB?”
Here are some videos you might find interesting. From Don Lincoln, an overview if the CMB and what we can learn from it - Secrets of the Cosmic Microwave Background [LINK] . From PBS Space Time, Baryon Acoustic Oscillations - Sound Waves from the Beginning of Time [LINK] and Secrets of the Cosmic Microwave Background [this video]
Recommends Python House · 2024-12 · Physics Stack Exchange · on “Is the angular diameter distance to the surface of last scattering the product of a circular argument?”
12.71 Mpc comes from solving the integral This fairly well known. As to you first question, it's also fairly well known but you can watch a video explaining it here ~ [this video]
Recommends mmesser314 · 2025-01 · Physics Stack Exchange · on “What is the relative speeds of objects (stars, galaxies and clusters) with respect to the rest of the masses of the universe?”
Careful measurement of the CMB tells us, among many other incredible things, the velocity of Earth with respect to the CMB. Here is a video from Don Lincoln of FermiLab - Secrets of the Cosmic Microwave Background [LINK] You didn't ask, but there is a lot of information in the CMB. Here are a couple more videos about it from PBS Space Time. Secrets of the Cosmic Microwave Background [this video] and Sound Waves from the Beginning of Time [LINK] More information about the motion of the Earth, planets, Solar system, and galaxy through the universe is this PBS Space Time video. How Earth REALLY Moves Through the Galaxy [LINK]
Cites P. C. Spaniel · 2024-05 · Physics Stack Exchange · on “Why do Baryonic acoustic oscillations imply peaks in the probability distribution of the position of galaxies?”
That makes sense! I don't know if you have time to watch 5 minutes of a video, but I guess my follow up question is: Is the explanation here [this video] complete nonsense then? He talks about the different overdensities having time to expand and contract many number of times and the ones that got caught at max or minimum density at the time of recombination are responsible for the peaks on the CMB's power spectrum... That is a complete different explanation than simply: There's one bump in physical space, so a series of bumps in frequency space